Complement components (C3, C4) as Inflammatory markers in asthma.

Objective. To assess the serum levels of complement factors C3 and C4 in Egyptian asthmatic children. Methods. This case-controlled study comprised of 60 Egyptian children with the diagnosis of bronchial asthma (not in acute attack) and 60 age-and sex-matched healthy controls. All candidates were subjected to a thorough clinical study, complete blood counts, absolute eosinophil count and serum complements (C3, C4). Results. Serum C3 was significantly higher in asthmatics when compared to controls (140.60 ± 38.80 mg/dl vs 107.70 ± 45.00 mg/dl respectively, (p = 0.01). However, differences in serum C4 levels were not significant (41.30±48.80 mg/dl vs 44.60 ± 39.70 mg/dl respectively, p = 0.69). There was a significant positive correlation between severity of asthma and serum C3 (p=0.02) but not with serum C4. Conclusions. Serum levels of C3 - but not C4 - are elevated in children with stable asthma, with a positive correlation between serum C3 and severity of asthma.

Glomerular C4d Deposition Indicates in situ Classic Complement Pathway Activation, but is not a Marker for Lupus Nephritis Activity

This study was designed to evaluate whether glomerular C4d deposition may be a useful marker of lupus nephritis activity. Twenty-one patients diagnosed as having lupus nephritis (WHO class III: 4 cases; IV: 12 cases; V: 5 cases) were included. Mean patient age was 29.3 +/- 13.5 years (range: 7-55 years). The presence and intensity of glomerular C4d deposition were compared with the corresponding histologic activity index for each case. Immunofluorescence for C4d showed diffusely granular staining along glomerular capillary loops, in all cases examined (1+, in 8 cases; 2+, in 7 cases; 3+, in 6cases). In eight cases, C4d deposition was found in the absence of capillary or mesangial C4 deposits. Moreover, the intensity of C4d deposits correlated with those of capillary IgG, IgA, C4, C1q, and fibrinogen deposits. However, C4d staining intensity did not correlate with the lupus nephritis activity index. Although glomerular capillary C4d deposition is a sensitive marker of classic complement pathway activation, it is not a sensitive marker for active lupus nephritis.

Estudio longitudinal de las concetraciones de C3 y C4 del complemento sérico en glomerulonefritis aguda del niño / Longitudinal study of C3 and C4 concentrations of serum complement in acute glomerulonephritis of the child

Se estudiaron 54 niños portadores de glomerulonefritis aguda admitidos al Servicio de Nefrología Pediátrica del Hospital Central de Valencia, de edades comprendidas entre 2 y 13 años; 60% correspondieron al sexo masculino; 85% tuvieron antecedente infeccioso reciente fundamentalmente en piel y 67% mostró evidencia indirecta de estreptococcia reciente con elevación del título de antiestreptolisinas "O". Se determinaron las concentraciones de las fracciones C3 y C4 del complemento sérico por inmunodifusión radial en forma longitudinal, durante la fase aguda del síndrome nefrítico y a la 5a y 10a semana de evolución; simultáneamente se estudió un grupo control (n-40). La fracción C3 se encontró muy deprimida durante la fase inicial del proceso en comparación con lo valores normales (p < 0.001), con recuperación de los valores a la 5a. y 10a. semana, pero sin alcanzar los níveles del grupo control (p < 0,05). Las concentraciones de C4 se encontraron estables en todas las fases estudiadas del Síndrome nefrítico, sin diferencia significativa con el grupo control (p < 0.05). Nuestros resultados sugieren consumo de C3 a expensas de la vía alterna del complemento, lo cual podría deberse a utilización de C3b en la solubilización de los complejos inmunes, aumento del catabolismo, disminución de la sintesis de C3 o fragmentación de C3 por la convertasa de C3 de la vía alterna, unida a la pared del capilar glomerular