Successful salvage therapy of Ruxolitinib on interstitial pneumonia after long COVID or post COVID-19 syndrome with follicular lymphoma: two-case report and literature review

Abstract Immunocompromised caused by B lymphocyte deficiency and hypogammaglobulinemia after anti-CD19 Chimeric antigen receptor (CAR) T cell therapy for patients with relapsed/refractory (R/R) follicular lymphoma (FL) are high risks of severe COVID-19 infection. In our study, two patients with refractory FL had persistence of COVID-19 infection after their anti-CD19-CAR T cell therapy. They were diagnosed with Post COVID-19 syndrome or Long COVID-19 with interstitial inflammation and persistent hypoxemia. They received Molnupiravir and/or Paxlovid, methylprednisolone therapy when their interleukin (IL)-6 was is at a high level. There was no response in interstitial inflammation, persistent hypoxemia and persistent positive expression of SARS-CoV-2 to the therapy above, but the level of IL-6 was decreased after these therapies. These two patients subsequently received low-dose of Ruxolitinib (5mg, twice a day) as a salvage therapy in combination with a gradually reduced dosage of methylprednisolone. One to two months of Ruxolitinib therapy, the persistent hypoxemia was relieved and the interstitial inflammation was significantly absorbed. At the same time, the SARS-CoV-2 detection was found to be negative. Even if SARS-CoV-2 was positive again, the interstitial pneumonia did not progress again and the symptoms such as dyspnea did not develop again. Ruxolitinib might be a safe and effective alternative salvage therapy for COVID-19 infection patients with interstitial inflammation and persistent hypoxemia who had no response to corticosteroid therapy.