Problem: To determine whether natural killer (NK) cells cytotoxicity in peripheral blood is altered in patients with a history of recurrent spontaneous abortion (RSA); also, if there is any correlation between cytokine production and NK cytotoxicity.
Method of study: In this case-control study, 21 patients with RSA within 24 hr of the last abortion (group I), and 32 pregnants with no history of abortion (group II) were surveyed. NK cell cytotoxicity was evaluated by flow cytometry, and IL-2, IL-10, transforming growth factor beta1 were measured in cell culture supernatant by ELISA method.
Results: Group I showed higher NK cytotoxicity than group II at all of effector to target (E:T) ratios (P < or = 0.045). The correlation between production of IL-2 and NK cytotoxicity was positively significant (R = 0.350, P = 0.001). Group I had significantly higher levels of IL-2 than group II (P = 0.001). In group II, the production of IL-10 by peripheral blood mononuclear cells was higher than group I (P = 0.002).
Conclusion: Increased NK cell cytotoxicity and high level of IL-2 may be considered as a risk factor for RSA.