compared to patients with ≤10%. There was no difference in PFT and residual CT lesions between patients who received steroids and those who did not. Conclusion:The majority of patients have altered PFT at three months, even in patients with mild initial disease, with significantly lower function in patients with residual CT lesions. Steroids do not seem to modify functional and radiological recovery. Long-term follow-up is needed.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected millions of people worldwide, and pneumonia affects 90% of patients. This raises the possibility of millions of people with altered lung function. Few data exist to date on pulmonary function after SARS-CoV-2 infection, but alteration of diffusion capacity of CO (DLCO) is the most frequently described abnormality. First, we present original data on lung function at 3 months after SARS-CoV-2 infection and discuss the effect of using European Coal and Steel Community (ECSC) or Global Lung Function Initiative (GLI) reference equations to diagnose diffusion capacity. Second, we review existing data on DLCO alteration after SARS-CoV-2 infection and discuss the implication of restrictive disorder in DLCO alteration. Last, we discuss the pathophysiology of DLCO alteration and try to disentangle vascular damage and fibrosis.