RESUMEN
X linked agammaglobulinemia (XLA) is rarely reported from developing countries especially from South East Asia. It appears that X linked agammaglobulinemia is less common in certain ethnic groups. It is very uncommon in black people in USA and South Africa. In multiracial Malaysia we have documented five XLA in Malays and Indians but not in the Chinese that constitute about 31% of the population. First degree relatives afflicted with XLA or other primary immunodeficiencies occurred more often in our study. All showed lung involvement although the etiologic organisms involved were atypical, being Gram negative.
Asunto(s)
Agammaglobulinemia/etnología , Etnicidad , Ligamiento Genético , Cromosoma X , Adolescente , Adulto , Agammaglobulinemia/complicaciones , Agammaglobulinemia/genética , Agammaglobulinemia/inmunología , Niño , Preescolar , Humanos , India/etnología , Malasia/epidemiología , Masculino , Infecciones del Sistema Respiratorio/complicacionesRESUMEN
A new laser nephelometric technique that measures C4d for the assessment of the activation of the classical complement pathway was developed. C4d was isolated from other larger C4 related molecules at a final concentration of polyethylene glycol of 12% and then quantitated by laser nephelometry using a commercially available antiserum, which reacts with C4d determinants. C4d standard (100%) was produced by exhaustive activation of the classical pathway in pooled normal human serum using heat aggregated human immunoglobulin. Serial dilutions of the standard provided a reference curve against which clinical samples were read. Patients with rheumatoid arthritis showed significantly higher C4d values (mean 53.8%) than controls (21.7%; p less than 0.001). The technique proved accurate, rapid, and suitable for the routine laboratory evaluation of complement activation through the classical pathway, and it may be useful in the management of those conditions in which complement activation has a pathogenic role.
Asunto(s)
Activación de Complemento , Complemento C4/análisis , Complemento C4b , Vía Clásica del Complemento , Fragmentos de Péptidos/análisis , Adolescente , Adulto , Anciano , Artritis Reumatoide/inmunología , Femenino , Humanos , Inmunoelectroforesis , Masculino , Persona de Mediana Edad , Nefelometría y TurbidimetríaRESUMEN
Of 26 patients with autoimmune chronic active hepatitis (CAH) starting in childhood 18 (69%) had low C4 and 5 (19%) had low C3 serum levels. Impaired hepatic synthesis and immune-consumption were unlikely since transferrin levels were normal in all patients, albumin levels were persistently low in only 3, and only 3 had raised levels of activation fragment C3d. C4d was normal in all patients studied. In the families of 12 probands with low C4, 7 parents had low C4 and 2 had levels which were at the lower limit of normal. 5 of 10 siblings from 5 families had low C4. These results suggest that low C4 levels in CAH are genetically determined. C4 phenotyping in 20 patients and in 26 parents showed that 90% and 81%, respectively, had null allotypes at either the C4A or C4B locus compared with 59% in controls, indicating that defective expression of structural genes may contribute to the observed C4 deficiency.
Asunto(s)
Enfermedades Autoinmunes/genética , Complemento C4/genética , Hepatitis Crónica/genética , Adolescente , Adulto , Enfermedades Autoinmunes/sangre , Niño , Preescolar , Complemento C3/deficiencia , Complemento C3/genética , Complemento C4/deficiencia , Susceptibilidad a Enfermedades , Femenino , Genes , Hepatitis Crónica/sangre , Hepatitis Crónica/inmunología , Humanos , Masculino , Fenotipo , Polimorfismo GenéticoRESUMEN
A new nephelometric technique to measure C3d as an indicator of complement activation, is described. C3d is isolated at high concentration of polyethyleneglycol (PEG), incubated with commercially available anti-C3d antiserum at a final concentration of 2.5% PEG and then measured in a Behring Laser Nephelometer. In contrast to previously available techniques our assay detects the low concentrations of C3d present in all normal subjects, which result from the continuous C3 catabolism occurring in vivo. We have also measured C3d blood concentrations in a large number of patients with diseases associated with complement activation. Raised C3d concentrations were found in 68% of rheumatoid arthritis, 57% of primary biliary cirrhosis, 38% of chronic active hepatitis, 100% of Gram-negative bacteraemia and 100% of malaria. The nephelometric technique has proved to be sensitive, economical and fast, and could be adapted for routine determination of C3d blood concentrations to monitor disease activity and response to treatment.