The relationship between serum tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) with pelvic pain symptoms in women with endometriosis

Abstract

OBJECTIVE: Il-6 and TNF-α have been implicated in the initiation and maintenance of endometriosis implants; however, their role in the development of pelvic pain remains unclear. This study seeks to evaluate the relationship of these cytokines to pain perception in women with endometriosis and chronic pelvic pain (CPP).DESIGN: This is a cross-sectional study to assess serum IL-6 and TNF-α levels and pelvic pain symptoms in women with endometriosis and CPP, endometriosis without CPP, and pain-free controls.MATERIALS AND METHODS: 38 women with surgically-confirmed endometriosis and 39 controls underwent medical interviews, physical exams, and validated questionnaires to assess pain severity. CPP was defined as ≥6 months of pelvic pain, occurring for >7 days per month. Serum IL-6 and TNF-α levels were measured via standard enzyme-linked immunosorbent assay (ELISA). The relationship between serum cytokine levels and pain severity was evaluated with the Kruskall-wallis test and Spearman's correlation coefficient, as appropriate, using STATA 10.0.TableSerum cytokine levels in women with endometriosis and pain-free controlsEndometriosis with CPP (n=18)Endometriosis without CPP (n=14)Pain-free controls (n=39)K-wallis p-valueTNF-α8.6 (4.9, 14.2)7.8 (5.1, 12.5)5.2 (4.6, 7.0)0.07IL-62.2 (0, 2.9)2.7 (1.8, 3.0)2.2 (0, 2.5)0.28Values expressed as median (95% CI) Open table in a new tab However, neither TNF-α nor IL-6 correlated with overall pain intensity, or with severity of dysmenorrhea, dypareunia, dyschezia, or dysuria.CONCLUSIONS: Although it appears as though serum TNF-α (but not IL-6) is elevated in women with endometriosis, it was elevated in women with and without CPP, and neither of these measures appear related to severity of pain symptoms in this cohort. OBJECTIVE: Il-6 and TNF-α have been implicated in the initiation and maintenance of endometriosis implants; however, their role in the development of pelvic pain remains unclear. This study seeks to evaluate the relationship of these cytokines to pain perception in women with endometriosis and chronic pelvic pain (CPP). DESIGN: This is a cross-sectional study to assess serum IL-6 and TNF-α levels and pelvic pain symptoms in women with endometriosis and CPP, endometriosis without CPP, and pain-free controls. MATERIALS AND METHODS: 38 women with surgically-confirmed endometriosis and 39 controls underwent medical interviews, physical exams, and validated questionnaires to assess pain severity. CPP was defined as ≥6 months of pelvic pain, occurring for >7 days per month. Serum IL-6 and TNF-α levels were measured via standard enzyme-linked immunosorbent assay (ELISA). The relationship between serum cytokine levels and pain severity was evaluated with the Kruskall-wallis test and Spearman's correlation coefficient, as appropriate, using STATA 10.0. Values expressed as median (95% CI) However, neither TNF-α nor IL-6 correlated with overall pain intensity, or with severity of dysmenorrhea, dypareunia, dyschezia, or dysuria. CONCLUSIONS: Although it appears as though serum TNF-α (but not IL-6) is elevated in women with endometriosis, it was elevated in women with and without CPP, and neither of these measures appear related to severity of pain symptoms in this cohort.