Yonago Acta medica 1997;40:125–131

Interstitial Pneumonia Developed in HTLV-I Carriers: Report of Two
Cases
Naoto Burioka, Hisashi Suyama, Yuji Sugimoto, Hiroki Chikumi, Hiroki Yajima,
Katsuyuki Tomita, Eiji Hoshino, Yukio Matsumoto, Takao Sasaki and Makoto
Motoi*
Third Department of Internal Medicine and *Second Department of Pathology, Faculty of
Medicine, Tottori University, Yonago 683, Japan
Two carriers of human T-cell lymphotropic virus type I (HTLV-I) with interstitial
pneumonia are described. The first case, a 60-year-old man, was admitted with coughand dyspnea on exertion. Light microscopy of a lung specimen obtained by a transbronchial lung biopsy (TBLB ) showed thickening of the alveolar walls with infiltrationof lymphocytes and fibrosis of the pulmonary parenchyma. Immunohistochemical analysis of the TBLB specimen showed positive staining in the lymphocytes for UCHL-1.
This case was suspected as HTLV-I associated bronchiolo-alveolar disorder. The second
case, a 74-year-old man, visited our hospital because of a persistent productive coughand dyspnea on exertion. Light microscopy of the TBLB showed a slight thickening of
the alveolar walls and fibrosis of the pulmonary parenchyma with minimal infiltrationof lymphocytes. Only 2.2% of the bronchoalveolar lavage fluid consisted of lymphocytes.
The findings of the second case suggest that some factors other than T-lymphocytes
may be related with the development of interstitial pneumonia in HTLV-I carriers.
Interstitial pneumonia in HTLV-I carriers may be caused by as yet undiscovered mechanisms. A cohort study involving residents of an area where HTLV-I is endemic should
be conducted to clarify the mechanism of pulmonary involvement in HTLV-I carriers.
Key words: human T-cell lymphotropic virus type I; HTLV-I associated bronchiolo-alveolar
disorder; HTLV-I associated bronchopneumopathy; interstitial pneumonia; pulmonary fibrosis

Human T-cell lymphotropic virus type I (HTLVI) is an oncogenic retrovirus. HTLV-I is endemic in the southwestern region of Japan. Most
HTLV-I infected subjects are non-symptomatic
carriers. HTLV-I has been implicated in thedevelopment of such diseases as HTLV-I associated myelopathy (HAM) (Roman and Osame,1988), HTLV-I associated bronchiolo-alveolar
disorder (HABA) (Kimura, 1992) [also called

as HTLV-I associated bronchopneumopathy(HAB) (Maruyama et al., 1988)], autoimmune
thyroiditis (Akamine et al., 1996) and HTLV-I
associated uveitis (Mochizuki et al., 1992).
Inflammatory disorders can occur in the carrierstate in HTLV-I infected individuals without
adult T-cell leukemia-lymphoma (ATLL). We
report two carriers of HTLV-I who exhibitedinterstitial pneumonia.

Abbreviations: ATLL, adult T-cells leukemia-lymphoma; BAL, bronchoalveolar lavage; bp, base pair; DLco,pulmonary diffusing capacity for carbon monoxide; HAB, HTLV-I associated bronchopneumopathy; HABA,HTLV-I associated bronchiolo-alveolar disorder; HAM, HTLV-I associated myelopathy; HTLV-I, human Tcell lymphotropic virus type I; LDH, lactic acid dehydrogenase; PBMC, peripheral blood mononuclear cell;
PCR, polymerase chain reaction; sIL-2R, soluble interleukin-2 receptor; TBLB, transbronchial lung biopsy;
UIP, usual interstitial pneumonia; VC, vital capacity125

N. Burioka et al.

Table 1. Results of bronchoalveolar lavage
Case 1
Total cell countCell differentiation

Lymphocytes subset(106/dL)
Macrophages (%)
Lymphocytes (%)
Neutrophils (%)
Eosinophils (%)
Basophils
(%)
CD3
(%)
CD4
(%)
CD8
(%)
CD4/CD8

23.0
86.0
10.0
1.2
2.6
0.2
39.6
24.7
19.3
1.3

Patient Report

Case 1
A 60-year-old Japanese man, a resident of Oki
Island in Shimane Prefecture, was admitted toour hospital in March 1991 because of coughand dyspnea on exertion. He smoked 60 cigarettes daily for 30 years but quit smoking 2
years prior to admission. Auscultation of thelungs revealed fine crackles in both lower lungfields. Laboratory data showed an elevatedwhite blood cell count (11,300/mm3; segmental
neutrophils 44%, band neutrophils 4%, lymphocytes 35%, monocytes 7%, eosinophils 10%)and lactic acid dehydrogenase (LDH; 257 IU/
L). Atypical lymphocytes were not detected inperipheral blood. Arterial blood gas analysis
showed hypoxemia (PaO 2; 67 mmHg). He
tested negative for hepatitis C
virus antibody, rheumatoid factor
and anti-nuclear antibody. HTLVI antibody was positive (2560fold). Bronchoalveolar lavage(BAL) was performed in the rightB4 (Table 1). Although the total
cell count in the BAL fluid waselevated, the ratio of lymphocytes
was within the normal range (The
Case 2BAL Cooperative Group Steering
Committee, 1990). Spirography
66.0
revealed a decreased vital capacity
97.6
2.2(VC) and a restrictive pattern (%VC,
0.2
68.4%). The pulmonary diffusing ca0
pacity for carbon monoxide (DLco)0
was decreased (%D Lco , 59.3%).
83.4
Computed tomography of the chest
60.8
16.4
demonstrated bilateral reticulo3.7
nodular and honey-combed shadowsin the lung fields (Fig.1). Light microscopy of the transbronchial lungbiopsy (TBLB) specimen showed thickening of
the alveolar walls with infiltration oflymphocytes and fibrosis of the pulmonary
parenchyma. No atypical lymphocytes weredetected in the infiltrating cells. Immunohistochemical analysis of the TBLB specimen showed positive staining of lymphocytes for UCHL1 (Nichirei Co., Tokyo, Japan) by the streptoavidin-biotin method [HISTOFINE SABPO(MULTI) KIT, Nichirei Co.] (Fig. 2).
This patient developed interstitial pneumonia and died in December 1992. The autopsy
revealed the following: the lung—diffuse
honey-combed lungs, usual interstitial pneumonia (UIP) and acute bronchopneumonia; theheart—hypertrophy of the heart; the pancreas—
chronic pancreatitis; the thyroid—adenomatousgoiter; the bone marrow—no atypical findingsin the bone marrow; the lymph nodes—noatypical lymphocytes in the lymph nodes.

Fig. 1. Computed tomography of thechest in case 1.

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HTLV-I carriers with lung involvement

Fig. 2. Immunohistochemical staining of the specimen obtained from TBLB. Positive reactions ofinfiltrating lymphocytes for UCHL-1 are shown. × 100.

Case 2
A 74-year-old Japanese man who lived in
Yonago city in Tottori Prefecture visited our
hospital in October 1995 because of a persistentproductive cough, and dyspnea on exertion. He
had stopped smoking 20 years previously, but
until then, he had smoked 40 cigarettes daily forabout 35 years. Abnormal findings on a chest
radiograph were detected when he was about 60
years old. Chest auscultation revealed fine crackles in both lower lung fields. Laboratory data
revealed an increased erythrocyte sedimentation rate (70 mm/h), but normal hematologicalfindings (white blood cell count; 8900/mm3;
segmental neutrophils 64%, band neutrophils
2%, lymphocytes 25%, monocytes 9%). No
atypical lymphocytes were found in the peripheral blood. Serum LDH was within the normal range (190 IU/L). Analysis of arterial blood
gas showed hypoxemia (PaO2;71 mmHg). The
patient tested negative for hepatitis C virus
antibody, rheumatoid factor and antinuclear
antibody. HTLV-I antibody was positive(32,000-fold). Serum soluble interleukin-2
receptors (sIL-2R) were elevated (784 U/mL),but those in the BAL fluid were not (< 85 U/mL). BAL was performed in the right B4 (Table
1). Although the total cell count in the BAL
fluid was markedly elevated, only a low percent(2.2%) was lymphocytes. Pulmonary function
testing demonstrated a restrictive pattern ofdisturbance (%VC, 54%) with a decreased DLco(%DLco, 61%). Computed tomography of thechest demonstrated bilateral reticulo-nodular
and honey-combed shadows in the lung fields(Fig. 3). Light microscopy of the TBLB specimen showed a slight thickening of the alveolar
walls and fibrosis of the pulmonary parenchyma with minimal infiltration by lymphocytes. No atypical lymphocytes were detectedin the infiltrating cells. Immunohistochemical
analysis of the TBLB specimen showed partly
positive staining of lymphocytes for UCHL-1(Fig. 4).
To detect the HTLV-I provirus in the peripheral blood lymphocytes of this patient, we
examined the separated peripheral blood mono-127

N. Burioka et al.

nuclear cells (PBMCs). The
PBMCs were incubated for 15
min at 70˚C with 1 mL of cell
lysis buffer that consisted of 10
mM Tris-HCl, pH 7.5/10 mM
EDTA, 1% sodium dodecyl sulfate and protease K. Protease K
was added once more and the solution was incubated overnight at
37˚C. Total cellular DNA was extracted according to the phenolchloroform method. The polymerase chain reaction (PCR) was
performed by using the primers
designed to amplify a 159-base
Fig. 3. Computed tomography of the chest in case 2.
pair (bp) segment in the pX region of HTLV-I (Seiki et al.,1983) (5'-CGGATACCCAGTCTACGTGT transferred to Hybond N+ (Amersham Japanand 5'-GAGCCGATAACGCGTCCATCG, Co., Ltd., Tokyo, Japan). A 25-base oligorespectively) (Hatanaka and Kawanishi, 1990). nucleotide probe (5'-TACTGGCCACCTGTC
Sample DNA (1 µg) was denatured at 95˚C, CAGAGCATCA) that hybridized to an interafter which PCR was performed by step cycle at vening sequence between two primers of
94˚C for 20 s, at 50˚C for 30 s, and at 72˚C for HTLV-I was labeled with horseradish peroxy30 s for a total of 35 cycles. The amplified product dase by using ECL direct nucleic acid labelingwas electrophoresed in 3% agarose gel and and a detection system (Amersham Japan).

Fig. 4. Immunohistochemical staining of the specimen obtained from TBLB. Positive reactions of a few
infiltrating lymphocytes for UCHL-1 are shown. × 100.

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HTLV-I carriers with lung involvement

Results of PCR-Southern analysis of this patient are shown in Fig. 5. A markedly amplified
and hybridized product was detected.

Discussion
The incidence of pulmonary complications ismarkedly higher in ATLL than in other hematological malignancies (Yoshioka et al., 1985).
However, most of the HTLV-I infected subjects
are non-symptomatic carriers. Even so, HTLV-I
is implicated as a cause of such inflammatory
disorders as HABA (Kimura, 1992) [or HAB(Maruyama et al., 1988)]. The pulmonary involvement seen in HABA (HAB) is mainly manifested as interstitial pneumonia (Maruyama et al.,
1988; Setoguchi et al., 1991; Kimura, 1992) ora diffuse panbronchiolitis-like lesion (Kimura,
1992; Mukae et al., 1994; Kikuchi et al., 1996).
The mechanism of pulmonary involvementwith HTLV-I remains unclear. Salahuddin andcoworkers (1984) reported that T-cells transformed in vitro by HTLV-I acquired the ability
to release a considerable number of biologic
response modifiers. Recent reports show that Tlymphocyte alveolitis is common in the chronic
spastic myelopathy that is associated with
HTLV-I infection (Sugimoto et al., 1987;
Vernant et al., 1988). Sugimoto and coworkers(1989) reported that sIL-2R was increased in
the BAL fluid of HAM patients, and suggested
that the increased T-lymphocytes in the lungwere activated locally to produce sIL-2R.
Therefore, immune mechanisms may be important in the development of pulmonary lesions. The activation of T-lymphocytes by the
HTLV-I tax gene may trigger an effect in the
immune system (Tanaka et al., 1990). Maruyama
and colleagues (1988, 1989, 1992) reported that
HAB seemed to occur in healthy carriers as wellas in patients with HAM. CD4+ lymphocytes
and the ratio of CD4/CD8 were increased in the
BAL fluid of these patients. These investigators also reported a high rate of T cells infiltration in the lung specimens.
We encountered two HTLV-I carriers withpulmonary involvement. Case 1 died from

Fig. 5. PCR-Southern analysis of HTLV-I provirus
in peripheral blood lymphocytes of the patient incase 2. Lane 1, case 2; Lane 2, a HAM patient who
is an HTLV-I carrier; Lane 3, an idiopathic interstitial pneumonia patient without HTLV-I; Lane 4,
an HTLV-I carrier.

developed interstitial pneumonia in December
1992. The autopsy revealed that this patient
was an HTLV-I carrier. In case 2, no atypicallymphocytes were detected in the peripheral
blood. Since the HTLV-I provirus was detected
in his peripheral blood by PCR (Fig. 5), we believe that case 2 was also a carrier of HTLV-I.
The chest radiograph findings and histological analysis in case 1 suggested a diagnosis
of UIP. The total cell count in his BAL fluid
was elevated compared with that of healthy exsmokers (The BAL Cooperative Group Steering Committee, 1990). The infiltrative lymphocytes in the lung showed positive staining for
UCHL-1 on immunohistochemical analysis(Fig. 2). UCHL-1 recognizes specifically the
180 kD low molecular weight isoform of
CD45RO or leukocyte common antigen family(Terry et al., 1988). UCHL-1 labels most of thethymocytes, a subpopulation of resting T cells
within both the CD4 and CD8 subsets, and themature activated T cells. Although cells of the
myelomonocytic series are also labeled by
UCHL-1, normal B cells or NK cells are consistently negative (Smith et al., 1986). The
UCHL-1-positive infiltrating lymphocytes
were thought to be mainly T-cells in this case.
We suspected that case 1 was HABA in broad
sense, which has been reported (Kimura, 1992).
The histological findings in case 2 revealed
fibrosis of pulmonary parenchyma and minimal
infiltration of lymphocytes that stained partly

129

N. Burioka et al.

positive for UCHL-1 (Fig.4). The total cellcount of BAL fluid was markedly elevated, but
the percentage of lymphocytes was low (2.2%)
compared with that of healthy ex-smokers (TheBAL Cooperative Group Steering Committee,
1990). The value of sIL-2 in the BAL fluid was
not elevated. These findings differ from thoseof previous reports (Maruyama et al., 1988,
1989, 1992), and suggest that undeterminedmechanisms may cause interstitial pneumonia
in this HTLV-I carrier. Although the mechanism is unclear, activated alveolar macrophages
may have played an important role in thedevelopment of pulmonary fibrosis (Martinet etal., 1987) in case 2, as suggested by the marked
increase in the total count of alveolar macrophages in his BAL fluid. Abnormalities shownon the chest radiograph in this case had been
pointed out at least 14 years previously, demonstrating that long-term survival of HTLV-I
carriers with interstitial pneumonia is possible.
A cohort study involving residents of a region
where HTLV-I is endemic will be needed toclarify the mechanism of pulmonary involvement in carriers of HTLV-I.
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(Received April 21, Accepted May 8, 1997)

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