Natural killer (NK) cell receptors' repertoire in couples with recurrent spontaneous abortions.
OBJECTIVE
Natural killer (NK) cell receptors (NKRs) have been suggested to protect trophoblast, but their function at the fetomaternal interface remains unknown. To investigate if the outcome of pregnancy depends on women's NKRs, we studied the NKR repertoire in couples with recurrent spontaneous abortions (RSA).


METHODS
Twenty-six childless couples with > or = 2 abortions, characterized by alloimmune abnormalities, and 26 control couples were genotyped for five killer immunoglobulin-like receptors (KIR) and two CD94/NKG receptors, known to have as ligands human leukocyte antigen (HLA) class I molecules with trophoblastic expression: inhibitory 2DL1,2,3 and activating 2DS1,4 KIRs, inhibitory NKG2A and activating NKG2C. Detected repertoires of women and partners were compared between the two groups.


RESULTS
Less aborters than controls were found to have all three inhibitory KIRs (30.77% versus 69.23%, P = 0.01), some of them had only one inhibitory KIR (19.23% versus 3.85%, P = 0.08) and most of them were lacking inhibitory KIRs possessed by their husbands (57.69% versus 15.38%, P = 0.001).


CONCLUSIONS
Women with alloimmune abortions have a limited inhibiting KIR repertoire and such miscarriages may occur because trophoblastic HLA class I molecules are recognized by decidual NK cells lacking the appropriate inhibitory KIRs.
Varla-Leftherioti
Marighoula
M
Immunology Department and RSA Clinic, Helena Venizelou Maternity Hospital, Athens, Greece. gr1bmdr@hol.gr
Spyropoulou-Vlachou
Maria
M
Niokou
Demetra
D
Keramitsoglou
Theodora
T
Darlamitsou
Areti
A
Tsekoura
Christina
C
Papadimitropoulos
Miltiadis
M
Lepage
Virginia
V
Balafoutas
Christos
C
Stavropoulos-Giokas
Catherine
C
D000026:Abortion, Habitual / Q000097:blood / Q000235:genetics / Q000276:immunology*; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D005191:Family Characteristics; D005260:Female; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism; D008297:Male; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000235:genetics* / Q000378:metabolism; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D055607:Receptors, Natural Killer Cell; D014327:Trophoblasts / Q000276:immunology / Q000378:metabolism
D015703:Antigens, CD; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; C527054:KLRC1 protein, human; C527059:KLRC2 protein, human; C497869:KLRD1 protein, human; D037181:Lectins, C-Type; D055654:NK Cell Lectin-Like Receptor Subfamily C; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D055607:Receptors, Natural Killer Cell