Assessment of serum interleukin 19 level in patients with warts

Background: Warts are viral cutaneous infections caused by human papilloma virus (HPV), presented by verrucous growth over the skin surface. The cell mediated immune response is considered to play a crucial role in HPV clearance. The viral load and number of lesions increase when there is an imbalance between the T-helper 1 and T-helper 2 immune responses. Interleukin (IL)-19 is a cytokine that belongs to interleukin 10 cytokines family and constitutes a sub-family with IL-20, IL-22 and IL-24. IL-19 is mainly produced by activated monocytes and to a lesser extent by B-cells, keratinocytes and fetal membranes. IL-19 was found to shift T-cell maturation away from the pro-inflammatory T-helper 1 cells toward the anti-inflammatory T-helper 2 cells. It induces IL-4 and IL-13 production in T cells and apoptosis in monocytes. Aim: This study aimed to measure serum level of IL-19 in patients with warts compared to healthy controls and to find out the correlation between this level and number, size and clinical types of warts. Methods: The study included 50 patients with warts and 50 control subjects. Serum concentration of IL-19 was measured by enzyme-linked immune sorbent assay. Results: Interleukin-19 serum level was significantly lower in patients with warts than in controls (P < 0.003). Moreover, there was a significant positive correlation between IL-19 serum level and the number of warts (P = 0.027). Conclusion: Serum level of IL-19 was significantly lower in patients with warts, and this low level might be crucial for an effective cell mediated immunological response to HPV.