Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Context: The B cell chemoattractant chemokine ligand 13 (CXCL13) is emerging as a new biochemical marker in RA. This study was undertaken to dissect the relationship between CXCL13 expression levels in the synovium and clinico-pathological variables relevant to RA pathogenesis and outcome.', 'Synovial tissues from 71 RA patients were evaluated by immunohistochemistry. Thirty paired samples were used for comparative gene expression analysis by quantitative real-time PCR. CXCL13 levels were analysed in relation to cellular, molecular and clinical features of inflammation, lymphocyte activation and joint damage.', 'In patients with early disease (<12 months duration), CXCL13 expression correlated significantly with synovial markers of local disease activity and systemic inflammation. Such correlation was less evident in established RA. Notably, the association with lymphocyte infiltration and with expression of B/T cell-related activation and proliferation genes, such as activation-induced cytidine deaminase, IFN-γ and IL-2, remained highly significant independent of disease duration and local disease activity. Patients featuring the highest levels of CXCL13 were more frequently ACPA positive and IgG ACPA titres were increased in the high CXCL13 expression group. Furthermore, the frequency of erosive disease on radiographs was significantly higher in the upper tertile of CXCL13 expression (P = 0.01 with adjustment for disease duration and ACPA). Accordingly, synovial CXCL13 and the local receptor activator of nuclear factor κB ligand (RANKL)/osteoprotegerin (OPG) ratio significantly co-varied (ρ = 0.52, P < 0.01), independent of the level of local inflammation.
Answer: Synovial CXCL13 appears to be a marker of a more severe pattern of RA disease, characterized by increased lymphocyte activation and bone remodelling beyond the level of conventional markers of inflammation.
Are high expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium a marker of severe disease?

Context: Suboptimal adherence to antiretroviral therapy (ART) is a strong predictor of virologic failure (VF) among people with HIV. Various methods such as patient self-report, pill counts and pharmacy refills have been utilized to monitor adherence. However, there are limited data on the accuracy of combining methods to better predict VF in routine clinical settings. We examined various methods to assess adherence including pill count, medication possession ratio (MPR), and self-reported adherence in order to determine which was most highly associated with VF after > 6 months on ART.', 'We conducted a secondary analysis of data from a case-control study. At enrollment, pharmacy refill data were collected retrospectively from the medical chart, pill counts were completed to derive a pill count adherence ratio (PCAR) and a self-report questionnaire was administered to all participants. Parametric smooth splines and receiver operator characteristic (ROC) analyses were carried out to assess the accuracy of the adherence methods.', '458 patients were enrolled from October 2010 to June 2012. Of these, 158 (34.50%) experienced VF (cases) and 300 (65.50%) were controls. The median (IQR) PCAR was 1.10 (0.99-1.14) for cases and 1.13 (1.08-1.18) for controls (p < 0.0001). The median MPR was 1.00 (0.97-1.07) for cases and 1.03 (0.96-1.07) for controls (p = 0.83). Combination of PCAR and self-reported questions was highly associated with VF.
Answer: In this setting, a combination of pill count adherence and self-report adherence questions had the highest diagnostic accuracy for VF. Further validation of this simple, low-cost combination is warranted in large prospective studies.
Is the combination of pill count and self-reported adherence a strong predictor of first-line ART failure for adults in South Africa?

Context: Prolactin levels have been shown to be increased by different types of psychosocial stress. Since burnout is a consequence of long-term psychosocial stress, prolactin levels might also be affected in burnout. The aim of this study was to investigate whether there are differences in prolactin levels between individuals who report burnout and others.', 'Morning fasting serum prolactin levels were compared between individuals who reported burnout (24 men and 25 women) and individuals who reported no burnout (25 men and 13 women). Women were tested in the follicular phase of the menstrual cycle. Men and women were analysed separately.', 'Men who reported burnout exhibited significantly higher (34%) serum prolactin levels compared to men who reported no burnout. The prolactin levels in women who reported burnout were not different from the levels in the women who reported no burnout before or after adjusting for estradiol levels.
Answer: This study indicates that prolactin levels are higher in men with burnout than men without burnout but not affected in women with burnout. Why no association was seen in women needs to be further explored.

Is burnout associated with elevated prolactin levels in men but not in women?