Clinical and peculiar immunological manifestations of SARS-CoV-2 infection in systemic lupus erythematosus patients.

Objectives The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with systemic lupus erythematosus (SLE) remains unclear and data on clinical manifestations after infection are lacking. The aim of this multicentre study is to describe the effect of SARS-CoV-2 in SLE patients. Methods SLE patients referring to 4 Italian centres were monitored between February 2020 and March 2021. All patients with SARS-CoV-2 infection were included. Disease characteristics, treatment, disease activity, and SARS-CoV-2 related symptoms were recorded before and after the infection. Results Fifty-one (6.14%) SLE patients were included among 830 regularly followed-up. Nine (17.6%) had an asymptomatic infection. Five (9.8%), out of 42 (82.6%) symptomatic, developed interstitial pneumonia (no identified risk factor). The presence of SLE major organ involvement (particularly renal involvement) was associated with asymptomatic SARS-CoV-2 infection (p-value = 0.02). Chronic corticosteroid therapy was found to be associated with asymptomatic infection (p-value = 0.018). Three SLE flares (5.9%) were developed after SARS-CoV-2 infection: one of them was characterized by MPO-ANCA positive pauci-immune crescentic necrotizing glomerulonephritis and granulomatous pneumonia. Conclusions SARS-CoV-2 infection determined autoimmune flares in a small number of our patients. Our data seem to confirm that there was not an increased risk of SARS-CoV-2 in SLE. Patients with asymptomatic SARS-CoV-2 infections were those having major SLE organ involvement. This may be explained by the high doses of corticosteroids and immunosuppressive agents used for SLE treatment.