Utility of serum ERAP1 and ERAP2 as novel biomarkers in the management of recalcitrant warts: A cross-sectional study.

Background The exact mechanisms underlying the eradication of the human papillomavirus (HPV) by cellular immunity remain obscure. Individuals with treatment-resistant warts frequently have immune deficiencies. Amino-peptidases (ERAP1, ERAP2) of the endoplasmic reticulum are essential for the production of antigenic epitopes that attach to the Major Histocompatibility Complex (MHC) class I and activate T-lymphocytes or natural killer (NK) cells. Aim To assess ERAP1 and ERAP2 serum concentrations in patients with resistant warts. Methods The current study included 200 subjects. They were split into 2 groups. Group (I) patients had resistant warts (n = 100), and group (II) age- and sex-matched subjects had a history of treated warts with no recurrence (n = 100). Clinical assessment and ERAP1 and ERAP2 serum level determination via ELISA were conducted. Results ERAP1 and ERAP2 levels were significantly lower in group (I) than in group (II) (p < 0.0001 for each). A significant positive relationship was observed between ERAP1 and ERAP2 (p < 0.001). A significant negative correlation was found between ERAP1, ERAP2, the number of warts, and a number of recurrences (p < 0.001). Limitations The small sample size, the lack of measurements of ERAP1 and ERAP2 before and after the treatment, and the exclusion of medical conditions such as diabetes mellitus and hypertension. Conclusion The current study findings highlight the potential utility of serum ERAP1 and ERAP2 as novel biomarkers for identifying patients with recalcitrant warts.