Homologous 111In-Radiolabeled Platelet Survival and Sequestration Exploration for Refractory Immunologic Thrombocytopenic purpura in Children: A Strategy to Avoid Unnecessary Splenectomy.

Immunologic thrombocytopenic purpura (ITP) is a condition that affects four to 18 per 100 000 children every year. In most cases, spontaneous remission occurs, but splenectomy may be proposed. Exploring the site of platelet sequestration can help to better predict potential poor responders to splenectomy, but 111In-radiolabeled platelet scintigraphy (IPS) can be difficult to perform in children with very few platelets. A 12-year-old boy suffering from refractory ITP was referred for evaluation of platelet survival and sequestration and consideration of splenectomy. His platelet count consistently remained below 10 000/mm3. An exceptional procedure was set up to use homologous platelets to perform the IPS. Splenectomy was ruled out based on the results of 111In-radiolabeled homologous platelet scintigraphy. The attending pediatrician intensified medical treatments, resulting in a significant improvement in platelet count. This increase in platelet levels allowed for 111In-radiolabeled autologous platelet scintigraphy, which confirmed the absence of splenic sequestration. This allowed us to reject splenectomy in this child. Homologous IPS could help clinicians to choose splenectomy as a treatment option for ITP in children with a very low platelet count, and its use should be promoted after failed thrombopoietin receptor agonist (TPO-RA) treatment. More systematic studies are needed to confirm the predictive response to splenectomy of homologous IPS.