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At least 883 records · Page 49Linked to original sources
PubMed1981

A fluorescent assay for complement activation.

We report here a rapid assay for the complement enzymes CVFBb, C4b2a and Cls. This assay involves the use of a peptide substrate that releases a fluorescent coumarin derivative (AMC) upon cleavage by the convertase. The substrate, BocLeuGlyArgAMC, was chosen because its sequence is similar to the carboxyl terminus of C3a, and identical to that of C5a. The Km of this substrate are about 125 microM for the C3/5 convertase CVFBb, 169 microM for C4b2a, and 140 microM for C1s.

Complement Activation↗
PubMed1981

New evidence of circulating immune complexes in Crohn's disease using two sensitive methods.

Circulating immune complexes (AgAb) were studied in 183 serum samples from 119 patients with Crohn's Disease. AgAb were studied by the solid phase C1q binding test in all sera and also by the conglutinin binding assay in 161 sera. A significantly higher prevalence of circulating AgAb was observed in Crohn's disease patients in comparison with the control population. About one half of the sera were AgAb positive when the results of both tests were combined whereas AgAb were found in about one third of the sera by each individual method. Complexes revealed by the C1q-SP appeared to be related to the disease activity and to the occurrence of complications. Such a correlation was not observed as far as conglutinin results are concerned. Data emerging from the present investigation indicate that circulating AgAb may be present in Crohn's disease and suggest that the AgAb material is heterogeneous. They also suggest the possibility that AgAb represent a secondary phenomenon.

Antigen-Antibody Complex↗
PubMed1978

Glomerular lesions in patients with Schistosoma haematobium infection.

In order to investigate the prevalence and type of glomerular lesions in patients with overt Schistosoma haematobium (S H) infection, renal biopsies obtained from 13 patients were studied by light microscopy (in 13), ultra-structural (in 9) and immunofluorescence (in 11) techniques. Renal function was normal in all patients, only two had mild proteinuria. Glomerular deposits were absent in four patients. Electron microscopy showed in four cases an increase of the mesangial matrix with subendothelial deposits in the mesangial area. Subepithelial deposits were also present in one of these cases. Associated or isolated deposits of IgM, IgG, Clq, C3 were identified in the glomeruli of seven patients. Attempt to detect schistosomal antigen by using a high titer human anti-SH conjugate serum was unsuccessful. The relation between the glomerular lesions observed and schistosomiasis and other parasitic diseases is discussed.

Adult↗
PubMed1980

Immune complexes in scabies. In vitro study of the serum C1q fixation in the presence of mite and unparasited human scale extracts.

The in vitro addition of mice or human unparasited scale extracts to the serum of 8 patients with scabies and 5 healthy controls did not significantly modify the fixation of 125I-C1q as compared to control tubes (serum with physiological saline). These results suggest that antigens or substances derived from the scabies mite are not involved in the immune complexes present in the serum of the parasited patients.

Adolescent↗
PubMed1980

Circulating immune complexes and serum immunoglobulins in acute poststreptococcal glomerulonephritis.

Acute poststreptococcal glomerulonephritis (APSGN) is a disease thought to be induced by the renal deposition of circulating immune complexes. In order to test this possibility, serum samples from 119 patients with APSGN were studied for Clq binding activity (ClqBA), levels of IgG, IgM, IgA, C3 and antibody titers to streptococcal enzymes. These parameters were analyzed in relation to the clinical and laboratory data of the acute nephritic syndrome and with respect to the time elapsed from streptococcal infection and from the onset of nephritis. Elevated ClqBA was found in 66.7% of the patients in the first week of the disease and this frequency decreased progressively to 17.6% after the second week. Normal ClqBA was found in patients after the third week of nephritis. Serum levels of IgG and IgM were elevated in over 95% of the patients. Levels of IgG in excess of 2400 mg/dl were detected in 71.1% of the cases. No correlation could be found between the ClqBA and the clinical or immunoserological findings of the disease. The data support the hypothesis that circulating immune complexes are responsible for the nephritis that follows streptococcal infection.

Acute Disease↗
PubMed1980

Circulating immune complexes, complement and complement component levels in childhood Hodgkin's disease.

Serum levels of circulating immune complexes (CIC) assayed by the Raji cell radioimmunoassay, total haemolytic complement (TCH50), Clq and C3 were correlated with clinical stage, histological type, age, sex and treatment of eighty-six children with Hodgkin's disease over a period of 4 years. Most significant findings were the changes of levels of CIC, TCH50, Clq and C3 during disease activity and following treatment. Significant perturbations were also seen in association with relapse. Levels of C and CIC were significantly elevated (P less than 0.001) at the time of diagnosis prior to splenectomy and/or any treatment. In the group before treatment, 81 percent of CIC levels were above 16 micrograms/ml with a maximum value of 1120 micrograms/ml. During treatment 33 percent were still above normal with a maximum of 320 micrograms/ml. Within 1 year after cessation of treatment, 37 percent also remained above normal levels with a maximum of 240 micrograms/ml. At relapse prior to treatment, 63 percent were again elevated with a maximum of 1280 micrograms/ml. The most significant difference on TCH50 levels relates to treatment periods. Sera of patients with active disease who are previously untreated show elevation of TCH50 levels (P less than 0.001) (average 127 CH50 mu/ml. During and after treatment eht TCH50 levels drop to 96 and 102 CH50 mu/ml, as compared to normal control of 100 CH50 mu/ml. In sera of patients at the first, second or third relapse, the combined TCH50 levels are significantly different from controls and across treatment periods (P less than 0.005).

Adolescent↗
PubMed1980

The use of C1q, conglutinin and low affinity rabbit IgM antibody to human Fc in a ligand coctail radioassay for detecting and characterizing immune complexes in pathological sera.

A ligand radioassay for the detection of IC which utilizes C1q, bovine conglutinin and low affinity rabbit IgM anti-human Fc in a reagent coctail, is presented. IC are first isolated from serum by precipitation in polyethylene glycol, then analysed for their ability to react with the ligand coctail. Dual-label studies with 125I and 131I-tagged ligands, designed to determine whether the ligands bound independently to IC, indicate that the binding of each ligand to IC is not significantly affected by the presence of the other two ligands. The results of assaying pathological sera for IC by the ligand coctail radioassay correlate well with the results of three other assays. The assay system is also flexible enough to allow other low affinity IgM reagents to be used which could potentially cover the whole range of immunoglobulin classes occurring in pathological IC.

Antibody Affinity↗