The complement components CH50, C3, C4, and C1q, factor B, nephritic factor (NF), and circulating immune complexes (CIC) have been studied in 22 patients with chronic mesangiocapillary glomerulonephritis (CMCGN). Of the 22 patients studied, eight had normal complement levels and 14 had hypocomplementemia with marked reductions of C3 and CH50. Of the latter 14 patients, nine disclosed an activation pattern that followed the alternate pathway, while in the other five the classical pathway was followed. The patients with hypocomplementemia following the alternate pathway and with positive NF activity (five cases) had a histologic pattern of type II CMCGN with dense deposits within the basal membrane, while those with hypocomplementemia following the classical pathway and negative NF activity disclosed a histologic pattern of type I CMCGN. The etiopathogenesis of these two types of glomerulonephritis remains to be elucidated. Although the presence of CIC is discussed and they are only rarely detected with the usual techniques, immune complexes have been implicated as possible responsible factors in these diseases. It has been demonstrated that the NF is an IgG with the characteristics of an autoantibody specific against the C3bB and C3bBb convertases of the alternate pathway, thus forming the trimolecular complex C3bBbNF. Because serum NF is frequently associated to type II CMCGN, it could be speculated that this trimolecular complex behaves as an immune complex, the convertase C3b beeing the antigen and the NF, the antibody, and that, under certain circumstances and because of its low molecular weight, it could cause nephritis by its deposit in the glomerular basal membrane.

Antigen-Antibody Complex↗

PubMed1981

Further evidence against preeclampsia as an immune complex disease.

Sera from 25 preeclamptic women were examined for the presence of circulating immune complexes (CICs) by the radioisotopic C1q binding assay (C1q-BA), the polyethylene glycol precipitation-complement consumption (PEG-CC) test, and the microcomplement consumption test (MCT). Five abnormal values were found by the MCT; 4 became normal after delivery, as did the preeclamptic clinical signs. Normal values were obtained by the C1q-BA and the PEG-CC test in all preeclamptic patients. In addition, maternal HLA antibodies and complement levels were investigated. There was no correlation between lymphocytotoxic activity and CICs in sera from patients with preeclampsia. Complement levels were in the normal range in all cases. It is concluded that CICs do not play a significant role in the pathogenesis of preeclampsia.

Antigen-Antibody Complex↗

PubMed1980

[Lupus nephritis: clinicomorphological manifestations (author's transl)].

Forty patients with systemic lupus erythematosus have been evaluated for clinicopathological evidence of renal involvement. Average age at the onset of the disease was 23 years; 90 percent of the patients were women. Indications for renal biopsy included clinical symptoms of nephropathy (34 patients) and signs of immunological activity (6 patients(. All biopsied specimens were examined under light microscope; 28 of them under immunofluorescence, and 18 under electron microscope. Histological classification was as follows: I) Normal kidney (2 patients); II) mesangial glomerulonephritis (6 patients); III) focal glomerulonephritis (10 patients); IV) diffuse proliferative glomerulonephritis (19 patients), and V) membranous glomerulonephritis (3 patients). Six patients had no clinical nephritis, two of them had normal kidneys and four had a mesangial glomerulonephritis. Patients in groups III, IV, and V showed clinical and biological evidence of renal involvement. Highest incidence of renal failure, nephrotic syndrome or high blood pressure was found among cases in group IV. Group IV accounted also for the highest mortality rate. Clinical course of 25 cases (1 of type II, 8 or type III, and 16 of type IV) on corticosteroid therapy for an average follow-up of 22.8 months has showed greater clinical improvement (proteinuria and renal function) of nephropathy type III than nephropathy type IV. Renal biopsy is a useful diagnostic and prognostic method in patients with systemic lupus erythematosus, even in those cases without clinical evidence of renal disease.

Adolescent↗

PubMed1979

[Hemodialysis and complement (author's transl)].

After observing alterations in the activity of the serum complement in patients undergoing periodic hemodialysis, the authors performed a preliminary study to determine repeatedly the activity of C3, C4, and CH50 in 44 patients. They discovered a consistent drop in C3 and CH50 while C4 remained normal. An attempt to explain these findings with information from the literature offered no more than a hypothesis for further study. While the possibility of a decline in the synthesis of the complement factors cannot be disregarded, the authors believe it is much more probable that they are consumed at a rate higher than normal. Since the C4 factor does not appear to be involved, activation is probably along the alternative pathway. Defective synthesis cannot be attributed to liver disease because the latter is not always present and because there is no relationship between C3 levels and levels of albumin or the presence of hepatopathy. The literature was reviewed for data that might support the idea that the complements in these patients are activated continuously by some process in connection with dialysis, by chemical products employed for to clean the machines, by commonly administered drugs, etc. Because so few data could be found on the subject, the authors consider that is necessary to study these mechanisms and their repercussions over a longer period of time.

Acute Kidney Injury↗

PubMed1976

[Sodium metabolism, plasma renin activity and arterial pressure in patients treated with periodic hemodialysis].

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Adult↗

PubMedDate not supplied

Serum levels of soluble interleukin-2 receptor in patients with ANCA-associated vasculitis.

Serum soluble interleukin-2 receptor (sIL-2R) concentrations were determined using the ELISA method in 19 cases of ANCA-associated vasculitis. These patients were classified as 7 cases of Wegener's granulomatosis (WG) and 12 cases of microscopic polyangiitis (MPA). Elevated levels of sIL-2R were present in the sera of these patients. Levels of serum sIL-2R were not significantly different in patients with WG and MPA either in the active or inactive phase, so the results were expressed as a unified ANCA associated vasculitis group. Concentrations of serum sIL-2R were significantly higher in ANCA-associated vasculitis during the active phase than during the inactive phase (p<0.05), and serum sIL-2R levels were significantly increased in these patients, in the active or inactive stage, compared with a group of healthy subjects (p<0.05). In patients with vasculitis, serum sIL-2R levels correlated with serum levels of C-reactive protein (p<0.05). In the active phase, concentrations of serum sIL-2R correlated to creatinine concentrations. No correlation was found between sIL-2R and ANCA levels in any of the stages of the disease. These findings suggest cellular immune activation in ANCA associated vasculitis.

Adult↗

PubMedDate not supplied

High prevalence of antithyroid antibodies in anti-glomerular basement membrane antibody-mediated disease.

Anti-glomerular basement membrane antibody (anti-GBM Ab)-mediated disease and autoimmune thyroiditis are characterized by the presence of organ-specific antibodies. The diagnosis of autoimmune thyroiditis is usually based on the presence of serum antithyroid antibodies. Few studies have addressed the relationship between anti GBM-Ab mediated disease and autoimmune thyroid pathology. Given that this disorder is often asymptomatic, associations of the two pathologies may be under-diagnosed. This study investigated the prevalence of serum antithyroid antibodies (antithyroglobulin (anti-TG) and anti-thyroid peroxidase (anti-TPO)) in patients with anti-GBM Ab-mediated disease. Antithyroid antibodies presence was investigated in sera from 35 patients in whom anti-GBM Ab-mediated disease had been diagnosed. Anti-glomerular basement membrane antibodies and anti-thyroid antibodies (anti-TG and anti-TPO) were assayed using an enzyme-linked immunosorbent assay. Forty-five percent of patients with anti-GBM Ab-mediated disease (16/35) had positive antithyroid antibody titers. Eighteen percent (3/16) suffered from subclinical hypothyroidism. In conclusion, the high prevalence of antithyroid antibodies in these patients suggests a possible pathogenic link between autoimmune thyroiditis and anti GBM Ab-mediated disease.

Adult↗

PubMedDate not supplied

[Anti-glomerular basement membrane disease: a new disease causing fever of unknown origin?].

Antiglomerular basement membrane disease is an autoimmune disorder characterized by the presence of antibodies directed against glomerular basement membrane. Pyrexia of unknown origin (PUO) is defined as temperatures higher than 38.3 degrees C on several occasions, with a duration of more than 3 weeks, and failure to reach a diagnosis despite 1 week of in-patient investigation. There is a large list of causes of PUO including infections, malignancies and autoimmune diseases, but antiglomerular basement disease has not been described as a cause. We present the first case of antiglomerular basement disease which presented with PUO.

Anti-Glomerular Basement Membrane Disease↗

PubMedDate not supplied

[Rapid-detection GBM-ANCA ELISA. An emergency tool for the early diagnosis of type I and II rapidly progressive glomerulonephritis].

Rapidly progressive glomerulonephritides (RPGN) are forms of necrotizing glomerulonephritis associated with anti-glomerular basement membrane (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) against the antigens proteinase-3 (anti-PR3) and myeloperoxidase (anti-MPO). RPGN have a course of rapid progression to renal failure. We compared the results from the semiquantitative ELISAs for anti-GMB antibodies, PR3-ANCA and MPO-ANCA and the indirect immunofluorescence technique (IIF) against a new rapid assay (30 minutes) for the same antibodies in patients with clinically suspected RPGN. The semiquantitative ELISAs for anti-GBM antibodies and PR3-ANCA and MPO-ANCA have a proven diagnostic significance in patients with RPGN I and III. There were no significant differences between the ANCA-GBM screening test and the results from the semiquantitative ELISAs (p > 0.05). We did not find significant differences between the results for PR3-ANCA and MPO-ANCA from the ANCA-GBM screening test with C-ANCA and P-ANCA IIF values (p > 0.05). We also corroborated that the ANCA-GBM screening test is a diagnostic tool for RPGN I and III as useful as the semiquantitative ELISAs and the IFF technique. The ANCA-GBM ELISA screening test is a tool as useful as the semiquantitative ELISA against anti-GBM antibodies for diagnosis of RPGN I. The comparison of the screening ELISA with the IIF technique and the semiquantitative ELISAs against PR3-ANCA and MPO-ANCA showed similar utility for diagnosis of RPGN III. The advantages of the new screening assay are that three antibodies are tested at the same time, yielding results in only 30 minutes.

Adolescent↗

PubMedDate not supplied

[Anti-glomerular basement membrane antibody mediated disease: revision of 32 cases and follow-up at one year of the diagnosis].

Anti-basement membrane antibody mediated disease is an unfrequent entity but with a high mortality and morbidity. We present a revision of 32 patients diagnosed of anti-basement membrane antibody mediated disease between 1983 and 1997, and their evolution at one year of the diagnosis. The clinical pattern of presentation was as a Goodpasture's syndrome (glomerulonephritis and lung haemorrhage) in 15 patients and glomerulonephritis without lung involvement in 17. We reviewed retrospectively the features at the clinical presentation, the different treatments, and the delay of the starting of it since the beginning of the symptoms, in order to evaluate a prognosis dats of the disease. After the retrospective study we deduce that anti-basement membrane antibody mediated disease has a high mortality although the different regimes of treatment applied (25%), and the need of renal replacement therapy at one year of diagnosis is also high (70.8%). The renal survival at one year of the diagnosis is low and the response to therapy depends on the serum creatinine value at the diagnosis. The contribution of immunocompetent leucocytes to renal hypercellularity suggests that both humoral and cell-mediated immunity play a role in this disease.

Adolescent↗

PubMedDate not supplied

[Circulating immune complexes in systemic lupus erythematosus].

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Antigen-Antibody Complex↗