Increases in Inflammatory Markers, Leukocyte Profile May Impact HS Severity

Levels of inflammatory markers and leukocyte profiles have implications for the severity of hidradenitis suppurativa (HS) over time, say new study findings.

The retrospective findings come from a novel longitudinal analysis of 400 patients, which the researchers said validates and further underscores the utility of laboratory parameters for the management of HS. While measures such as Hurley staging are used for clinical assessment of HS, cross-sectional studies have rarely exclusively studied objective disease markers.

“These novel associations not only allow for us to further understand the pathogenesis of HS but also translate to the clinical and research setting,” wrote the researchers. “Clinically, providers can use these findings to objectively evaluate and monitor disease progression, limiting potential interobserver variability in HS scoring. This can be further extended to allow for a robust assessment of HS disease status in trials and other research studies.”

Each patient included in the study had up to 4 visits at the Einstein/Montefiore HS Center in New York between March 2019 and November 2020. The mean time in between visits was 112.6 days; the researchers noted incongruent follow-up times across the group.

Examining the multiple visits longitudinally and adjusting for multiple variables, including age and body mass index, the researchers found that increases in C-reactive protein (CRP) (odds ratio [OR] 1.87; 95% CI, 1.49-2.34), erythrocyte sedimentation rate (OR 1.04; 95% CI, 1.03-1.04), and interleukin-6 (IL-6) (OR 1.08; 95% CI, 1.00-1.16) were strongly associated with severe disease.

Similarly, the researchers found that increases in various leukocyte profiles, including leukocytes and neutrophils, were associated with severe disease, which the researchers said aligns with the hypothesized inflammatory pathogenesis of HS, as leukocytosis in the disease has been shown to be neutrophil dominated compared with controls.

When examining the multiple visits longitudinally and adjusting for multiple variables, the researchers found that increases in leukocytes increased the risk of severe disease by 22% and neutrophils, known to play a large role in inflammation, increased the risk of severe disease by 31%.

“The role of these molecules in HS pathogenesis likely explains their correlation with disease severity and utility as biomarkers. The interplay between IL-6 and CRP contributes to HS disease activity,” explained the researchers.

They continued, “Neutrophils and macrophages stimulate the production of IL-6, a proinflammatory cytokine. This contributes to the development of T helper 17 (Th17) lymphocytes. Dysregulation of the Th17 ratio to regulatory T cells has been postulated to contribute to HS immunopathogenesis. Additionally, IL-6 induces the expression of acute phase proteins, including CRP, that act as a principal downstream mediator of acute-phase responses following an inflammatory event.”

Other leukocyte profiles associated with an increased risk of severe disease included eosinophils (OR 14.40; 95% CI, 2.97-69.74), basophils (OR 2.53; 95% CI, 1.09-5.85), monocytes (OR 5.36; 95% CI, 2.49-11.53), and neutrophil-lymphocyte ratios (OR 1.63; 95% CI, 1.35-1.96). Meanwhile, increased levels of lymphocytes (OR 0.86; 95% CI, 0.68-1.10) were associated with a decreased risk of severe disease.

Reference:

Andriano TM, Benesh G, Babbush KM, Hosgood HD, Lin J, Cohen SR. Serum inflammatory markers and leukocyte profiles accurately describe hidradenitis suppurativa disease severity. Int J Dermatol. Published online May 11, 2022. doi:10.1111/ijd.16244