RENAL-DISEASE IN LYMPHATIC FILARIASIS - EVIDENCE FOR TUBULAR AND GLOMERULAR DISORDERS AT VARIOUS STAGES OF THE INFECTION

Brugia malayi-infected patients, endemic normals with high levels of s pecific antibodies and European controls were investigated for kidney disorders by noninvasive techniques. Groups of patients with filarial infections included asymptomatic, microfilaraemic cases (group I), pat ients with filarial fever (group 2) and with obstructive filariasis (g roup 3). Several patients underwent a treatment course with diethylcar bamazine (DEC) when blood and urine samples were collected. Urine samp les were investigated for proteinuria and analysed by SDS-PAGE to disc riminate between proteinurias caused by tubular and glomerular disorde rs. In addition, urine levels of alpha-I microglobulin, of the brush b order antigen gp400 and of N-acetyl-beta-glucosaminidase (NAG) activit y were determined as indicators of tubular disorders, the albumin cont ent of the urines served as indicator of glomerular alterations. IgG r heuma factors were also determined in the serum as possible reasons fo r glomerulonephritis. Neither in the endemic normals nor in the Europe an controls there was evidence for kidney disorders. Infected patients had significantly increased proteinuria compared to controls. There w ere no significant differences between the 3 groups of infected person s, although the mean protein levels were highest in cases with chronic disease and lowest in asymptomatic patients. Quantitative urine analy ses and results of accompanying tests suggest predominantly tubular bu t generally relatively weak disorders in asymptomatic infections; abun dant involvement of the kidney which involves both compartments of the organ in the course of filarial fever; and partly severe and probably chronically progredient kidney alterations, which predominantly affec t the glomerula in symptomatic cases. IgG rheuma factors do not seem t o play a role in filarial infection associated renal disease. DEC-trea tment indeed did not significantly alter degree and character of the p roteinuria, but relatively high albumin levels in the urine of treated persons yet suggest increased glomerular disorders in these cases. In conclusion, renal disease appears to be a common event in Brugia fila riasis; involving both the tubular and glomerular compartment of the o rgan its pathogenesis is obviously complex and nor only immune complex -mediated.