Determination of Clinical Cellular Immune Markers in Women with Recurrent Pregnancy Loss

Problem Dysregulated natural killer ( NK ) immunity and T ‐cell immunity are associated with recurrent pregnancy loss ( RPL ). We aim to define clinically relevant NK and T ‐cell parameters for RPL and determine their cutoff values. Methods of study Ninety‐five women with RPL ( > 3) including 42 idiopathic and 53 known‐etiology RPL , and 29 age‐matched fertile controls were enrolled. Peripheral blood immunophenotype, NK cell cytotoxicity ( NKC ), and T ‐helper (Th) 1 and Th2 cytokine producing cell ratios (Th1/Th2) were measured using flowcytometry. The cutoff values were determined using Y ouden's J with likelihood ratio ( LR ) >2. Results Natural killer cell percentage and NKC , TNF ‐α + Th1 cells, and TNF ‐α/ IL ‐10 producing Th1/Th2 cell ratio were significantly higher in idiopathic RPL than controls. By the area under the curve ( AUC ) analysis, NK cell percentage ( AUC  = 0.691), NKC ( AUC  = 0.649), TNF ‐α + Th1 cells ( AUC  = 0.681) and Th1/Th2 cell ratio ( AUC  = 0.660) were highly specific for RPL . The cutoff values for NK cell percentage, NKC (E:T cell ratio 25:1), and TNF ‐α/ IL ‐10 producing Th1/Th2 cell ratio are 16.1, 23.8, and 36.2%, respectively. Seventy‐six percent of idiopathic RPL showed at least one of more immune abnormalities by these criteria. Conclusion Differences in NK cell percentages, NKC and Th1/Th2 cell ratio differentiated RPL from fertile controls.