Pretransplant histocompatibility testing algorithm: Laboratory and clinical approach in the Indian context

Abstract

Remarkable advances in histocompatibility testing have immensely improved the safety of transplantation and have decreased the incidence of rejections. Human leukocyte antigen (HLA) typing and crossmatches by complement-dependent cytotoxicity or flow cytometer-based methods are the vital tests involved in pretransplant histocompatibility testing. Continuous development in these testing technologies since the 1960s has refined these methodologies that can be used to predict graft rejection. Advancements from polymerase chain reaction-based methods to sequence based in HLA typing, and from cell-based cross-matches to virtual cross-matches using advanced solid-phase platforms, have enhanced our understanding about the donor-specific antibodies (DSAs) and have challenged the concept that the presence of DSA is an absolute contraindication to transplantation. Despite various developments, it is very difficult to perform a plethora of tests for pretransplant workup due to cost constraints in a developing country like India. In this review, we would discuss the advantages, limitations, and cost involved in the pretransplant immunologic workup along with an algorithmic approach for physicians that may help in decision-making amidst multiple information from different platforms.