KIR gene content varies between individuals who can exhibit seven to fourteen inhibitory and activating KIR genes, defining multiple KIR genotypes. 8 Here, we investigated KIR genes as additional markers for early chimerism assessment after dUCBT. Natural killer (NK) cells are the first population to reconstitute the patient’s hematopoietic system following hematopoietic stem cell transplantation, before T lymphocytes, 7 and we previously reported that cord blood NK cells express killer cell immunoglobulin-like receptors (KIR). In this context, additional approaches are needed. 5, 6 However, this method may be limited by the lack of available in-house SNP discriminant markers between both umbilical cord blood (UCB) units and patients and may not be reliable to assess early chimerism status after dUCBT. 4 Up to now, real-time quantitative polymerase chain reaction (PCR) of single nucleotide polymorphism (SNP) markers remains the best method to accurately assess and quantify chimerism. 1– 3 The use of a precise method to evaluate residual host hematopoiesis is imperative because it has been reported that the risk of relapse is higher in patients with mixed chimerism. It has been established that hematopoietic chimerism after double umbilical cord blood transplantation (dUCBT) can predict disease relapse and detect potential engraftment failure.

Flowjo 7.6.1