Focal and segmental glomerulosclerosis in nephrotic syndrome: a new profile of adult nephrotic syndrome in Zaire.

In order to assess renal pathology, 92 clinically well-documented cases of nephrotic syndrome (NS) in adults (median age: 29) were systematically biopsied upon admission to the University Hospital of Kinshasa, between 1986 and 1989. All biopsies were paraffin embedded and histologically assessed by the routine methods of light microscopic examination. Histologic lesions were classified according to standard criteria. Focal and segmental glomerulosclerosis (FSG) was found in 41% of patients. The remaining 59% included minimal epithelial disease or minimal change nephropathy (MCN) responsive to corticosteroid therapy (14%), proliferative glomerulonephritis (PGN) (11%), membranous glomerulopathy (MGP) (10%), amyloidosis (10%), membrano-proliferative glomerulonephritis (MPGN) (8%), and "end stage kidney" (ESK) (7%). These results strikingly indicate the high prevalence of FSG. In comparison with previous findings from the same milieu, there is a seven-fold increase of this entity (41% versus 6%). The findings herein reported define a new histologic profile of NS in Zaire, characterized by the predominance of FSG. While in the past the vast majority of NS (52%) were putatively related to the intercurrent parasitic diseases, among which malaria was the chief etiology, similar associations were less important. Instead, no definite causative agent emerged for this apparently idiopathic condition. Further epidemiological and morphological intercorrelation studies, as well as the studies aimed at the relationships with AIDS, are in progress, with the purpose of identifying putative etiologies and risk factors responsible for the increase of FSG in Zaire.

Free intraglomerular malarial antigens.

Infection with Plasmodium berghei leads to a rapidly lethal disease in different strains of mice. Nude athymic mice are not able to produce circulating antibodies (IgG or IgM) against plasmodial antigens. Nevertheless, plasmodium-related antigens can be detected in the glomeruli of nude mice, in relation to the rising parasitaemia. This deposition is unrelated to the deposition of other immunoreactants (IgG, IgM or C3). The presence of the latter as well as the circulating auto-antibodies did not correlate with the intercurrent infection and control and experimental animals behaved likewise. These results indicate an intraglomerular localization of free malarial antigens. It is suggested that this may represent a basic mechanism for in situ formation of immune complexes in immunocompetent mice.

Nephrotic syndrome in Zaire. Morphological and aetiological aspects.

Morphological and aetiological aspects of 88 renal biopsies for nephrotic syndrome (NS) from Zaire are reported. About 52% were associated with a single or multiple infectious diseases particularly of parasitic origin. Three additional cases were associated with local non infectious conditions including the sickle cell disease and the abuse of mercuric-containing compounds. However, the histopathology was indistinguishable in both "idiopathic" and parasite-associated NS, and showed a wide range of common glomerulopathies. We conclude that the glomerular damage of the majority of NS from this area is probably mediated by nephritogenic immune complexes induced by several parasitic diseases, and would need further immunocytochemical investigations.