Prevalence and predictors of airflow obstruction in an HIV tertiary care clinic in Montreal, Canada: a cross-sectional study

Objectives

The reported prevalence of chronic obstructive pulmonary disease (COPD) in people living with HIV (PLWHIV) varies widely. Our objective was to estimate the prevalence of airflow obstruction and COPD in unselected PLWHIV and identify characteristics that increase the risk of nonreversible airflow obstruction in order to guide case finding strategies for COPD.

Methods

All adults attending the Chronic Viral Illness Service were invited to participate in the study, regardless of smoking status or history of known COPD/asthma. Individuals underwent spirometric testing both before and after use of a salbutamol bronchodilator. Airflow obstruction was defined as forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) < 0.7 post‐bronchodilation, whereas COPD was defined as FEV₁/FVC < 0.7 post‐bronchodilation and Medical Research Council (MRC) score > 2. Multivariate logistic regression was used to evaluate risk factors associated with airflow obstruction, reported as adjusted odds ratios (aORs).

Results

Five hundred and three participants successfully completed spirometry testing. The median (Q1; Q3) age was 52 (44; 58) years. The median (Q1; Q3) CD4 count was 598 (438; 784) cells/μL and the median (Q1; Q3) nadir CD4 count was 224 (121; 351) cells/μL. There were 119 (24%) current smokers and 145 (29%) former smokers. Among those screened, 54 (11%) had airflow obstruction whereas three (1%) of the participants had COPD. Factors that were associated with airflow obstruction included a history of smoking [aOR 2.2; 95% confidence interval (CI) 1.1; 4.7], older age (aOR 1.6; 95% CI 1.2; 2.2), and lower CD4 count (aOR 0.8; 95% CI 0.7; 1.0).

Conclusions

Airflow obstruction was relatively uncommon. Our findings suggest that PLWHIV who are ≥50 years old, smokers and those with nadir CD4 counts ≤ 200 cells/μL could be targeted to undergo spirometry to diagnose chronic airflow obstruction.

Evaluation of the Upgraded Version 2.0 of the Roche COBAS® AmpliPrep/COBAS® TaqMan HIV-1 Qualitative Assay in Central African Children

Background:

Several commercially available molecular techniques were developed based on subtype B of HIV-1, which represents only 10% of HIV strains worldwide. Indeed, in sub-Saharan Africa, non-B subtypes of HIV-1 are predominant. The aim of this study was to evaluate the performances of the COBAS^® AmpliPrep/COBAS^® (CAP/CTM) HIV-1 Qualitative assays to detect the broad range of HIV-1 variants circulating in Central Africa and compare to the outgoing CAP/CTM HIV-1 Quantitative test v2.0 (Roche Molecular Systems), chosen as reference gold standard molecular assay.

Methods:

The CAP/CTM HIV-1 Qualitative tests versions 1.0 and 2.0 (Roche Molecular Systems, Inc., Branchburg, NJ, USA) were evaluated compared to CAP/CTM TaqMan HIV-1 Quantitative test v2.0 (Roche Molecular Systems) on 239 dried plasma spot (DPS) from 133 HIV-1-infected (with detectable plasma HIV RNA load) and 106 uninfected children, followed-up at Complexe Pédiatrique, Bangui, Central African Republic.

Results:

The version 1.0 showed low sensitivity (93.2%), with 9 (6.8%) false negative results, demonstrating under-detection of non-B HIV-1 subtypes. In contrast, the upgraded version 2.0 showed 100%-sensitivity, 100%-specificity and perfect agreement (κ coefficient, 1.0).

Conclusion:

Our evaluation in the Central African Republic demonstrates the clinical implications of the accuracy and reliability of the CAP/CTM HIV-1 Qualitative assay for early diagnosis of HIV-1 in Central African children.

Soluble CD40-ligand (sCD40L, sCD154) plays an immunosuppressive role via regulatory T cell expansion in HIV infection

CD40/CD40-ligand (CD40L) signalling is a key stimulatory pathway which triggers the tryptophan (Trp) catabolizing enzyme IDO in dendritic cells and is immunosuppressive in cancer. We reported IDO-induced Trp catabolism results in a T helper type 17 (Th17)/regulatory T cell (Treg ) imbalance, and favours microbial translocation in HIV chronic infection. Here we assessed the link between sCD40L, Tregs and IDO activity in HIV-infected patients with different clinical outcomes. Plasmatic sCD40L and inflammatory cytokines were assessed in anti-retroviral therapy (ART)-naive, ART-successfully treated (ST), elite controllers (EC) and healthy subjects (HS). Plasma levels of Trp and its metabolite Kynurenine (Kyn) were measured by isotope dilution tandem mass spectrometry and sCD14 was assessed by enzyme-linked immunosorbent assay (ELISA). IDO-mRNA expression was quantified by reverse transcription-polymerase chain reaction (RT-PCR). The in-vitro functional assay of sCD40L on Treg induction and T cell activation were assessed on peripheral blood mononuclear cells (PBMCs) from HS. sCD40L levels in ART-naive subjects were significantly higher compared to ST and HS, whereas EC showed only a minor increase. In ART-naive alone, sCD40L was correlated with T cell activation, IDO-mRNA expression and CD4 T cell depletion but not with viral load. sCD40L was correlated positively with IDO enzymatic activity (Kyn/Trp ratio), Treg frequency, plasma sCD14 and inflammatory soluble factors in all HIV-infected patients. In-vitro functional sCD40L stimulation induced Treg expansion and favoured Treg differentiation by reducing central memory and increasing terminal effector Treg proportion. sCD40L also increased T cell activation measured by co-expression of CD38/human leucocyte antigen D-related (HLA-DR). These results indicate that elevated sCD40L induces immunosuppression in HIV infection by mediating IDO-induced Trp catabolism and Treg expansion.

Assessment of chloroquine as a modulator of immune activation to improve CD4 recovery in immune nonresponding HIV-infected patients receiving antiretroviral therapy

OBJECTIVES

Chloroquine (CQ), an anti-inflammatory drug, inhibits Toll-like receptor (TLR) signalling in plasmacytoid dendritic cells (pDCs) and may be beneficial for HIV-infected patients in whom immune activation persists despite effective antiretroviral therapy (ART). The effect of CQ on CD4 T-cell recovery and immune activation in immune nonresponding patients receiving successful ART was therefore studied.

METHODS

Nineteen adults on ART with CD4 counts ≤ 350 cells/μL and undetectable viral load (VL) orally received CQ at 250 mg/day for 24 weeks. Side effects, CD4 and CD8 T-cell counts, VL, T-cell activation, pDC proportion and plasma inflammatory markers were assessed at baseline, at 24 weeks, and at 12 weeks after CQ discontinuation (clinicaltrial.org registration #NCT02004314).

RESULTS

CQ was well tolerated and all patients maintained an undetectable VL. The absolute CD4 and CD8 T-cell counts and their percentages, the pDC proportion, T-cell activation, D-dimer and C-reactive protein (CRP) plasma levels and the kynurenine/tryptophan ratio did not change with CQ treatment. Among nine cytokines/chemokines measured, only levels of interferon (IFN)-α2 were significantly increased by CQ treatment.

CONCLUSIONS

CQ was well tolerated in patients with low CD4 T-cell counts despite long-term effective ART; however, 24 weeks of CQ treatment did not improved CD4 T-cell recovery, lymphoid and myeloid immune activation or inflammatory markers.