Track

Clinical Studies

Abstract

Biological therapies for psoriasis are becoming increasingly prevalent, however, clinical outcomes are widely variable. Patient characteristics which could predict treatment responsiveness would be immensely valuable. In this preliminary study, we summarize the histopathological features that are associated with successful treatment with type-3 immune response modulators, namely IL-23 and/or IL-17 inhibitors. A retrospective chart and slide review was performed (2014-2023). Amongst 1291 pre-treatment biopsies consistent with a clinical diagnosis of psoriasis, 22 patients (9 responders and 13 non-responders determined by change in body surface area involvement) met inclusion criteria. Histopathological findings typical of psoriasiform dermatitis, including surface (intracorneal neutrophils, serum crust, hyper/parakeratosis), epidermal (acanthosis, rete ridge elongation, intraepidermal neutrophils and lymphocytes, basal mitoses, spongiosis, necrotic keratinocytes), and dermal features (superficial vessel dilation, suprapapillary plate thinning, dermal edema, RBC extravasation, and dermal inflammatory composition) were scored. Clustering analysis identified distinct histopathologic patterns to discern responders from non-responders. We found that treatment response was significantly associated with increased basal mitoses (histologic score averages 3.56 +/- 0.44 vs 0.85 +/- 0.41, p = 0.0003) and dermal edema (histologic score averages 0.44 +/- 0.18 vs 0.08 +/- 0.08, p = 0.045). Responders also tended to have increased necrotic keratinocytes, serum crust, superficial vessel dilation, and dermal neutrophils, and decreased lymphocyte exocytosis and intracorneal neutrophils. Limitations include retrospective design, small sample size, and potential use of concomitant therapies. Overall, these data indicate baseline histopathologic findings carry predictive significance for biological therapies in psoriasis.