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

Background: Immunocompromised patients with B lymphocyte deficiency and hypogammaglobulinemia after anti-CD19 chimeric antigen receptor (CAR) T cell therapy for relapsed/refractory follicular lymphoma (FL) are at high risk of severe coronavirus disease 2019 (COVID-19) infection.

Case description: In our study, two patients with refractory FL had persistent COVID-19 infection after their anti-CD19 CAR T cell therapy. The patients were diagnosed with post-COVID-19 syndrome or COVID-19 with interstitial inflammation and persistent hypoxemia. The patients received molnupiravir and Paxlovid, along with methylprednisolone therapy when their interleukin (IL)-6 levels were high. No response was observed in interstitial inflammation, persistent hypoxemia, or persistent positive expression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, the level of IL-6 decreased after these therapies. These two patients subsequently received low-dose ruxolitinib (5 mg, twice daily) as salvage therapy in combination with a gradually reduced dosage of methylprednisolone. After 1-2 months of ruxolitinib therapy, persistent hypoxemia was relieved, and interstitial inflammation was significantly absorbed. At the same time, the SARS-CoV-2 detection was found to be negative.

Conclusions: Ruxolitinib might be a safe and effective alternative salvage therapy for patients with COVID-19 having interstitial inflammation and persistent hypoxemia without high cytokine levels and no response to corticosteroids.