A rare post-infectious autoimmune manifestation of COVID-19

The incidence of post-infectious autoimmune diseases has been on the rise following the COVID-19 pandemic. Recently, an autistic patient was admitted to the hospital presenting with a mild upper respiratory system COVID-19 infection. Months after recovery and polymerase chain reaction negativity, the patient developed HEp-2 cell positivity and presented with relapsing polychondritis (RP), a rare autoimmune disease. The mechanism of this autoimmune invasion is ultimately caused by activating a myriad of immune reactions. Lymphocytopenia almost always accompanies various clinical forms of COVID-19; however, it may drive the lymphocytopenia-induced proliferation of autoreactive T cells via the activation of interleukin-6 (IL-6). Moreover, high levels of neutrophils during infection promote autoimmune disease by releasing cytokine and chemokine cascades that accompany inflammation, and neutrophil extracellular traps regulating immune responses through cell–cell interactions. Furthermore, autism spectrum disorder patients display an altered immune system that includes an augmented inflammatory cytokine milieu leading to an increased pro-inflammatory Th1/Th2 ratio. In addition, the pathophysiology of RP is majorly associated with a cell-mediated immune reaction; thus, the predisposing exaggerated immune system of such patients must also be considered as a predisposing factor to the development of post-infectious autoimmune diseases.