Relationship between Brucella immunocomplex and glomerulopathies

Background: Brucellosis is a zoonotic disease with a very wide spectrum of clinical findings. Brucellosis is about 10 times more prevalent in patients with renal failure (dialysis patients) compared to population background. Precipitation of immunocomplexes produced by brucellosis is important in causing glomerulonephritis. Because the hallmark of glomerular diseases is abnormal protein loss in the urine we have decided to study proteinuria in brucellosis immunocomplex. The aim of this study was to evaluate probable relationship between brucellosis and glomerulonephritis. Patients and methods: This cross sectional study, performed on 200 patients with a history of the disease for about 1 year, diagnosed as having chronic brucellosis. The diagnosis was confirmed in 150 patients and by applying Brucella Standard Agglutination Test (SAT) and 2-mercaptoethanol test (2-ME). Titers of IgG/IgM and IgG/IgA in two groups of "with proteinuria" and "without proteinuria" was measured. Results: Both SAT and 2-ME tests test demonstrated that proteinuria increases with rising antibodies titers. In SAT, titer 1/160 was the most frequent, observed in 44% of the patients. In 2-ME test 1/40 titer was observed in 44% of the patients and was the most frequent. Conclusion: Our results clearly demonstrated that in both chronic and acute patients, proteinuria increases with rising IgG/IgA and IgM/IgG titers. Therefore brucellosis can cause nephropathy but chronic or untreated brucellosis is more important because it can permanently damage kidney.