Are SARS-CoV-2 reactive T cells detectable and potentially protective in patients under anti-CD20 treatment with an impaired humoral response?

Abstract

The pandemic attributable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has greatly changed life in most countries of the world for more than 1.5 years now. The spread could be more or less well-controlled and fatalities could partly be avoided by obligatory wearing of masks, contact restrictions and since the beginning of the year by vaccinations. Patients with chronic inflammatory diseases and organ transplant patients under immunosuppression, are somewhat more at risk to become ill with coronavirus disease 2019 (COVID-19). The probability and severity of an infection depends on the ability of the humoral and cellular immune systems to effectively combat the virus. This can be substantially improved by vaccination. The B cell depleting monoclonal antibody rituximab (RTX) is frequently employed in rheumatic diseases, whereby antibody formation against the new pathogen within the framework of vaccination is restricted. Recent study results in patients treated with RTX indicate that an effective cellular immune response can be developed despite the impaired humoral response.