Pediatric Sinusoidal Obstruction Syndrome (SOS) Diagnostic Criteria Comparison in a Single Pediatric Institution

Abstract

Introduction Current sinusoidal obstruction syndrome (SOS) diagnostic criteria utilized for pediatric hematopoietic stem cell transplant (HSCT) patients are the same as those for adults, most commonly the Modified Seattle criteria and the Baltimore criteria. This is challenging, however, due to differences in pediatric incidence, risk factors and presentation. While the Modified Seattle criteria has been shown to allow for upwards of a four-fold increase in diagnoses when compared to Baltimore criteria, the diagnosis of pediatric SOS can still be missed. The European Society for Blood and Marrow Transplantation (EBMT) sought to develop pediatric specific criteria to increase appropriate recognition and early treatment in children. Objectives The objectives of this project were to review and compare the current standard diagnostic criteria for SOS and to analyze their differences in time to diagnosis within the pediatric HSCT patient population. Methods Retrospective investigation of pediatric HSCT patients requiring treatment with defibrotide, and time to SOS diagnosis with different criteria methods was collected and analyzed in order to assess the appropriateness of screening, diagnosis, and initiation of treatment in pediatric patients within the institution. Results EBMT criteria allowed for earliest diagnosis of SOS in all patients (N=8). Four patients (50%) met criteria on the same day when using the Modified Seattle criteria or the EBMT criteria, but both significantly earlier than Baltimore criteria. On average, EBMT criteria allowed for diagnosis 1.38 days earlier than Modified Seattle criteria and 7.38 days earlier than Baltimore criteria. Two patients assessed by the Modified Seattle criteria and four patients by the Baltimore criteria never met criteria before receiving treatment, based on day cutoff for assessment. EBMT criteria allowed for earlier diagnosis most commonly because of platelet refractory thrombocytopenia and increasing bilirubin over three consecutive days. Conclusion The use of the EBMT criteria as a diagnostic standard for SOS in pediatric HSCT patients should be considered to allow for earlier diagnosis and more prompt initiation of treatment. Treatment initiation should be carefully considered with concern for the possibility of over-diagnosis due to a wider criteria allowance and no cutoff time for utilization. Further definition of platelet refractory thrombocytopenia, weight gain parameters with diuretic usage, hepatomegaly and ascites may be beneficial.