Is hidradenitis suppurativa associated with increased levels of interleukin-6 (IL-6)?

Hidradenitis Suppurativa and Interleukin-6 Levels

Yes, hidradenitis suppurativa is associated with increased levels of interleukin-6 (IL-6), which contributes to the systemic inflammatory burden of the disease. 1

Inflammatory Biomarkers in Hidradenitis Suppurativa

• Small cohort studies have linked hidradenitis suppurativa (HS) to elevated levels of several inflammatory biomarkers, including interleukin-6 (IL-6) 1
• HS is characterized by chronic inflammation with increased expression of proinflammatory cytokines, including IL-6 and TNF, which are observed at higher levels in both HS and associated conditions like depression 1
• The significant inflammatory response seen in HS has led researchers to consider it a disease of aberrant immunity, which explains why immunomodulatory treatments targeting various inflammatory pathways can be beneficial 1

Pathogenesis and Inflammatory Mechanisms

• HS pathogenesis is complex and involves multiple immune mechanisms, including innate immune pathways where IL-6 plays a significant role 2
• The systemic inflammation in HS contributes to both cutaneous manifestations and various comorbidities, with IL-6 being one of the key inflammatory mediators 1
• The link between HS and mood disorders like depression may be partially explained by shared inflammatory pathways, including elevated IL-6 levels 1
• Chronic inflammation in HS leads to irreversible skin damage with tunnel formation and scarring, which may be mediated by persistent elevation of inflammatory cytokines including IL-6 2

Clinical Implications of Elevated IL-6

• The elevated IL-6 levels in HS may contribute to the higher overall comorbidity burden seen in HS patients compared to those with psoriasis 1
• Systemic inflammation, including elevated IL-6, may support a biological link between HS and cardiovascular disease through mechanisms such as endothelial dysfunction, atherosclerosis, and thrombosis 1
• Monitoring inflammatory biomarkers like IL-6 may potentially help in understanding individual differences in HS pathogenesis and evaluating disease severity, though this is not yet part of routine clinical practice 3

Treatment Considerations

• Current treatment approaches for HS target various inflammatory pathways, with biologics directed against TNF-α (adalimumab), IL-17 (secukinumab and bimekizumab) being FDA-approved options 2, 4
• While IL-6 is elevated in HS, there are currently no approved treatments specifically targeting the IL-6 pathway for HS management 4
• The complex inflammatory nature of HS, involving multiple cytokines including IL-6, explains why targeting single inflammatory pathways may not be sufficient for all patients 5, 4

Monitoring Inflammation in HS

• While small cohort studies have demonstrated elevated IL-6 in HS, routine biomarker testing for IL-6 is not currently recommended in clinical practice for diagnosis or monitoring 1
• High-sensitivity C-reactive protein (hs-CRP) may be a more practical marker of systemic inflammation and treatment response in HS compared to direct measurement of cytokines like IL-6 3
• The presence of elevated inflammatory markers, including IL-6, supports the conceptualization of HS as a systemic inflammatory disorder rather than merely a skin condition 1, 2