Long COVID-19 Infections and Organizing Pneumonia in a Series of Patients with Indolent Lymphoma Treated with Rituximab

Background: Patients with hematologic malignancies have an increased risk of complications and mortality from COVID-19 (SARS-CoV-2). These patients are often more susceptible to protracted COVID-19 infections (e.g., long COVID-19). In addition, patients treated with the CD20-targeted immunotherapy rituximab in B-cell lymphomas are at greater risk for a protracted clinical course with COVID-19, including care in the ICU for respiratory failure. Hypogammaglobulinemia is an independent predictor of increased risk for long-COVID19. Immune depletion both leads to a persistent detection of SARS-CoV-2 and an inability to mount a sustained immune response. Other authors have reported on the appearance of a delayed organizing pneumonia (OP) after acute COVID-19 infection, but these patients were not immunocompromised by rituximab. In this case series, we report on three patients with indolent lymphoma who had the delayed presentation of long COVID-19 after an acute infection. All three were previously treated with rituximab, and each case was notable for prolonged OP that was refractory to steroid therapy.

Methods: Summative data for the three patient cases was aggregated from the medical record including available physician notes, diagnostic body imaging, and laboratory data.

Results: In total, we found three cases of long COVID-19 in patients with indolent lymphoma from our institution (Table 1). Patient 1 received just two doses of rituximab, Patient 2 received three doses of rituximab, and Patient 3 was treated with rituximab intermittently for nearly three years. All three patients experienced their first COVID-19 infections in August 2022 and had low IgG. This was followed by complications including acute hypoxemic respiratory failure, pulmonary embolism, and organizing pneumonia in these patients two to three months thereafter. These patients continue to have ongoing chronic hypoxemic respiratory failure requiring immune suppression and continuous oxygen support.

Conclusions: Immune depletion with rituximab in patients with indolent lymphomas can put them at significant risk of long COVID-19, OP, and chronic hypoxemic respiratory failure after contracting SARS-Cov-2. Such patients may benefit from prolonged immune suppression, but the exact duration remains unclear. The mechanism of long COVID-19 and refractory OP is unclear and complex. Possible mechanisms may include inadequate clearance of virus or a dysfunctional immune response.

Table 1: Lymphoma patients who received rituximab and then developed long COVID-19