Elevated levels of testosterone receptors in keloid tissue: an experimental investigation

Effect of testosterone replacement therapy on scar quality in gender-affirming mastectomies

BACKGROUND

The term transgenders refer to people who sense discordance between their gender identity and the sex assigned to them at birth. Some transgenders receive hormonal therapy, which may lead to specific skin conditions. The purpose of the present study was to determine whether a causal relationship exists between hormonal therapy (specifically testosterone therapy) and unsatisfying surgical scarring, including hypertrophic and keloid scars. In addition, this study may serve as a basis for future studies, which may test means that aim to reduce such undesired effects.

METHODS

In this retrospective, observational cohort study, data were collected regarding 170 patients who underwent mastectomy as a gender-affirming surgery by the senior author between 2003 and 2021. The medical records were analysed to obtain personal, medical (including the duration of testosterone treatment) and surgical information from the patients' medical files. A blinded evaluator assessed the surgical scars by reviewing the postoperative clinical pictures of the patients. The scars were rated using the validated Stony Brook Scar Evaluation Scale (SBSES). The use of pictures to assess surgical scars is described in the validation study of the SBSES and is, therefore, accepted.

RESULTS

In total, 63 patients were included in the testosterone group and 63 were included in the non-testosterone treated group. The averages of the SBSES score were 2.74 and 2.66, respectively. The difference between the two averages was not statistically significant.

CONCLUSION

In our retrospective cohort study, we did not find the effect of testosterone therapy on post-operative surgical scars to be significant.

EVIDENCE BASED MEDICINE (EBM) LEVEL

3.

Over 90% Percent of Childhood BCG Vaccine-Induced Keloids in Japan Occur in Women

INTRODUCTION

Keloids are a fibroproliferative, multifactorial, cutaneous disorder whose pathophysiology is not completely understood. Various factors such as high blood pressure, pregnancy, female gender, mechanical tension of local sites, and prolonged wound healing are known to worsen keloids. Childhood-onset keloids are keloids that form before 10 years of age, before various factors in adulthood come into play, and thus studying childhood-onset keloids may provide additional insight into the underlying mechanisms that lead to keloid formation.

METHODS

Retrospective chart review was performed on all patients with childhood-onset keloids who were evaluated at our plastic surgery clinic (one of the largest keloid referral centers in Japan) over a 1-year period.

RESULTS

Of the 1443 patients with diagnosis of keloids, 131 patients had childhood-onset keloids. Of these, 106 patients (80.9%) were female, 38.9% of patients had family history of keloids, and 48.9% of patients had allergies or allergy-related conditions (asthma, atopic dermatitis, or allergic rhinitis). Vaccination (47.5%) and chickenpox (19.9%) were the most common triggers. Of vaccinations, BCG was the most common trigger. The majority of keloids from BCG were in female patients (92.9%). The most common location was the chest in male patients (30.0%) and the arm in female patients (41.1%).

CONCLUSION

To our knowledge, this is the largest report in the literature on childhood-onset keloids. There was overall female predominance in childhood-onset keloids, and even more significant female predominance in BCG-induced keloids.

Implications of Testosterone Therapy on Wound Healing and Operative Outcomes of Gender-Affirming Chest Masculinization Surgery

The increased awareness of the transgender population and their medical needs has given rise to a wide array of gender-affirming surgeries and hormonal therapies. To better understand the implication of testosterone therapy on female-to-male gender-affirming mastectomies, we conducted a retrospective cohort study based on the medical histories of 170 transgender males operated on by a single surgeon over 18 years. One hundred and one (59.4%) patients received hormonal therapy. The average age of patients in the testosterone treatment group was 20.6 ± 5.3 (range 14-49) years. The median weight of resected breast tissue was 318 g (IQR 221-515) and 311.5 g (IQR 223-480) in patients treated with testosterone, compared to 380 g (IQR 225-735) and 370 g (IQR 240-700) in patients without testosterone treatment (for the right and left breast, respectively). Supplementary liposuction was performed in 35 patients, of whom 23 (64%) were treated with testosterone. Fifty-four patients (31.7%) experienced surgical complications, and 55.6% of complications were recorded in the group treated with testosterone. Forty-nine patients (28.8%) recorded their satisfaction using the Likert satisfaction scale; the average satisfaction was 4.86 ± 0.35 in the non-testosterone group and 4.63 ± 0.69 in the testosterone group. Opposing previous cohorts, we did not find a statistically significant association between testosterone and increased surgical complications in gender-affirming mastectomies. Possible explanations include our practice of avoiding testosterone therapy several weeks before the operation and vigorous hemostasis methods.

A Novel Mouse Model for Investigating the Effects of Gender-affirming Hormone Therapy on Surgical Healing

Wound healing problems are a major cause of morbidity for gender-affirming surgery (GAS) patients. Prior studies have shown sex differences in wound healing may exist. We hypothesized exogenous testosterone supplementation may impair post-GAS wound healing and developed a model to investigate this phenomenon. Mice were randomized by hormone regimen and gonadectomy (OVX). Gonadectomy or sham occurred on day 0 and mice were assigned to no testosterone (-T), mono- or bi-weekly (T/2T) testosterone groups. Dorsal splinted wounding occurred on day 14 and harvest on day 21. Serum testosterone levels were quantified with mass spectrometry. Tissue underwent analysis with planimetry, qPCR, ELISA, and immunofluorescence. Mean testosterone trough levels for bi-weekly regimen were higher compared to mono-weekly (397 versus 272 ng/dL; P = 0.027). At POD5, 2T injections led to 24.9% and 24.7% increases in mean wound size relative to SHAM and OVX/-T, respectively (P = 0.004; 0.001). Wounds in OVX/+2T mice demonstrated increased gene expression for inflammatory cytokines and macrophage marker F4/80 (P < 0.05). ELISA confirmed elevated wound TNFα levels (P < 0.05). Quantitative multiplex immunofluorescence with F4/80/NOS2/ARG1 showed significant increases in macrophage prevalence in OVX/+2T (P < 0.05). We developed a novel model of GAS hormonal milieu to study effects of exogenous testosterone on wound healing. Optimized twice-weekly dosing yielded serum levels comparable to clinical therapy. We showed exogenous testosterone administered to XX/OVX mice significantly impairs wound healing. A hyperinflammatory wound environment results in increased macrophage proliferation and elevated cytokines. Future efforts are directed toward mechanistic investigation and clinical validation.

Risk factors associated with the progression from mild keloids to severe mild keloids

Background:

Keloids are benign fibrous growths that are caused by excessive tissue build-up. Severe keloids exert more significant effects on patients’ quality of life than do mild keloids. We aimed to identify factors associated with the progression from mild keloids to severe keloids, as distinct from those associated with the formation of keloids.

Methods:

In this retrospective case-control study, 251 patients diagnosed with keloids at West China Hospital between November 2018 and April 2021 were grouped according to the severity of lesions (mild [n = 162] or severe [n = 89]). We collected their basic characteristics, living habits, incomes, comorbidities, and keloid characteristics from Electronic Medical Records in the hospital and the patients’ interviews. Conditional multivariable regression was performed to identify the independent risk factors for the progression of keloids.

Results:

Eighty-nine patients (35.5%) were classified as having severe keloids. We found the distribution of severe keloids varied with sex, age, excessive scrubbing of keloids, family income, the comorbidity of rheumatism, disease duration, characteristics of the location, location in sites of high-stretch tension, the severity and frequency of pain, the severity of pruritus, and infection. Multivariable analysis revealed significant associations between severe keloids and infection (odds ratio [OR], 3.55; P = 0.005), excessive scrubbing of keloids (OR, 8.65; P = 0.001), low or middle family income (OR, 13.44; P = 0.021), comorbidity of rheumatism (OR, 18.97; P = 0.021), multiple keloids located at multiple sites (OR, 3.18; P = 0.033), and disease duration > 15 years (OR, 2.98; P = 0.046).

Conclusion:

Doctors should implement more active and thorough measures to minimize the progression of mild keloids in patients who have any of the following risk factors: infection, excessive scrubbing of keloids, low or middle family income, comorbidity of rheumatism, multiple keloids located at multiple sites, and disease duration > 15 years.

The relationship between testosterone levels and Peyronie's disease

Aetiologic and predisposing factors are still controversial about Peyronie's disease (PD). However, it is thought to be the result of connective tissue disorder or healing defect. Androgens are known to affect collagen metabolism and wound healing in the body. The aim of this study was to investigate the relationship between PD and low testosterone levels. One hundred and forty-seven Peyronie patients and 137 healthy volunteers were included in the study. In both groups, demographic data, medical history, physical examination and erectile capacity were recorded. Blood samples were collected from all subjects in the early morning hours after an overnight fast. The mean level of serum total testosterone was lower in men with PD compared with the controls (3.9 ± 1.1 vs. 4.2 ± 1.7 ng/ml respectively) (p = .062). However, statistically significant relationship was not found between PD and low serum testosterone levels. There was no significant correlation between penile plaque dimension or penile curvature degree and testosterone levels. Large randomised-controlled prospective studies are needed to reveal this possible association.

Keloids: Which Types Can Be Excised without Risk of Recurrence? A New Clinical Classification

A surgical team from Interplast-Germany removed 387 keloids in 302 patients during 4 visits to Goma, Democratic Republic of the Congo, from 2015-2018. Preoperative and postoperative photographs and a thorough anamnesis of keloids were done for all patients. In addition, 18 selected biopsies from 4 types of keloids were histologically examined in Germany.

Methods

Treatment options were tested and keloid recurrence rates were compared with data from questionnaires, photographs, and histology.

Results

Keloids were classified accordingly as follows: (1) fresh nodular (continuously growing) keloids had a 30% recurrence rate after surgery: no common adjuvant therapy but triamcinolone acetonide (TAC) injections on onset, only; (a) earlobe keloids had the lowest recurrence rate after complete excision with negative resection margins; (2) superficial spreading (or butterfly) keloids were treated with TAC injections only; (3) mature (nongrowing or burned-out) keloids had also a low recurrence rate of 4.5%, which were then treated with TAC on onset, only; and (4) multiple keloids comprise various types in different stages.

Conclusions

According to this classification, about 50% of keloids may be removed surgically without risk of recurrence in the examined patient population in Africa, where only TAC injections, but no radiation, are available. Adjuvant TAC or radiation should be started at the onset of recurrence and not generally.

When Testosterone Needs to be Contrasted: A Preliminary Study of Scar Prevention in Transmen Top Surgery with an Innovative Galenic Preparation

BACKGROUND

Transmen are individuals who live a marked incongruence between the assigned gender and the experienced gender. Crucial and life-changing steps in their transition are testosterone treatment and mastectomy to remove the stigma of feminine identity. After surgery, patients' attention turns to the scars, often not aesthetically pleasant. We thus created an innovative galenic preparation for scar treatment after surgery composed by spironolactone, alfa bisabolol and silicone gel. Functional outcomes, side effects and satisfaction were assessed.

METHODS

For the present prospective randomized controlled study, 30 patients with similar demographic characteristics who underwent double incision mastectomy with NA grafts between February 2014 and June 2019 were selected. The treatment Group A (n = 15) was treated for 12 months with "Top Surgery Scar go," the control Group B (n = 15) with silicon gel. Statistical analysis including Wilcoxon test and Kruskal-Wallis test per variable was performed. To assess satisfaction, a second Wilcoxon test was applied.

RESULTS

The differences between Group A and Group B were statistically significant, especially at T12 with very low p values. Satisfaction was greater in Group A (p value = 3e-4). No major side effects were noticed in Group A.

CONCLUSIONS

TSSgo scar innovative treatment showed long-term efficacy in comparison with silicon gel in terms of improved scar tissue texture, pigmentation, pliability and height. It is easy to set up, cost-effective and safe. Further studies are necessary to better assess efficacy and validity of TSSgo, but it appears to be promising as the new treatment of reference for scar management after top surgery in transmen.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Keloid and Hypertrophic Scar Formation, Prevention, and Management: Standard Review of Abnormal Scarring in Orthopaedic Surgery

Keloid and hypertrophic scar formation after orthopaedic surgical closure is a complex issue. The nature and location of procedures maximize wound tension, leave foreign bodies, and diminish dermal supply, all potentiating keloid formation. There is little discussion regarding the pathophysiology and management of this recurrent problem in orthopaedic literature. Keloid formation is a fibroproliferative disorder resulting in extensive production of extracellular matrix and collagen, but prevention and treatment is poorly understood. Patient and surgical factors contributing to the development of this condition are discussed. The treatments include both medical and surgical therapies that work at a biologic level and attempt to produce a cosmetic and complication-free management strategy. Medical options that have been investigated include combinations of intralesional steroid therapy, laser therapy, and biologics. Preventive surgical closure and excision remain mainstays of treatment. Radiation therapy has also been used in refractory cases with mixed results. Despite medical therapies and surgical excision aimed at treating the resulting scar, recurrence rate is very high for all modalities that have been studied to this point. Future work is being done to better understand the pathophysiology leading to keloid and hypertrophic scar formation in an effort to find preventive methods as compared to treatment strategies.

Histopathology and immunohistochemical analysis of 5-fluorouracil and triamcinolone treated keloids in double-blinded randomized controlled trial

Keloids are a major complication related to surgical wound healing and very challenging condition to treat. Many treatment options are available, but the efficacy of the treatment is poor in most of cases and some keloids do not respond to the treatment at all. We compared the efficacy of intralesional 5-fluorouracil (5-FU) and triamcinolone (TAC) injections in a double-blind randomized controlled trial (RCT). Forty-three patients with 50 keloid scars were treated with either intralesional TAC or 5-FU-injections over 6 months. We wanted to find out whether biological features (cell density, cell proliferation rate, vascular density, myofibroblast numbers, steroid hormone receptor expression) in keloids could be used to predict the response to therapy and define the biological changes that take place in patients receiving a response. As there was no statistically significant difference in the remission rate between TAC and 5-FU treatments, all patients were combined and analyzed as responders and nonresponders. Although responders have slightly more myofibroblasts than the nonresponders in their keloids in the pretreatment biopsy samples, we could not identify a single predictive factor that could identify those patients that respond to drug injections. The good clinical response to therapy is associated with the simultaneous reduction of myofibroblasts in the keloid. This study demonstrates that myofibroblasts are reduced in number in those keloids that were responsive to therapy, and that both 5-FU and TAC injections are useful for keloid treatment.

High in situ mRNA levels of IL-22, TFG-β, and ARG-1 in keloid scars

Keloid scars are currently considered a chronic inflammatory process and no longer a benign skin tumor. Keloids are defined as highly inflamed, hyperproliferative pathological scars. Growth factors and cytokines have important functions in the keloid inflammatory etiopathogenesis. The aim of this study was to analyze the in situ expression of cytokines and growth factors in keloid scars in comparison with that in normal scars. Among them, we specifically assessed TGF-β, FGF, IL-33, IL-22, ARG-1, ARG-2, iNOS, VIP, VIP-R1, TAC, and TAC-R1. A total of 98 biopsies were evaluated, including of 53 keloid and 45 normal scars. The age of patients with keloids ranged from 11 to 73 years, with a mean age of 28 years and predominance of the female gender (58.5% of the total patients). Around 64.15% of the patients belonged to the black ethnic group. Evaluated keloids were most commonly located in the earlobe because of ear piercing, representing 73.6% of the cases. We found significantly greater expression of TGF-β, IL-22, and ARG-1 in keloids when compared with that in normal scars. As for IL-33, ARG-2, and VIP-R1, despite the higher number of mRNA copies found in keloids, this difference was not significant. Furthermore, FGF, iNOS, VIP, TAC, and TAC-R1 mRNA levels were not detectable, and therefore these results were inconclusive in this study. Considering these results, understanding the cellular and molecular mechanisms that control the inflammatory response during cutaneous healing may promote the development of strategies to improve the treatment of patients with keloids.

Pathophysiologic Mechanisms and Current Treatments for Cutaneous Sequelae of Burn Wounds

Burn injuries are a pervasive clinical problem. Extensive thermal trauma can be life-threatening or result in long-lasting complications, generating a significant impact on quality of life for patients as well as a cost burden to the healthcare system. The importance of addressing global or systemic issues such as resuscitation and management of inhalation injuries is not disputed but is beyond the scope of this review, which focuses on cutaneous pathophysiologic mechanisms for current treatments, both in the acute and long-term settings. Pathophysiological mechanisms of burn progression and wound healing are mediated by highly complex cascades of cellular and biochemical events, which become dysregulated in slow-healing wounds such as burns. Burns can result in fibroproliferative scarring, skin contractures, or chronic wounds that take weeks or months to heal. Burn injuries are highly individualized owing to wound-specific differences such as burn depth and surface area, in addition to patient-specific factors including genetics, immune competency, and age. Other extrinsic complications such as microbial infection can complicate wound healing, resulting in prolonged inflammation and delayed re-epithelialization. Although mortality is decreasing with advancements in burn care, morbidity from postburn deformities continues to be a challenge. Optimizing specialized acute care and late burn outcome intervention on a patient-by-patient basis is critical for successful management of burn wounds and the associated pathological scar outcome. Understanding the fundamentals of integument physiology and the cellular processes involved in wound healing is essential for designing effective treatment strategies for burn wound care as well as development of future therapies. Published 2018. Compr Physiol 8:371-405, 2018.

Treatment of Keloids With Excision and Adjuvant Radiation: A Single Center Experience and Review of the Literature

BACKGROUND

Management of keloids has remained a conundrum, because an optimum treatment regimen has yet to be elucidated. Currently, treatment varies widely between more conservative measures, such as steroid injections, topical medications, and silicone sheeting, to more aggressive options, such as surgery and postoperative radiation. The latter combination has been touted to have superior results, with the lowest rates of pathologic scar recurrence.

METHODS

We performed a retrospective review to critically evaluate the effectiveness of surgical excision and radiation treatment in patients with keloids. Surgical resection of surgeon-selected keloids, combined with state-of-the-art postoperative cutaneous radiation therapy, was used at a major tertiary referral center. For patients with poor follow-up, phone calls were made to determine recurrence. In addition, we present a review of the current literature to provide a comprehensive synopsis of current keloid treatment.

RESULTS

A total of 69 patients' records were reviewed. There were a total of 84 keloids upon pathology review. The overall recurrence rate for all keloids was 27%, and in those followed greater than 1 year, recurrence for keloids was 74%. About half the patients with more than 1 year of follow-up experienced recurrence more than 1 year after treatment.

CONCLUSIONS

At this time, the evidence supporting surgery and radiation for the treatment of keloids remains equivocal, and randomized controlled studies are needed to determine the efficacy of this treatment protocol. Most importantly, our data reinforce the need for long-term follow-up in this patient population.

A pregnant patient with fetal distress with severe post burn contracture of anterior trunk and perineum: A surgeon's nightmare!

Introduction:

A case report of a pregnant lady in the third trimester, presenting in the emergency with absent fetal movements is being described. A multi-speciality expertise was involved and a full term female baby was delivered.

Presentation:

The patient presented in a Government hospital, Dehradun, India. At the time of presentation the fetal heart sounds were absent and subsequently the severe post-burn deformity involving the anterior trunk, perineum and thighs were discovered.

Management:

Immediately a multi-speciality approach involving the plastic, obstetrics and pediatrics field were called for and an emergency caesarean with simultaneous contracture release with split skin grafts were performed after optimizing the patient for surgery.

Conclusion:

This is one of the first case reports reporting this rare combination of post burn contracture of trunk and perineum with fetal distress requiring emergency caesarean section along with release of abdominal and perineal post-burn contracture. This case interestingly reinforces that in such complicated cases a systematic and a combined multi-speciality approach still holds the key to patient's treatment even in district hospitals.

Identification of biomarkers involved in differential profiling of hypertrophic and keloid scars versus normal skin

Among raised dermal scar types, keloid (KS) and hypertrophic scars (HS) are considered to present clinical similarities, but there are no known specific biomarkers that allow both scar types to be easily distinguished. Development and progression of raised dermal scars comprises the activation of several molecular pathways and cell defence mechanisms leading to elevated extracellular matrix component synthesis, delayed apoptosis, altered migration and differentiation. Therefore, the aim here was to identify biomarkers that may differentiate between KS and HS compared to normal skin (NS). To achieve this aim, NS (n = 14), KS (n = 14) and HS (n = 14) biopsies were evaluated using histology by H&E staining. Tissue biopsies and primary fibroblasts (passages 0-4) were employed to assess the gene expression levels of 21 biomarkers selected from our previous microarray studies using qRT-PCR. Finally, protein expression was evaluated using In-Cell Western Blotting in primary fibroblasts (p 0-4). Our results demonstrated that out of the 21 biomarkers screened at mRNA and protein levels, α2β1-integrin, Hsp27, PAI-2, MMP-19 and CGRP showed significantly higher expression (p < 0.05) in KS compared to NS and HS. Additionally, these five key biomarkers were found to be significantly higher (p < 0.05) at mRNA level in KS taken from the sternum, a region known to be subjected to high mechanical forces in the body during the performance of daily movements. In conclusion, our findings offer potential molecular targets in raised dermal scars differentiation. Future targeted research may allow provision of diagnostic and prognostic markers in keloid versus hypertrophic scars.

Pathological niche environment transforms dermal stem cells to keloid stem cells: a hypothesis of keloid formation and development

Keloid is a disease that is difficult to cure because of its high recurrence rate after chemotherapy or radiotherapy, therefore it is considered as a benign skin tumor. Tumor stem cells are proposed as the source for tumor development and post-therapy recurrence. Interestingly, keloid stem cells have also been discovered, which share some characters with those of skin progenitor cells. Keloid patients possess specific diathesis including genetic predisposition and gene mutation, abnormal levels of hormones, growth factors and cytokines, and strong inflammatory response. This article reviews related literatures and hypothesizes that keloid stem cells might be transformed from normal dermal progenitor cells in the pathological niche of keloid tissues. These keloid stem cells are highly self-renewal and drug resistant, and can sustain themselves by asymmetric division, and continually generate new keloid cells to replenish the cells killed by drugs or radiation, thus leading to over growth of keloid and high post-therapy recurrence rate.

Pharmacological treatment for keloids

INTRODUCTION

Keloids are fibroproliferative disorders that are characterized by histological accumulation of collagens and fibroblasts, refractory clinical symptoms such as itching, topical invasiveness, and frequent postsurgical recurrence. At present, to treat or prevent keloids, new drugs are currently being designed and the pharmaceutical indications of known drugs are being expanded.

AREAS COVERED

The current pharmacological interventions for keloids are mainly described on the basis of the various hypotheses on keloid etiology and the keloid ingredients that are targeted. These interventions include angiotension-converting enzyme inhibitors and calcium-channel blockers (based on hypertension hypothesis), selective estrogen receptor modulator (based on endocrinological hypothesis), vitamins and essential fatty acids (based on immunonutritional hypothesis), and transglutaminase inhibitor (based on metabolic hypothesis). Drugs that directly target the reduction or destruction of the major extracellular matrix or cellular constituents of keloids are also included. Besides, drugs that indirectly modulate the biochemical microenvironment are described. These include growth factors, immunomodulators, and anti-inflammation and anti-allergy drugs.

EXPERT OPINION

Due to the unclear etiology of keloids and the lack of animal models, efficient, reliable, and specific pharmaceutical interventions for keloids continue to be lacking. The reliability of current data and clinical observations must be strengthened by large-scale, randomized, controlled clinical trials.

Psychological stress as a risk factor for postoperative keloid recurrence

OBJECTIVE

To investigate psychological stress on the prognosis of the postoperative recurrence of keloids.

METHODS

Patients with keloids (n=25), candidates for surgical resection and postoperative radiotherapy, had their psychological stress evaluated on the day before the surgical procedure. The parameters evaluated were pain and itching (Visual Numerical Scale), quality of life (Questionnaire QualiFibro/Cirurgia Plástica-UNIFESP), perceived stress (Perceived Stress Scale), depression and anxiety (Hospital Depression and Anxiety Scale), salivary cortisol and minimum and maximum galvanic skin responses (GSR) at rest and under stress (i.e., while the questionnaires were being filled out). Patients were evaluated during the 3rd, 6th, 9th and 12th months of postoperative care. During each return visit, two experts classified the lesions as non-recurrent and recurrent.

RESULTS

The recurrence group presented the greatest values in GSR during a stressful situation. The chance of recurrence increased by 34% at each increase of 1000 arbitrary units in maximum GSR during stress.

CONCLUSION

Psychological stress influenced the recurrence of keloids.

Hypertrophic scarring and keloids: pathomechanisms and current and emerging treatment strategies

Excessive scars form as a result of aberrations of physiologic wound healing and may arise following any insult to the deep dermis. By causing pain, pruritus and contractures, excessive scarring significantly affects the patient's quality of life, both physically and psychologically. Multiple studies on hypertrophic scar and keloid formation have been conducted for decades and have led to a plethora of therapeutic strategies to prevent or attenuate excessive scar formation. However, most therapeutic approaches remain clinically unsatisfactory, most likely owing to poor understanding of the complex mechanisms underlying the processes of scarring and wound contraction. In this review we summarize the current understanding of the pathophysiology underlying keloid and hypertrophic scar formation and discuss established treatments and novel therapeutic strategies.

Keloid scarring: bench and bedside

Wound healing is a fundamental complex-tissue reaction leading to skin reconstitution and thereby ensuring survival. While, fetal wounds heal without scarring, a normal "fine line" scar is the clinical outcome of an undisturbed wound healing in adults. Alterations in the orchestrated wound healing process result in hypertrophic or keloid scarring. Research in the past decades attempted to identify genetic, cellular, and molecular factors responsible for these alterations. These attempts lead to several new developments in treatments for keloids, such as, imiquimod, inhibition of transforming growth factor beta, and recombinant interleukin-10. The urgent need for better therapeutics is underlined by recent data substantiating an impaired quality of life in keloid and hypertrophic scar patients. Despite the increasing knowledge about the molecular regulation of scar formation no unifying theory explaining keloid development has been put forward until today. This review aims to give an overview about the genetic and molecular background of keloids and focus of the current research on keloid scarring with special emphasis on new forthcoming treatments. Clinical aspects and the spectrum of scarring are summarized.

The hormonal regulation of cutaneous wound healing

Conditions of impaired wound healing in the elderly are associated with substantial morbidity and mortality and impose a significant financial burden upon the world's health services. The findings of a series of recent studies have served to highlight the contrasting contributions made by sex steroid hormones to the regulation of cutaneous repair processes. Although estrogens accelerate healing, the actions of the "male" sex hormones 5alpha-dihydrotestosterone and testosterone are primarily deleterious. The shift that occurs in the balance between serum estrogen and androgen levels as a normal feature of human aging may therefore have important consequences for fundamental tissue repair processes.

Characteristics of occurrence for Han Chinese familial keloids

AIM

To elucidate the characteristics of occurrence for Han Chinese familial keloids.

METHOD

To find out their common characteristics of occurrence by studying the clinical and genetic information of six Han Chinese pedigrees with familial keloids with all the family members having no recorded marriage history to other races except Han people.

RESULT

Most of these familial keloids occur spontaneously during puberty, often displaying symmetrically at chest, back and shoulder with respective specific shapes, presenting with variable clinical expression and incomplete clinical penetrance and showing the characteristics of an autosomal dominant mode of inheritance with reduced penetrance.

CONCLUSION

These Han Chinese familial keloids present with many similar characteristics of occurrence differing from those of sporadic cases. The pattern of inheritance observed in these Han Chinese pedigrees with familial keloids is consistent with an autosomal dominant mode with incomplete clinical penetrance and variable expression.

Upregulation of transforming growth factor-beta1 and vascular endothelial growth factor in cultured keloid fibroblasts: relevance to angiogenic activity

Keloids are tumor-like lesions that result from excessive scar formation during healing of wounds. Histologically, keloids show an increased blood vessel density compared with normal dermis or normal scars. However, the angiogenic activity of keloid fibroblasts remains unknown. In this study, we investigated angiogenic activity of keloid fibroblasts. Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor (VEGF) were investigated as elements of the angiogenic factors. Expressions of TGF-beta1 and VEGF in conditioned medium were measured with enzyme-linked immunosorbent assay (EIA) and Northern blot analysis. Participation of TGF-beta1 in the production of VEGF was also investigated with addition of TGF-beta1 and a neutralizing anti-TGF-beta1 antibody. A modified Boyden chamber assay was performed to assess the chemotactic activity of vascular endothelial cells. Angiogenic activity in vivo was evaluated by neovascularization of nodules formed by implantation of fibroblasts into severe combined immunodeficiency (SCID) mice. EIA showed that the concentrations of TGF-beta1 and VEGF in conditioned medium were increased 2.5- and 6-fold, respectively, after the culture of keloid fibroblasts compared with normal fibroblasts. Northern blot analysis revealed that the expression of TGF-beta1 and VEGF mRNA was upregulated 3.6- and 6-fold, respectively, in keloid fibroblasts compared with normal fibroblasts. Addition of TGF-beta1 to keloid fibroblast cultures increased VEGF production by 3.5-fold, while there was a 6-fold in culture of normal fibroblasts. A neutralizing anti-TGF-beta1 antibody reduced VEGF secretion to control levels, suggesting that TGF-beta1 mediated the upregulation of VEGF expression. A modified Boyden chamber assay demonstrated that the chemotactic activity of vascular endothelial cells was more strongly (sevenfold) induced by keloid fibroblast-conditioned medium than by normal fibroblast-conditioned medium. Anti-VEGF antibody inhibited chemotaxis to basal levels. When SCID mice underwent implantation of fibroblasts into the back, the nodules formed by keloid fibroblasts were three times larger than those formed by normal fibroblasts. Although abundant neovascularization was observed in keloid fibroblast nodules, neovascularization was scarce in normal fibroblast nodules. Both in vitro and in vivo studies confirmed the significantly higher angiogenic activity of keloid fibroblasts compared with normal fibroblasts, and TGF-beta1 and VEGF were clearly shown to be involved. These results suggest that angiogenesis in keloids is promoted by endogenous TGF-beta1 and VEGF.

Keloid heterograft in the hamster (Mesocricetus auratus) cheek pouch

PURPOSE: To study the integration of keloid heterograft in hamster (Mesocricetus auratus) cheek pouch. METHODS: The sample is formed by 18 male hamsters, heterogenic ones, aged between 10 and 14 weeks. Keloid fragments were obtained from keloid scars of the breast region of adult female mulatto patient. Each hamster received keloid fragments into both of its pouches, in a total of 36 grafted fragments. Animals were distributed into 6 groups for having their grafts assessed in the days 5, 12, 21, 42, 84, and 168. A macroscopic assessment is performed by comparing the pouch containing the grafted fragment, at each time point, with the same pouch in the immediate post surgical moment through a comparison of standardized photographs. Under microscope, the presence of blood vases is considered within the conjunctive tissue of the grafted fragment, as a criterion of its integration. Other events, as keratin secretion, the presence of cellular infiltrated, epithelium and keloid collagen fibers aspects are also analyzed. RESULTS: Macroscopy reveals intensive vascularization of the pouch up to 12 days from the transplantation and the presence of constant dark brown pigmentation on the grafted keloid fragments. In microscopy, the integration of keloid fragments is considered by the presence of blood capillary vases within conjunctive tissue. The presence of intensive cellular inflammatory type infiltrated up to 12 days is also observed, as well as the remaining of keloid epithelium up to 21 days, and the appearing of melanocytes from the day 42. CONCLUSION: Hamster cheek pouch represents, a priori, an experimental model for the investigation of keloid.

Keloids - clinical diagnosis, pathogenesis, and treatment options. Keloide - klinische Diagnose, Pathogenese und Behandlungsoptionen

Keloids are defined as excessive scar tissue formation extending beyond the area of the original skin injury and occurring in predisposed individuals. They are considered to be a result of abnormal wound healing. The pathogenetic mechanisms that cause keloids remain unknown. Experiments with cells derived from keloid tissue revealed a number of abnormalities in cellular functions, such as in proliferation, apoptosis, or expression of growth factors and extracellular matrix proteins. Furthermore, several studies have reported altered keratinocyte-fibroblast interactions in keloids. Despite the diverse pathological changes in cellular functions and expression profiles of cells derived from keloid tissue, recent genetic studies have provided evidence that single genes may act as major regulators of keloid formation. We provide an overview of the pathogenetic mechanisms of keloid formation in the context of their clinical characteristics and current therapeutic approaches.

Investigação do transplante heterólogo de quelóide na bolsa jugal do hamster (Mesocricetus auratus)

OBJETIVO: Descrever a integração do transplante heterólogo de quelóide no subepitélio da bolsa jugal do hamster (Mesocricetus auratus). MÉTODOS: A amostragem consiste de 18 hamsters machos, não isogênicos, com 10 a 14 semanas de idade. Fragmentos de quelóide foram obtidos de cicatrizes queloideanas da região mamária de paciente adulta parda. Cada hamster foi enxertado em ambas as bolsas com fragmentos de quelóide, totalizando 36 fragmentos enxertados. Os animais foram distribuídos, em 6 grupos, para exame dos fragmentos enxertados com 5, 12, 21, 42, 84 e 168 dias. Uma avaliação macroscópica é realizada comparando a bolsa contendo o fragmento enxertado em cada período com a mesma bolsa no pós-operatório imediato, mediante a comparação de fotografias padronizadas. À microscopia, considera-se a presença de vasos sangüíneos no tecido conjuntivo do fragmento enxertado como critério de integração do mesmo. Outros eventos, como secreção de queratina, presença de infiltrados celulares e aspecto do epitélio e das fibras colágenas do quelóide, também são observados. RESULTADOS: A macroscopia revela intensa vascularização na bolsa até 12 dias de enxertia, e a presença constante de pigmentação castanho-escura nos fragmentos de quelóide enxertados. Na microscopia constata-se a integração dos fragmentos de quelóide pela presença de capilares sangüíneos no tecido conjuntivo. Observa-se, também, a presença de intenso infiltrado celular do tipo inflamatório até 12 dias, a permanência do epitélio do quelóide até 21 dias, e o aparecimento de melanócitos a partir de 42 dias. CONCLUSÃO: A bolsa jugal do hamster representa, a priori, modelo experimental para investigação do quelóide.