Polyarteritis Nodosa Following mRNA-1273 COVID-19 Vaccination: Case Study and Review of Immunological Mechanisms

Abstract

Numerous post-vaccine complications have been reported secondary to the COVID-19 vaccine. Many of these complications are believed to be due to a hyperactive immune system. A 59-year-old woman developed diffuse abdominal pain two days after receiving the mRNA-1273 COVID-19 vaccine (Moderna). A computerized tomography (CT) angiogram of the abdomen and pelvis revealed the presence of numerous vascular irregularities in the celiac axis, bilateral renal arteries, and inferior mesenteric artery consistent with polyarteritis nodosa (PAN), a medium-vessel vasculitis. The patient was managed with intravenous methylprednisolone 500 mg daily for three days and was then placed on oral methotrexate (MTX) 12.5 mg daily for immunosuppressive maintenance treatment. Until now, a limited number of cases of polyarteritis nodosa secondary to the COVID-19 vaccine have been reported. Major mechanisms of post-vaccine autoimmunity are molecular mimicry and autoantibody production. Although rare adverse events from COVID-19 vaccination are possible, there remains an immense benefit to vaccination in preventing COVID-19-related morbidity and mortality.

Keywords: coronavirus disease 2019; covid 19; moderna covid-19 vaccine; moderna mrna adverse effects; mrna-1273 vaccine; pfizer-biontech covid-19 vaccine; pfizer-biontech covid-19 vaccine related adverse events; polyarteritis nodosa; sars-cov-2; severe acute respiratory syndrome coronavirus 2.

Figure 1. Initial computerized tomography (CT) angiography of the abdomen and pelvis

(A) Irregularity of the distal portion of the right renal artery with multifocal aneurysmal dilatation. (B) Slight narrowing at the proximal aspect of the splenic artery. (C) Irregularity and dilatation of the proximal aspect of the inferior mesenteric artery. (D) Heterogenous hypo-enhancement of the posterior aspect of the right kidney.

Figure 2. Repeat CT abdomen and pelvis angiography two months after discharge.

(A-C) Resolution of prior vascular irregularities of the left renal, splenic, and inferior mesenteric arteries. (D) Resolution of renal parenchymal hypo-enhancement.

Figure 3. Molecular mimicry hypothesis

This figure was created using BioRender [17]