ABSTRACT
Background: Case reports of autoimmune hematological diseases secondary to COVID-19 infection or vaccination are emerging. However, there are limited case series that analyze patterns of presentation, treatment patterns and responses. Most reports have limited follow-up duration, occurred prior to the incorporation of corticosteroid in COVID-19 treatment, and did not report on vaccine re-challenge. Aim(s): To characterize case presentations, severity, treatment courses and response of immune thrombocytopenia (ITP), autoimmune hemolytic anemia (AIHA) and thrombotic thrombocytopenic purpura (TTP) associated with COVID-19 infection, or vaccination. Method(s): In this multi-centre case series, adults (>18) diagnosed with de novo or relapsed ITP, AIHA and TTP associated with COVID-19 infection or vaccination (January-December 2021) were recruited from hematologists at two academic hospitals in Edmonton, Alberta (population 1.5 million). The Brighton Collaboration criteria was used to adjudicate diagnostic certainty. Research ethics approval and informed consent were obtained. Result(s): Thirteen patients presented with 14 autoimmune hematological complications (Tables 1-2). Following the BNT162b2 (n = 7) or mRNA-1273 (n = 2) vaccine, we diagnosed 6 cases of ITP (5 de novo) and 3 AIHA (1 de novo). A greater proportion of hematological disorders developed after second-doses of vaccine compared to first (66 vs 33%). Three individuals received subsequent doses of COVID-19 vaccine without disease relapse. In addition, 5 patients developed ITP (3), AIHA (1) and relapsed TTP (1) precipitated by COVID-19 infection. Among 8 patients with de novo autoimmune hematological disorders, the majority (75%) achieved complete or partial response at a median follow-up of 4.6 months, only three individuals had relapses requiring subsequent treatment. All patients were managed with glucocorticoids, 3 received IVIG and 4 required second-line therapy. Conclusion(s): Autoimmune hematological conditions due to COVID-19 infection or vaccination present, and are successfully managed similarly to cases unrelated to COVID-19. Among vaccine-associated hematological disorders, repeat doses of vaccine may be safely administered.