Human dermal fibroblast subpopulations and epithelial mesenchymal transition signals in hidradenitis suppurativa tunnels are normalized by spleen tyrosine kinase antagonism in vivo

Hepatocyte Growth Factor Has Unique Functions in Keratinocytes that Differ from those of IL-17A and TNF and May Contribute to Inflammatory Pathways in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that is difficult to control, and its mechanism remains unclear. Hepatocyte GF (HGF) has been reported to be significantly upregulated in the serum and skin of patients with HS, especially in the lesions with tunnels. In this study, we examined the transcriptome of HGF-treated keratinocytes and compared it with genetic profiling of HS lesions. HGF was highly expressed in HS skin, especially in the deep dermis, compared with that in healthy controls, and its source was mainly fibroblasts. HGF upregulated more genes in keratinocytes than IL-17A or TNF-a, and these genes included multiple epithelial-mesenchymal transition-related genes. Differentially expressed genes in HGF-stimulated keratinocytes were involved in activation of epithelial-mesenchymal transition-related pathways. These HGF-induced genes were significantly upregulated in HS lesions compared with those in healthy skin and nonlesions and were more strongly associated with HS tunnels. In summary, HGF was highly expressed in HS and induced epithelial-mesenchymal transition-related genes in keratinocytes; HGF-induced genes were highly associated with gene profiling of HS with tunnels, suggesting that HGF may be involved in HS tunnel formation through epithelial-mesenchymal transition.

A systematic review of Janus kinase inhibitors and spleen tyrosine kinase inhibitors for Hidradenitis suppurativa treatment

BACKGROUNDS AND AIMS

Hidradenitis suppurativa (HS) is a challenging skin disease with an underlying inflammatory process. Substantial progress has been made in our understanding of HS over the last few years, with the advancement of novel treatment approaches. The current systematic review aims to evaluate the safety and efficacy of Janus kinase (JAK) inhibitors and spleen tyrosine kinase (Syk) inhibitors in treating HS.

METHOD

A thorough systematic search was performed on PubMed/Medline, Web of Science, and Ovid Embase databases up to September 23th, 2023. Clinical studies published in English were included.

RESULTS

Our search yielded ten articles with a total of 165 patients treated with four types of JAK inhibitors (upadacitinib, povorcitinib, tofacitinib, and baricitinib) and one Syk inhibitor (fostamatinib). Upadacitinib, povorcitinib, and tofacitinib improved clinical outcomes, with a significant reduction in hidradenitis suppurativa clinical response (HiSCR) and abscess and inflammatory nodule count (AN count) during the treatment period. Also, these drugs are well tolerated in most HS patients with minimal adverse events (AEs). Moreover, baricitinib depicted an amelioration in signs and symptoms of HS in one case report. Also, fostamatinib exhibited favorable tolerability throughout a 12-week in moderate-to-severe HS patients. The remarkable clinical improvement, as assessed through HiSCR and hidradenitis suppurativa severity (IHS4), corresponded closely with serological indicators of inflammation following fostamatinib administration was achieved.

CONCLUSION

JAK and Syk inhibitors are potentially efficacious in managing moderate-to-severe HS since the proinflammatory cytokines are mediated by JAK and Syk signaling pathways. However, further research with a more rigorous examination is mandatory to evaluate such medication's long-term safety and efficacy.