Research priorities in the management of hidradenitis suppurativa

Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS): a prospective cohort study

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, painful disease affecting flexures and other skin regions, producing nodules, abscesses and skin tunnels. Laser treatment targeting hair follicles and deroofing of skin tunnels are standard HS interventions in some countries but are rarely offered in the UK.

OBJECTIVES

To describe current UK HS management pathways and influencing factors to inform the design of future randomized controlled trials (RCTs).

METHODS

THESEUS was a nonrandomized 12-month prospective cohort study set in 10 UK hospitals offering five interventions: oral doxycycline 200 mg daily; oral clindamycin and rifampicin both 300 mg twice daily for 10 weeks, extended for longer in some cases; laser treatment targeting hair follicles; deroofing; and conventional surgery. The primary outcome was the combination of clinician-assessed eligibility and participant hypothetical willingness to receive each intervention. The secondary outcomes were the proportion of participants selecting each intervention as their final treatment option; the proportion who switch treatments; treatment fidelity; and attrition rates. THESEUS was prospectively registered on the ISRCTN registry: ISRCTN69985145.

RESULTS

The recruitment target of 150 participants was met after 18 months, in July 2021, with two pauses due to the COVID-19 pandemic. Baseline demographics reflected the HS secondary care population: average age 36 years, 81% female, 20% non-White, 64% current or ex-smokers, 86% body mass index ≥ 25, 68% with moderate disease, 19% with severe disease and 13% with mild disease. Laser was the intervention with the highest proportion (69%) of participants eligible and willing to receive treatment, then deroofing (58%), conventional surgery (54%), clindamycin and rifampicin (44%), and doxycycline (37%). Laser was ranked first choice by the greatest proportion of participants (41%). Attrition rates were 11% and 17% after 3 and 6 months, respectively. Concordance with doxycycline was 52% after 3 months due to lack of efficacy, participant choice and adverse effects. Delays with procedural interventions were common, with only 43% and 26% of participants starting laser and deroofing, respectively, after 3 months. Uptake of conventional surgery was too small to characterize the intervention. Switching treatment was uncommon and there were no serious adverse events.

CONCLUSIONS

THESEUS has established laser treatment and deroofing for HS in the UK and demonstrated their popularity with patients and clinicians for future RCTs.

Treatment of Hidradenitis Suppurativa Evaluation Study: the THESEUS prospective cohort study

Background

Hidradenitis suppurativa is a chronic inflammatory skin disease characterised by recurrent inflammatory lesions and skin tunnels in flexural sites such as the axilla. Deroofing of skin tunnels and laser treatment are standard hidradenitis suppurativa interventions in some countries but not yet introduced in the United Kingdom.

Objective

To understand current hidradenitis suppurativa management pathways and what influences treatment choices to inform the design of future randomised controlled trials.

Design

Prospective 12-month observational cohort study, including five treatment options, with nested qualitative interviews and an end-of-study consensus workshop.

Setting

Ten United Kingdom hospitals with recruitment led by dermatology and plastic surgery departments.

Participants

Adults with active hidradenitis suppurativa of any severity not adequately controlled by current treatment.

Interventions

Oral doxycycline 200 mg once daily; oral clindamycin and rifampicin, both 300 mg twice daily for 10 weeks initially; laser treatment targeting the hair follicle (neodymium-doped yttrium aluminium garnet or alexandrite); deroofing; and conventional surgery.

Main outcome measures

Primary outcome was the proportion of participants who are eligible, and hypothetically willing, to use the different treatment options. Secondary outcomes included proportion of participants choosing each of the study interventions, with reasons for their choices; proportion of participants who switched treatments; treatment fidelity; loss to follow-up rates over 12 months; and efficacy outcome estimates to inform outcome measure instrument responsiveness.

Results

Between February 2020 and July 2021, 151 participants were recruited, with two pauses due to the COVID-19 pandemic. Follow-up rates were 89% and 83% after 3 and 6 months, decreasing to 70% and 44% at 9 and 12 months, respectively, because pandemic recruitment delays prevented all participants reaching their final review. Baseline demographics included an average age of 36 years, 81% female, 20% black, Asian or Caribbean, 64% current or ex-smokers and 86% with a raised body mass index. Some 69% had moderate disease, 19% severe disease and 13% mild disease. Regarding the study's primary outcome, laser treatment was the intervention with the highest proportion (69%) of participants who were eligible and hypothetically willing to receive treatment, followed by deroofing (58%), conventional surgery (54%), the combination of oral clindamycin and rifampicin (44%) and doxycycline (37%). Considering participant willingness in isolation, laser was ranked first choice by the greatest proportion (41%) of participants. The cohort study and qualitative study demonstrated that participant willingness to receive treatment was strongly influenced by their clinician. Fidelity to oral doxycycline was only 52% after 3 months due to lack of effectiveness, participant preference and adverse effects. Delays receiving procedural interventions were common, with only 43% and 26% of participants commencing laser therapy and deroofing, respectively, after 3 months. Treatment switching was uncommon and there were no serious adverse events. Daily pain score text messages were initiated in 110 participants. Daily responses reduced over time with greatest concordance during the first 14 days.

Limitations

It was not possible to characterise conventional surgery due to a low number of participants.

Conclusion

The Treatment of Hidradenitis Suppurativa Evaluation Study established deroofing and laser treatment for hidradenitis suppurativa in the United Kingdom and developed a network of 10 sites for subsequent hidradenitis suppurativa randomised controlled trials.

Future work

The consensus workshop prioritised laser treatment and deroofing as interventions for future randomised controlled trials, in some cases combined with drug treatment.

Trial registration

This trial is registered as ISRCTN69985145.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/35/64) and is published in full in Health Technology Assessment; Vol. 27, No. 30. See the NIHR Funding and Awards website for further award information.

Discovering KYNU as a feature gene in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic auto-inflammatory skin condition characterized by nodules, abscesses, and fistulae in skin folds. The underlying pathogenesis of HS remains unclear, and effective therapeutic drugs are limited.

METHODS

We acquired mRNA expression profiles from the Gene Expression Omnibus (GEO) database and conducted differential expression analysis between control and HS samples using R software. Four machine learning algorithms (SVM, RF, ANN, and lasso) and WCGNA were utilized to identify feature genes. GO, KEGG, Metascape, and GSVA were utilized for the enrichment analysis. CIBERSORT and ssGSEA were employed to analyze immune infiltration.

RESULTS

A total of 29 DEGs were identified, with the majority showing up-regulation in HS. Enrichment analysis revealed their involvement in immune responses and cytokine activities. KEGG analysis highlighted pathways such as IL-17 signaling, rheumatoid arthritis, and TNF signaling in HS. Immune infiltration analysis revealed the predominant presence of neutrophils, monocytes, and CD8 T cells. Machine learning algorithms and WCGNA identified KYNU as a feature gene associated with HS. We have also identified 59 potential drugs for HS based on the DEGs. Additionally, ceRNA network analysis identified the MUC19_hsa-miR-382-5p_KYNU pathway as a potential regulatory pathway.

CONCLUSIONS

KYNU emerged as a feature gene associated with HS, and the ceRNA network analysis identified the MUC19_hsa-miR-382-5p_KYNU pathway as a potential regulator.