Modulation of cytokine production by dydrogesterone in lymphocytes from women with recurrent miscarriage Raj Raghupathy, a Esraa Al Mutawa, a Ma’asoumah Makhseed, b Fawaz Azizieh, a Julia Szekeres-Bartho c Objective To examine the effects of dydrogesterone on the production of Th1 and Th2 cytokines by lym- phocytes from women undergoing unexplained recurrent spontaneous miscarriage (RSM). Design Controlled prospective, clinical study conducted in a maternity hospital and a university-based immu- nology laboratory. Setting Faculty of Medicine, Kuwait University and Kuwait Maternity Hospital. Sample Thirty women with unexplained RSM. Methods Peripheral blood mononuclear cells (PBMC) from women with unexplained RSM were isolated from venous blood by density gradient sedimentation and stimulated with phytohaemagglutinin (PHA). Culture supernatants assayed for interferon (IFN)-g, tumour necrosis factor (TNF)-a, interleukin (IL)-4, IL-6 and IL-10 by ELISA. Levels of the progesterone-induced blocking factor (PIBF) were also measured. Main outcome measures Cytokine production in the presence and absence of progesterone and dydrogesterone. Results Dydrogesterone significantly inhibited the production of the Th1 cytokines IFN-g (P ¼ 0.0001) and TNF-a (P ¼ 0.005) and induced an increase in the levels of the Th2 cytokines IL-4 (P ¼ 0.03) and IL-6 (P ¼ 0.017) resulting in a substantial shift in the ratio of Th1/Th2 cytokines. The effect of dydrogesterone was blocked by the addition of the progesterone-receptor antagonist mifepristone, indicating that dydro- gesterone was acting via the progesterone receptor. Dydrogesterone induced the production of PIBF. Conclusion Dydrogesterone inhibits the production of the Th1 cytokines IFN-g and TNF-a from lympho- cytes and up-regulates the production of the Th2 cytokines IL-4 and IL-6, inducing a Th1 to Th2 cytokine shift. INTRODUCTION Cytokines associated with the cellular immune response may be responsible for at least a proportion of ‘unexplained’ recurrent spontaneous miscarriages (RSMs), 1,2 which accounts for about 40–60% of all cases of RSMs. 3 It has been suggested that successful pregnancy is associated with a down-regulation of Th1-type activity and enhancement of Th2-type activity. 1,2,4 – 6 Interleukin (IL)-2, interferon (IFN)-g and tumour necrosis factor (TNF) are cytokines with adverse effects on the conceptus and are characteristic of Th1-type T cells. These cytokines induce cytotoxic and inflammatory reactions and are responsible for the induc- tion of cell-mediated inflammation. 7 Th2 cells secrete IL-4, IL-5, IL-6, IL-10 and IL-13, which are associated with the induction of humoural immunity. Some of these cytokines have anti-inflammatory activity. 7 Elevated levels of the Th1 cytokines IL-2 and IFN-g, and decreased levels of the Th2 cytokine IL-10, have been reported after antigen- and mitogen-induced activation of peripheral blood mononuclear cells (PBMC) from women with spontaneous recurrent miscarriage. 8 The activation of PBMC with trophoblast antigens has shown that women with unexplained RSM have a Th1-type cytokine profile. 1 We have previously demonstrated increased production of IFN-g, TNF-a, TNF-h and IL-2 by mitogen-activated PBMC from women with RSM and increased production of IL-4, IL-5, IL-6 and IL-10 by PBMC from women with normal pregnancy at the end of the first trimester. 9 A sim- ilar Th1 bias in unexplained RSM and a Th2 bias in suc- cessful pregnancy is seen after stimulation with autologous placental cells and with trophoblast antigens. 10 Piccinni et al. 11 demonstrated significantly greater numbers of IL-4- and IL-10-producing T cell clones generated from cells infiltrating the decidua of women with normal pregnancy compared with those undergoing unexplained RSM. These data support the contention that women with normal preg- nancy have a higher Th2 bias, while women with a history of unexplained RSM have a bias towards Th1 reactivity. BJOG: an International Journal of Obstetrics and Gynaecology August 2005, Vol. 112, pp. 1096–1101 D RCOG 2005 BJOG: an International Journal of Obstetrics and Gynaecology www.blackwellpublishing.com/bjog a Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait b Department of Obstetrics and Gynecology, Faculty of Medicine, Kuwait University, Kuwait c Department of Medical Microbiology and Immunology, Pecs University Medical School, Hungary Correspondence: Dr R. Raghupathy, Department of Microbiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, 13110, Kuwait. DOI:10.1111/j.1471-0528.2005.00633.x