Serum levels of TNF-α and antioxidant enzymes and placental TNF-α expression in unexplained recurrent spontaneous miscarriage

Abstract

It has been proposed that many factors have been implicated in the pathogenesis of unexplained recurrent spontaneous miscarriage (URSM). The objective of this study was to evaluate the levels of some antioxidants, tumor necrosis factor-alpha (TNF-alpha), luteinizing (LH) and follicle-stimulating hormone (FSH) in URSM. Serum levels of superoxide dismutase (SOD), catalase (CAT), LH, FSH as well as TNF-alpha in serum and the expression of TNF-alpha positive cells in placental tissues, were assayed in women suffering from unexplained first trimester miscarriage. Two groups were included, the first was represented by 16 women with URSM (number of abortions: 3-5) and the second one included 24 women with URSM (number of abortions > 5). The control groups included 20 women within their first trimester of pregnancy and 20 non pregnant healthy females within their follicular phase. The obtained results showed a highly significant decrease in serum levels of SOD and CAT, in the URSM groups compared to control groups (p < 0.05 for each comparison). Higher serum levels of TNF-alpha were detected in URSM groups compared to control groups (p < 0.05 for each comparison). A significant increase in serum levels of LH was encountered between URSM groups compared to control groups; on the other hand the mean levels of FSH expressed no significant changes among URSM groups as compared to first trimester pregnancies control group. A positive correlation was noticed between serum levels of TNF-alpha and the levels of LH (p < 0.05). We conclude that antioxidant enzymes (CAT, SOD), TNF-alpha, LH and FSH may play a major role in the pathogenesis of URSM. Much more work is required before the mechanisms, which lead to RSM, can be fully understood.