Membrane attack complex (C5b-9 complex or Mac), is strongly present in lesional skin from patients with endemic pemphigus foliaceus in El Bagre, Colombia.

BACKGROUND: El Bagre endemic pemphigus foliaceus (El Bagre-EPF) is a new variant of endemic pemphigus foliaceus present in the El Bagre area of Colombia, South America. Here, we investigate the presence of complement/C5-b9 in lesional skin of patients and matched controls from the endemic area. We also aim to compare the patient's autoantibody levels using indirect immunofluorescent titers (IIF) and correlate with the lesional presence of complement/C5b-9. METHODS: A case-control study was carried out by testing for the presence of complement/C5b-9 in lesional skin in 43 patients affected by El Bagre-EPF, as well as 43 matched, healthy controls from the endemic area. Skin biopsies were obtained and evaluated via hematoxylin and eosin staining, and immunohistochemistry. RESULTS: The presence of complement/C5b-9 was observed in all cases of the patients affected by El Bagre-EPF and was not observed in the controls from the endemic area (P < 0.001). The patients' autoantibody titers utilizing IIF for IgG and IgM showed correlation between higher autoantibody titers and stronger intensity of staining with complement/C5-b9 staining (P < 0.001). CONCLUSION: Patients affected by El Bagre-EPF have lesional deposition of complement/C5b, which correlates with disease severity and previously established serologies.

[Utilidad del complejo soluble de ataque a membrana para determinar actividad clínica de la dermatomiositis y respuesta al tratamiento].

INTRODUCTION: Dermatomyositis is an autoimmune disease and the most common idiopathic inflammatory myopathy. During patient follow-up, determining biochemical parameters is required in order to assess for disease activity and treatment efficacy. OBJECTIVE: To determine the relationship between the degree of activation of the complement system through the soluble membrane attack complex (c5b-9), dermatomyositis clinical activity and its variations with conventional treatment. METHOD: Forty-five patients with active and inactive dermatomyositis were studied. Chemical parameters and clinical severity were established and correlated with ELISA-determined C5b-9 serum levels. RESULTS: There was positive correlation between dermatomyositis cutaneous and muscular activity and C5b-9 serum levels, which was lower than with traditional biochemical markers. In the case of treatment response, C5b-9 showed significant reduction, similar to clinical severity; with biochemical parameters, the reduction was not significant at one month of treatment with systemic steroids. CONCLUSIONS: Serum levels of C5b-9 levels of C5b-9 are higher in patients with dermatomyositis than in healthy subjects; dermatomyositis active and inactive cases were determined by means of their measurement. They can be a reliable parameter of therapeutic response, more accurate than muscle enzymes measurement, particularly creatine phosphokinase.

INTRODUCCIÓN: La dermatomiositis es una enfermedad autoinmune y es la más común de las miopatías inflamatorias idiopáticas. Durante el seguimiento de los pacientes se requiere determinar parámetros bioquímicos para precisar la actividad de la enfermedad y la eficacia de los tratamientos. OBJETIVO: Definir la relación entre el grado de activación del sistema del complemento a través del complejo soluble de ataque a membrana (C5b-9), la actividad clínica de la dermatomiositis y sus variaciones con el tratamiento convencional. MÉTODO: Se estudiaron 45 pacientes con dermatomiositis activa e inactiva. Se establecieron parámetros bioquímicos, severidad clínica y se correlacionaron con los niveles séricos de C5b-9, determinados mediante ELISA. RESULTADOS: Existió correlación positiva entre la actividad cutánea y muscular de la dermatomiositis y los niveles séricos de C5b-9, menor que con los marcadores bioquímicos tradicionales. En la respuesta al tratamiento, C5b-9 mostró reducción significativa, similar a la severidad clínica; con los parámetros bioquímicos, la reducción no fue significativa a un mes de tratamiento con esteroides sistémicos. CONCLUSIONES: Los niveles séricos de C5b-9 en pacientes con dermatomiositis están más elevados que en los sujetos sanos; con su medición se identificaron los casos activos e inactivos de dermatomiositis. Pueden ser un parámetro fiable de respuesta terapéutica, más precisos que la medición de enzimas musculares, particularmente creatinfosfosquinasa.

Do Archaea and bacteria co-infection have a role in the pathogenesis of chronic chagasic cardiopathy?

Chronic cardiopathy (CC) in Chagas disease is a fibrotic myocarditis with C5b-9 complement deposition. Mycoplasma and Chlamydia may interfere with the complement response. Proteolytic enzymes and archaeal genes that have been described in Trypanosoma cruzi may increase its virulence. Here we tested the hypothesis that different ratios of Mycoplasma, Chlamydia and archaeal organisms, which are frequent symbionts, may be associated with chagasic clinical forms. MATERIALS AND METHODS: eight indeterminate form (IF) and 20 CC chagasic endomyocardial biopsies were submitted to in situ hybridization, electron and immunoelectron microscopy and PCR techniques for detection of Mycoplasma pneumoniae (MP), Chlamydia pneumoniae(CP), C5b-9 and archaeal-like bodies. RESULTS: MP and CP-DNA were always present at lower levels in CC than in IF (p < 0.001) and were correlated with each other only in CC. Electron microscopy revealed Mycoplasma, Chlamydia and two types of archaeal-like bodies. One had electron dense lipid content (EDL) and was mainly present in IF. The other had electron lucent content (ELC) and was mainly present in CC. In this group, ELC correlated negatively with the other microbes and EDL and positively with C5b-9. The CC group was positive for Archaea and T. cruzi DNA. In conclusion, different amounts of Mycoplasma, Chlamydia and archaeal organisms may be implicated in complement activation and may have a role in Chagas disease outcome.