Eradication of a dysfunctional HLA-haploidentical T cell system by a second HLA-identical BMT

A 12-year-old boy treated for SCID at 1 month of age by HLA-haploidentical BMT developed a lymphoproliferative disease of unknown etiology at the age of 9 years characterized by sustained, marked elevation of circulating CD8( +) donor T cells and by diffuse infiltration of the liver by CD8(+) T cells . Because of progressive liver disease, the patient underwent a second BMT from a younger HLA-matched sister. This treatment induced an effective graf t-versus-graft reaction and led to complete replacement of the HLA-nonident ical, dysfunctional T cell system, resolution of the hepatopathy and full r econstitution of T and B cell functions.