Fibronectin and the extracellular matrix in the perforating disorders of the skin

Novel insights into PORCN mutations, associated phenotypes and pathophysiological aspects

BACKGROUND

Goltz syndrome (GS) is a X-linked disorder defined by defects of mesodermal- and ectodermal-derived structures and caused by PORCN mutations. Features include striated skin-pigmentation, ocular and skeletal malformations and supernumerary or hypoplastic nipples. Generally, GS is associated with in utero lethality in males and most of the reported male patients show mosaicism (only three non-mosaic surviving males have been described so far). Also, precise descriptions of neurological deficits in GS are rare and less severe phenotypes might not only be caused by mosaicism but also by less pathogenic mutations suggesting the need of a molecular genetics and functional work-up of these rare variants.

RESULTS

We report two cases: one girl suffering from typical skin and skeletal abnormalities, developmental delay, microcephaly, thin corpus callosum, periventricular gliosis and drug-resistant epilepsy caused by a PORCN nonsense-mutation (c.283C > T, p.Arg95Ter). Presence of these combined neurological features indicates that CNS-vulnerability might be a guiding symptom in the diagnosis of GS patients. The other patient is a boy with a supernumerary nipple and skeletal anomalies but also, developmental delay, microcephaly, cerebral atrophy with delayed myelination and drug-resistant epilepsy as predominant features. Skin abnormalities were not observed. Genotyping revealed a novel PORCN missense-mutation (c.847G > C, p.Asp283His) absent in the Genome Aggregation Database (gnomAD) but also identified in his asymptomatic mother. Given that non-random X-chromosome inactivation was excluded in the mother, fibroblasts of the index had been analyzed for PORCN protein-abundance and -distribution, vulnerability against additional ER-stress burden as well as for protein secretion revealing changes.

CONCLUSIONS

Our combined findings may suggest incomplete penetrance for the p.Asp283His variant and provide novel insights into the molecular etiology of GS by adding impaired ER-function and altered protein secretion to the list of pathophysiological processes resulting in the clinical manifestation of GS.

Kyrle's disease in a patient of diabetes mellitus and chronic renal failure on dialysis

Kyrle's disease (KD) is an acquired perforating dermatosis associated with an underlying disorder such as diabetes mellitus or chronic renal failure. It presents as multiple discrete, eruptive papules with a central crust or plug, often on the lower extremities. A keratotic plug is seen histologically in an atrophic epidermis and may penetrate the papillary dermis with transepidermal elimination of keratotic debris without collagen or elastic fibers. Various therapies have been reported that include cryotherapy, laser therapy, narrow-band ultraviolet B and use of topical or systemic retinoids. Hereby a case of 64-year-old male, a known case of diabetes mellitus, hypertension and chronic renal failure who developed KD is presented.

Transepidermal elimination in cutaneous leishmaniasis: a multiregional study

BACKGROUND

Transepidermal elimination has been documented in a myriad of infectious diseases; however, its occurrence in cutaneous leishmaniasis has not been evaluated.

METHODS

Skin biopsies (n = 212) with cutaneous leishmaniasis in Lebanon (n = 46), Syria (n = 53), Saudi Arabia (n = 45) and Pakistan (n = 68) were evaluated. Clinical data collected included age, gender, eruption type (papule, nodule, verrucous or scar), duration and anatomic location. Histopathologically, multiple parameters were recorded including Ridley's parasitic index and pattern, transepidermal elimination, interface changes, ulceration and necrosis. Transepidermal elimination was defined as the presence of amastigotes in the epidermis in all layers, limited to the basal layer or present in a perforating plug. All cases were confirmed by polymerase chain reaction (PCR) analysis followed by restriction fragment length polymorphism analysis for molecular subspeciation.

RESULTS

Leishmania tropica was identified in 88.2% and Leishmania major in 11.8% of all cases. Transepidermal elimination was observed in 28.3% of cases (29 perforating plug, 19 all layers and 12 basal layer) with a significant prevalence of L. major in this group (35 vs. 2%, p < 0.001). Cases with transepidermal elimination were associated with interface changes and higher parasitic index (p < 0.001) but not with an increased ulceration rate (p > 0.05). Multivariate analysis showed that transepidermal elimination was independently predicted by L. major [OR (95% confidence interval) = 80 (9-712); p < 0.001], parasitic index [OR = 3.4 (2.1-5.3); p < 0.001], interface changes [OR = 6.24 (2.2-17.8); p < 0.001] and necrosis [OR = 0.2 (0.1-0.8);p = 0.026].

CONCLUSIONS

We report the largest multiregional cutaneous leishmaniasis series with a 28.3% documented transepidermal elimination incidence of which 48% were perforating plug; a significant prevalence of L. major was also identified in the transepidermal elimination group. The association of transepidermal elimination with interface changes and a higher parasitic index, without an increased ulceration rate, may reflect a unique biologic alteration in the epidermis, serving to facilitate the extrusion of the parasites through the skin.

Acquired reactive perforating collagenosis: current status

Acquired reactive perforating collagenosis is a unique perforating dermatosis, characterized clinically by umbilicated hyperkeratotic papules or nodules and histologically by a focal hyperkeratosis in direct contact with transepidermal perforating dermal collagen. Several inflammatory or malignant systemic diseases may coexist with acquired reactive perforating collagenosis. The possible biochemical or immunological mechanisms of the systemic diseases, potentially responsible for the development and appearance of acquired reactive perforating collagenosis, are still under investigation. Several topical treatments, ultraviolet B phototherapy and allopurinol p.o. administration may be effective.

Familial reactive perforating collagenosis

Background:

Reactive perforating collagenosis (RPC) is one of the rare forms of transepidermal elimination in which genetically altered collagen is extruded from the epidermis. This disease usually starts in early childhood as asymptomatic umbilicated papules on extremities, and the lesions become more conspicuous with age.

Aims:

The objective of our study was to determine the clinico-pathological features of RPC and the response to various treatment modalities.

Methods:

Ten patients of RPC, belonging to five different families, were studied clinically. Various laboratory investigations were carried out and diagnosis was made by histopathology of the lesions. Patients were given various topical and oral treatments.

Results:

RPC is familial in most cases without any definite inheritance pattern. It begins in childhood and the lesions are usually recurrent and become profuse and large with age. Systemic diseases have no role in the onset of lesions.

Conclusion:

Oral and topical retinoids in combination with emollients is the best treatment option.

Viral TNF inhibitors as potential therapeutics

The immune system functions by maintaining a delicate balance between the activities of pro-inflammatory and anti-inflammatory pathways. Unbalanced activation of these pathways often leads to the development of serious inflammatory diseases. TNF (Tumor Necrosis Factor) is a key pro-inflammatory cytokine, which can cause several inflammatory diseases when inappropriately up-regulated. Inhibition of TNF activities by using modulatory recombinant proteins has become a successful therapeutic approach to control TNF activity levels but these anti-TNF reagents also have risks and certain limitations. Biological molecules with a different mode of action in regulating TNF biology might provide a clinically useful alternative to the current therapeutics or in some cases might be efficacious in combination with existinganti-TNF therapies. TNF is also a powerful host defense cytokine commonly induced in the host response against various invading pathogens. Many viral pathogens can block TNF function by encoding modulators of TNF, its receptors or downstream signaling pathways. Here, we review the known virus-encoded TNF inhibitors and evaluate their potential as alternative future anti-TNF therapies.

Cutaneous manifestations of chronic kidney disease

Among the most common systemic diseases associated with cutaneous manifestations is kidney failure. Most of these occur in the setting of chronic kidney disease. In the following review, we will target 6 of these conditions in details. The entities are as follows: pruritus acquired perforating dermatoses, nail disorders, bullous disorders, calciphylaxis, and nephrogenic fibrosing dermopathy.

Characteristics of acquired reactive perforating collagenosis

The status of the patient's associated disease can generally affect the onset or healing of acquired reactive perforating collagenosis (ARPC). We treated eight cases of ARPC and noted that the patients had similar findings. However, it was not clear why ARPC developed in the patients with these diseases. Nevertheless, several factors related to the diseases associated with ARPC could affect the degeneration of collagen fibers or the production of dermal products. Some patients had diseases that were characterized by fibrosis and an increased amount of reticular fibers. Factors related to tissue remodeling might act not only in diseases associated with ARPC but also in ARPC itself.

Regression of skin lesions of Kyrle's disease with metronidazole in a diabetic patient

We describe here in a case of a 41-year-old man, with diabetes mellitus, who presented manifestations of Kyrle's disease. Administration of metronidazole, 500 mg twice daily for 1 month, resulted in complete regression of skin lesions with no recurrence during 12 months of follow-up. This successful antibiotic treatment is to support the role of infectious agents (anaerobic bacteria) in the pathogenesis of Kyrle's disease.

Dermatose perfurante adquirida associada à insuficiência hepática em paciente transplantado de fígado

A dermatose perfurante adquirida é entidade clinicopatológica caracterizada por eliminação transepitelial de material dérmico degenerado, ocorrendo em muitas condições, entre elas diabetes mellitus, insuficiência renal crônica e colangite esclerosante. Relata-se o caso de paciente de 17 anos, com dermatose perfurante adquirida associada à insuficiência hepática crônica, conseqüente à complicação hepática de transplante de fígado para tratamento de sua doença de base, a glicogenose tipo I.

Perforating folliculitis associated with tumour necrosis factor-? inhibitors administered for rheumatoid arthritis

Perforating dermatoses are characterized by transepithelial elimination of dermal structures. We report a 61-year-old man with rheumatoid arthritis who developed a perforating folliculitis following the administration of two tumour necrosis factor (TNF)-alpha inhibitors, infliximab and etanercept. To our knowledge, no perforating disorders have been reported associated with these drugs. This report suggests, for the first time, a role for TNF-alpha in the pathogenesis of perforating folliculitis.

Acquired reactive perforating collagenosis: four patients with a giant variant treated with allopurinol

Reactive perforating collagenosis (RPC) is one of the four essential acquired perforating dermatoses. The condition is characterized by the transepidermal elimination of altered collagen. This paper describes four patients with a giant variant of RPC which has not previously been documented. Three of the patients had associated diabetes mellitus and one had chronic renal failure secondary to fetal scarring. Three of the four patients had a significant improvement in their lesions and symptoms following treatment with allopurinol.

Proteolytic digest derived from bovine Ligamentum Nuchae stimulates deposition of new elastin-enriched matrix in cultures and transplants of human dermal fibroblasts

BACKGROUND

Diverse topical products and injectable fillers used for correcting facial wrinkles induce rather short-lived effects because they target replacement of dermal collagen and hyaluronan, matrix components of limited biologic durability.

OBJECTIVE

Present studies were aimed at stimulation of fully differentiated human dermal fibroblasts to resume deposition of new extracellular matrix rich of elastin, the most durable and metabolically inert component of dermal ECM.

METHODS

We have created a novel proteolytic digest of bovine ligamentum nuchae (ProK-60), and tested its potential biological effect on dermal fibroblasts derived from females of different ages. Northern blots, quantitative immunohistochemistry and metabolic assays were used to assess effects of ProK-60 on proliferation and matrix production in primary cultures of dermal fibroblasts, in cultures of skin explants and after implantation of stimulated fibroblasts into the skin of athymic nude mice.

RESULTS

ProK-60 increased proliferation (25-30%) of cultured dermal fibroblasts and significantly enhanced their production of new elastic fibers (>250%) and collagen fibers (100%). These effects were mostly mediated by stimulation of cellular elastin receptor. In contrast, ProK-60 inhibited production of fibronectin (-30%) and chondroitin sulfate proteoglycans (-50%). ProK-60 also activated proliferation of dermal fibroblasts, mostly derived from the stratum basale and induced deposition of elastic fibers in cultures of skin explants. Moreover, human fibroblasts pre-treated with ProK-60 produced abundant elastic fibers after their injection into the skin of athymic nude mice.

CONCLUSION

The described biological effects of ProK-60, including its unique elastogenic property, encourage use of this compound in cosmetic formulations stimulating rejuvenation of aged skin.

Regression of skin lesions of Kyrle's disease with clindamycin: implications for an infectious component in the etiology of the disease

We report our experience with the management of a 44-year-old man with manifestations of Kyrle's disease. The patient presented to us with skin lesions of two different types. The old lesions were large hyperkeratotic plaques with burrows without signs of inflammation. The newer lesions were also hyperkeratotic plaques but they clearly had signs of inflammation. The patient was successfully managed with combined surgical and medical management; removal of the large hyperkeratotic skin lesions combined with administration of clindamycin, which led to regression of the smaller skin lesions. The regression of the lesions of the initial stage of Kyrle's disease with clindamycin suggests that infectious agents (probably anaerobic bacteria) may play a role in the pathogenesis of the disease.

[Kyrle's disease]

INTRODUCTION

Hyperkeratosis follicularis et parafollicularis in cuten penetrans known as Kyrle's disease is a recessive hereditary genodermatosis. Generally, Kyrle's disease appears between 30 to 50 years of age and women are affected more than men.

CASE REPORT

We report a case of a 40-year-old man, a worker in a cement factory, who noticed the first skin lesions six years ago. Those were follicular papules on the left leg. He had been in good health beforehand, although an alcoholic for many years. Based on laboratory and other findings, chronic hepatitis was diagnosed. Histopathological analysis of skin lesions showed presence of hyperkeratosis and partial parakeratosis with acanthosis of the epidermis.

DISCUSSION

Kyrle's disease is classified among the perforating dermatoses with perforating folliculitis, perforating serpiginous elastosis and perforating reactive collagenosis. Kyrle's disease is often associated with hepatic, renal or diabetic disorders, and may be a paraneoplastic disease.

CONCLUSION

The course of this disease is chronic. If the associated diseases are treated, patients may have a better prognosis.

Alterations in distribution of tenascin, fibronectin and fibrinogen in vulval lichen sclerosus

BACKGROUND

The pathophysiology of lichen sclerosus remains uncertain. The clinical features, including increased fragility and scarring, and the histology suggest that significant reorganisation of the extracellular matrix is occurring. Tenascin, fibrinogen and fibronectin are extracellular matrix components that play a significant role in tissue remodelling, for example during wound repair.

AIM

To examine the distribution of tenascin, fibrinogen and fibronectin in vulval lichen sclerosus.

MATERIALS AND METHODS

Immunohistochemical staining was performed to study the distribution of tenascin, fibronectin and fibrinogen in 16 specimens of untreated vulval lichen sclerosus and 1 specimen of extragenital lichen sclerosus. Haematoxylin and eosin staining of the specimens was also performed to identify the position of the pale staining homogenous zone/zone of sclerosis and the inflammatory infiltrate below this. The control tissues studied included biopsies taken from the uninvolved thigh of 13 of the lichen sclerosus patients and 6 samples of normal vulva tissue obtained during gynaecological procedures from women of similar age to the lichen sclerosus women.

RESULTS

All the lichen sclerosus specimens demonstrated increased immunostaining of tenascin in the upper dermis and comparing this with the haematoxylin and eosin staining this corresponded to the zone of sclerosis with relatively little tenascin staining associated with the inflammatory band. In 14 out of the 16 vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen fibrinogen immunostaining was increased in the upper dermis which corresponded--in haematoxylin and eosin staining --to the zone of sclerosis. There was also slightly increased fibrinogen staining in the mid dermis which corresponded to the inflammatory band. Fibronectin staining was reduced in the upper dermis of 12 of the vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen which corresponded to the zone of sclerosis. However, in 14 of the vulval lichen sclerosus specimens and the extragenital lichen sclerosus specimen, fibronectin was slightly increased in the mid and deeper dermis which corresponded to the zone of inflammatory cells and the area below this. There was also increased fibronectin staining around blood vessel walls both in the mid dermis and within the zone of sclerosis.

CONCLUSION

The distribution of tenascin, fibrinogen and fibronectin is altered in lichen sclerosus and the alteration in these extracellular matrix components may be relevant to the initiation of scarring in lichen sclerosus and the associated increased skin fragility.