ALTERED INTERLEUKIN-12 AND NITRIC-OXIDE LEVELS IN RECURRENT MISCARRIAGE

The causes of recurrent miscarriage are not fully understood. Recent s tudies have suggested that whilst a T-H 2 type immune response may be associated with a healthy pregnancy, miscarriage may be associated wit h a T-H 1 type response. Serum levels of nitric oxide (NO) and Interle ukin 12 (IL 12) were measured in; healthy non-pregnant women; healthy pregnant women; women suffering spontaneous abortion; pregnant women w ith a history of recurrent miscarriage, non-pregnant women with a hist ory of recurrent miscarriage. Normal pregnancy was associated with a s ignificant decrease in serum levels of nitrite (13.0 vs. 22.0 P<0.0001 ). In women admitted with spontaneous abortion there was a significant increase in the levels of nitrite (16.0 vs. 13.0 P<0.05), but no chan ge in IL 12 compared to normal pregnant women. In pregnant women with a history of recurrent miscarriage levels of nitrite (16.0 vs. 13.0 P< 0.05) and IL 12 (10.0 vs. 6.0 P<0.0006) were significantly elevated co mpared to normal pregnancy. When these women were sampled prior to bec oming pregnant the levels of NO were found to be significantly lower t han those in the non-pregnant control group (13.1 vs. 22.0 P<0.05) alt hough levels of IL 12 were unchanged. No correlation was found between serum nitrite and IL 12 levels. This report further supports the idea that polarisation of the immune response during pregnancy may predisp ose to recurrent miscarriage. (C) 1997 Elsevier Science Ireland Ltd.