Killer immunoglobulin-like receptors (KIRs) and HLA-C allorecognition patterns implicative of dominant activation of natural killer cells contribute to recurrent miscarriages

This case-control study assessed maternal KIR genotypes together with HLA-C allorecognition patterns in recurrent miscarriage. By comparing activating and inhibitory receptor combinations, the work showed that genotype constellations favoring dominant natural killer cell activation were overrepresented among affected pregnancies. The findings supported an immunogenetic model in which excessive maternal NK-cell activation at the trophoblast interface contributes to pregnancy failure.