TGF-β1 -509C/T polymorphism and susceptibility to keloid disease: a systematic review and meta-analysis

Global insights into keloid formation: An international systematic review of regional genetic risk factors and commonalities

Keloid disorder is a morbid and disfiguring benign fibroproliferative disease with a higher incidence in groups with darker skin pigmentation. Predicting keloidogenesis in patients is difficult with treatment primarily aimed at preventing further scar expansion and improving aesthetics without addressing their unknown underlying pathophysiology. We aimed to identify potential genetic predispositions to keloid scarring in the literature. A search was conducted on 21 August 2023, by the first and second authors independently from 1985 to August 2023 using PubMed, MEDLINE, Embase, Web of Science, Scopus and CINAHL. The following MeSH terms were used: 'Keloid', 'Risk' and 'Genetic'. Two researchers independently searched for studies based on titles and abstracts and screened filtered articles by reviewing full text. If no agreement could be reached, a third senior author designated whether the article should be included. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement as the basis of our organisation. Human studies with genetic analysis to determine an association of a protein or gene to keloidogenesis were selected for inclusion. Studies in languages other than English, reviews, conference articles, and book chapters were excluded. Fifty studies met inclusion criteria. The human leukocyte antigen (HLA) system was broadly implicated, and the DRB1*15 allele was associated with an increased risk of keloid in three separate ethnic groups. Some HLA Class I alleles were associated with keloid in one population but not in others. Additionally, polymorphisms in the E3 ubiquitin-protein ligase (NEDD4) signal cascade and vitamin D receptor (VDR) have been implicated in diverse groups. No current genetic test can predict keloid risk. Our review identified candidate predisposing genes, including NEDD4, VDR and components of the HLA system. Further studies in heterogeneous populations are needed to identify reliable screening targets.

Outcomes of Surgical Excision and High-Dose-Rate Brachytherapy for Earlobe Keloids

BACKGROUND

Radiotherapy as an adjuvant therapy to surgical resection has shown variable rates of recurrence treating earlobe keloids. The purpose of this study was to describe our experience with surgical excision followed by high-dose-rate brachytherapy and present our outcomes after 24 months of follow-up.

METHODS

Retrospective chart of 14 patients with 14 earlobe keloids treated with surgical excision followed by high-dose-rate brachytherapy, between January 2015 and May 2016 were enrolled. Database included demographics, Fitzpatrick skin type, laterality, lesion size, and follow-up visits information. Outcomes were assessed in terms of keloid recurrence rates, complications, and patient subjective aesthetical result satisfaction after 24 months of follow-up.

RESULTS

All procedures were completed without complications. Three patients experienced keloid recurrence after 6 (14.28%) and 12 months (7.14%). Three patients experienced mild signs of self-limited post-radiation dermatitis. Self-assessment of aesthetical result was considered "very good" in 71.43% of patients.

CONCLUSION

Surgical excision followed by high-dose-rate brachytherapy is secure and effective to treat earlobe keloids, and can be considered a first line combined treatment. Larger clinical trials comparing different irradiation protocols are still needed.

TGF-β1 -509C/T polymorphism and susceptibility to keloid disease: a systematic review and meta-analysis

Background:

Keloid disease (KD) is common and often refractory to treatment. Definition of the genetic mechanisms of KD can lead to a better understanding of the disease and suggest more effective treatment strategies.

Objectives:

To quantitatively estimate the association between KD susceptibility and the -509C/T polymorphism in the TGF-β1 gene.

Methods:

PubMed, Embase and CNKI databases were searched using a combination of the Medical Subject Headings (MeSH) and relevant words in titles. Analyses were performed with STATA 12.0.

Results:

Five case-control studies encompassing a total of 564 keloid cases and 620 healthy controls were pooled in the final meta-analysis. Among the five studies, no significant association was detected between the TGF-β1 -509C/T polymorphism and KD under all of the five genetic models (allele comparison, heterozygote comparison, homozygote comparison, dominant model and recessive model) for the overall analyses and for the subgroup analyses based on DNA extraction method, participant ethnicity and group size. When stratified by study quality, three high-quality studies showed significant association under allele comparison and homozygote model (C versus T: OR = 0.80, 95% confidence interval [CI] = 0.65–0.98, P = 0.03; I² = 0%, P = 0.64; CC versus TT: OR = 0.62, 95% CI = 0.41–0.94, P = 0.02; I² = 0%, P = 0.79); while two moderate-quality studies showed significant association under allele comparison, homozygote model and recessive model (C versus T: OR = 1.52, 95% CI = 1.15–2.01, P = 0.004; I² = 39%, P = 0.20; CC versus TT: OR = 2.14, 95% CI = 1.24–3.70, P = 0.02; I² = 19%, P = 0.27; CC versus CT+TT: OR = 2.04, 95% CI = 1.29–3.24, P = 0.002; I² = 0%, P = 0.35).

Conclusions:

The current meta-analysis suggests that the TGF-β1 -509C/T polymorphism is not associated with KD susceptibility. High-quality and large-scale studies are needed to validate our findings.

Keloid scars are thick and lumpy scars that behave almost like tumours. They grow, are unsightly and itchy, and difficult to treat as they can get worse after attempts at treating them. This article reviews the scientific evidence for a link between a certain gene variation, specifically `509C/T polymorphism in the TGF-β1 gene’. After an extensive scientific database search, five studies were found, and no significant association was detected between the TGF-β1 -509C/T polymorphism and Keloid scarring. High quality and large-scale studies are needed to validate our findings.