bluuebunny/crossref_metadata_2025 huggingface dataset:
IL-12 inhibits in vitro immunoglobulin production by human lupus peripheral blood mononuclear cells (PBMC)
Authors: HOUSSIAU F A , MASCART-LEMONE F , STEVENS M , LIBIN M , DEVOGELAER J-P , GOLDMAN M , RENAULD J-C
Published: November 2003

Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease characterized by polyclonal B cell activation and by the production of anti-double-stranded (ds) DNA antibodies. Given the inhibitory effects of IL-12 on humoral immune responses, we investigated whether IL-12 displayed such an activity on in vitro immunoglobulin production by SLE PBMC. Spontaneous IgG, IgG1, IgG2, IgG3 and IgM antibody production was dramatically reduced by addition of IL-12. These results were confirmed by Elispot assays detecting IgG- and anti-dsDNA-secreting cells. While IL-6 and TNF titres measured in PBMC supernatants were not modified by addition of IL-12, interferon-gamma (IFN-γ) titres were up-regulated and IL-10 production down-regulated. Since addition of IFN-γ did not down-regulate immunoglobulin production and since the inhibitory activity of IL-12 on immunoglobulin synthesis was not suppressed by anti-IFN-γ antibody, we concluded that the effect of IL-12 on immunoglobulin production was not mediated through IFN-γ. Our data also argue against the possibility that down-regulation of endogenous IL-10 production was responsible for the effect of IL-12. Thus, inhibition of IL-10 production by IFN-γ was not accompanied by inhibition of immunoglobulin production, and conversely, restoration of IL-10 production by anti-IFN-γ antibody did not suppress the inhibitory activity exerted by IL-12 on immunoglobulin production. Taken together, our data indicate that reduction of excessive immunoglobulin and anti-dsDNA antibody production by lupus PBMC can be achieved in vitro by IL-12, independently of IFN-γ and IL-10 modulation.
Increased levels of IL-13 mRNA, but not IL-4 mRNA, are found in vivo in peripheral blood mononuclear cells (PBMC) of patients with atopic dermatitis (AD)
Authors: KATAGIRI K , ITAMI S , HATANO Y , TAKAYASU S
Published: November 2003

Previous studies using in vitro systems with various stimuli have shown that PBMC from patients with AD show increased levels of IL-4 but decreased levels of interferon-gamma (IFN-γ) compared with PBMC from normal controls. However, in vitro conditions do not always mimic the in vivo condition. We therefore believe that it is important to quantify the expression of these cytokines in freshly isolated PBMC. This study examines the expression of IFN-γ, IL-4 and IL-13 mRNA in freshly isolated PBMC from adult patients with AD, from patients with psoriasis vulgaris and from healthy adults, using the semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. Levels of IFN-γ mRNA were significantly lower in PBMC of patients with AD than in controls. IL-4 mRNA levels did not differ significantly between groups. Conversely, levels of mRNA for IL-13 were significantly greater in PBMC of patients with AD than in controls. An increase in IL-13 expression may regulate the in vivo synthesis of IgE in patients with AD.
Intravenous immunoglobulin (IVIG) treatment of experimental colitis induced by dextran sulfate sodium in rats
Authors: SHINTANI N , NAKAJIMA T , NAKAKUBO H , NAGAI H , KAGITANI Y , TAKIZAWA H , ASAKURA H
Published: November 2003

We investigated the therapeutic effect and immunological action mechanism of IgG in experimental colitis induced by 3% dextran sulfate sodium in rats. Intravenous injection of homologous (rat) IgG (400 mg/kg per day) caused a significant suppression of occult blood discharge and ulcerative lesions in the colon, while no suppressive effect was observed in the case of heterologous (human) IgG. The positive effect of rat IgG on the lesions was also clearly shown by the histological examinations. Generation of proinflammatory cytokines, i.e. tumour necrosis factor-alpha (TNF-α) and IL-1α, in the lesions was found to be inhibited by administration of rat IgG. Little or no suppressive action was exerted by human IgG. Careful examination of recruited T cells and macrophages, both of which are thought to play important roles in the development of ulcerative colitis, indicated that rat IgG, but not its human counterpart, decreased the number of immunocompetent cells in colonic mucosa. Meanwhile, in an in vitro study, both forms of IgG were shown to suppress production of TNF-α and IL-1α from lamina propria mononuclear cells isolated from rat colon. These findings suggest that, mainly by suppressing recruitment of immunocompetent cells into the lesions, homologous IgG may reduce the occurrence of colitis.
Defective antigen presentation by lavage cells from terminal patients with cystic fibrosis
Authors: KNIGHT R A , KOLLNBERGER S , MADDEN B , YACOUB M , HODSON M E
Published: November 2003

Macrophages separated from lavage samples obtained from lungs removed at transplantation from patients with cystic fibrosis (CF) and other lung diseases, have been compared with circulating monocytes from the same patients for their ability to stimulate allogeneic normal circulating lymphocytes and to present antigen to autologous hilar lymph node cells. In general, macrophages separated from lavage samples from CF patients were unable to stimulate allogeneic lymphocytes and to present antigen, although monocytes from the same patients were functional in both assays. In contrast, lavage cells from non-CF patients were generally effective in both allogeneic stimulation and antigen presentation. These data suggest that immune cells within the lungs of CF patients are functionally compromised, a deficiency which may contribute to the recurrent infections characteristic of the disease.
Effect of immunoglobulin therapy on phagocytosis by polymorphonuclear leucocytes in whole blood of neonates
Authors: FUJIWARA T , TANIUCHI S , HATTORI K , KOBAYASHI T , KINOSHITA Y , KOBAYASHI Y
Published: November 2003

There has been some disagreement as to the clinical effect of intravenous immunoglobulin (IVIG) therapy on neonatal bacterial infections. We therefore evaluated the effect of IVIG therapy on neonatal polymorphonuclear leucocyte (PMN) functions by monitoring phagocytosis and hydrogen peroxide (H2O2) production. Subjects were 10 mature neonates who had normal plasma levels (i.e. equal to adult plasma levels) of IgG and nine premature neonates who had lower plasma levels of IgG. Phagocytosis by PMN was measured using flow cytometric analysis of whole blood. Addition of γ-globulin to the whole blood of mature neonates increased phagocytosis, but not significantly. Higher doses of added γ-globulin (> 2·0 mg/ml, the concentration was expressed as that in the final reaction volume) decreased phagocytosis to under baseline level. In premature neonates addition of γ-globulin increased phagocytosis and the significant maximum effect was observed with 0·5 mg/ml of the additional γ-globulin. Higher doses of additional γ-globulin (2·5 mg/ml) decreased phagocytosis to baseline level. Phagocytosis in four mature and four premature neonates was compared before and after 1 g/kg of IVIG therapy. Phagocytosis in mature neonates after IVIG therapy did not change compared with the pretreatment level. On the other hand, phagocytosis in premature neonates after IVIG therapy significantly increased compared with its pretreatment level. In both mature and premature neonates H2O2 production following phagocytosis varied in parallel with changes of phagocytosis. The patterns of H2O2 production following phagocytosis were essentially similar to those observed with phagocytosis. The above results are expected to form the basis for a rational indication for IVIG therapy against bacterial infections in neonates with low plasma IgG levels.
Regulation of endotoxin-induced IL-6 production in liver sinusoidal endothelial cells and Kupffer cells by IL-10
Authors: KNOLLE P A , LÖSER E , PROTZER U , DUCHMANN R , SCHMITT E , ZUM BÜSCHENFELDE K-H M , ROSE-JOHN S , GERKEN G
Published: November 2003

Sinusoidal endothelial cells and Kupffer cells are the first cell populations in the liver that come into contact with gut-derived endotoxin in portal blood. Although endotoxin concentrations as high as 1 ng/ml are physiologically present in portal blood, no local inflammation is seen. We show that the proinflammatory cytokine IL-6, which is central to the development of inflammatory reactions in the liver, is produced by sinusoidal endothelial cells and Kupffer cells in response to low concentrations of endotoxin (100 pg/ml to 1 ng/ml). The anti-inflammatory cytokine IL-10 down-regulated endotoxin-induced IL-6 release in endothelial and Kupffer cells. Importantly, Kupffer cells secreted IL-10 after endotoxin stimulation and may therefore participate in the local regulation of inflammation. We have found that IL-6 secretion in Kupffer cells is tightly regulated by endogenous IL-10, because increased IL-6 secretion resulted when neutralizing antibodies to IL-10 were added to resting and endotoxin-challenged Kupffer cells. Furthermore, repeated exposure of endothelial cells to endotoxin induced a state of tolerance which resulted in decreased release of IL-6 in response to a second endotoxin challenge. Our results support the notion that inflammatory reactions in the liver in response to endotoxin are down-regulated by local release of the anti-inflammatory cytokine IL-10 that is produced by Kupffer cells.
CD8+ T cells and not CD4+ T cells are hyporesponsive to CD28- and CD40L-mediated activation in HIV-infected subjects
Authors: VINGERHOETS J , KESTENS L , PENNE G , DE VUYST H , VANDENBRUAENE M , PELGROM Y , BOSMANS E , DE BOER M , KASRAN A , AZUMA M , COLEBUNDERS R , CEUPPENS J L , VANHAM G
Published: November 2003

T cell dysfunction in HIV-infected subjects could be the consequence of altered sensitivity of CD4+ or CD8+ T cells to various costimulatory signals. Therefore, we studied proliferation and cytokine production in highly purified CD8+ and CD4+ T cells from HIV-infected and HIV− subjects, induced by co-activation via cell-bound CD80, CD86 and CD40 or by allo-activation. Regardless of the nature of the first and the costimulatory signal, CD8+ T cells from patients proliferated consistently less than controls, while responses from CD4+ T cells were similar in patients and controls. This phenomenon was observed after ligation of CD28 combined with anti-CD3 or phorbol myristate acetate (PMA), but also after allogeneic stimulation and after activation by CD40 and anti-CD3. Anti-CD3 combined with CD80 or CD86 induced a mixed Th1/Th2-type cytokine profile in both CD4+ and CD8+ T cells from controls, whereas anti-CD3 plus CD40 induced only low levels of Th2-type cytokines and no interferon-gamma (IFN-γ) in CD4+ T cells. Compared with controls, CD4+ T cells from patients produced slightly lower levels of IL-10 but equal amounts of IFN-γ, IL-4 and IL-5, while CD8+ T cells from patients produced less of all cytokines tested. In conclusion, responses of purified CD4+ T cells from HIV+ subjects to various costimulatory pathways are relatively intact, whereas CD8+ T cells are hyporesponsive at the level of proliferation and cytokine production. A generalized intrinsic CD8+ T cell failure might contribute to viral and neoplastic complications of HIV infection.
Establishment and characterization of cloned CD4− CD8−αβ-T cell receptor (TCR)-bearing autoreactive T cells from autoimmune NZB×NZW F1 mice
Authors: CHEN Y-C , YE Y-L , CHIANG B-L
Published: November 2003

Murine models such as NZB/W F1, NZB.H-2bm12 and MRL.lpr/lpr mice have provided greater insight into the pathogenic mechanisms of lupus. To understand further the roles of T cells and cytokines in the pathogenesis of murine lupus, 11 cloned anti-DNA antibodies augmenting autoreactive T cell lines were derived from NZB/W F1 mice. All these autoreactive cells responded to syngeneic splenic cells and helped syngeneic B cells to produce anti-DNA antibodies, especially the IgG antibody. Ten out of 11 autoreactive T cell lines expressed neither CD4 nor CD8 cell surface markers on their surface. In addition, the cytokine production pattern of these autoreactive T cell lines was predominantly of type 0 (Th0) or type 2 T helper cells (Th2). To further investigate the role of accessory molecules in the activation of these autoreactive T cell lines, expression of IL-2R and heat-stable antigen (HSA) on these autoreactive T cells was analysed. Results suggest that the HSA played a critical role in the activation and function of these double-negative cloned autoreactive T cells.
Role of IL-15 in HIV-1-associated hypergammaglobulinaemia
Authors: KACANI L , STOIBER H , DIERICH M P
Published: November 2003

IL-15 is a novel cytokine, produced by monocytes/macrophages, with biological activities similar to IL-2 but with no significant sequence homology. IL-15 also stimulates human B cells to proliferation and immunoglobulin secretion. We measured serum levels of IL-15 in 84 HIV-1-infected individuals at different stages of disease in reference to 41 healthy blood donors. Our results show a marked elevation of IL-15 serum levels during HIV-1 infection. Moreover, we found that this increase correlated with serum levels of IgG (r=0.376, P<0.0001), and partly with serum IgM (r=0.265, P<0.0015). A significant increase of IL-15 production by cultured peripheral blood mononuclear cells (PBMC) and purified monocytes in the presence of HIV-1 virus suggests that monocytes/macrophages may be a source of higher IL-15 serum levels in HIV-1-infected individuals. These findings indicate a participation of IL-15 in the hypergammaglobulinaemia frequently associated with HIV-1 infection.
Role of leucocyte adhesion molecules in aminonucleoside of puromycin (PAN)-associated interstitial nephritis
Authors: MARTÍN A , ESCUDERO E , MAMPASO F
Published: November 2003

Rats receiving a single dose (10 mg/100 g body wt) of PAN develop severe proteinuria and acute interstitial nephritis. To investigate the mechanisms involved in interstitial leucocyte accumulation, we examined the expression of adhesion molecules on kidney tissue sections as well as on endothelial cell cultures. We also performed in vivo treatments with antibodies against adhesion molecules. Enhanced expression of intercellular adhesion molecule-1 (ICAM-1) was found on day 7 of the disease, when interstitial nephritis was first detected. Also, rat endothelial cells in culture showed maximal expression of ICAM-1 in the presence of 10−9–10−11 m PAN. Adhesion of peripheral blood mononuclear cells (PBMC) on kidney sections from PAN-treated rats was highest on day 7 (3·05±0·7 (mean±s.e.m.); controls 0·75±0·5). Such increased adhesion was notably blocked after PAN-treated rat kidney sections were incubated with anti-ICAM-1 MoAb (0·9±0·4). In addition, adhesiveness of PBMC to PAN-stimulated endothelial cells in culture was enhanced (25±2·5%; non-stimulated cells 13±3·1%). The addition of specific MoAbs against ICAM-1 and lymphocyte function-associated antigen-1 (LFA-1) produced a high blockage of adhesiveness induced by exposure to PAN (inhibition 58±3%; non-stimulated cells 40±7%). Simultaneous administration to PAN-treated rats of anti-LFA-1 and anti-ICAM-1 MoAbs reduced the number of interstitial cells by 70% compared with the 30% of reduction obtained when anti-very late antigen-4 (VLA-4) MoAb and anti-vascular cell adhesion molecule-1 (VCAM-1) antibodies were used. Our results suggest that the LFA-1/ICAM-1 pathway plays a principal role in the interstitial nephritis occurring in rats with PAN-nephrosis.
Rapid cytotoxicity of human B lymphocytes induced by VH4-34 (VH4.21) gene-encoded monoclonal antibodies, II
Authors: BHAT N M , BIEBER M M , HSU F J , CHAPMAN C J , SPELLERBERG M , STEVENSON F K , TENG N N H
Published: November 2003

We have previously described complement-independent killing of human B lymphocytes by two IgM MoAbs derived from the VH4-34 (VH4.21) gene. Analysis of 17 independently derived VH4-34-encoded MoAbs shows that B cell toxicity is not limited to the two described MoAbs, but is a general property shared by a subset of MoAbs derived from the VH4-34 gene. As observed by two independent microscopy techniques, giant membrane pores were formed on target B cells within 10–15 min of exposure to cytotoxic VH4-34-derived MoAbs. Toxicity by individual MoAb correlated directly to its B cell binding intensity measured by FACS, i.e. stronger the binding greater the killing. Sequence analysis showed that VH region in germ-line or in near germ-line configuration was necessary but not sufficient for B cell binding. In addition, a particular sequence motif enriched in basic amino acids in the CDR3 may be required to supplement the reactivity mediated by the VH region of the MoAb molecule. VH4-34-encoded antibodies that fulfil the above sequence requirements have cold agglutinin activity towards the i antigen of cord erythrocytes. In vivo, such anti-i/anti-B cell antibodies are rarely detected in healthy adults, but serum levels are dramatically elevated in selective pathological conditions, such as systemic lupus erythematosus and infectious mononucleosis. This strict regulation may be related to the novel and rapid mechanism of human B cell toxicity demonstrated by antibodies encoded by a single human VH gene.
Down-regulatory role of surface CD4 molecules on autoreactive helper T cells during B cell activation
Authors: AIZAWA K , HAMANO T , IWASAKI T , KAKISHITA E
Published: November 2003

MS202 is an IL-2-dependent Th2 clone reactive to auto-MHC class II antigens as previously reported. It expresses CD4, TCR-αβ, Thy 1.2 and H-2k on the cell membrane, as well as CD40 ligand. In order to investigate a functional role of surface CD4 molecules on Th2 cells during B cell activation, we attempted to establish a CD4− variant subclone derived from the CD4+ MS202, and its effect on B cell activation was examined. Briefly, MS202 was incubated with ethyl methanesulfonate to induce mutation followed by extensive treatment with anti-CD4 MoAb and complement. MS1.1.2, a representative subclone of resulting cell lines, was shown to lack CD4 molecules on the cell membrane, although it possessed almost the same amount of surface molecules other than CD4 compared with the original MS202 by analysis with flow cytometry. Interestingly, MS1.1.2 induced the maturation of B cells into IgM-producing cells more potently than MS202. This differentiative effect was markedly greater on activated B cells than resting B cells; each population was prepared from splenic B cells by a gradient separation method, but after treatment with anti-IgM antibodies, resting B cells responded to MS1.1.2, resulting in the secretion of a comparative amount of IgM. Furthermore, the effect of MS1.1.2 on DNA synthesis of activated B cells was much greater than that of MS202. The present results suggest that surface CD4 molecules on Th2 cells may not be substantially required for B cell activation, and rather mediate a down-regulation signal to B cells.
Synergistic mechanisms by which sirolimus and cyclosporin inhibit rat heart and kidney allograft rejection
Authors: STEPKOWSKI S M , TIAN L , NAPOLI K L , GHOBRIAL R , WANG M E , CHOU T C , KAHAN B D
Published: November 2003

The studies presented herein examined the mechanism(s) whereby sirolimus (SRL) and cyclosporin (CsA) act synergistically to block allograft rejection. Combination index (CI=1 reflects additive, CI<1 antagonistic, and CI<1 synergistic, effects) analysis documented potent synergism between SRL and CsA to block allograft rejection. Combinations of the two drugs produced synergistic prolongation of heart (CI=0.001–0.2) or kidney (CI=0.03–0.5) allograft survival at SRL/CsA ratios ranging from 1:12.5 to 1:200. Pharmacokinetic analysis of the individual drugs showed that CsA does not affect the blood levels of SRL, and SRL mildly increases the levels of CsA in SRL/CsA-treated rats. Quantitative polymerase chain reaction analysis was used to document that both subtherapeutic (1.0 mg/kg) and therapeutic (2.0 or 4.0 mg/kg) CsA doses inhibited the expression of interferon-gamma (IFN-γ) (P<0.03) and IL-2 (P<0.003) mRNA produced by T helper (Th) 1 cells, as well as IL-10 (P<0.001), but not IL-4 (NS) mRNA produced by Th2 cells. Contrariwise, all tested SRL doses (0.02, 0.04 or 0.08 mg/kg) did not affect cytokine mRNA expression. However, heart allografts from rat recipients treated with synergistic SRL/CsA doses displayed reduced levels of IFN-γ (P<0.01), IL-2 (P<0.001) and IL-10 (P<0.001) mRNA. Thus, because subtherapeutic doses of CsA reduce Th1/Th2 activity, thereby facilitating the inhibition of signal transduction by low does of SRL, the two agents act synergistically to inhibit allograft rejection.
Production of interleukins 10 and 12 by peripheral blood mononuclear cells (PBMC) in chronic hepatitis C virus (HCV) infection
Authors: KAKUMU S , OKUMARA A , ISHIKAWA T , IWATA K , YANO M , YOSHIOKA K
Published: November 2003

We previously reported that interferon-gamma (IFN-γ) production by PBMC in response to HCV core protein was increased in patients with type C chronic liver disease. To understand better the pathophysiology of this disease, we evaluated production of IL-10 and IL-12 by PBMC from 41 patients with chronic HCV infection, including asymptomatic HCV carriers with persistently normal serum ALT values. IL-10 is known to inhibit many effector functions of the immune system, suppressing Th1-type cell development, while IL-12 stimulates differentiation of Th1-type cells, facilitating cell-mediated immunity. IL-10 production was determined by culturing lymphocytes with concanavalin A (Con A), while IL-12 was produced by monocytes in the presence of Staphylococcus aureus Cowan 1 (SAC) with or without recombinant HCV core protein, respectively. The cytokine levels in culture supernatants were measured by ELISA. Spontaneous IL-10 production was greater in patients with chronic hepatitis (CH) (229±119 pg/ml, P<0·01) and liver cirrhosis (LC) (185±88 pg/ml, P<0·05) than in controls (119±27 pg/ml), while it was decreased during IFN treatment (70±25 pg/ml). Both HCV core protein and Con A enhanced IL-10 production by cells from HCV-infected patients. IL-12 was not detectable in medium alone cultures, and SAC-induced IL-12 production did not differ between various patient groups and controls. Simultaneous addition of HCV protein resulted in an increase of IL-12 production in chronic liver disease compared with SAC-alone cultures. Addition of IL-10 to the cultures equally suppressed IFN-γ production for both controls and patient groups, but the enhancing effect of IL-12 on IFN-γ production was significantly less in LC than in controls and other patient groups. The findings suggest that secretion of IL-10/IL-12 by cells from control individuals and various patient groups may be different, and that the cytokines might show different effects on IFN-γ production by some cells.
Induction of oral tolerance with effects on numbers of IgE-carrying mast cells and on bystander suppression in young rats
Authors: DAHLMAN-HÖGLUND A , HANSON L Å , AHLSTEDT S
Published: November 2003

The presence of IgE+ mast cells in the small intestine, bystander suppression of DTH and antibody responses to human serum albumin (HSA) were studied in young rats, made tolerant to ovalbumin (OA) by feeding an OA-containing diet for 1–4 weeks starting from weaning, and in sensitized control rats. One week after finishing the OA diet, both groups of rats were immunized with a mixture of OA and HSA in Freund's complete adjuvant (FCA) at one site on the back. The animals were then colonized for 5 days with a genetically manipulated Escherichia coli producing OA. Immunohistochemical staining of the small intestine of the rats fed the OA diet for 4 weeks showed significantly fewer IgE+ mast cells in the lamina propria, a lower level of MHC class antigen was found in the epithelial cells and in the lamina propria, and the villus crypt depth was also significantly less in tolerant compared with sensitized rats (P<0.003, 0.007, 0.003, respectively). Sensitized rats showed a mild diarrhoea during the colonization in contrast to tolerant rats. All rats fed OA showed a significantly reduced IgE anti-OA antibody and DTH response to OA before colonization compared with the sensitized rats. Bystander suppression of IgG and IgE anti-HSA antibody responses was also seen, but only in the rats fed OA for either 1 or 4 weeks. Rats fed the OA-containing diet for 1, 3, or 4 weeks showed bystander suppression of the DTH response to HSA. After colonization with E. coli producing OA, rats tolerant to OA after either 1 or 4 weeks on an OA diet maintained tolerance to OA and bystander suppression HSA. These results suggest that oral tolerance to OA down-regulates signs of local inflammatory response by IgE, IgG antibody and T cell responses to OA, but also provides bystander suppression to an unrelated antigen, HSA.
Antigen presentation by common variable immunodeficiency (CVID) B cells and monocytes is unimpaired
Authors: THON V , EGGENBAUER H , WOLF H M , FISCHER M B , LITZMAN J , LOKAJ J , EIBL M M
Published: November 2003

CVID is a primary immunodeficiency syndrome comprising a heterogeneous group of patients with hypogammaglobulinaemia and defective formation of specific antibodies. Previous studies demonstrated defective T cell responsiveness to antigen in a major subgroup of patients. In the present study we investigated the capacity of peripheral blood monocytes and Epstein–Barr virus (EBV)-transformed B cell lines from seven patients with CVID, including two patients expressing an extended MHC haplotype described to be associated with CVID, to present antigen (Tet. Tox.) to CD4+ antigen-specific T cell lines from healthy controls. The results presented show an unimpaired capacity of peripheral blood monocytes to present antigen in all patients studied. In addition, the present study demonstrates for the first time that CVID B cells function normally as antigen-presenting cells (APC). These findings indicate that expression of a certain MHC phenotype in CVID is not associated with a defect in the presentation of recall antigen by monocytes and B cells. Based on these studies, uptake, processing and re-expression of recall antigen in association with MHC class II molecules on the APC surface are functional and there is no indication for structural abnormalities of the MHC class II molecules expressed by the patients studied that could be essential for their function in antigen binding and presentation.
Lack of specific antibody response in common variable immunodeficiency (CVID) associated with failure in production of antigen-specific memory T cells
Authors: KONDRATENKO I , AMLOT P L , WEBSTER A D B , FARRANT J
Published: November 2003

Several T cell defects have been described in the antibody deficiency disease, CVID, but there have been few data on the generation of responses of specific T cell populations to primary neoantigens. We have now used immunization with the neoantigens, keyhole limpet haemocyanin (KLH) and DNP-Ficoll, to evaluate immune responses in CVID patients and normal donors. B and T cell responses were examined 2 and 4 weeks post-immunization. Sera were examined for IgM and IgG anti-KLH responses by ELISA and for anti-DNP-Ficoll activity by haemagglutination. The frequency of KLH-responsive T cells was measured by DNA synthesis in a limiting dilution culture system. Low density cells enriched for dendritic cells were pulsed with KLH and cultured with different numbers of autologous T cells. T cells from normal donors and from patients showed a low frequency of antigen-specific precursor T cells (≤1:200 000). After KLH immunization the frequency increased in normal donors (1:60 000 and 1:30 000 at 2 and 4 weeks, respectively), while in CVID patients it did not change from the pre-immunization level. The defect may extend to a dysfunction of antigen-specific cells, rather than being solely due to the reduced numbers of cells, since mean responses of ‘positive’ wells were also reduced. The serum-specific antibody response paralleled the T cell data, in that all normal donors but none of the CVID patients generated IgG KLH-specific antibodies. CVID patients did produce IgM antibodies against the T-independent DNP-Ficoll, but at a lower level than normal controls. These data show that both T and B cells from CVID patients have defective responses to specific antigen, implicating both lineages in the antibody deficiency.
Characterization of HIV-related periodontitis in AIDS patients: HIV-infected macrophage exudate in gingival crevicular fluid as a hallmark of distinctive etiology
Authors: SUZUKI T , TAI H , YOSHIE H , JEANNEL D , FOURNIER S , DUPONT B , DE THÉ G , HARA K
Published: November 2003

In an attempt to clarify the immunobiological events featuring periodontitis lesions of AIDS patients in the late stage of the disease, peripheral blood (PB) and gingival crevicular fluid (GCF) leucocytes from periodontitis lesions of 23 late-stage AIDS patients were analysed by three-colour flow cytometry for detection and identification of intracytoplasmic p24+ cell fractions. The cells were reacted with CD14 and CD68 for mononuclear phagocytes or with CD4 and CD14 for Th cells, then with anti-p24 MoAb. To detect HIV proviral sequences and intracellular p24 RNA sequences, genomic DNA and cellular RNA from leucocytes were extracted for semi-nested polymerase chain reaction (PCR) amplification. CD68+/p24+ and CD14+/CD68+/p24+ fractions were larger in GCF than in PB (P < 0·0001; P < 0·003). CD14+/p24+ fraction was lower in GCF than in PB (P < 0·05). The fluorescence intensities (FI) for intracellular p24 in CD68+ and CD14+/CD68+ cells were higher in GCF than in PB (P < 0·003; P < 0·02), whereas those of CD14+ macrophages did not differ. The p24 FI of CD68+ macrophages in GCF correlated with CD4+ lymphocyte counts in PB (P < 0·005). p24 FI levels of CD14+ monocytes in GCF and PB significantly correlated (P < 0·02), whereas that of CD68+ macrophages did not. PCR and reverse transcriptase (RT)-PCR of cellular DNA and RNA yielded positive signals, demonstrating viral integration and production in GCF leucocytes. These results show that periodontitis lesions in AIDS patients can be characterized by a rapid macrophage turnover, and these HIV-infected macrophage exudates in GCF may be considered as a within-mouth source of virus.
Decreased expression of 20-kD homologous restriction factor (HRF20, CD59) on T lymphocytes in Epstein–Barr virus (EBV)-induced infectious mononucleosis
Authors: KAWANO M , TSUNODA S , KONI I , MABUCHI H , MURAMOTO H , YACHIE A , SEKI H
Published: November 2003

HRF20 (CD59) is one of the membrane-associated complement regulatory proteins. The characteristic function of CD59 is to prevent membrane attack complex (MAC) formation on the cell surface and to protect the cell from complement-mediated cell lysis. We examined the expression of CD59 antigen on T cell subpopulations in patients with acute infectious mononucleosis (IM) and analysed the relationship between the amount of CD59 expression and activation-induced cell death of mature T cells with apoptosis. Decreased expression of CD59 on CD8+ T cells, especially on CD45RO+ and HLA-DR+ activated T cells, was marked in acute IM patients. In contrast, activated CD4+ T cells from IM patients expressed as much CD59 antigen as CD4+ T cells from healthy volunteers. After incubation-induced cell death, viable CD8+ T cells showed normal amounts of CD59 antigen on their surface. CD59dim CD8+ T cells were more susceptible to apoptosis than CD59bright CD8+ T cells. These findings suggest that decreased expression of CD59 on CD8+ T cells may discriminate the susceptibility of activated CD8+ T cells to activation-induced cell death in IM.
Characteristics of the pituitary gland in elderly subjects from magnetic resonance images: relationship to pituitary hormone secretion
Authors: Terano Takashi , Seya Akira , Tamura Yasushi , Yoshida Sho , Hirayama Toshio
Published: November 2003

OBJECTIVE Physiological changes in the pituitary gland with age have not been fully evaluated. The aim of this study was to clarify the morphological characteristics of the pituitary gland by magnetic resonance imaging(MRI) in elderly subjects and to relate them to pituitary hormone secretion.

DESIGN AND PATIENTS We investigated the pituitary MRI in 59 elderly (15 males, 44 females; median 82 years) and 41 young (13 males, 28 females; median 34 years) healthy subjects.

RESULTS Pituitary height, width and volume in the elderly subjects were less than those in the young subjects. Empty sella was more frequently observed in the elderly subjects (19%), especially women, than in the young ones. However, no relation was observed between the pituitary size or volume and basal levels of anterior pituitary hormones. Posterior pituitary bright signal(PBS) on T1‐weighted MRI, which is thought to reflect its storage of the neurophysin‐peptide complex, was not detected in 29% of the elderly subjects while it could be detected in all the young subjects. None of the elderly subjects showed clinical signs or symptoms of diabetes insipidus. Fasting plasma osmolarity and AVP in the elderly subjects were significantly higher than in the young subjects. Moreover, plasma AVP was significantly higher in the elderly subjects without the PBS than in those with the PBS.

CONCLUSIONS It is suggested that the excessive release of AVP from the posterior pituitary as a result of persistently raised plasma osmolality in the elderly subjects may lead to depletion of the neurosecretory granules in the posterior pituitary gland and may result in disappearance of the posterior pituitary bright signal on T1‐weighted MRI. As these morphological changes might relate to the normal physiological occurrence of ageing, we should be cautious in evaluating MRI of the pituitary gland in elderly subjects.
A comparison of 20 or 40 mg per day of carbimazole in the initial treatment of hyperthyroidism
Authors: Page S. R. , Sheard C. E. , Herbert M. , Hopton M. , Jeffcoate W. J.
Published: November 2003

OBJECTIVE The optimal dosage regimen for carbimazole (CBZ) in the treatment of hyperthyroidism remains uncertain, despite clinical use of the drug for approximately fifty years. We have compared the early clinical and biochemical responses to 20 or 40 mg/day of CBZ given as initial treatment for hyperthyroidism.

DESIGN Prospective open multicentre trial.

PATIENTS Sixty‐three patients presenting with hyperthyroidism.

MEASUREMENTS Serum total and free thyroid hormones, serum TSH and SHBG were measured at baseline and at 4 and 10 weeks after start of therapy. Weight, pulse and a symptom questionnaire were also monitored at 6 and 12 weeks.

RESULTS Patients randomized to a starting dose of 40 mg/day CBZ had lower total (98 ± 10 it 158 ± 11 nmol/l, P < 0.001) and free T4 (19.4 ± 2.6 vs 35.2 ± 3.7 pmol/l, P < 0.001) and total (2.6 ± 0.3 vs 4.3 ± 0.4 nmol/l, P < 0.001 and free T3 (8.3 ± 1.0 vs 13.7 ± 1.2 pmol/l, P < 0.01) at 4 weeks than those receiving 20 mg/day. Clinical responses at 6 and 12 weeks (weight, pulse, symptom score) and SHBG concentrations were similar. Drug‐related hypothyroidism was less likely to occur at 4 and 10 weeks in those patient who initially received 20 mg CBZ/day, but this dose was less effective at controlling hyperthyroidism in those with more severe hyperthyroidism with baseline TT4 > 260 nmol/l.

CONCLUSIONS In treating hyperthyroidism, 20 mg/day carbimazole is effective, convenient and has a lower risk than 40 mg/day of iatrogenic hypothyroidism in patients with mild or moderate hyperthyroidism. Higher doses are required for those with severe hyperthyroidism.
Pit‐1 gene expression in human pituitary adenomas using the reverse transcription polymerase chain reaction method
Authors: Yamada Shozo , Takahashi Michie , Hara Masayuki , Hattori Atsuhiko , Sano Toshiaki , Ozawa Yasunori , Shishiba Yoshimasa , Hirata Kazuaki , Usui Masaaki
Published: November 2003

OBJECTIVE Previous studies of Pit‐1 expression in human pituitary tumours have produced conflicting results. We have studied expression of Pit‐1 mRNA in human pituitary adenomas, as well as in normal human and rat pituitaries, and results were compared with clinical, histological, and immunohistochemical features. In addition, expression of GH, PRL, and TSH‐β mRNA was also studied and compared with Pit‐1 gene expression.

MATERIAL AND METHODS The adenomas consisted of 13 GH cell adenomas, 7 PRL cell adenomas, 3 TSH cell adenomas, 4 ACTH cell adenomas, and 10 clinically non‐functioning adenomas. Expression of the Pit‐1, its isoforms, and each hormone, was studied using the reverse transcription polymerase chain reaction.

RESULTS Pit‐1 mRNA was expressed not only in normal human and rat pituitaries, but also in all GH, PRL and TSH cell adenomas. There was no correlation between Pit‐1 transcripts and biological behaviour or histological findings in these three types of adenoma, suggesting that Pit‐1 is generally required for the determination of cell phenotype but is insufficient for the regulation of hormonal activity and tumour growth in these pituitary adenomas. In addition, Pit‐1 was also expressed in some ACTH cell (2/4) and non‐functioning adenomas (7/10). Although there were no GH, PRL or TSH‐β transcripts in Pit‐1 mRNA‐negative ACTH cell and non‐functioning adenomas, PRL mRNA was detected in all Pit‐1 mRNA‐positive ACTH cell adenomas and GH, PRL and/or TSH‐β mRNA were found in four of seven Pit‐1 mRNA‐positive non‐functioning adenomas. In contrast, Pit‐1 mRNA was expressed without any GH, PRL, or TSH‐β transcripts in only three non‐functioning adenomas. These data suggest that expression of Pit‐1 mRNA in these two types of adenomas can be mainly attributed to the presence of GH, PRL and/or TSH‐β mRNA expressing cells and that true Pit‐1 transcripts found in non‐functioning adenomas may be a rare event. Moreover, there were two cases which expressed Pit‐1α mRNA, but failed to show other Pit‐1 isoform mRNA. There were, however, no clinical or histological differences between these two adenomas showing only Pit‐1α mRNA and the others expressing both Pit‐1α mRNA and other Pit‐1 isoform mRNA.

CONCLUSIONS Pit‐1 mRNA was expressed not only in GH, PRL and TSH cell adenomas but also in other types of adenoma. However, it is suggested that expression of Pit‐1 mRNA in most ACTH cell and non‐functioning adenomas can be attributed to GH, PRL and/or TSH‐β mRNA expressing cells. Further studies are necessary to elucidate the role of Pit‐1 transcripts in the three non‐functioning adenomas without GH, PRL and/or TSH‐β mRNA expression.
Oestrogen producing adrenocortical adenoma: clinical, biochemical and immunohistochemical studies
Authors: Goto Toshikazu , Murakami Osamu , Sato Fumitoshi , Haraguchi Masaomi , Yokoyama Koichi , Sasano Hironobu
Published: November 2003

Oestrogen producing adrenocortical tumours are extremely rare. We report a 65‐year‐old woman who presented with abnormal vaginal bleeding, with no significant abnormalities in her uterus or ovaries, who was found to have a right adrenal mass by radiological examination. Excessive secretion of oestrogens from the tumour was demonstrated by adrenal venous sampling. Basal levels of corticosteroids were within normal limits. Adrenalectomy was performed and pathological examination revealed an adrenocortical adenoma measuring 5.5 cm in its greatest dimension, in which both clear and compact tumour cells were observed. Oestrogen levels normalized following the removal of the adrenal mass. Tissue concentrations of oestrone and oestradiol in the tumour were 6.9 (69.5 pmol/g wet tissue weight) and 34.6 (93.6 pmol/g wet tissue weight)‐fold greater respectively than those of adjacent non‐neoplastic adrenal cortex. Aromatase activity in the tumour tissue determined by the 3H‐water method was 118.6 pmol/h/mg protein, equivalent to that of a full‐term human placenta. Immunohistochemical analysis of aromatase demonstrated immunoreactivity in the tumour cells, especially in compact cells, but not in adjacent non‐neoplastic adrenal cells. This is the first reported case of an oestrogen producing adrenocortical adenoma in which aromatase in the tumour cells was documented.
The role of plasma renin activity in evaluating the adequacy of mineralocorticoid replacement in primary adrenal insufficiency
Authors: Fiad Tarek M. , Conway J. Donald , Cunningham Sean K. , McKenna T. Joseph
Published: November 2003

BACKGROUND Elevation of plasma renin activity (PRA) is a feature of mineralocorticoid deficiency in patients with primary adrenal insufficiency. This study was designed to assess the usefulness of PRA as an index of adequacy of fludrocortisone (FC) replacement in patients with primary adrenal failure, paying particular attention to the variability in PRA levels during FC and glucocorticoid treatment.

METHODS Twenty‐two patients with mineralocorticoid deficiency due to primary adrenal disease were studied at 3 time points: 8, 24 and 32 hours following the administration of FC replacement. Body weight, blood pressure while supine and erect, PRA, and plasma or serum levels of aldosterone, urea, sodium and potassium were measured at each time. The clinical and biochemical consequences of adjusting the FC dose were monitored in 5 patients with PRA levels above the range seen in normal subjects and in one hypokalaemic patient with normal PRA levels.

RESULTS At 8 and 32 hours following FC administration, PRA levels were not significantly different. PRA levels were significantly higher at 32 hours following FC administration (4.7 ±1.1 nmol/l/h) than at 24 hours (4.2 ±1.1 nmol/l/h, mean ± SEM, P <0.05). At 8 and 32 hours following FC administration, potassium levels were similar. Potassium levels were significantly higher at 32 hours following FC administration (3.9 ± 0.1 mmol/l) than at 24 hours (3.6 ±0.1 mmol/l, P < 0.05). No changes in measurements of sodium, urea, mean supine and erect arterial pressure or body mass index were noted at the different study points. Attempted lowering of elevated PRA in 5 normokalaemic subjects by raising the dose of FC led to normalization of PRA in all of these patients but 2 developed hypokalaemia and oedema. Lowering of FC dose in one hypokalaemic patient with normal PRA levels led to the PRA levels rising to a supranormal value while the hypokalaemia was corrected.

CONCLUSIONS These results indicate that when plasma renin activity is estimated in patients with primary adrenal insufficiency replaced with daily doses of fludrocortisone, the time of day of blood sampling is not critical. Lowering elevated plasma renin activity levels to normal in patients who were considered to be otherwise normal may lead to over‐treatment in some patients. Therefore, optimal fludrocortisone replacement may be associated with mildly elevated plasma renin activity levels. The information obtained by monitoring plasma renin activity adds little to the assessment of patients based on clinical evaluation and measurement of urea and electrolyte levels in blood.
Undiagnosed morbidity in adult women with Turner's syndrome
Authors: Garden Anne S. , Diver Michael J. , Fraser William D.
Published: November 2003

OBJECTIVE Adult patients with Turner's syndrome are rarely followed up at specialist clinics after discharge from paediatric care but do have a predisposition to several long‐term medical problems. We have assessed the undiagnosed morbidity that exists among adult women with Turner's syndrome.

PATIENTS A group of 32 women (age range 17–52 years; mean 25 years) attending a specialist out‐patient clinic.

MEASUREMENTS Blood samples were obtained at the initial visit for lipid assessment, thyroid function, gonadal status and routine biochemical profile. Bone mineral density (BMD) was measured in 31 of the women.

RESULTS Thirty‐one women were receiving some form of oestrogen replacement. Two were receiving T4 therapy. In 50%, total cholesterol was greater than 5.2 mmol/l (range 3.4–9.3 mmol/l, mean 5.8 mmol/l) and 28% had an abnormality of thyroid function tests. Two women were newly diagnosed as hypothyroid, 6 had compensated hypothyroidism and one was under‐replaced with T4. Lumbar spine BMD was below 100% of age matched reference range in 84% and below 75% in 26% of patients. Femoral neck BMD was below 100% of age matched reference range in 90% and below 75% in 10% of patients.

CONCLUSIONS There is a high incidence of undiagnosed lipid, thyroid and bone mineral density abnormalities in the adult population with Turner's syndrome. Doctors caring for these women need to be aware of and look for the potential problems. Appropriate long‐term treatment should be commenced to help prevent the development of lipid, skeletal and thyroid abnormalities which may cause these patients major problems in the future.
Normal growth hormone secretion in growth hormone insufficient children retested after completion of linear growth
Authors: Wacharasindhu S. , Cotterill A.M. , Camacho‐Hübner C. , Besser G.M. , Savage M.O.
Published: November 2003

OBJECTIVE The recognition of the syndrome of adult GH deficiency suggests that young GH deficient adults, deprived of GH replacement at completion of linear growth, may suffer effects of GH deficiency. We assessed GH reserve in young adults previously diagnosed as having idiopathic GH insufficiency, who were treated with hGH replacement (14 IU/m2/week) in childhood.

DESIGN Eight patients (7 males, 1 female) diagnosed as having GH insufficiency by insulin tolerance test (ITT) in childhood (ages 8.5–15.6 years) were retested by ITT at completion of linear growth (ages 15.1–19.6 years), 3 months after discontinuation of hGH therapy.

MEASUREMENTS GH reserve was measured during ITT at diagnosis and at retesting. Height velocity (HV) and HV SDS were calculated before and during GH therapy.

RESULTS At diagnosis, the mean peak GH response to ITT was 10.5 ± 2.0 mU/l (range 7.7–13.6). At retesting, mean GH was 52.4 ± 33.2 mU/l (range 10.4–100), 7/8 subjects having peak GH levels greater than 15 mU/l. During hGH therapy mean HV increased from 4.0 ± 1.5 cm/year at diagnosis to 7.3 ± 1.9 cm/year during the 1st year (P = 0.004) and 6.9 ± 2.3 cm/year during the 2nd year (P = 0.02). Mean HVSDS increased from −1.6 ± 2.1 at diagnosis to 3.1 ± 2.9 during the 1st year (P = 0.004) and 2.2 ± 4.2 during the 2nd year (P = 0.05, NS) of treatment.

CONCLUSIONS Seven out of 8 children diagnosed as having idiopathic GH insufficiency had normal GH secretion at completion of linear growth. Children with GH insufficiency cannot be assumed to become GH deficient adults and should not continue on GH therapy into adult life without reinvestigation. All who were GH insufficient children should be retested at completion of linear growth to identify those who are truly GH insufficient adults and may benefit from replacement therapy.