Determinación de la actividad anti-C3d en reactivos antiglobulina humana / Determination of the anticomplement activity in human antiglobulin reagent

La evaluación de la actividad de anti-C3d en reactivos de Coombs poliespecíficos, con los procedimientos clásicos presenta, según la experiencia de los autores, dificultades técnicas y falta de reproductibilidad. El objetivo de este trabajo fue describir una técnica para controlar la actividad de los reactivos antiglobulina humana (AGH) poliespecíficos y monoespecíficos anti-C3d, utilizando glóbulos rojos de carnero (GRc) sensibilizados con fragmentos de complemento (C'). La obtención de GRc sensibilizados con C3d, se evaluó con reactivos de calidad certificada por la firma comercial. Se obtuvieron reacciones de aglutinación francamente positivas con reactivos de Coombs poliespecíficos y con reactivos anti-C3d, -C3d monoespecíficos. La sensibilidad, especificidad y sencillez de esta técnica induce a proponerla dentro del protocolo de Control de Calidad de los antisueros AGH poliespecíficos y anti-C3d, -C3d, utilizados de rutina en los Servicios de Medicina Transfusional

A sequential study of circulating immune complexes, complement and immunoglobulins in borderline tuberculoid leprosy patients with and without reactions.

Sequential estimates of the levels of circulating immune complexes (CIC), complement catabolic fragment C3d, complement-mediated immune complex solubilization (CMS) and immunoglobulins were made in 24 newly diagnosed with borderline tuberculoid leprosy over a 20 month period after initiation of chemotherapy. Fourteen of these patients had not suffered from reversal reactions either at the time of presentation or during the follow-up. The levels of CIC were evaluated in them from the third to the eleventh month after starting chemotherapy and immunoglobulin G (IgG) levels were evaluated up to eight months. The concentrations of C3d and immunoglobulins A (IgA) and M (IgM) were normal in these patients. The other ten patients had reversal reaction at the time of diagnosis which subsided by the third month after starting treatment. They did not have reversal reactions later. The levels of CIC and IgG were elevated and those of CMS were depressed throughout the study period. Serum C3d level was initially elevated but came down to normal by the third month while IgA and IgM levels were within normal limits. The relevance of these findings to the genesis of reversal reaction is discussed in this communication.

The possible role of circulating immune complexes in the deficiency of cell-mediated immunity in paracoccidioidomycosis

1. The nature and extent of immune abnormalities was studied in 28 untreated patients with a chronic moderate form of paracoccidioidomycosis (PCM). 2. The patients presented hyporeactivity to skin tests, diminished lymphocyte transformation by mitogens such as phytohamgglutinin-P and concanavalin A and by Paracoccidioides brasiliensis protein antigen. They also presented peripheral blood leukocytosis but normal absolute numbers of T-cell and T-cell subsets. 3. The patients had increased serum levels of C3d, as well as high levels of circulating immune complexes (CIC) detected by C1q-binding and protein A-binding assays. 4. There was a significant negarive correlation between lymphocyte transformation by mitogens and CIC levels which suggested that CIC may be involved in the genesis of the depressed cell-mediated immunity in PCM patients