(1105) Multisystem Inflammatory Syndrome in a Pediatric Heart Transplant Recipient: A Case Report

INTRODUCTION: Multisystem inflammatory syndrome in children (MIS-C) is an inflammatory reaction that occurs weeks after SARS-CoV-2 infection. Solid organ transplant recipients may be protected due to immunosuppression, but this is not yet established in the literature. CASE REPORT: A 13-month-old male status post heart transplant for ACTC1 gene-positive dilated cardiomyopathy had a post-operative course complicated by rhinovirus/enterovirus, respiratory syncytial virus, and norovirus infections within the first two months. He then presented at 11 weeks post-transplant with high fevers, macular rash, emesis, and diarrhea in the setting of SARS-CoV-2 exposure three weeks prior. Viral panel was negative for active infections, but SARS-CoV-2 antibodies were positive. He developed a mild troponin leak and rising inflammatory markers, ferritin, D-dimer, and NT-proBNP, meeting clinical criteria for MIS-C. No cardiac dysfunction or coronary dilation was present on 2D echocardiography. Tacrolimus levels had large fluctuations in the first three days but later stabilized. Intravenous immunoglobulin, steroids, and anakinra were given with clinical improvement and rapid normalization of laboratory findings, allowing discharge from the hospital in one week. Repeat echocardiogram 10 days after discharge was stable. SUMMARY: There is a paucity of MIS-C cases in pediatric solid organ transplant recipients, with only one liver transplant recipient described in the literature. We hypothesize chronic immunosuppression protects against inflammatory reactions, supported by the fact that Kawasaki disease is also not described in transplant recipients. To our knowledge, this is the first reported MIS-C case in a pediatric heart transplant recipient. Recent viral infections may have led to immune system activation that allowed development of MIS-C. The patient has demonstrated good response to anti-inflammatory therapy; however, close follow up for long-term sequelae is warranted.