Donor chimerism and minimal residual disease monitoring in leukemia patients after allo-HSCT

In present research the comparative analysis of donor chimerism (DC) using different tests was performed to improve the diagnostic tool in patients with malignant hematological disorders after allo-HSCT. The RBC antigen typing, identification of ABO blood type and quantitative analysis of InDel-, STR-, Y-polymorphisms were carried out for detection of DC. In addition, the expression of well-known oncogenes and CD-markers for monitoring MRD was evaluated to predict relapse and clinical outcome. According to our research, the analysis of InDel polymorphism using AlleleSEQR-PCR is more sensitive test for estimation of DC as compared with other assays. Moreover, the sensitivity of AlleleSEQR-PCR may be increased after isolation of the CD34 cell population in bone marrow. Nevertheless, observation of high levels in DC (³95%) in some leukemia patients (ALL, Ph+, bcr-abl/p190+) during first 6 months after HSCT cannot exclude the possibility of relapse. Thus, the combined monitoring of both DC (InDel) and MRD (oncogenes, WT1 and CD-markers) is a more advisable and useful test in managing hematologic malignancies and predicting relapse risk after allo-HSCT.