Quantification studies in human seminal plasma samples identify prolactin inducible protein as a plausible marker of azoospermia.

Background: Prolactin inducible protein (PIP) is a ~17 kDa protein, which is known to play vital roles in immunoregulation, fertility, antimicrobial activity, apoptosis and tumour progression.

Objectives: This study reports quantification of PIP concentration in human seminal plasma (SP) samples.

Methodology: PIP was purified by immunoprecipitation and its concentration in human SP samples was quantified by ELISA method.

Results: Average concentration of PIP in normozoospermia, oligozoospermia and azoospermia was 290.3 ± 71.5 µg/mL, 306.4 ± 71.2 µg/mL and 60.5 ± 23.6 µg/mL respectively.

Conclusion: There was no significant variation in PIP levels in normozoospermia and oligozoospermia while its expression was down-regulated in azoospermia, indicating that PIP may be a plausible marker of azoospermia.