Persistent COVID-19 Pneumonia in a Patient on Rituximab.

Immunosuppressed patients have increased morbidity and mortality due to SARS-CoV-2 infection. They can have reduced protective antibodies levels or reduced cellular immunity resulting in inability to clear the virus and persistent viremia and virus-induced inflammation. We present the case of a 52-year-old male, immunosuppressed due to use of rituximab for treatment of chronic inflammatory demyelinating polyneuropathy, who developed pneumonitis from SARS-CoV-2 infection. The patient required hospitalization 4 times over a 3-month period due to recurring pneumonitis symptoms, including fever, dyspnea, and a severe cough. The final diagnosis was delayed due to negative SARS-CoV-2 polymerase chain reaction tests on 7/8 of nasopharyngeal specimens, as well as failure to clinically improve with administration of remdesivir after the sole positive test. He was thought to have rituximab-induced organizing pneumonia, but his condition gradually worsened with additional immunosuppression directed against that condition. His active SARS-CoV-2 infection was eventually confirmed from a bronchoalveolar lavage specimen on the final hospitalization, and he was then treated with a multimodal regimen that included an antiviral agent (nirmatrelvir/ritonavir), a Janus Kinase inhibitor (baricitinib), intravenous immunoglobulin, and intravenous methylprednisolone. He had a prompt and sustained clinical response to this multimodal regimen. Persistent COVID-19 should be considered in the differential diagnosis in patients with unexplained organizing pneumonia, and can be treated effectively with multimodal therapy as above.