Immunohistochemical expression of p57 (Kip2) in first trimester abortion specimens of molar and non-Molar pregnancies

Introduction: The aim was to study the expression of p57(KIP2) immunohistochemical marker in first trimester abortion specimens of molar and non-molar pregnancies. Materials and Methods: The study design was a cross-sectional study conducted in the Department of Pathology of a teritiary health care centre in South India. 100 cases of first trimester abortion specimens of molar and non-molar pregnancies were studied.The study duration was two years. The IHC used is p57(KIP2) which is a mouse derived monoclonal antibody and its expression in decidual and villous tissue of abortion specimens were observed. Result: Of 100 cases of first trimester abortion specimens 25 cases were complete mole, 17 were partial mole and rest 58 cases were normal abortions. p57 gene is paternally imprinted and maternally expressed, and the presence of its protein product serves as an useful adjuvant marker for the nuclear maternal genome. Regarding the expression of p57(KIP2) immunomarker in partial mole(PM) diagnosed previously by H&E 88% expressed positive results. These findings were highly statistically significant. The results of p57 IHC marker expression in cases of complete mole diagnosed previously by H&E, 96% expressed negative results which confirmed the complete mole diagnosis. Conclusion: The study of p57 immunohistochemistry in abortion specimens has proved to be an ancillary diagnostic tool in the diagnosis of complete mole. The sensitivity and specificity of p57 were very high in diagnosing complete mole from its close mimic partial mole in early first trimester abortions. The sensitivity and specificity were 96% and 88% respectively.