Analysis of Chimerism After Stem Cell Transplantation

In recent years, considerable progress has been made in the analysis of hematopoietic chimerism after allogeneic stem cell transplantation (SCT). The introduction of polymerase chain reaction (PCR)-based methods for the characterization of “variable number of tandem repeats” (VNTR) and “short tandem repeats” (STR) has made it possible to analyze donor/recipient chimerism in a sensitive and quantitative fashion in all patients except those with syngeneic donors. In turn, this has allowed the serial monitoring of engraftment and study of the kinetics of graft failure and graft rejection after allo-SCT (1 -4 ). These methods also allow the identification of patients with the highest risk of relapse after allo-SCT (5 -7 ). In consequence, analysis of chimerism has become a routine diagnostic instrument at many centers performing allo-SCT (8 -11 ). This chapter concentrates on PCR-based techniques for the amplification of STRs, using either (a) conventional PCR and polyacrylamide gel electrophoresis (PAGE) of reaction products or (b) PCR using fluorescent labeled primers with size resolution by capillary electrophoresis. Both methods are described in detail.