Transfusion-associated graft-versus-host disease in a patient treated with Cladribine (2-chlorodeoxyadenosine): demonstration of exogenous DNA in various tissue extracts by PCR analysis.

Transfusion-associated graft-versus-host disease can occur in both immunocompetent and immunocompromised hosts. Cladribine is a synthetic analogue of adenine used in the treatment of lymphoid malignancies, commonly associated with a decrease in T lymphocytes. Cladribine was given for a low-grade non-Hodgkin's lymphoma with thrombocytopenia as the main side-effect. Six units of pooled non-irradiated platelets were transfused from six unrelated donors; 10 d later a clinical picture typical of graft-versus-host disease resulted. Polymerase chain reaction of the highly polymorphic DNA minisatellites and HLA-DR oligotyping were used to demonstrate the exogenous DNA. In the patient's blood and tissues, only the pattern of donor 5 was found. The patient (DRB10301/1101; DRB30101/02) and this donor (DRB10301/1104; DRB302) by chance shared a partial common haplotype. This complication highlights the sensitivity of DNA minisatellite analysis. It further raises the question of transfusion and of prophylactic irradiation of all blood products in immunosuppressed patients and those treated with cladribine. This case represents a previously unreported situation where an immunosuppressed patient was able to eliminate cells from five totally HLA-DR dissimilar donors but not from one heterozygous donor with strong HLA-DR similarity.