PubMed · 7749251
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M Pagano. Diagnostic tests: statistical considerations.. https://pubmed.ncbi.nlm.nih.gov/7749251/
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Natural killer (NK) cell-mediated cytolysis is stimulated and downregulated through the interaction of distinct human leukocyte antigen (HLA) class I molecules on target cells with specific killer cell immunoglobulinlike receptors (KIRs) on NK cells. Killer cell immunoglobulinlike receptors are highly polymorphic and are clonally distributed on NK cell populations within individuals. However, the regulation of KIR expression by individual HLA class I phenotypes is not well understood. To examine a potential influence of the HLA class I phenotype on KIR expression patterns we studied the KIR expression in individuals that were subgrouped according to the major HLA-C encoded KIR-epitopes (group C1 versus C2). In these individuals, NK cells were analyzed for KIR expression using flow cytometry and RNA-based expression analysis. Our results demonstrate that KIR genes are transmitted very heterogeneously with two main patterns of KIR genotypes as previously described; group A and group B (with 21 different genotypes). There are distinct populations exhibiting different densities of CD158a and/or CD158b positive NK cells that coexist in all individuals. A clear correlation between KIR expression and the currently known HLA class I ligands was not observed. In conclusion, the surface expression of KIRs in individuals with different HLA class I genotypes indicates that other non-HLA class I encoded factors contribute to the shaping of the KIR repertoire.
BACKGROUND AND OBJECTIVES: The characterization of lymphocyte subsets in blood donors has been utilized to determine the normal ranges that can be related to race. A study was performed in blood donors from two racial groups - Caucasian (Italians) and Asian (Philippinos) - to define respective T-lymphocyte subsets and levels of cytokines. MATERIALS AND METHODS: Ninety-two blood donors (46 Italians and 46 Philippinos) were enrolled. Blood count and immunophenotyping of lymphocytes by flow cytometry were carried out, and cytokine production was tested in six blood donors of each group. RESULTS: Philippino blood donors showed a significantly higher mean value of leucocytes (P = 0.01) and lymphocytes (P < 0.001) than Italians. The mean absolute count of lymphocyte subsets CD3- CD16+ CD56+ and CD3+ CD8+ were both significantly higher in Philippino than in Italian subjects, respectively, P < 0.01 and P < 0.0001. Philippinos showed a statistically significant higher frequency of lymphocytes producing interferon-gamma (IFN-gamma) compared to Italians (P = 0.02). CONCLUSIONS: T-lymphocyte subsets in Italian and Philippino blood donors seem to be correlated to ethnic background. The higher levels of CD3+ CD8+ T cells, natural killer (NK) cells and IFN-gamma-producing cells found in Philippinos suggest leucoreduction in Asian blood donors.