Asthma diagnosis and airway bronchodilator response in HIV-infected patients

Abstract

Background: Despite the high prevalence of respiratory symptoms and obstructive lung disease in HIV-infected subjects, the prevalence of bronchodilator reversibility (BDR) and asthma has not been systematically studied during the era of combination antiretroviral therapy (ART).

Objective: We sought to determine the prevalence of asthma diagnosis and related pulmonary function abnormalities in an HIV-infected cohort and to identify potential mechanisms.

Methods: We performed a cross-sectional analysis of 223 HIV-infected subjects with data on respiratory symptoms and diagnoses, pulmonary function, sputum cell counts, and asthma-related cytokines and chemokines in serum/sputum.

Results: Doctor-diagnosed asthma was present in 46 (20.6%), and BDR (≥200 mL and ≥12% increase in FEV(1) or forced vital capacity) was present in 20 (9.0%) participants. Pulmonary symptoms and function were worse in those with doctor-diagnosed asthma. Doctor-diagnosed asthma was independently associated with female sex (P = .04), body mass index of greater than 29.6 kg/m(2) (vs <29.6 kg/m(2), P = .03), history of bacterial or Pneumocystis pneumonia (P = .01), and not currently taking ART (P = .04) and in univariate analysis with parental history of asthma (n = 180, P = .004). High sputum eosinophil percentages (>2.3% based on the highest decile) were more likely in those with doctor-diagnosed asthma (P = .02) or BDR (P = .02). Doctor-diagnosed asthma tended to be more common with high sputum IL-4 (P = .02) and RANTES (P = .02) levels, whereas BDR was associated with high plasma macrophage inflammatory protein 1α (P = .002) and sputum macrophage inflammatory protein 1β (P = .001) levels.

Conclusion: Asthma diagnosis and BDR are prevalent in an HIV-infected outpatient cohort, and associations with family history, obesity, allergic inflammation, prior infection, absence of ART, and increased HIV-stimulated cytokines suggest possible mechanisms of HIV-associated asthma.

Figure 1

Prevalence of respiratory symptoms (a) and pulmonary function values (b) in participants diagnosed with asthma by their physician in the past and those without an asthma diagnosis. DL_CO = diffusion capacity for carbon monoxide, FEV₁ = forced expiratory volume in 1 second, FEF_25%–75% = forced expiratory flow between 25% and 75% of vital capacity, FVC = forced vital capacity, % = percent predicted.

Figure 2

Prevalence of a high (>2.3%) eosinophil count in induced sputum between participants with or without doctor-diagnosed asthma or positive bronchodilator reversibility (BDR).