Estudo da imunofluorescência direta, imunomapeamento e microscopia ótica na porfiria cutânea tardia / Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tarda

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 uma via adicional que leva à lesão endotelial.

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.

Study of direct immunofluorescence, immunofluorescence mapping and light microscopy in porphyria cutanea tarda.

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.

Mast cells and transforming growth factor-beta expression: a possible relationship in the development of porphyria cutanea tarda skin lesions.

BACKGROUND: Porphyria cutanea tarda (PCT) is a metabolic disease characterized by vesicles and blisters in sun-exposed areas and scleroderma-like lesions in sun-exposed and non-sun-exposed areas. Mast cells participate in the pathogenesis of bullous diseases and diseases that show sclerosis, including PCT. Moreover, transforming growth factor-beta (TGF-beta) is the main cytokine in the development of tissue sclerosis. The correlation of mast cells and TGF-beta with the lesions of PCT has not been examined, however. The possible role of mast cells and TGF-beta (and the relationship between them) in the development of PCT lesions is discussed. METHODS: To quantify mast cells and cells expressing TGF-beta in skin samples from patients with PCT and controls, immunohistochemical studies were performed in tissue sections allied to morphometric analyses. RESULTS: The numbers of mast cells and cells expressing TGF-beta per square millimeter were increased in the PCT group relative to controls, and there was a direct and significant correlation between the mast cell number and cells expressing TGF-beta in PCT. CONCLUSIONS: The results suggest that the increased number of mast cells and of cells expressing TGF-beta, as well as their direct correlation, may contribute to the pathogenesis of the skin lesions in PCT.

[Hepatitis C virus infection in patients with porphyria]. / Infección por virus C de la hepatitis en pacientes con porfiria.

Hepatitis C virus antibodies were studied in sera coming from 39 patients with porphyria (cutanea tarda in 17, variegate in 8, intermittent acute in 4, coproporphyria in 2 and protoporphyria in 8). Nine of 17 patients with porphyria cutanea tarda had positive antibodies, but none of the patients with other types of porphyria. All subjects with porphyria cutanea tarda had histological or laboratory liver abnormalities. There was no relationship between the presence of antibodies and frequency of alcoholism, diabetes, or carbohydrate intolerance. Family background of porphyria was significantly less frequent among patients with positive hepatitis C virus antibodies. In 13 patients, a liver biopsy was performed, always showing signs of chronic hepatitis, whose magnitude was higher in those with positive antibodies. It is concluded that, as reported previously, hepatitis C virus may be an activating factor for porphyria cutanea tarda or may potentiate its accompanying liver disease.