Severe graft-versus-host disease post allogeneic hematopoietic stem cell transplantation due to loss of HLA heterozygosity in recipient lymphocytes after full graft rejection.

ABSTRACT

Germ cell tumors complicated by hematological malignancy (HM) are a rare clinical phenomenon. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially effective therapy, but graft-versus-host disease (GVHD) is a life-threatening complication. We report a case of a 13-year-old female patient diagnosed with germ cell tumors followed by acute lymphoblastic leukemia. After chemotherapy, she received allo-HSCT and her chimerism rate decreased rapidly to near zero by 6 months without evidence of HM recurrence. However, she developed severe, multiorgan GVHD-like manifestations. DNA analysis revealed the pathogenesis of GVHD to be loss of HLA heterozygosity in recipient hematopoietic cells.