Hematologic abnormalities and venous thromboprophylaxis in MIS-C: Data from a multi-disciplinary working group at a pediatric tertiary care hospital

ABSTRACT

Background: On May 15, 2020 the World Health Organization published the preliminary case definition of multisystem inflammatory syndrome (MIS-C) in children and adolescents, a new clinical entity in the evolving COVID-19 pandemic. COVID-19 associated coagulopathy, with prominent elevations in d-dimers was widely reported in adults;in contrast to the sepsis-related disseminated intravascular coagulation (DIC), adult patients demonstrated hypercoagulability, not bleeding, with approximately 25% having overt venous thromboembolism (VTE)., There are limited data regarding coagulopathy and hypercoagulability in pediatric patients with acute COVID-19 or MIS-C to guide treating physicians in optimal management including VTE prevention strategies. We report the hematologic findings, VTE prophylaxis strategy, and thrombotic outcomes in a cohort of patients at a single pediatric center. Objectives: NA. Methods: At Children's Wisconsin we rapidly convened a multi-disciplinary MIS-C working group to create guidelines for evaluation and treatment of suspected/confirmed MIS-C patients. A MIS-C panel, including CBC, CMP, DIC panel, ESR, CRP , ferritin, troponin I, pro BNP, and COVID PCR was obtained for all patients presenting to the ER with fever for ≥4 days plus any of the following GI symptoms, rash, bilateral non-purulent conjunctivitis, cough, headache , and/or irritability. Specialty-specific treatment guidelines, including modifications of an existing VTE prophylaxis guideline, were established (Table 1). As a quality improvement measure, we performed electronic query of the use of the MIS-C panel including evaluating laboratory trends, and outcomes of cases receiving specific therapeutics, including anticoagulation. We present data regarding hematologic findings and outcomes of VTE prophylaxis in this cohort. Results: As of October 20, 2020, a total of 56 patients had an MIS-C panel obtained in the ER, of whom 12 (21.4%) met full criteria for MIS-C (Table 2). Of these, mild CBC abnormalities predominated as did mild coagulopathy, elevated fibrinogen levels, and d-dimers (on average 5.5 × upper limit of normal) (Table 2). Three (25%) patients met criteria for VTE prophylaxis with enoxaparin which was continued during hospitalization in 1 patient, and for 2 weeks following hospital discharge in the remaining 2. There were no reported thromboses in any patients, including those who did not meet criteria for thromboprophylaxis. Enoxaparin was well tolerated, and no patients had bleeding events despite having mild coagulopathy. Conclusions: We report an approach to evaluation of MIS-C, the hematologic abnormalities, and successful use of a VTE prophylaxis strategy in children. Given the drastic increase in COVID-19 cases in Wisconsin and the US as of October 2020, and limited large-scale pediatric studies to guide patient care, we recognize the importance of our own institutional surveillance and the need for collaboration amongst pediatric providers to gather data on outcomes of such patients. (Table Presented).