THE CASE
A 52-year-old man sought care at the emergency department for intermittent fevers that started within 6 days of receiving his second dose of the BNT162b2 mRNA COVID-19 vaccine (Pfizer/BioNTech). After an unremarkable work-up, he was discharged home. Six days later, he returned to the emergency department with a fever of 102 °F and new-onset, progressive tremors in all 4 of his extremities.
The patient had a history of rheumatoid arthritis, for which he was taking oral methotrexate 15 mg once weekly and golimumab 50 mg SQ once monthly, and atrial fibrillation. He’d also had mechanical aortic and mitral valves implanted and was taking warfarin (9 mg/d on weekdays, 6 mg/d on Saturday and Sunday). Aside from his fever, his vital signs were normal. He also had horizontal nystagmus (chronically present) and diffuse tremors/myoclonic movements throughout his upper and lower extremities. The tremors were present at rest and worsened with intention/activity, which affected the patient’s ability to walk and perform activities of daily living.
He was admitted the next day to the family medicine service for further evaluation. Neurology and infectious disease consultations were requested, and a broad initial work-up was undertaken. Hyperreflexia was present in all of his extremities, but his neurologic examination was otherwise normal. Initial laboratory tests demonstrated leukocytosis and elevated liver transaminases. His international normalized ratio (INR) and prothrombin time (PT) also were elevated (> 8 [goal, 2.5-3.5 for mechanical heart valves] and > 90 seconds [normal range, 9.7-13.0 seconds], respectively), thus his warfarin was held and oral vitamin K was started (initial dose of 2.5 mg, which was increased to 5 mg when his INR did not decrease enough).
By Day 2, his INR and PT had normalized enough to reinitiate his warfarin dosing. Results from the viral antibody and polymerase chain reaction testing indicated the presence of cytomegalovirus (CMV) infection with viremia; blood cultures for bacterial infection were negative. Brain magnetic resonance imaging was ordered and identified a small, acute left-side cerebellar stroke. Lumbar puncture also was ordered but deferred until his INR was below 1.5 (on Day 8), at which point it confirmed the absence of CMV or herpes simplex virus in his central nervous system.
THE DIAGNOSIS
The patient started oral valganciclovir 900 mg twice daily to ameliorate his tremors, but he did not tolerate it well, vomiting after dosing. He was switched to IV ganciclovir 5 mg/kg every 12 hours; however, his tremors were not improving, leading the team to suspect an etiology other than viral infection. A presumptive diagnosis of autoimmune movement disorder was made, and serum tests were ordered; the results were positive for antiphospholipid antibodies, including anticardiolipin and anti-ß2 glycoprotein-I antibodies. A final diagnosis of autoimmune antiphospholipid antibody syndrome (APS)–related movement disorder1 with coagulopathy was reached, and the patient was started on methylprednisolone 1 g/d IV.
We suspected the CMV viremia was reactivated by the COVID-19 vaccine and caused the APS that led to the movement disorder, coagulopathy, and likely, the thrombotic cerebellar stroke. The case was reported to the Vaccine Adverse Event Reporting System (VAERS).2
DISCUSSION
Clinically evident APS is rare, with an estimated annual incidence of 2.1 per 100,000 according to a 2019 longitudinal cohort study.3 Notably, all identified cases in this cohort had either a venous or arterial thrombotic event—a characterizing feature of APS—with 45% of patients diagnosed with stroke or transient ischemic attack.3,4
Continue to: The development of antiphospholipid antibodies...