Study of whole blood and T cell chimerism in monitoring HLA identical allogeneic hematopoietic transplantation

Abstract

Chimerism analysis is an important method for monitoring outcome of allogenic hematopoietic stem cell transplantation. Variable number tandem (VNTR) analysis is considered an informative technique to follow up chimerism state. The aim of the work is to study certain number of VNTRs to identify their potential value in the detection of chimerism in transplanted patients in conventional ablative transplants. Also to demonstrate the value of T cells subset analysis in detecting transplantation outcomes. This study included 17 pairs undergoing HSCT. Informative loci pre-transplantation using five VNTR loci and two gene loci were identified. After transplantation the informative loci were used to detect chimerism status. After DNA extraction from blood samples, amplification of VNTR loci was performed using a conventional PCR protocol. Extra sample post transplantation was collected and pre-treated with resetting technique in order to separate T cells, its product was subjected to DNA extraction then amplification of informative loci was done. Amplified product of DNA samples was run on 2% agarose gel stained using ethidium bromide. Fourteen recipients showed full done chimerism in both whole blood and T cells separated cells, one recipient died after HSCT, one recipient showed split chimerism and one pair failed to detect informative locus. VNTR analysis using a panel of five loci is suitable to detect state of chimerism after HSCT.