Glomerular involvement in human kala-azar. A light, immunofluorescent, and electron microscopic study based on kidney biopsies.

Glomerular involvement characterized by mesangial cell proliferation with fibrillar thickening of the axial region and deposits of immune complexes is reported in three human cases of kala-azar. IgG was seen in all 3 and Igm in 2 patients. Complement (C3) was detected in the glomeruli in all cases and fibrinogen in the only case in which it was tested for. The deposits appeared mainly along the mesangium and their staining was particularly strong for complement and IgG. Electron microscopy detected granular electron dense deposits mainly close to mesangial cells. In one case clumps made us of electron dense lamellae were seen in the glomerular basal membrane interpreted as evidence of focal membranolysis. No granulocytes were seen in the glomeruli. Attempts to demonstrate antigen were unsuccessful. The pattern of the lesion resembles that described in the kidney of human cases of hepatosplenic schistosomiasis, and the distribution of the deposits suggests that relatively large, poorly soluble complexes formed either in the presence of excess antigen or, under certain circumstances, in the presence of excess antibody, are trapped in the glomerular capillaries. The aggregates are partially shunted to the mesangial cells, which enlarge and proliferate.

Human schistosomiasis: Schistosoma mansoni antigen detection in renal glomeruli.

Twelve kidney, five biopsy and seven necropsy specimens, all from schistosomiasis mansoni patients were studied by light and immunoflurescent microscopy in an attempt to detect antigen in the glomerular walls. Deposits of IgM, IgG,I gA, IgE, complement C3 and fibrinogen were observered in most cases. Antigen was successfully detected in two cases(one biopsy and one necropsy specimen), both exhibiting proliferative glomerulonephritis. The only clinical manifestation was a slight proteinuria. IgG antibodies eluted from the sutopsy kidney homogenates showed specific binding mostly to Schistosoma mansoni gut, thus spggesting that the fixed antibodies (eluates) are, at least partially, consituted by antibodies similar to the anti-circulating antigen. These data reinfroce the hypothesis that renal injury in schistosomiasis is mediated through an immune complex disease.

Acute glomerulonephritis: three episodes demonstrated by light and electron microscopy, and immunofluorescence studies--a case report.

The patient, a white boy, had 3 episodes of recurrent acute glomerulonephritis at 7, 12 and 17 years of age. The episodes were preceded by impetigo and there was a good clinical and laboratorial recovery after all of them. Renal biopsies were performed during the acute episodes, and the light, immunofluorescence and electron microscopy studies showed only lesions typical of acute glomerulonephritis. Four months after the third episode another renal biopsy demonstrated only lesions compatible with the subsiding stages of acute glomerulonephritis.

[Hematuria in children: retrospective study of 128 pediatric patients] / Hematúria na criança: estudo retrospectivo de 128 casos.

OBJECTIVE: To evaluate the diagnostic frequency of the various diseases associated with the development of hematuria in children, in a pediatric nephrology unit pertaining to a university hospital. METHODS: The clinical records of 128 children (70 male, 50 female) who presented intermittent/persistent macroscopic hematuria or persistent microscopic hematuria as the chief clinical complaint/finding, in the period of 1978-1995, were retrospectively analyzed. This evaluation was performed with special attention to the patientacute;s clinical history, physical examination, personal and family morbid history information. Patients whose investigation was not complete were not considered for analysis. The mean age on presentation was 8.2 years (5 months - 16 years) and the mean period of observation was 3.2 years (1 month-15 years). RESULTS: Macroscopic hematuria occurred in 104 patients and persistent microscopic hematuria was present in 24 patients. Urinary metabolic disturbances and urinary lithiasis, alone or in association, were diagnosed in the majority of the patients (65.5%). Hypercalciuria was the urinary metabolic disturbance (90.1%) mostly detected, either alone (73.2%) or in association with hyperuricosuria (16.9%). A positive family history of lithiasis was reported in 32.1% of the patients in which the diagnosis of lithiasis/urinary metabolic disturbance was confirmed. Glomerulopathies were diagnosed in 25% of the patients, with the predominance of post-infectious acute glomerulonephritis (11 patients, 34%). In 6 children, the etiology of hematuria was not elucidated, despite extensive investigation, including renal biopsy.CONCLUSION: The authors present an algorithm for the diagnosis of hematuria in children and suggest that in cases of isolated hematuria, presenting without clinical clues to the possible etiology, laboratory investigation should be started with the evaluation of urinary metabolic disturbances / lithiasis.