Around 10-15% of pregnancies result in miscarriage, with no treatment available to prevent fetal loss and no biological markers to identify women at high risk. Macrophage inhibitory cytokine 1 (MIC 1) plays an important part in the immune system and is found in high concentrations at the interface between mother and fetus during pregnancy. Stephen Tong and colleagues from Monash University, Melbourne, and University of New South Wales, Sydney, Australia, investigated whether MIC1 plays a part in maintaining pregnancy viability by comparison of concentrations between failed and successful pregnancies.
The investigators found that MIC1 concentrations were around a third lower among 100 women who went on to miscarry than 200 women who delivered normally (the control group). MIC1 concentrations were measured in blood taken in the first trimester of pregnancy (6-13 weeks). There was no difference in reduced MIC1 concentrations in relation to the timing of miscarriage, although in most cases low MIC1 concentrations preceded miscarriage by several weeks.
Stephen Tong comments: "In view of the fact that MIC 1 might have actions favouring viability and is strongly localised at the materno-fetal interface, it is tempting to speculate that changed production of MIC 1 in the placenta is part of the mechanism initiating spontaneous pregnancy loss. If a causal link between low MIC 1 and miscarriage is confirmed, then MIC 1, or its synthetic analogues, might be useful in prevention of miscarriage."
In an accompanying Commentary (p 96), Galit Sarig and Benjamin Brenner from Rambam Medical Centre, Haifa, Israel, conclude: "If measurement of macrophage inhibitory cytokine-1 can predict miscarriage, such an assay could serve as a prognostic factor during gestation. However, the crucial question is whether the decrease in concentrations of macrophage inhibitory cytokine-1 is an epiphenomenon or an important pathological mechanism predisposing to pregnancy loss. If Tong and colleagues' results can be confirmed, the way is open to develop novel therapies to prevent pregnancy loss."
Associate Professor Euan Wallace, Department of Obstetrics and Gynaecology, Monash University, 246 Clayton Road, Clayton 3168, Victoria, Australia; T): 61-3-9594-5145 (office); 61-3-9578-7805 or 61-0-408-521-561 (out of office hours, thurs and Fri morning UK time only); F): 61-3-9594-6389; E): Euan.Wallace@med.monash.edu.au.
Dr. Benjamin Brenner, Thrombosis and Haemostasis Unit, Department of Haematology, Rambam Medical Centre, Haifa 31096, Israel; T): 972-4-854-2541; E): firstname.lastname@example.org.