The perfect storm: Thrombotic thrombocytopenic purpura (TTP) associated with COVID-19, a clinical case series and review.

This is a case series of three patients in our hospital system who developed acquired thrombotic thrombocytopenic purpura (aTTP) after testing positive for COVID-19 infection. Two patients had acute COVID-19 infections, and one had COVID-19 IgG antibodies consistent with prior COVID-19 infection. Twelve additional cases of aTTP after COVID-19 infection were found in the literature. COVID-19 creates alterations in the vWF-ADAMTS-13 axis with reduced ADAMTS-13 in acute illness that may lead those patients who are predisposed into fulminant aTTP. Further genetic studies are necessary to uncover why some patients with COVID-19 can have concurrent aTTP. For those with a prior COVID-19 infection, molecular mimicry with autoantibodies to ADAMTS-13 is likely the predominant trigger, but having an underlying predisposition (prior episode of TTP, genetic predisposition to autoimmune conditions, or breast cancer history) creates an environment that could be a possible trigger for aTTP.