engleski

Analysis of leukocyte subpopulations in ectopic pregnancy

In early normal human pregnancy, uterine NK cells of specific CD3-CD16-CD56 bright+ phenotype account up to 70% of decidual CD45+ cells. These cells are activated and contain cytolytic mediator perforin. Macrophages, as the second major leukocyte subpopulations in normal early pregnancy decidua are important source of cytokines that regulate NK cytolytic activity. The least abundant leukocyte population are T lymphocytes comprising both, CD3+CD4+ cells and CD3+CD8+ cells. Ectopic pregnancy represents abnormal implantation of a morphologically normal and hormonally activated trophoblast cells. This situation provides a model for analysing leukocyte subpopulations at non-physiologic implantation site during early gestation. The aim of this study was to analyze leukocyte subpopulations in tubal mucosa at the implantation site, tubal mucosa away from the implantation site and intrauterine decidua. Tubal mucosa at and away from the implantation site and intrauterine decidua of a women who had had ectopic pregnancy were used. CD3+, CD8+ and CD56+ lymphocytes were analysed by immunohistology in frozen tissue sections of each examined mucosal sites. A part of mucosal tisues were enzymaticaly digested and cell suspensions were centrifugated on the Ficoll gradient to obtain mononuclear cells. Mononuclear cells were single or double labeled for detection of lymphocyte T, lymphocyte B, NK cell and antigen presenting cell surface antigens. The data were analyzed by flow cytometer and expressed as percentage of positive cells or mean fluorescence intensity (MFI). Immunohistology showed predminance of CD3+ and CD8+ cells in tubal mucosa. Flow cytometry showed that CD3+ cells are the major lymphocyte population (about 60%) in tubal implantation site and distal tubal mucosa, while intrauterine decidua contained less then 10% of CD3+ cells. CD3+CD8 bright+ cells predominate over CD3+CD4+ cells in both examined tubal mucosa sites, but these CD3+ subpopulations are almost equaly present among lymphocytes of intrauterine decidua. Many CD56+ cells infiltrated intrauterine decidua in situ and NK cells of CD3-CD8dim+CD16-CD56bright+ phenotype account up to 70% of lymphocytes isolated from intrauterine mucosa. Percentage of NK cells were significantly lower in tubal mucosa at the implantation site (about 15%) and away from the implantation site (about 30%). CD14+ macrophages were the most numerous antigen presenting cells, while CD19+ B lymphocytes, CD1a+ and CD83+ dendritic cells were presented in equaly low percentages in each of examined sites. NK cells of CD16-CD56bright+ phenotype predominate in intrauterine mucosa resembling to decidua of early normal human pregnancy. Abundant number of CD3+CD8 bright+ lymphocytes and relative lack of NK cells in tubal mucosa at and away from the implantation site, although allows embryo implantation, seems to be insufficient to support later placental development events in ectopic pregnancy. Supported by Ministry of Science and Technology, Republic of Croatia (Grant No.0062029).

pregnancy; perforin; NK cells

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