B cells play a crucial role in the pathogenesis of many autoimmune diseases. Selective targeting of those cells has recently been achieved by chimeric antibody against the Pan-B cell surface marker CD20 (rituximab). Recent studies have demonstrated the efficacy of rituximab in several refractory autoimmune diseases like atrophic arthritis, systemic lupus erythematosus, immune idiopathic thrombocytopenic purpura, chronic cold agglutinin disease, IgM-mediated neuropathies, and mixed cryoglobulinemia. People with rheumatic and musculoskeletal diseases managed with rituximab might have an increased risk for intense COVID- 19 as opposed to those managed with other treatments.
According to the Lancet Rheumatology, 35% of the patients treated with rituximab developed severe COVID-19, resulting in admission to the intensive care unit or death, compared to 11% in the group without rituximab. These resulted in a significant odds ratio of 3.26 after adjusting for factors such as age, sex, comorbidities, and corticosteroid treatment using the inverse probability method of treatment.
According to Avouac, these findings remained constant secondary evaluation of sixty-three rituximab-handled subjected who had been matched with 250 non-rituximab handled. using a propensity rating matching method.
Importantly, there were some crucial findings in those who received a newer infusion of rituximab for severe COVID-19 than those with mild or moderate disease. The median time between the last rituximab infusion and the onset of COVID-19 symptoms was approximately 30 days in patients with severe disease, compared to approximately 100 and 120 days in patients with mild and moderate disease, respectively. These results suggest direct drug accountability for the association between rituximab and severe COVID-19.
Judicious use of rituximab is needed in patients, specifically in the presence of other comorbidities such as rheumatic and musculoskeletal inflammatory conditions, which may increase the risk of adverse COVID-19 outcomes.
The investigators note that mortality rates in the rituximab group were numerically higher than in the non-rituximab group (21% vs. 7%), but the difference between the groups after adjusting for confounders did not reach statistical significance.
According to Maxime, if possible, it is recommended to suspend the infusion of rituximab in patients whose rheumatic disease is in remission, or a therapeutic alternative can be offered in patients with risk of COVID-19 disease persistence.
However, that the problem is more delicate in patients with systemic autoimmune diseases controlled by rituximab alone and suggests that it may be possible to administer rituximab without prior administration of corticosteroids since corticosteroid therapy has a higher risk is of adverse COVID-19 outcomes. Another option is to reduce the dose of rituximab by increasing the interval between infusions or by decreasing the dose of each infusion.