Haplo-haploidentical HSCT with post-transplant cyclophosphamide (PT-Cy) is an emerging alternative in primary immune deficiency patients without sibling matched donor (MSD). There are very few reports of haplo-haploidentical HSCT with PT-Cy in WAS patients. The aim of the study is to report the results of this technique in a WAS patient.
We report the case of a 3-year-old boy followed for a WAS. His maternal cousin received HSCT for the same disease from MSD. He presented repetitive hemorrhagic syndrome with thrombocytopenia, eczema, autoimmune anemia, and locoregional becegitis. The detection of a WASp gene mutation confirmed the diagnosis. He has no MSD, so haplo-identical HSCT was performed from his mother.
Pre-transplant conditioning regimen included thymoglobulin, Busilvex, and Fludarabine. He received PT-Cy (day 3 and 4), in addition to Cyclosporine and Mycophenolate Mofetil. Graft CD34 were 3.75 106/kg. Neutrophile engraftment was achieved at day 20 post-HSCT. Chimerism showed donor cells at day 30. At day 30, he presented a severe cutaneous and digestive GVHD confirmed by biopsies. No sufficient improvement was noted after three first-line immunosuppressors. Cutaneous and digestive remission was obtained after treatment with rabbit thyroglobulin. CMV reactivation responsive to preemptive treatment occurred at day 45. Four months after HSCT, He is alive, infection free, no GVHD sign, but immune reconstitution is not yet achieved.
Haploidentical HSCT with PT-Cy is a new therapeutic alternative in WAS patients who do not have a MSD. However viral infections and GVHD could delay immune reconstitution and make management difficult.