Pilonidal pit fibroblasts release cytokines that differ by sex and are altered by estrogen.

PURPOSE: Female pilonidal patients have higher pain scores than males. Pain is often at gluteal cleft pit, which consists of fibroblasts. Skin fibroblasts can express estrogen receptors that secrete cytokines. We hypothesize that estrogen receptor binding on pilonidal pit fibroblast can release cytokines, resulting in pain. METHOD: Pilonidal pits were cultured. Triplicate fibroblast cultures in hormone-free media were treated with β-estradiol or control before media was collected and analyzed for 48 cytokines. Percentage change of cytokine level after estrogen was compared to those from control using Mann-Whitney test. RESULTS: Eight fibroblast cultures (4-males, 4-females) were established. Prior to estrogen, fibroblasts secreted eotaxin/CCL11, GROa, IL6, IL8/CXCL8, IL10/CXCL10, MCP-1/CCL2, VEGF-A. For males, estrogen on average changed eotaxin/CCL11 by 65%±73% compared to control, GROa 19%±17%, IL6 -2.0%±7.2%, IL8/CXCL8 56%±15%, IL10/CXCL10 7.9%±24%, MCP-1/CCL2 9.7%±8.5%, VEGF-A 9.9%±14%. For females, estrogen changed eotaxin/CCL11 by -2.0%±11% compared to control, GROa 22%±48%, IL6 90%±116%, IL8/CXCL8 5.3%±24%, IL10/CXCL10 -1.4%±4.1%, MCP-1/CCL2 18%±44%, VEGF-A -1.6%±10%. After estrogen stimulation, female fibroblasts increased IL6 and decreased eotaxin/CCL11 and IL8/CXCL8 secretion compared to males (p≤0.05). CONCLUSION: Pilonidal pit fibroblasts released cytokines which could contribute to pain symptoms. Estrogen increases IL6 release from female fibroblasts, providing a potential mechanism for females having higher pain intensity than males.