Homologous 111In-radiolabeled platelet survival and sequestration exploration for refractory immunologic thrombocytopenic purpura in children: a strategy to avoid unnecessary splenectomy

Abstract

Abstract Purpose Immunologic thrombocytopenic purpura (ITP) is a condition that affects 4 to 18 per 100 000 children every year. In most cases, spontaneous remission occurs, but splenectomy can be proposed to diminish excessive destruction of platelets when ITP is refractory. Exploring the site of platelet sequestration may help to better predict potential poor responders to splenectomy if no spleen sequestration is highlighted. The radiolabeled platelet sequestration test may be an option but can be difficult to perform in children with very few platelets. Methods A twelve-year-old boy suffering from chronical ITP was referred to evaluate platelet survival and sequestration, to discuss splenectomy. The patient was refractory to therapy and his platelet count consistently remained below 10 G.L-1. An exceptional procedure was set up to use homologous platelets to perform a radiolabeled platelet survival and sequestration test. A radiolabeled autologous platelet exam was carried five months later to confirm the test. Results Significantly reduced platelet lifespan and half-life was observed for both techniques. The splenic and hepatic ratio were below 1.2 at all time points, meaning that there was no organ sequestration. The fact that we confirmed our test by two different methods allowed us to reject the indication for splenectomy in this child. Strict intravascular destruction has been confirmed. Conclusions 111In-radiolabeled homologous platelets were used to perform the examination and confirmed the results obtained with autologous platelets. Homologous platelet scintigraphy could help clinicians to choose splenectomy as a treatment option for ITP in children with very low platelet count. Work must be done to promote its use.