Decidual Mast Cells Might Be Involved in the Onset of Human First‐Trimester Abortion

Abstract

PROBLEM: The aim of the present study was to identify the role of mast cells and substance P (SP)-containing nerve fibers in human decidua in normal and pathological pregnancies. METHOD OF STUDY: We collected decidua from women undergoing termination of normal pregnancies and from abortions. The presence of mast cells and SP was detected by immunohistochemistry. RESULTS: We observed a sparse distribution of mast cells in the normal pregnancies (36.7 tryptase+ mast cells/mm2 decidua). In the decidua from abortion, we found a dramatic increase in the number of mast cells (448.7 and 469.2 tryptase+ mast cells/mm2 decidua in primary and secondary abortions, respectively). In addition, we observed an increase of SP-positive nerve fibers in the decidua of abortions. CONCLUSIONS: Our data suggest that decidual mast cells may play an important role in the onset of abortion, due to the production of cytokines, such as tumor necrosis factor-alpha.