Cytokine gene polymorphisms in recurrent spontaneous abortions: a comprehensive review.
OBJECTIVE
Cytokine gene polymorphism studies in women with recurrent spontaneous abortion (RSA) are reviewed to provide comprehensive understanding and a direction for the future investigation.


METHODS
A search of PubMed was made to identify the published data between 2001 and 2007 regarding RSA and cytokine gene polymorphisms.


RESULTS
Either allele and/or genotype frequencies of the following polymorphisms were reported to be significantly different between women with RSA and controls: IFN-gamma +874A-->T, TA (P = 0.01), AA (P = 0.04); IL-6, -634C-->G CG/GG (P = 0.026); IL-10, -592C-->A CC (P = 0.016); IL-1B -511C (P = 0.035), -31T (P = 0.029); IL-1RA, IL1RN*2 (P = 0.002), and IL1RN*3 (P = 0.002). None of these studies was repeatedly reported by others to be significantly different. Among these, four cytokine polymorphisms (IFN-gamma, +874A-->T; IL-1B -511C; IL-1RA, IL1RN*2, IL1RN*3) were refuted by others and rest of them were studied once.


CONCLUSIONS
Multiple cytokine polymorphisms were reported to be associated with RSA. However, a majority of studies were not confirmed by other investigators or refuted by others. Inconsistent study results might be related to: (i) the production of these cytokines is partly under genetic controls and other factors affect cytokine levels; (ii) ethnic background, environmental factors, and selection criteria for study populations are different and (iii) the possibilities exist that multiple cytokine gene polymorphisms or other genes in linkage disequilibrium may play a role in RSA.
Choi
Yoon Kyong
YK
Reproductive Medicine, Department of Obstetrics and Gynecology, Rosalind Franklin University of Medicine and Science/The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA.
Kwak-Kim
Joanne
J
D000026:Abortion, Habitual / Q000235:genetics*; D016207:Cytokines / Q000235:genetics*; D005260:Female; D006801:Humans; D011110:Polymorphism, Genetic; D011247:Pregnancy
D016207:Cytokines