Interleukin-1 induces collagenase production by recessive dystrophic epidermolysis bullosa fibroblasts

Summary We examined the direct effect of interleukin-1 (IL-1) on the collagenase production by epidermolysis bullosa (EB) fibroblasts. Addition of IL-1 at concentrations of 2.5×10^–4 units/ml or below in the culture media greatly enhanced collagenase production by two cell lines of recessive dystrophic EB (RDEB) fibroblasts. They produced 4.82±0.04 to 5.93±0.39 units/ml of enzyme, as compared to 0.02±0.07 units/ml in the absence of IL-1. In contrast, collagenase production by two cell lines of dominant dystrophic EB (DDEB) and normal fibroblasts was not, or only slightly, increased up to 0.69±0.28 units/ml. IL-1 concentrations of 2.5×10^–3 units/ml or higher failed to induce collagenase production by all fibroblasts. ³H-thymidine uptake increased by about 110–376% of control after IL-1 treatment. In addition, these data were obtained using fibroblasts of the 13–15 passages, suggesting that the property might be determined genetically. Although RDEB seems to be a wide heterogeneous group, the present data strongly suggest that the property may be specific to and characteristic of some types of RDEB cells.     

Expression of collagenase and stromelysin in skin fibroblasts from recessive dystrophic epidermolysis bullosa

Collagenase and stromelysin expression in recessive dystrophic epidermolysis bullosa (RDEB) was studied at both the protein and the gene expression levels in fibroblast cultures. The amount of enzyme protein in the culture medium, as determined using a specific enzyme assay, showed a 9.7-fold increase in collagenase and a 2.7-fold increase in stromelysin in RDEB fibroblasts (n=4 patients) compared with controls (n=3 subjects with normal skin). Collagenase activity was extremely high in all RDEB fibroblasts. Gene expression, as assessed by Northern blot hybridization, was increased in two sets of RDEB fibroblasts with respect to collagenase, and in two other sets of RDEB fibroblasts with respect to stromelysin. The effect of interleukin-1 (IL-1) on metalloproteinase expression was also examined. The results revealed that: 1) collagenase and stromelysin expression was variably increased at both the protein and the gene expression levels in RDEB fibroblasts; (2) the gene expression level did not always reflect the corresponding protein level; and (3) IL-1 produced a differential effect on collagenase and stromelysin expression. Although the causative gene for RDEB is a type VII collagen, the abnormal expression of collagenase and/or stromelysin is still important in considering the pathophysiology of RDEB.     

Hallopeau-Siemens型营养不良型大疱性表皮松解症一例产前诊断

目的 鉴定一常染色体隐性遗传营养不良型大疱性表皮松解症家系的突变后,对患者的下一代开展产前诊断.方法 首先对患者和患者妻子进行COL7A1基因全部118个外显子的扩增和直接测序.然后从孕15周患者妻子的羊水中提取胎儿的DNA,应用聚合酶链反应(PCR)、DNA直接测序和限制性片段长度多态性(RFLP)的方法来检测突变位点,从而进一步确定该胎儿是否患病.结果 发现该患者COL7A1基因的1条等位基因第2号外显子上存在S48P的错义突变,而另1条等位基因第27号外显子上存在3625del11缺失突变,造成编码区阅读框架的移位,最终导致蛋白终止密码(PTC)的产生.患者妻子该基因全序列完全正常.胎儿COL7A1基因的1条等位基因第27号外显子上存在3625del11缺失突变,而另1个第2号外显子序列正常.因此证实该胎儿为携带者,胎儿出生后临床表型正常.结论 完成我国首例常染色体隐性遗传的营养不良型大疱性表皮松解症的DNA基础的产前诊断.     

Increased neutral protease and collagenase activity in recessive dystrophic epidermolysis bullosa

The enzyme activities of normal-looking skin and blister fluid from a patient with recessive dystrophic epidermolysis bullosa (RDEB) were measured. Of the hydrolytic enzymes measured, both collagenase and neutral protease activities were considerably increased in the skin and blister fluid samples compared with values found in normal control skin and in blister fluid from a patient with a burn. In addition, skin from a healthy person cultured with RDEB blister fluid showed dermal-epidermal separation. These findings suggest that collagenase and neutral protease may be involved in the formation of blisters in RDEB.     

A perspective on the role of collagenase in recessive dystrophic epidermolysis bullosa

The pathophysiology of tissue fragility in recessive dystrophic epidermolysis bullosa may be due in part to excessive destruction of interstitial collagens by a structurally altered, but catalytically active, form of human skin collagenase. Therapeutic attempts directed toward reducing the expression of this enzyme have resulted in clinical improvement in some patients with the disease.     

Phenytoin therapy in recessive dystrophic epidermolysis bullosa

A case of recessive dystrophic epidermolysis bullosa in a 17-year-old boy is described. The diagnosis was based on clinical and histophathological findings. The patient is being treated with 200-300 mg of phenytoin sodium per day maintaining a blood level of 13-15 mg/litre and is under remission for 1 year.     

Renal amyloidosis in recessive dystrophic epidermolysis bullosa

BACKGROUND: Although it is known that renal amyloidosis may complicate several dermatoses, recessive dystrophic epidermolysis bullosa (RDEB) complicated by nephropathy has been thought to be rare. We, however, had seen a young adult with RDEB who died of renal failure due to systemic amyloidosis. OBJECTIVE: A retrospective study was performed in order to investigate the incidence and etiology of renal amyloidosis in RDEB. METHODS: Routine urinalysis, serum amyloid A protein (SAA) and creatinine levels were repeatedly determined in 11 patients with RDEB (mean age 17.7 years, range 5-28, 7 males, 4 females). Nephropathy was defined as the presence of both proteinuria and hematuria with red blood cell casts. RESULTS: Seven out of 9 generalized RDEB patients had nephropathy including 3 cases with end-stage renal disease (2 died within 2 years from the onset of nephropathy), while 2 patients with localized RDEB did not. Levels of SAA were significantly higher in patients with nephropathy than those in patients without nephropathy (p<0.05). CONCLUSION: Nephropathy is a common and serious complication of RDEB. Renal amyloidosis may play an important role in its etiology. We recommend that patients with RDEB should be periodically screened for nephropathy due to amyloidosis by urinalysis and measuring SAA levels.     

Globalization of DNA-based prenatal diagnosis for recessive dystrophic epidermolysis bullosa

Globalization of economies and improvements in international telecommunications has led to increased demand for better access to the latest developments in healthcare, wherever they may be available. In this report, we describe the first case from Thailand of DNA-based prenatal testing of a mother at risk for recurrence of severe recessive dystrophic epidermolysis bullosa (RDEB), whose affected child had died in early childhood. In the absence of previous access to prenatal diagnostic tests, the mother had undergone several terminations for fear of having another affected child. To prevent this happening again, DNA from the mother and her consanguineous partner was sent from Bangkok to a specialist laboratory at St John's Institute of Dermatology in London and screened for pathogenic mutations in the COL7A1 gene: both individuals were shown to be heterozygous carriers of a splice-site mutation, c.2440G --> C. In a subsequent pregnancy, amniocentesis was performed at 18 weeks' gestation in Bangkok, and fetal DNA was extracted and sent to London for analysis. Restriction endonuclease digestion of the amplified fetal DNA revealed the wild-type COL7A1 sequence only, and 5 months later, a clinically unaffected boy was born. This case represents the first example of DNA-based prenatal diagnosis for RDEB in Thailand and illustrates the benefits for patients in establishing international links with diagnostic centres with technological expertise that is not widely available in certain countries.     

Oro-dental manifestations in Hallopeau-Siemens-type recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa of Hallopeau-Siemens (RDEB-HS) is a rare genetic disorder characterized by trauma-induced blisters, milia, acral pseudosyndactyly, and scarring. RDEB-HS patients present with a distinct pattern of oral involvement consisting of microstomia, ankyloglossia, vestibule obliteration and dental caries. In this review, we describe the orodental manifestations of RDEB-HS and present our experience in a cohort of six new cases of RDEB-HS in children aged 6-10 years, documenting the presence of microstomia, ankyloglossia and vestibule obliteration in childhood. We also show that compared with unaffected control children, RDEB-HS subjects have a greater risk of developing high caries indices with early onset, both for permanent or deciduous teeth, and a worse oral hygiene index (scored as OHI). Tooth malpositions and the cross-bite relationship between maxilla and mandible could play a major role in promoting these events. We propose that dental management of RDEB-HS subjects should commence as soon as tooth eruption begins.     

Generalised recessive dystrophic epidermolysis bullosa in two sisters

Two female siblings of a family presented with a mechanobullous disorder since birth. Both had retarded physical development, flaccid bullac, extensive cutaneous erosions and scars, mucosal erosions, milia, corneal haziness, deformed and carious teeth, dystrophic nails, cicatricial alopecia of scalp and positive Nikolsky's sign. Skin biopsy revealed subepidermal bulla. They were diagnosed as generalized recessive dystrophic epidermolysis bullosa. They were given oral phenytoin but failed to show significant response.     

常染色体隐性遗传的Hallopeau-Siemens型营养不良型大疱性表皮松解症1例

报告1例常染色体隐性遗传的Hallopeau—Siemens型营养不良型大疱性表皮松解症。患者男,27岁。周身皮肤反复起水疱、破溃27年。患者出生后即出现四肢伸侧皮肤缺损,双手十指指甲完全缺如,双足十趾融合形成袜套样并趾。口腔黏膜反复发生溃疡,形成瘢痕致舌不能完全伸出。皮肤组织病理检查示表皮下水疱。透射电镜示：表皮下裂隙,致密板下锚丝纤维形态异常。     

Two cases of recessive dystrophic epidermolysis bullosa diagnosed as severe generalized

Recessive dystrophic epidermolysis bullosa (RDEB) is a congenital bullous disease resulting from defective anchoring fibrils at the dermal-epidermal junction and mutations in the type VII collagen gene. In this report, we describe two patients with severe generalized RDEB. Patient 1 was a 24-day-old male infant, and patient 2 was a 1-day-old female infant. Immunofluorescence microscopy demonstrated absence of type VII collagen labeling in a skin sample of patient 1, and reduced staining in patient 2. Electron microscopy revealed absence of anchoring fibrils below the lamina densa in patient 1, and reduced or rudimentary anchoring fibrils in patient 2. Mutation analyses of COL7A1 in these patients revealed heteroallelic recessive mutations which resulted in premature termination codons (PTC): 6573+1G>C in intron81 and 886del6ins14 in exon 7 in patient 1, and 6573+1G>C in intron81 and 4535insC in exon 44 in patient 2. Heteroallelic combinations of PTC mutation generally result in the severe generalized type. Patient 2 has developed a digital fusion at age 2, which is a typical manifestation of severe generalized RDEB. The RDEB subtype is considered to be determined based on comprehensive information, including analysis of alleles, protein expression, ultrastructure and clinical symptoms after growth. However, mutation analyses of COL7A1 can provide valuable information estimating a diagnosis in early infancy.     

Antenatal diagnosis of hereditary epidermolysis bullosa

Among the genetic disorders of the skin, the heterogeneous group of epidermolysis bullosa includes some of the most severe. Prenatal diagnosis is of considerable importance to the families who have had an affected child, or in which one of the parents is affected. The prenatal diagnosis is performed using fetoscopy and fetal skin biopsy. Fetal skin samples are taken at 20 weeks of gestation and are examined by light and electron microscopy to determine whether the fetus is affected. We report here the French experience on prenatal diagnosis of the severe inherited epidermolysis bullosae. Given the severity and frequency of Herlitz syndrome, it is not surprising that this is the most frequently encountered disease in our series of prenatal diagnosis (14 of 21 epidermolysis bullosae), followed by Hallopeau-Siemens (6 cases), and Pasini type (1 case). Our exclusion diagnosis of a Pasini fetus was the first prenatal diagnosis of this type of epidermolysis bullosa performed and reported in the literature. We stress here in this paper that observing the site of separation in the epidermal dermal junction is not sufficient to make a positive prenatal diagnosis. Prenatal diagnosis depends on the observation of the specific ultrastructural marker of the disease such as: hypoplasia and absence of hemidesmosomes and sub-basal dense plate in junctional epidermolysis bullosa-Herlitz, collagenolysis in recessive dystrophic epidermolysis bullosa-Hallopeau-Siemens, and absence and hypoplasia of anchoring fibrils in dominant dystrophic epidermolysis bullosa-Pasini. Until biochemical defects are clarified and suitable tests become available, electron microscopy remains the only current means for reliable, genetically useful, diagnosis of epidermolysis bullosa. In 62 per cent of cases of our series a prenatal diagnosis of exclusion of disease was made and we would stress that in high risk families repeated fetoscopies for prenatal diagnosis are possible in consecutive pregnancies thus allowing the family to have only normal children.     

Squamous cell cancers in Hallopeau-Siemens recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa is one of the most severe hereditary mechano-bullous diseases, characterized by scarring blister formation, nail dystrophy and onycholysis, cutaneous contractures, synechiae, mutilations of the hands and feet and oesophageal stenosis. With increasing age the patients may develop multiple, fast-growing and early-metastasizing squamous cell carcinomas. When epidermolysis is present, precise determination of which of the various forms is concerned is necessary soon after birth, to make it possible to advise parents about the prognosis of the disease and the likelihood of its occurrence in further children. In pregnancies at risk of severe epidermolysis bullosa a prenatal diagnosis should be performed. We present two siblings with recessive dystrophic epidermolysis bullosa, each of whom developed two squamous cell carcinomas.