Intraepidermal expression of basement membrane components in the lesional skin of a patient with dystrophic epidermolysis bullosa

Self-improving dystrophic epidermolysis bullosa: First report of clinical, molecular, and genetic characterization of five patients from Southeast Asia

Self-improving dystrophic epidermolysis bullosa is a rare subtype of dystrophic epidermolysis bullosa (DEB) characterized by significant improvement in skin fragility within the first few years of life. Genetic inheritance has previously been reported as autosomal dominant or recessive with both forms harboring mutations in COL7A1. To date, there have been no reports of this rare clinical entity from various Southeast Asian ethnicities. Here, we describe the clinical and molecular features of five patients from the Southeast Asia region who presented with predominantly acral-distributed blisters and erosions in the first few days of life. Blistering resolved over several months, without appearance of new blisters. By immunofluorescence, intraepidermal retention of Type VII collagen was observed in all patient skin biopsies when investigated with antibody staining. Genetic analysis of four patients revealed pathogenic variants in COL7A1 which have not been previously reported. The clinical diagnosis in these rare patients is confirmed with molecular histology and genetic characterization.

Bullous dermolysis of the newborn: four new cases and clinical review

Bullous dermolysis of the newborn (BDN) is a subtype of dystrophic epidermolysis bullosa caused by mutations in type VII collagen resulting in disorganized anchoring fibrils and sublamina densa blister formation. Disease activity is usually confined to the first year of life, with restoration of physiologic type VII collagen localization. We report four new cases of BDN and review the utility of immunofluorescence mapping in establishing the diagnosis.

Immunohistological analysis of immune cells in blistering skin lesions

BACKGROUND

Bullous skin lesions are characterised by the presence of intraepidermal or subepidermal bullae. Although inflammatory cell infiltrate is a constant feature in these lesions, their immunophenotypic characterisation is still incomplete.

AIM

To determine whether the development of bullous skin diseases is associated with changes in the inflammatory cell infiltrate.

MATERIALS AND METHODS

34 cases representing lesions with both intraepidermal and subepidermal bullae were examined using immunoperoxidase staining methods and antibodies targeting antigens for histiocytes (CD68), B cells (CD20+), T cells (CD3+), T cells with cytotoxic potential (T cell intracellular associated antigen, TIA1+) and activity (granzyme B, GRB+). The adjacent normal skin (lesions) and an additional five cases of normal skin were also examined (controls).

RESULTS

The transition from normal skin to lesional skin (lesions with intraepidermal and subepidermal bullae) was associated with a significant increase (p< or =0.05) in the density of total inflammatory cell infiltrate, CD68+ cells, CD3+ T lymphocytes, CD20+ B lymphocytes, TIA1+ -resting cytotoxic T cells and GRB+ T cells with cytotoxic activity.

CONCLUSIONS

The increase in inflammatory cell infiltrate during the transition from normal to lesional skin may reflect the presence of an increased antigenicity of the lesional cells or a response to some basement membrane components. CD68+ and CD3+ cells, especially the resting cytotoxic ones, achieved numerical dominance in these lesions. Cell-mediated immunity seems to have critical role in the development of these lesions.

Transient bullous dermolysis of the newborn in three generations

Transient bullous dermolysis of the newborn (TBDN) is a rare form of dystrophic epidermolysis bullosa (DEB) that presents with neonatal skin blistering but which usually improves markedly during early life or even remits completely. Skin biopsies reveal abnormal intraepidermal accumulation of type VII collagen which results in poorly constructed anchoring fibrils and a sublamina densa plane of blister formation. The reason for the spontaneous clinical improvement is not known, but there is a gradual recovery in type VII collagen secretion from basal keratinocytes to the dermal-epidermal junction, with subsequent improvement or correction of anchoring fibril morphology. In this report, we describe TBDN occurring in three generations of the same family. Blistering occurred only during the first few months after birth, and all affected individuals were found to have a heterozygous glycine substitution mutation in exon 45 of the type VII collagen gene, COL7A1, designated G1522E. This mutation represents the third report of a pathogenic COL7A1 mutation in TBDN. Despite limited understanding of the disease mechanism in TBDN, this distinct form of DEB is important to recognize as it typically has a benign and self-limiting course. However, not all cases of DEB associated with intraepidermal type VII collagen are 'transient'. Genetic counselling in such patients therefore should be guarded until the pathophysiology of TBDN is better understood.