Inhibitory and activatory KIR gene frequencies in the Polish population

Killer cell immunoglobulin-like receptors (KIRs) present on natural killer cells and minor subpopulations of T cells recognize class I human leukocyte antigen (HLA) molecules on the surface of target cells. Human individuals differ by the presence or absence of some KIR genes on their chromosomes (haplotypic polymorphism). As KIRs (especially two-immunoglobulin-domain-like containing, or KIR2D, molecules) are important for the outcome of tissue (particularly for haematopoietic stem cell) transplantation and possibly for pregnancy, the knowledge of KIR gene distribution in a given human population is of practical value. Therefore, we tested 175 healthy individuals from Poland for the presence or absence of these KIR genes which show haplotypic polymorphism and are expressed. Results were compared with those published for other human populations, showing close relations with other Caucasoids.