Maternal KIR repertoire is not associated with recurrent spontaneous abortion.
BACKGROUND
In view of evidence suggesting an immunological cause of recurrent spontaneous abortions (RSA) and the large number of maternal natural killer (NK) cells present in the pregnant uterus, we investigated the genetic polymorphism of the killer cell immunoglobulin-like receptors (KIR) in women with RSA.


METHODS
KIR gene repertoire and KIR2DL4 (a receptor for HLA-G) genotyping were determined by SSP and SSCP respectively, in women experiencing RSA and controls.


RESULTS
The KIR repertoire did not differ between RSA patients and controls in terms of: (i) the number of inhibitory receptors; (ii) the number of activating receptors; (iii) the ratio of inhibitory to activating receptors. KIR2DL4, a receptor for HLA-G, has different transmembrane alleles, which produce functionally different phenotypes. The frequency of KIR2DL4 transmembrane genotypes differed significantly between RSA patients and controls (P=0.03). However, although homozygosity for a membrane-bound receptor was more frequent in patients (25%) than controls (10%), other genotypes that would produce the same phenotype were not more frequent in patients than controls.


CONCLUSIONS
The data provide little evidence that KIR polymorphism plays a role in predisposition to RSA.
Witt
C S
CS
Department of Clinical Immunology, Royal Perth Hospital, Perth, West Australia. Campbell.Witt@health.wa.gov.au
Goodridge
J
J
Gerbase-Delima
M G
MG
Daher
S
S
Christiansen
F T
FT
D000026:Abortion, Habitual / Q000235:genetics*; D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011971:Receptors, Immunologic / Q000097:blood* / Q000235:genetics*; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D054345:Receptors, KIR2DL4
C093100:KIR2DL1 protein, human; C515079:KIR2DL4 protein, human; C496212:KIR2DS1 protein, human; C433932:KIR2DS2 protein, human; C473953:KIR2DS4 protein, human; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054342:Receptors, KIR2DL1; D054345:Receptors, KIR2DL4