Studies of laminin and type IV collagen in blisters of porphyria cutanea tarda and drug-induced pseudoporphyria

Dabski, Christopher; Beutner, Ernst H.

doi:10.1016/0190-9622(91)70169-3

Cited by 41 publications

(28 citation statements)

References 21 publications

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“…36 It is believed that such difference is related to solubility of the involved porphyrins. 37 Some studies using electron microscopy and immunomapping (antigenic immunomapping of the dermal-epidermal junction) observed different bulla cleavage levels: basal keratinocytes, 108 lamina lucida, 109,110 dense sublamina 105 and papillary dermis. 36 …”

Section: Histopathologymentioning

confidence: 99%

Porfiria cutânea tardia

Vieira

Martins

2006

An. Bras. Dermatol.

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Section: Histopathologymentioning

confidence: 99%

Porfiria cutânea tardia

Vieira

Martins

2006

An. Bras. Dermatol.

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“…24 (3). C5-with inactive PCT presented milder vascular changes in the active phase or because the remission period was long and vascular changes improved during that period.…”

Section: Discussionmentioning

confidence: 99%

“…29 This degenerative phenomenon in the basal cells would explain why some authors claim that bullae can occur above the basal membrane. 3,27,28,30 They conclude that cleavage is a consequence of photodynamic injury of lysosomes, affecting endothelial cells, keratinocytes and dermal cells of the basal layer. 29 In our study, we used antigen immunomapping to determine the level of cleavage of bullae in seven patients.…”

Section: Clinical Diagnosismentioning

confidence: 99%

“…This explains why vascular injury is more pronounced than changes at the DEJ in this condition. 16 In PCT, the blisters result from variable cleavage, sometimes in the lamina lucida, 3,27,28 sometimes in the papillary dermis 2,15,29 or at the level of basal keratinocytes that show degenerative changes. 30 In some patients, the three types of cleavage can be observed in different biopsies, or even in the same biopsy.…”

Section: Pb180mentioning

confidence: 99%

“…In order to better understand the physiopathology of lesions in PCT, subepidermal blisters were subjected to antigen immunomapping, indirect immunofluorescence which uses specific labeled antibodies directed against known antigens of the DEJ, such as the bullous pemphigoid antigen, laminin, type IV collagen and type VII collagen, to determine the level of cleavage in the DEJ. 3 The bullous pemphigoid antigen is located above the lamina lucida in epidermal cells of the basal layer. Laminin, a non-collagen glycoprotein present in the basement membrane, has been implicated in the adhesion of epidermal cells to the basement membrane and it is the main component of the lamina lucida.…”

Section: Introductionmentioning

confidence: 99%

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Estudo da imunofluorescência direta, imunomapeamento e microscopia ótica na porfiria cutânea tardia

Vieira¹,

Aoki

Oliveira

et al. 2010

An. Bras. Dermatol.

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L Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tardaEstudo da imunofluorescência direta, imunomapeamento e microscopia ótica na porfiria cutânea tardia Abstract: BACKGROUND: Even though porphyria cutanea tarda is the most frequent type of porphyria, there are few studies about its cutaneous physiopathology. OBJECTIVE: To evaluate skin changes in porphyria cutanea tarda using light microscopy and direct immunofluorescence before and after treatment with chloroquine. To perform antigen immunomapping of bullae to study their level of cleavage. METHODS: Light microscopy and direct immunofluorescence of 28 patients are reported in three different phases: 23 patients with active porphyria before treatment (Phase A), 7 patients with clinical remission during treatment (Phase B), and 8 patients with biochemical remission (Phase C). Immunomapping was performed on 7 patients. RESULTS: In active porphyria, direct immunofluorescence showed homogenous and intense fluorescence on the inside and on the walls of blood vessels as well as in the dermal-epidermal junction. In clinical remission (Phase B) and biochemical remission (Phase C), the deposit of immunoglobulins was maintained, but the deposit of complement was reduced in most cases. Immunomapping revealed no standard cleavage plane. CONCLUSION: No correlation was observed between clinical response and immunoglobulin deposits. The reduction of complement favors the hypothesis that activation of the complement cascade represents an additional pathway that leads to endothelial damage. Keywords: Fluorescent antibody technique; Microscopy; Porphyria cutanea tarda; Porphyria cutanea tarda/physiopathology Resumo: FUNDAMENTO: Apesar de a porfiria cutânea tardia ser a mais frequente das porfirias, há poucos estudos que abordam sua fisiopatologia cutânea. OBJETIVO: Avaliar as alterações cutâneas na porfiria cutânea tardia utilizando a microscopia ótica e a imunofluorescência direta, antes e depois do tratamento com cloroquina. Realizar o imunomapeamento antigênico da bolha para estudo do seu nível de clivagem. MÉTODOS: Relata-se a microscopia ótica e imunofluorescência direta de 28 pacientes em três fases diferentes: 23 pacientes com porfiria ativa antes do tratamento (Fase A), sete pacientes com remissão clínica durante o tratamento (Fase B) e oito pacientes com remissão bioquímica (Fase C). O imunomapeamento foi realizado em sete pacientes. RESULTADOS: Na porfiria ativa, a imunofluorescência direta demonstrou fluorescência homogênea e intensa no interior e na parede dos vasos e na junção dermoepidérmica. Na remissão clínica (Fase B) e na remissão bioquímica (Fase C), o depósito de imunoglobulinas se manteve, mas o depósito de complemento apresentou diminuição na maioria. O imunomapeamento não demonstrou plano de clivagem fixo. CONCLUSÃO: Não houve correlação entre a resposta clínica e os depósitos de imunoglobulinas. A diminuição do complemento favorece a hipótese de que a ativação da cascata do complemento representa u...

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