BackgroundDiagnosis and treatment of latent tuberculosis infection (LTBI) is the most effective strategy to control tuberculosis (TB) among patients with HIV infection. The tuberculin skin test (TST) was the only available method to identify LTBI. The aim of the present work was to evaluate the usefulness of the interferon-gamma release assays (IGRAs): QuantiFERON-tuberculosis (TB) Gold-In-Tube test (QFG) and T-SPOT.TB for the diagnosis of LTBI in a diverse cohort of HIV-infected patients.MethodsA prospective study was carried out in consecutive patients cared for in a single institution in Spain from January 2009 to October 2010. IGRAs and TST were performed simultaneously. TST induration ≥ 5 mm was considered positive.ResultsQFG, T-SPOT.TB and TST were performed in 373 subjects. Median CD4 cell count was 470/μl with a median nadir of 150/μl. TST, QFG and T-SPOT.TB were positive in 13.3%, 7.5% and 18.5% cases respectively. Among 277 patients with neither past or current TB nor previous treatment for LTBI and who had TST results, a positive TST result was obtained in 20 (7.2%) cases. When adding QFG results to TST, there were a total of 26 (8.6%) diagnoses of LTBI. When the results of both IGRAs were added, the number of diagnoses increased to 54 (17.9%) (incremental difference: 10.7% [95% confidence interval [CI]:5.3-16.2%] [p < 0.001]), and when both IGRAs were added, the number of diagnoses reached 56 (18.5%) (incremental difference: 11.3% [95% CI:5.7%–16.9%] [p < 0.001]). Patients with a CD4 cell count greater than 500 cells/μl and prior stay in prison were more likely to have a diagnosis of LTBI by TST and/or QFG and/or T-SPOT.TB (adjusted odds ratio [aOR]: 3.8; 95% CI, 1.4 – 9.9; and aOR: 3.3; 95% CI, 1.3 – 8.3, respectively).ConclusionsIGRAs were more sensitive than TST for diagnosis of M. tuberculosis infection in HIV-infected patients. Dual sequential testing with TST and IGRAs may be the optimal approach for LTBI screening in this population.

Initiation of combined antiretroviral therapy (cART) is associated with bone loss, which may be more intense with regimens including tenofovir. The underlying mechanisms are not well understood. Cross-sectional data have linked tenofovir with higher parathyroid hormone (PTH) concentrations in patients with vitamin D deficiency. We performed a longitudinal study with a 48-week follow-up to evaluate sequential changes in PTH and 25-hydroxyvitamin D [25(OH)D] levels in patients starting cART with either tenofovir/emtricitabine or abacavir/lamivudine. Fifty-seven patients were included, 31 initiating tenofovir/emtricitabine and 26 initiating abacavir/lamivudine. Median PTH levels turned out to be significantly higher among tenofovir/emtricitabine users at week 4 (p=0.01), week 24 (p=0.008), and week 36 (p=0.02), and were above the upper limits of normal values (ULN) at weeks 24, 36, and 48 only in patients receiving tenofovir/emtricitabine. 25(OH)D, serum and urine calcium and phosphate, and renal-tubular maximum reabsorption of phosphate to the glomerular filtration rate (TmP/GFR) levels did not differ between the two treatment arms over the study period. Among tenofovir/emtricitabine users, median (interquartile range) PTH concentrations were significantly higher in patients with suboptimal 25(OH)D levels (<30 μg/liter) at week 24 [63 (57.8-82.4) ng/liter vs. 54.3 (34.4-63.067.5) ng/liter, p=0.05] and week 48 [67.5 (59.6-86.0) ng/liter vs. 41.9 (37.3-68.8) ng/liter, p=0.03]. A multivariable logistic regression model showed that tenofovir/emtricitabine use was an independent predictor of high PTH levels (≥53 ng/liter). Starting cART with tenofovir regimens is associated with an elevation in PTH plasma concentrations soon after introducing the drug. Suboptimal baseline 25(OH)D levels increase the risk of developing secondary hyperparathyroidism among tenofovir users.

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To compare the tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube test (QFG) for the detection of latent tuberculosis infection among patients with immune-mediated inflammatory diseases before antitumor necrosis factor-α therapy. A prospective study including 153 consecutive patients with rheumatoid arthritis (n = 53), psoriasis (n = 45), inflammatory bowel disease (n = 25), and spondyloarthropathy (n = 22) were included. QFG and TST were performed simultaneously. TST was positive in 43/153 (28.1 %) patients. QFG (cutoff ≥ 0.35 IU/ml) was positive in 15/153 (9.8 %) patients, and indeterminate in one (0.7 %). QFG (cutoff ≥ 0.10 IU/ml) was positive in 25/153 (16.3 %). 59.5 % of the patients were on immunosuppressive therapy at the time of testing. There was a significant difference in the rate of positive QFG between patients with and without immunosuppressive therapy after adjustment for age and gender (cutoff ≥ 0.35 IU/ml, 4.6 vs. 17.4 %; adjusted odds ratio [AOR], 0.2; 95 % confidence interval [CI], 0.06-0.8; p = 0.03 and cutoff ≥ 0.10 IU/ml, 11.2 vs. 24.2 %; AOR, 0.3; 95 % CI, 0.1-0.93; p = 0.04). Agreement between TST and QFG was 'fair' (κ = 0.354 and κ = 0.365, for cutoffs ≥ 0.35 and ≥0.10 IU/ml, respectively). Among patients without immunosuppressive therapy, the concordance between TST and QFG was 'moderate-substantial' (κ = 0.593 and κ = 0.690, for cutoffs ≥ 0.35 IU/ml and ≥0.10 IU/ml, respectively). By contrast, among patients on immunosuppressive therapy the concordance was 'poor' (κ = 0.085; κ = 0.041, respectively). Immunosuppressive therapy affects negatively QFG performance. In patients with immune-mediated inflammatory diseases, QFG may have a limited role for screening of latent tuberculosis infection.

BackgroundRelationship of hepatitis C virus (HCV) infection with an increased risk of cardiovascular disease (CVD) in HIV-infected patients remains controversial. We evaluated endothelial function and subclinical atherosclerosis in HIV-infected patients with and without HCV.MethodsFlow-mediated dilatation (FMD) of the brachial artery and circulating levels of cell adhesion molecules (CAM) were measured in HCV/HIV-coinfected and HIV-monoinfected patients. Subclinical atherosclerosis was assessed by carotid intima-media thickness (cIMT).Results63 (31%) HCV/HIV-coinfected and 138 (69%) HIV-monoinfected patients were included. Median soluble vascular CAM-1 (sVCAM-1) and intercellular CAM-1 (sICAM-1) levels were significantly higher in HIV/HCV-coinfected patients (P < 0.001 for both cases). Median (interquartile range) FMD was 6.21% (2.86-9.62) in HCV/HIV-coinfected and 5.54% (2.13-9.13) in HIV-monoinfected patients (P = 0.37). Adjustment for variables associated with HCV and FMD disclosed similar results. FMD correlated inversely with cIMT and age. Carotid IMT did not differ between HCV/HIV-coinfected and HIV-monoinfected patients in unadjusted (0.61 [0.55-0.65] mm vs 0.60 [0.53-0.72] mm; P = 0.39) or adjusted analyses.ConclusionHCV infection was associated with higher levels of sICAM-1 and sVCAM-1, but no evidence of increased subclinical atherosclerosis was found when endothelial function was evaluated through FMD, or when assessing the cIMT.