Secondary organising pneumonia associated to COVID-19 infection in patients with central nervous system inflammatory demyelinating diseases treated with anti-CD20 therapies.

Background: Organizing pneumonia (OP), an interstitial lung disease, has been observed in patients with inflammatory demyelinating diseases (IDDs) treated with anti-CD20, particularly after COVID-19, but data are limited.

Aim: To provide a detailed characterization of COVID-19-associated OP in IDD patients treated with anti-CD20.

Methods: Bi-centric retrospective cohort study including patients with multiple sclerosis (MS), aquaporin-4-positive neuromyelitis optica spectrum disorder (AQP4 + NMOSD), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) who received anti-CD20 and were diagnosed with COVID-19-associated OP between March 2020 and October 2023.

Results: Nineteen patients were included (mean age 46.8 years; 52.6% female; 63% rituximab, 37% ocrelizumab). Sixteen had MS, two MOGAD, and one AQP4 + NMOSD. Intermittent fever was the predominant symptom. Hospitalization occurred in all but one patient, without fatalities. Chest CT consistently showed OP patterns. Thirteen patients had positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR in bronchoalveolar lavage. Treatments included corticosteroids, antivirals, monoclonal antibodies, and convalescent plasma. Fourteen patients postponed infusions; nine resumed post-recovery (median 11.9 months), two switched due to hypogammaglobulinemia, and three stopped. After a mean follow-up of 1.5 years, lung abnormalities and clinical manifestations resolved in 18 patients; however, 13 experienced long-COVID.

Conclusions: In anti-CD20-treated patients with recurrent fever and distinctive CT features, COVID-19-associated OP should be considered.