Dupuytren's disease. The way forward?

Scarring and Skin Fibrosis Reversal with Regenerative Surgery and Stem Cell Therapy

Skin scarring and fibrosis affect millions of people worldwide, representing a serious clinical problem causing physical and psychological challenges for patients. Stem cell therapy and regenerative surgery represent a new area of treatment focused on promoting the body's natural ability to repair damaged tissue. Adipose-derived stem cells (ASCs) represent an optimal choice for practical regenerative medicine due to their abundance, autologous tissue origin, non-immunogenicity, and ease of access with minimal morbidity for patients. This review of the literature explores the current body of evidence around the use of ASCs-based regenerative strategies for the treatment of scarring and skin fibrosis, exploring the different surgical approaches and their application in multiple fibrotic skin conditions. Human, animal, and in vitro studies demonstrate that ASCs present potentialities in modifying scar tissue and fibrosis by suppressing extracellular matrix (ECM) synthesis and promoting the degradation of their constituents. Through softening skin fibrosis, function and overall quality of life may be considerably enhanced in different patient cohorts presenting with scar-related symptoms. The use of stem cell therapies for skin scar repair and regeneration represents a paradigm shift, offering potential alternative therapeutic avenues for fibrosis, a condition that currently lacks a cure.

Biological Targets for Dupuytren Disease

ABSTRACT

Dupuytren disease is a connective tissue disorder occurring on the palm, causing flexion contractures of fingers. There is a pressing need for therapeutic interventions that can slow, stop, or even incrementally reverse the progression of the disease. Numerous in vitro studies have shed light on cellular and molecular agents that contribute to contractures. This article comprehensively reviews various growth factors that can be targeted to prevent and limit the progression and recurrence of Dupuytren contracture (DC). Fibroblasts are the major cell population that has been reported for the contractures in DC, and they are also known to exacerbate the cytokine production. Limiting the fibroblast function by targeting the growth factor production will be of great benefit in treating DC. This review will focus on the studies that have shown to limit the exaggerated function of fibroblasts by reducing the expression of profibrotic growth factors by using antagonizing agents.

Basics of Radiation Biology When Treating Hyperproliferative Benign Diseases

For decades, low- and moderate-dose radiation therapy (RT) has been shown to exert a beneficial therapeutic effect in a multitude of non-malignant conditions including painful degenerative muscoloskeletal and hyperproliferative disorders. Dupuytren and Ledderhose diseases are benign fibroproliferative diseases of the hand/foot with fibrotic nodules and fascial cords, which determine debilitating contractures and deformities of fingers/toes, while keloids are exuberant scar formations following burn damage, surgery, and trauma. Although RT has become an established and effective option in the management of these diseases, experimental studies to illustrate cellular composites and factors involved remain to be elucidated. More recent findings, however, indicate the involvement of radiation-sensitive targets like mitotic fibroblasts/myofibroblasts as well as inflammatory cells. Radiation-related molecular mechanisms affecting these target cells include the production of free radicals to hamper proliferative activity and interference with growth factors and cytokines. Moreover, an impairment of activated immune cells involved in both myofibroblast proliferative and inflammatory processes may further contribute to the clinical effects. We here aim at briefly describing mechanisms contributing to a modulation of proliferative and inflammatory processes and to summarize current concepts of treating hyperproliferative diseases by low and moderate doses of ionizing radiation.

Epidermal Growth Factor Receptor (EGF-R) in Dupuytren’s Disease

The aim of this paper was to examine participation of the epidermal growth factor receptor (EGF-R) signal pathway in the pathogenesis of Dupuytren’s disease. The study showed changes in the ratio of membrane EGF-R to its intracellular level during the different clinical stages of Dupuytren’s contracture progression. Our observations of a high ratio of surface to intracellular EGF-R in the palmar aponeurosis of patients with second degree of Dupuytren’s disease (Iselin’s classification), which was significantly higher than this ratio in control palmar fascia ( P = 0.022), would suggest that EGF-R has a role in the involutional phase of the disease.

The Genetic Basis of Peyronie Disease: A Review

INTRODUCTION

Peyronie disease (PD) is a progressive fibrotic disorder of the penile tunica albuginea that results in fibrotic penile plaques and can lead to penile deformity. Characterized by aberrant fibrosis resulting in part from the persistence of myofibroblasts and altered gene expression, the molecular factors underpinning PD and other related fibrotic diatheses are just being elucidated. A genetic link to PD was first identified three decades ago using pedigree analyses. However, the specific genetic factors that predispose patients to aberrant fibrosis remain unknown, and the relations between these fibrotic conditions and other heritable diseases, including malignancy, are uncharacterized.

AIM

To review the current landscape linking molecular and genetic factors to aberrant fibrosis in PD and related fibrotic diatheses, including Dupuytren disease.

METHODS

Review and evaluation of the literature from 1970 to the present for genetic factors associated with PD were performed.

MAIN OUTCOME MEASURES

Data describing the genetic factors associated with PD were obtained.

RESULTS

We describe the known structural chromosomal abnormalities and single-nucleotide polymorphisms associated with fibrotic diatheses and discuss the spectrum of differential gene expression data comparing normal tissues with those derived from men with PD or Dupuytren disease. We discuss epigenetic mechanisms that might regulate gene expression and alter predisposition to fibrosis.

CONCLUSION

Although the current understanding of the genetic factors associated with PD is limited, significant advances have been made during the past three decades. Further research is necessary to provide a more comprehensive understanding of the landscape of genetic factors responsible for the development of PD.

Radiotherapy in fascial fibromatosis: a case series, literature review and considerations for treatment of early-stage disease

INTRODUCTION

Palmar and plantar fascial fibromatoses are benign hyperproliferative disorders of the deep fascia of the palm and sole. This study seeks to examine the role of radiotherapy in the management of fascial fibromatosis.

METHOD

Six consecutive cases of early-stage fascial fibromatosis treated with radiotherapy at the Adelaide Radiotherapy Centre between July 2008 and May 2011 were analysed. The results of the case series were compared with a systematic review of the literature.

RESULTS

All six cases regressed or showed a reduction of symptoms following radiotherapy. Treatment was well tolerated with minor toxicities. Median follow-up for the case series was 38.5 months. The systematic review identified seven studies describing the use of radiotherapy as primary treatment for fascial fibromatosis between 1946 and 2013. The literature indicates that radiotherapy can prevent disease progression and improve symptoms for early-stage disease, with low likelihood of significant toxicities.

CONCLUSION

Early results from our case series are consistent with the literature, showing that radiotherapy can provide an effective management option for patients with early-stage fascial fibromatosis, and justify consideration of radiotherapy as a primary treatment for early-stage disease.

Expression of VEGF, its receptors, and HIF-1α in Dupuytren's disease

BACKGROUND AND PURPOSE

Dupuytren's disease (DD) is a benign fibroproliferative process that affects the palmar fascia. The pathology of DD shows similarities with wound healing and tumor growth; hypoxia and angiogenesis play important roles in both. We investigated the role of angiogenic proteins in DD.

PATIENTS AND METHODS

The expression of vascular endothelial growth factor (VEGF), its receptors vascular endothelial growth factor receptor 1 (VEGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2), hypoxia-inducible factor alfa (HIF-1α), and alfa-smooth muscle actin (α-SMA) were analyzed immunohistochemically in fragments of excised Dupuytren's tissue from 32 patients. We compared these values to values for expression in a control group.

RESULTS

15 of 32 samples could be attributed to the involutional phase (α-SMA positive), whereas 17 samples were considered to be cords at the residual phase (α-SMA negative). In the involutional phase, the HIF-1α and VEGFR2 expression was statistically significantly higher than in the residual phase and in the controls.

INTERPRETATION

Both the VEGFR2 receptor and HIF-1α were expressed in α-SMA positive myofibroblast-rich nodules with characteristics of DD in the active involutional phase. Thus, hypoxia and (subsequently) angiogenesis may have a role in the pathophysiology of DD.

Dupuytren's: a systems biology disease

Dupuytren's disease (DD) is an ill-defined fibroproliferative disorder of the palm of the hands leading to digital contracture. DD commonly occurs in individuals of northern European extraction. Cellular components and processes associated with DD pathogenesis include altered gene and protein expression of cytokines, growth factors, adhesion molecules, and extracellular matrix components. Histology has shown increased but varying levels of particular types of collagen, myofibroblasts and myoglobin proteins in DD tissue. Free radicals and localised ischaemia have been suggested to trigger the proliferation of DD tissue. Although the existing available biological information on DD may contain potentially valuable (though largely uninterpreted) information, the precise aetiology of DD remains unknown. Systems biology combines mechanistic modelling with quantitative experimentation in studies of networks and better understanding of the interaction of multiple components in disease processes. Adopting systems biology may be the ideal approach for future research in order to improve understanding of complex diseases of multifactorial origin. In this review, we propose that DD is a disease of several networks rather than of a single gene, and show that this accounts for the experimental observations obtained to date from a variety of sources. We outline how DD may be investigated more effectively by employing a systems biology approach that considers the disease network as a whole rather than focusing on any specific single molecule.

Reactive oxygen and nitrogen species induce protein and DNA modifications driving arthrofibrosis following total knee arthroplasty

Background

Arthrofibrosis, occurring in 3%-4% of patients following total knee arthroplasty (TKA), is a challenging condition for which there is no defined cause. The hypothesis for this study was that disregulated production of reactive oxygen species (ROS) and nitrogen species (RNS) mediates matrix protein and DNA modifications, which result in excessive fibroblastic proliferation.

Results

We found increased numbers of macrophages and lymphocytes, along with elevated amounts of myeloperoxidase (MPO) in arthrofibrotic tissues when compared to control tissues. MPO expression, an enzyme that generates ROS/RNS, is usually limited to neutrophils and some macrophages, but was found by immunohistochemistry to be expressed in both macrophages and fibroblasts in arthrofibrotic tissue. As direct measurement of ROS/RNS is not feasible, products including DNA hydroxylation (8-OHdG), and protein nitrosylation (nitrotyrosine) were measured by immunohistochemistry. Quantification of the staining showed that 8-OHdg was significantly increased in arthrofibrotic tissue. There was also a direct correlation between the intensity of inflammation and ROS/RNS to the amount of heterotopic ossification (HO). In order to investigate the aberrant expression of MPO, a real-time oxidative stress polymerase chain reaction array was performed on fibroblasts isolated from arthrofibrotic and control tissues. The results of this array confirmed the upregulation of MPO expression in arthrofibrotic fibroblasts and highlighted the downregulated expression of the antioxidants, superoxide dismutase1 and microsomal glutathione S-transferase 3, as well as the significant increase in thioredoxin reductase, a known promoter of cell proliferation, and polynucleotide kinase 3'-phosphatase, a key enzyme in the base excision repair pathway for oxidative DNA damage.

Conclusion

Based on our current findings, we suggest that ROS/RNS initiate and sustain the arthrofibrotic response driving aggressive fibroblast proliferation and subsequent HO.

The fascia of the limbs and back--a review

Although fasciae have long interested clinicians in a multitude of different clinical and paramedical disciplines, there have been few attempts to unite the ensuing diverse literature into a single review. The current article gives an anatomical perspective that extends from the gross to the molecular level. For expediency, it deals only with fascia in the limbs and back. Particular focus is directed towards deep fascia and thus consideration is given to structures such as the fascia lata, thoracolumbar fascia, plantar and palmar fascia, along with regional specializations of deep fascia such as retinacula and fibrous pulleys. However, equal emphasis is placed on general aspects of fascial structure and function, including its innervation and cellular composition. Among the many functions of fascia considered in detail are its ectoskeletal role (as a soft tissue skeleton for muscle attachments), its importance for creating osteofascial compartments for muscles, encouraging venous return in the lower limb, dissipating stress concentration at entheses and acting as a protective sheet for underlying structures. Emphasis is placed on recognizing the continuity of fascia between regions and appreciating its key role in coordinating muscular activity and acting as a body-wide proprioceptive organ. Such considerations far outweigh the significance of viewing fascia in a regional context alone.

Keloid scarring, but not Dupuytren's contracture, is associated with unexplained carotid atherosclerosis

BACKGROUND

Atherosclerosis, a response to injury, may be thought of as scarring in the artery wall. TGF-beta and associated signaling molecules have been implicated in the pathophysiology of keloid scarring, Dupuytren's Contracture and atherosclerotic plaques in independent studies.

PURPOSE

To test the hypothesis that excess cutaneous scarring and Dupuytren's contractures predispose independently to carotid atherosclerosis .

METHODS

Among 1,747 patients with plaque measurements and complete data for multivariable regression analysis, 57 Caucasian patients had Dupuytren's contractures and 12 had keloid scars. Carotid total plaque area (TPA) was measured by 2-Dimensional ultrasound.

RESULTS

In linear multivariable regression analysis with coronary risk factors, keloid scars were associated with TPA (P= 0.018), but Dupuytren's contractures were not. Patients with keloid scarring were younger (P < 0.0001), and more likely to be diabetic (P < 0.0001)

CONCLUSIONS

Keloid scarring is a clinical clue to excess atherosclerosis not explained by traditional risk factors. Such patients may benefit from therapy directed at targets related to signalling molecules common to both the process of keloid scarring and atherosclerosis. These findings suggest previously unexplored possibilities for the prevention and treatment of atherosclerosis. The differences between Dupuytren's and keloid scars that may identify such targets are discussed.

Matrix metalloproteinase inhibition reduces contraction by dupuytren fibroblasts

PURPOSE

Dupuytren's disease is a common fibroproliferative condition of the hand characterized by fibrotic lesions (nodules and cords), leading to disability through progressive digital contracture. Although the etiology of the disease is poorly understood, recent evidence suggests that abnormal matrix metalloproteinase (MMP) activity may play a role in cell-mediated collagen contraction and tissue scarring. The aim of this study was to investigate the efficacy of ilomastat, a broad-spectrum MMP inhibitor, in an in vitro model of Dupuytren fibroblast-mediated contraction.

METHODS

Nodule-derived and cord-derived fibroblasts were isolated from Dupuytren patients; carpal ligament-derived fibroblasts acted as control. Stress-release fibroblast-populated collagen lattices (FPCLs) were used as a model of contraction. FPCLs were allowed to develop mechanical stress (48 hours) during treatment with ilomastat (0-100 micromol/L), released, and allowed to contract over a 48-hour period. Contraction was estimated by measuring lattice area compared with untreated cells or treatment with a control peptide. MMP-1, MMP-2, and MT1-MMP levels were assessed by zymography, Western blotting, and enzyme-linked immunosorbent assay.

RESULTS

Nodule-derived fibroblasts contracted lattices (69% +/- 2) to a greater extent than did cord-derived (55% +/- 3) or carpal ligament-derived (55% +/- 1) fibroblasts. Exposure to ilomastat led to significant inhibition of lattice contraction by all fibroblasts, although a reduction in lattice contraction by nodule-derived fibroblasts was most prominent (84% +/- 8). In addition, treatment with ilomastat led to a concomitant suppression of MMP-1 and MMP-2 activity, whereas MT1-MMP activity was found to be upregulated.

CONCLUSIONS

Our results demonstrate that inhibition of MMP activity results in a reduction in extracellular matrix contraction by Dupuytren fibroblasts and suggest that MMP activity may be a critical target in preventing recurrent contracture caused by this disease.

The expression of myoglobin and ROR2 protein in Dupuytren's disease

BACKGROUND

Dupuytren's disease (DD) is a hand disease inherited as an autosomal dominant trait with variable penetrance, especially among populations of northern European ancestry. The etiology and pathophysiology of DD are not clear. The purpose of this study was to examine the gene expression profiles of palmar fascia of DD and healthy patients using microarray analysis to highlight the genes that might contribute to the pathogenesis of DD.

MATERIALS AND METHODS

Dupuytren contracture samples were taken from excised mature cords of DD patients during aponeurectomies. Control samples were collected from healthy hand trauma patients. Microarray analysis was performed with the Affymetrix HGU133A genome array (Affymetrix, Santa Clara, CA). Expression changes of selected proteins were confirmed at the protein level with Western and dot blotting or by immunohistochemistry.

RESULTS

At least an 8-fold change in gene expression was found with 127 genes, including a 90-fold down-regulation of myoglobin and a 14-fold up-regulation of tyrosine kinase-like orphan receptor 2 (= ROR2) from absent to present during the disease. The changes in myoglobin and ROR2 expression were confirmed at the protein level.

CONCLUSIONS

In this study, we showed for the first time the connection of ROR2 in Dupuytren's disease. ROR2 and myoglobin may play an important role in the pathophysiology of this disease.

Factors in the pathogenesis of Dupuytren's contracture

This article reviews the basic science elements involved in the pathogenesis of Dupuytren's disease. Dupuytren's contracture is effected by a multitude of complex processes at the cellular level and the exact relative contribution of each is unknown. Various investigators have proposed different theories and documented individual findings regarding the pathophysiology of Dupuytren's contracture. The current report attempts to summarize many of these findings together in a schema of pathogenesis.

Dupuytren's contracture; increased cellularity--proliferation, is there equality?

BACKGROUND

Dupuytren's disease is a chronic inflammatory process which causes contractures of the fingers by shortening and thickening the palmar fascia. During the proliferative phase, fibroblasts transform into myofibroblasts apparently under the influence of several different factors. The disease usually develops slowly, but in some patients it tends to develop aggressively. The pathogenesis of Dupuytren's disease remains unsolved. In this study, we analyzed some histological characteristics that seem to predict rapid recurrence.

MATERIAL AND METHODS

21 patients were divided into two groups. In 11 patients the disease was classified as aggressive because it had recurred within two years after an operation. In 10 cases it was non-aggressive, as no recurrence had been seen. Five control samples were taken from healthy palmar aponeurosis. The differences in cellularity, collagen, Ki-67, MSA, alpha-SMA and tenascin between the specimens were analyzed using immunohistochemistry.

RESULTS

Alpha-SMA and Ki-67 were present more often in the aggressive specimens. Immunohistochemical stainings for macrophages and lymphocytes were negative.

CONCLUSION

There may be differences in the histology and/or immunohistochemical appearance of pathological palmar connective tissue cords in aggressive and normal Dupuytren's disease. Further studies are needed to elucidate the pathogenesis of this disease.

Comparison of gene expression profiles between Peyronie's disease and Dupuytren's contracture

OBJECTIVES

To compare the gene expression alterations in human Peyronie's disease (PD) and Dupuytren's disease (DD) to determine whether they share a common pathophysiology. Multiple mRNA expression profiles of human PD have previously shown that genes that regulate fibroblast replication, myofibroblast differentiation, collagen metabolism, tissue repair, and ossification are involved. DD, a palmar fascia fibrosis, may be associated with PD.

METHODS

Total RNA samples from PD plaques, normal tunica albuginea, Dupuytren's nodules, and normal palmar fascia (nine samples per group) were subjected to differential gene expression profile analysis (Clontech Atlas DNA microarray) comparing PD with tunica albuginea and DD with normal palmar fascia. Changes of more than 2.0 in PD and DD compared with tunica albuginea and normal palmar fascia, respectively, were recorded. Reverse transcriptase-polymerase chain reactions were performed for some genes whose expression was altered in PD.

RESULTS

Some of the gene families upregulated in both PD and DD were (a) collagen degradation: matrix metalloproteinase (MMP), with MMP2 and MMP9, and thymosins (MMP activators), with TMbeta10 and TMbeta4; (b) ossification: osteoblast-specific factors (OSFs) OSF-1 and OSF-2 (DD only); and (c) myofibroblast differentiation: RhoGDP dissociation inhibitor 1. The genes upregulated in PD only were decorin (an inhibitor of transforming growth factor-beta1 and a part of fibroblast replication/collagen synthesis) and early growth response protein. Reverse transcriptase-polymerase chain reaction confirmed these changes.

CONCLUSIONS

These data demonstrate that the pattern of alterations in the expression of certain gene families in PD and DD is similar, suggesting that they share a common pathophysiology and may be amenable to the same therapeutic regimens.

Vasoprotective VEGF as a candidate for prevention of recurrence of fibrotic diseases such as Dupuytren's contracture

Dupuytren's contracture is a disease caused by the proliferation of contractile, fibroblastic cells adjacent to the palmar fascia of the hand. Cellular proliferation is apparently related to similar 'fibroblast' proliferation in wound healing, but continues in the absence of wounding. I propose that this is a similar processes to that which happens in the vascular wall during vascular surgery, that the myofibroblasts are at least partially similar to smooth muscle cells in phenotype, and consequently that treatment with VEGF, either as protein or via gene therapy, which has proven successful in controlling aberrant, wounding-related cell proliferation in arterial grafting, may be valuable in preventing recurrence of Dupuytren's disease after surgery.

A clinical report of the effect of mechanical stress on functional results after fasciectomy for Dupuytren's contracture

Early postoperative treatment after Dupuytren's fasciectomy traditionally has included the application of mechanical stress to digital extension with splints and exercise. This study examines the effect of mechanical stress, which may compromise nutrient delivery to the tissues, on inflammation, flare, hypertrophic scar, digital range of motion (ROM), and therapy visits. The authors compared functional outcomes in operated digits treated postoperatively with tension applied (TA) and no tension applied (NTA), retrospectively from 1983 to 1993 (TA only) and prospectively from 1993 to 1999 (TA and NTA). The charts of 268 patients who underwent Dupuytren's fasciectomy were reviewed and divided into 2 groups (TA and NTA). Each case was analyzed with respect to age, sex, number of digits operated, postoperative management technique, therapy visits, metacarpophalangeal joint and proximal interphalangeal joint ROM, degree of flare, and scar. There were significant differences in ROM, scar formation, flare, and treatment time in favor of the NTA technique. The results indicate that postoperative management that prevents applied mechanical tension in the early phases of wound healing decreases complications after this surgery and that no digital motion is lost to extension with the NTA technique.

The effect of steroids on Dupuytren's disease: role of programmed cell death

This study compared the rates of proliferation and apoptosis of cells within nodules of Dupuytren's disease and nodules from patients that had been injected preoperatively with steroid (Depo-Medrone). It also compared the effects of steroids in apoptosis in cultured Dupuytren's cells and control fibroblasts from palmar fascia and fascia lata. Steroids reduced the rate of fibroblast proliferation and increased the rate of apoptosis of both fibroblasts and inflammatory cells in Dupuytren's tissue. Steroids also produced apoptosis of cultured Dupuytren's cells but not of palmar fascia and fascia lata cells.

Dupuytren's disease of the wrist

The authors present the case of a 47-year-old female who presents with bilateral Dupuytren's disease of the wrist. To date, three English language papers reporting on the occurrence of Dupuytren's disease at the wrist have been presented. These reports represent cases in males with unilateral involvement of their wrists where there has been primary Dupuytren's disease of the palm apparently spreading to the wrist in continuity. Our case demonstrates isolated bilateral Dupuytren's disease of the wrist in a female. The authors feel that this clinical presentation is rare and that consideration should be given to the diagnosis of Dupuytren's disease when there is a painful lesion of the soft tissues adjacent to the wrist. The presence of bilateral lesions at the wrist should further heighten the suspicion of Dupuytren's disease even in the absence of associated disease in the palm or fingers. A discussion of the previous reports is included.

Differences in alpha smooth muscle actin expression between fibroblasts derived from Dupuytren's nodules or cords

Dupuytren's contracture is a fibrotic lesion of the palmar fascia that includes two distinct structures, the nodule and the cord. Histologically the Dupuytren's nodule has a high cell density with numerous myofibroblasts (alpha smooth muscle actin-expressing fibroblasts). The Dupuytren's cord has a rich connective tissue matrix containing a low density of elongated spindle-shaped fibroblasts. The cytoskeletal structures of cultured fibroblasts derived from Dupuytren's nodules and cords of surgically treated patients were studied and compared. Immunohistology showed no obvious morphological differences between Dupuytren's nodule and cord cultured cells, when focal adhesions (vinculin), intermediate filaments (vimentin), microtubules (alpha tubulin), or microfilaments (filamentous actin) were viewed. However, a greater proportion of nodule cultured cells were positive for alpha smooth muscle actin compared to cord-derived cells. The increased expression in nodule cells of alpha smooth muscle actin was confirmed by Western blot analysis. It appears that fibroblasts derived from Dupuytren's nodules or cords retain in vivo cytoskeletal characteristics, when grown in tissue culture.

Langerhans cells in Dupuytren's contracture

We have examined biopsies of Dupuytren's contracture palmar fascia, overlying subcutis and skin, and have correlated the distribution of gross macroscopic changes in the hand, mapped pre- and intraoperatively, with light microscopic immunohistochemical findings. We report increased numbers of S100 positive Langerhans cells (an epidermal cell of dendritic lineage) and CD45 positive cells, both in "nodules" and at dermo-epidermal junctions, in the biopsied tissues. This suggests that Langerhans cells migrate from the epidermis into Dupuytren's contracture tissue, possibly in response to local changes in levels of inflammatory cytokines within the tissue. Our findings, together with other reports of increased numbers of dermal dendrocytes and inflammatory cells in Dupuytren's contracture tissue, lend circumstantial support to the "extrinsic theory" of the pathogenesis of Dupuytren's contracture. However, the earliest stages of the disease process have not been defined, and therefore the events which ultimately produce fibrosis in the palmar fascial complex in susceptible individuals could begin in the skin and/or within deeper tissues, especially where there is dysregulation of the immune system.