Abstract Background Miscarriage is a common complication of early pregnancy, mostly occurring in first trimester. However, the etiological factors, prognostic and diagnostic biomarkers are not well known. Neurokinin-1 Receptor (NK-1R) is a receptor of tachykinin peptide, Substance P (SP) and has a role in various pathological conditions, cancers but it’s association with miscarriages and significance as a clinicopathological parameter is not studied. Accordingly, the present study aimed to clarify the localization and expression for NK-1R in human retained products of conception. Role of NK-1R is not known in miscarriages. Materials and Methods NK-1R expression was assessed in products of conception by immunohistochemistry. Protein expression was evaluated using the nuclear labelling index (%). Results Ten human products of conception tissues were studied by immunohistochemistry to demonstrate the localization of NK-1R. The expression of NK-1R protein was high in all the cases of POCs. NK-1R expression showed no notable differences among different cases of miscarriages irrespective of the mother’s age and gestational age at which the event occurred. Conclusions Expression of NK-1R was similar in all the cases and it was intense. It shows that dysregulation of NK-1R along with its ligand Substance P might be involved in miscarriages. Our results provide fundamental data regarding this anti-NK-1R strategy. Thus, the present study recommends that SP/NK1R system might, therefore, be considered as an emerging and promising diagnostic and therapeutic strategy against miscarriages. Hence, we report for the first time, the expression and localization of NK-1R in products of conception. We suggest NK-1R antagonist in addition to the Immunoglobulins and Human chorionic gonadotropin, to diagnose and treat spontaneous miscarriages.

Elevated Neurokinin 1-Receptor Expression in uterine products of conception is associated with first trimester Miscarriages