Lung function impairment at pulmonary TB and HIV/TB diagnosis: a South African cross-sectional cohort analysis

Objectives To characterise the patterns and severity of impaired lung function at pulmonary tuberculosis (TB) diagnosis and assess the impact of HIV co-infection on TB-associated lung injury. Setting A cross-sectional analysis of adults with and without HIV who presented with newly diagnosed drug-susceptible pulmonary TB in Johannesburg, South Africa. Participants A total of 258 adults who were newly diagnosed with drug-susceptible pulmonary TB underwent comprehensive pulmonary function tests (PFT). Primary and secondary outcome measures Five key PFT manoeuvres were evaluated: forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, total lung capacity (TLC) and haemoglobin-corrected diffusion capacity of the lungs for carbon monoxide (DLCO). Three primary outcomes were modelled: (1) normal versus abnormal lung function, defined as any key PFT manoeuvre z-score 0.9). Conclusions Adults with HIV/TB co-infection demonstrated a distinct clinical phenotype of TB-associated lung injury at TB diagnosis characterised by less severe radiographic and lung function impairment compared with those without HIV.