Israel Medical Association Journal

Background: Anti-glomerular basement membrane (GBM) antibody disease, or Goodpasture’s disease, is the clinical manifestation of the production of anti-GBM antibodies, which causes rapidly progressive glomerulonephritis with or without pulmonary hemorrhage. Anti-GBM antibody detection is mandatory for the diagnosis of Goodpasture’s disease either from the serum or kidney biopsy. Renal biopsy is necessary for disease confirmation; however, in cases in which renal biopsy is not possible or is delayed, serum detection of anti-GBM antibody is the only way for diagnosis.

Objectives: To assess the predictive value of positive anti-GBM antibodies in a clinical setting. 

Methods: Data from anti-GBM antibody tests performed at one medical center between 2006 and 2016 were systematically and retrospectively retrieved. We recruited 1914 patients for the study. Continuous variables were computed as mean ± standard deviation, while categorical variables were recorded as percentages where appropriate. Sensitivity and specificity of anti-GBM titers were calculated. Kaplan–Meyer analysis was performed, stratifying survival according to the anti-GBM antibody titers.

Results: Of the 1914 anti-GBM test results detected, 42 were positive, 23 were borderline, 142 were excluded, and 1707 results were negative. Male-to-female ratio was 1:1.2. Sensitivity of anti-GBM test was 41.2% while specificity was 85.4%. Concerning the Kaplan–Meyer analysis, overall survival was 1163.36 ± 180.32 days (median 1058 days). 

Conclusions: Our study highlights the lack of sensitivity of serological testing of anti-GBM titers. Comparing survival curves, the survival correlated with anti-GBM titer only in a borderline way. Because highly sensitive bioassays are not routinely used in clinics, renal biopsy is still pivotal for Goodpasture’s disease diagnosis.

 

Background: The incidence of post-infectious glomerulonephritis (PIGN) has decreased over the last decades. As a result, recent epidemiological data from industrialized countries are scarce. 

Objectives: To evaluate patterns of PIGN in children and detect possible predictors of disease severity.

Methods: We collected clinical and laboratory data of patients with PIGN admitted to Schneider Children's Medical Center during 1994–2011. Diagnostic criteria included presence of hematuria with/without other features of nephritic syndrome along with hypocomplementemia and/or microbiological/serological evidence of streptococcal infection. Patients with other diseases (systemic lupus erythematosus, vasculitis, etc.) were excluded from the study. 

Results: A total of 125 patients with a mean age of 5.8 ± 3.3 years (range 1.5–17.6), of whom 16% were < 3 years, matched the study criteria. Presenting features included hypertension in 103 (82.4%) patients, azotemia in 87 (70.2%), fever in 49 (40%), and elevated C-reactive protein in 75 (81.5%). Isolated macrohematuria was found in 21 (16%). Full-blown nephritic syndrome was diagnosed in 51 patients (41.1%) and 28 (22.9%) had nephritic syndrome with nephrotic-range proteinuria. Depressed C3 complement levels were associated with the presence of nephritic syndrome (OR 0.73, 95%CI 0.60–0.88, P = 0.001) as well as older age (OR1.24, CI 1.08–1.43, P = 0.001). At last follow-up (mean 42 months) all examined patients (100 of 125) had normal renal function, 6 had hypertension, and 1 had proteinuria.

Conclusions: PIGN remains an important cause of glomerular disease in children and may affect very young patients. Nephrotic-range proteinuria with hypoalbuminemia seems to be more frequent than previously reported. Hypocomplementemia is associated with a more severe disease course, namely, azotemia and nephritic syndrome.