Treatment of hidradenitis suppurativa with adalimumab in the PIONEER I and II trials reduced indices of systemic inflammation, recognised risk factors for cardiovascular disease.

Abstract

Hidradenitis suppurativa (HS) is associated with increased cardiovascular disease (CVD) risk. Systemic immune inflammation index (SII), neutrophil/lymphocyte (NLR), platelet/lymphocyte (PLR) and monocyte/lymphocyte ratios (MLR) are biomarkers of systemic inflammation and CVD. One small study identified a lower NLR and PLR in patients treated with adalimumab. Our aim was to assess changes in SII, NLR, PLR and MLR in a larger cohort, and to evaluate their association with disease severity and treatment response. This was a post-hoc analysis of PIONEER I and PIONEER II, two phase 3 randomised placebo-controlled clinical trials of adalimumab for HS. SII, NLR, PLR and MLR were log10-transformed and linear mixed model was used to estimate treatment effect. SII, NLR, PLR and MLR reduced from baseline levels with adalimumab treatment by week 12, when the primary response endpoint was assessed. Significant changes first appeared at week 4 and were maintained to week 36. In contrast, no significant changes were observed in placebo-treated patients. In patients re-randomised at week 12 from placebo to adalimumab, SII, NLR, PLR and MLR also reduced within 4 weeks. In patients re-randomised from adalimumab to placebo, these biomarkers returned to baseline by week 36. In addition, SII, NLR and PLR correlated with draining fistula count (r=0.26-0.43, p<0.001). Adalimumab non-responders in PIONEER I had a higher SII, NLR and PLR at baseline and week 12, but this was not significant when adjusted for draining fistulae. Treatment of HS patients with adalimumab results in rapid sustained reduction in systemic inflammation measured by SII, NLR, PLR and MLR which correlate with CVD risk. SII, NLR and PLR may predict adalimumab response, although dependent on their interaction with the number of draining fistulae.