RESUMO
This study included 42 patients aged 12 to 20 years with nephritis, selected according to certain inclusion criteria to be evaluated histopathologically for determining the intensity of immunoglobulin and complement deposition in the glomeruli, as they have the most important role in glomerular injury and progression of the disease process in nephritis. After thorough clinical and laboratory evaluation of all cases, they were divided into three groups: Lupus nephritis [20 cases], acute post streptococcal glomerulonephritis [APSGN] [18 cases] and IgA nephropathy [4 cases]. Renal biopsy have been done for all cases and examined by light, electron and immunofluorescence microscopy. The results showed that cases of lupus nephritis were subdivided into: Stage II [3 cases], stage III [4 cases], stage IV [11 cases] and stage V [2 cases]. There were various amounts of immune complex and complement depositions in all stages [IgG, IgA, IgM, C3, C4 and Cql]. Stage lupus nephritis showed the highest intensity of immune complex deposition, specially IgG, IgM and C3. These deposits were more marked and more diffuse than other stages. In APSGN, 16 out of 18 cases showed mesangial deposits of all immune complexes, except Cql. All cases of APSGN showed marked significant deposition of C3 [100%] and C4 [75%]. The least deposited were IgA and IgM [3 and 2 cases, respectively]. All IgA nephropathy patients showed immune deposits in the mesangium and along the capillary wall. IgA was predominantly deposited in all cases [100%] and the second predominant immune complex was C3 [78.6%]. There was a strong correlation between intensity of immune complex deposits detected by IF microscopy and the ultrastructural changes were found on electron microscopy examination. Also, the degree of immune deposition is related to the severity of nephritis and to the pattern of glomerular damage