Introduction
In December 2019, the viral infection outbreak in Wuhan, China became a global pandemic that crossed borders and put the lives of populations in danger, especially those with immunodeficiency (1). During these challenging years and the management of COVID-19 disease, many questions have arisen regarding immunomodulatory and immunosuppressive therapies, especially, in patients with demyelinating disease (2). Given the reduced immune responses, immunodeficient patients are less prone to develop serious complications of COVID-19 and cytokine storm. However, they are more likely to develop opportunistic infections that can mimic the symptoms of SARS-CoV-2 infection (3).
Multiple sclerosis (MS), an autoimmune, demyelinating disease of the central nervous system (CNS), is mainly linked to the reaction of CD4+ T cells to the antigens of myelin membrane (4). Two previous randomized clinical trials (RCTs), has demonstrated that rituximab, a monoclonal anti-CD20 antibody, could be effective in primary progressive multiple sclerosis (PPMS) and relapsing-remitting multiple sclerosis (RRMS) (5). However, there are growing reports, introducing post-rituximab therapy Pneumocystis jirovecii pneumonia (PJP), in cases of systemic lupus erythematosus, Wegener’s granulomatosis, rheumatoid arthritis, lymphoma, and humoral renal transplant rejection (6). Given the fact that rituximab is a commonly used medication for the highly active forms of MS, it is important to consider the possible risk of PJP in these patients.
In the current study, we presented a case of COVID-19 infection, who was complicated with PJP, following treatment with rituximab for RRMS.