DLCO, spirometry and PET/CT findings after completing tuberculosis treatment - preliminary findings of StatinTB/ExtendTB trial

Morbidity and mortality rates after tuberculosis (TB) remain elevated. Persistent lung inflammation (PLI) has been associated with TB relapse. The ongoing StatinTB trial (NCT04147286), evaluates safety/efficacy of 40 mg atorvastatin to reduce PLI after TB treatment in HIV-/HIV+ adults measured by ¹⁸F-FDG-PET/CT, with a total follow-up of 96 weeks. We report findings at time of enrolment into StatinTB/ExtendTB of the first 106 participants. Participants with clinical response to TB treatment and a negative sputum culture for TB at 16 weeks were screened after completing 24 weeks of treatment for drug-sensitive TB. Complete pulmonary function and PLI were measured using EasyOne Pro®Lab and PET/CT. PLI was defined as total lung glycolysis (TLG) ≥50 SUVbw*mL. StatinTB/ExtendTB are conducted according to ICH-GCP. Of the 106 participants (32.1% women) aged 34.8±11.3 years who underwent PET/CT, 20.8% were HIV+, 57.5% smokers (4.6±4.2 pack years), 28.3% had previous TB; 13.2% reported ongoing cough and 8.5% shortness of breath. PLI was present in 50.0% of participants (mean TLG of 343.4±375.6 SUVbw*mL). Diffusing capacity of the lung for carbon monoxide (DLCO) was consistently reduced in participants with PLI (DLCO%Pred 73.2% vs. 94.6%; p=0.0001), as was FVC%Pred (81.5% vs. 95.6%; p=0.0001); FEV1%Pred was 78.0% vs 93.2%, p=0.0001. After accounting for other variables including HIV, smoking, FEV1 and FVC, every one percent increase in DLCO%Pred remained independently associated with a decrease of 4.7 SUVbw*mL of TLG (p=0.017). PLI is present in half of participants. Impaired DLCO is associated with PLI, in adults who have completed a 24-week treatment regimen for TB.