[A non frequent cause of kidney disease]. / Le cas clinique du mois. Une cause peu fréquente d'insuffisance rénale chronique.

The EDTA (European Dialysis and Transplantation Association) statistic data on kidney diseases in ageing population point out vascular and/or metabolic origins. We report here a case of a rare cause of renal insufficiency, a Gougerot-Sjögren primary syndrome, diagnosed in an old patient. Renal and salivary gland biopsies were performed. The invasive investigation allowed an accurate diagnosis and an etiologic treatment.

[How I investigate ... Alport's syndrome by skin biopsy. When the skin speaks for the kidney]. / Comment j'explore ... le syndrome d'Alport par la biopsie cutanée. Quand la peau parle pour le rein.

Alport's syndrome is a severe hereditary renal disease. Type IV collagen is abnormal in its molecular composition both in the kidneys and the skin. Immunohistochemistry performed on a conventional skin biopsy allows to prove the diagnosis in the affected subjects and in healthy women exhibiting the mutation on a single X chromosome.

[Pituitary diseases in elderly patients with chronic renal insufficiency]. / Anomalies hypophysaires chez le sujet âgé avec insuffisance rénale chronique.

Chronic renal failure (CRF) in the elderly is a cause of multiple endocrine dysfunctions. The three most common pituitary axes involved are the thyrotrope, lactotrope and gonadotrope axes. Thyroid dysfunction may be the consequence of thyroid or pituitary failure. Hyperprolactinemia results in gonadal failure and is present in 30% of patients. Early presentation of menopause and andropause are common in patients with CRF. Sexual hormonal replacement is controversial and must be individually tailored. We propose a systematic screening in the elderly with CRF: determination of TSH, TPO antibodies and cervical palpation, measures of PRL, LH, FSH and testosterone to explore lactotrope and gonadotrope axis.

[Clinical case of the month. A new case of nephropathia epidemica due to Puumala virus]. / Le cas clinique du mois. Un nouveau cas de néphropathie épidémique à Puumala virus.

Nephropathia epidemica due to Puumala virus has already been described in Belgium. Its evolution is usually favourable. The main symptoms are fever, a decrease platelet count, proteinuria and acute renal insufficiency, which, in an epidemiological context, quickly point the correct diagnosis. Acute and transitory myopia is typical. Nevertheless, the clinical presentation, including multisystemic symptoms may lead to the false diagnosis of an acute bacterial or immune disease.

[Acute tubulo-interstitial nephropathy with uveitis: apropos of case]. / Néphropathie tubulo-interstitielle aiguë avec uvéite: à propos d'un cas.

We report another case of acute interstitial nephritis with uveitis (TINU syndrome) in a 35-year-old woman. About thirty cases were described since the first ones 20 years ago. We discuss the assessment needed to reach the diagnosis. The evolution is unusually favourable with steroid therapy.

Possible pathogenic role of IgE in Henoch-Schönlein purpura.

The incidences of clinical and biological markers of atopy were investigated in 16 children with IgA nephropathy (IgAN) (group A) and in 22 with Henoch-Schönlein purpura nephritis (HSPN) (group B). The incidence of increased plasma IgE levels according to age-matched normal values was significantly higher in group B (17/22, 77%) than in group A (7/16, 44%) (P < 0.05). Although not significant, the incidences of positive RAST tests and of a history of typical atopic symptoms were also higher in group B [10/22 (45%) and 11/22 (50%), respectively] than in group A [4/16 (25%) and 5/16 (31%), respectively]. Moreover, IgE deposits were demonstrated by a peroxidase/anti-peroxidase method on cutaneous Langerhans and mast cells in 4 of 6 patients with HSPN. Thus immunoallergy might account, in some cases, for the cutaneous, intestinal and pulmonary signs observed in HSPN, but not in IgAN. We postulate stimulation of IgE-sensitized mast cells by specific antigens in the presence of IgA circulating immune complexes (CIC), release of vasoactive substances, increased capillary permeability and perivascular deposition of IgA CIC.

Acute experimental glomerulonephritis induced by the glomerular deposition of circulating polymeric IgA-concanavalin A complexes.

The perfusion of polymeric or secretory IgA-Concanavalin A complexes into the aorta of rats led to a mannose-dependent binding of both IgA and lectin to the glomerular capillary wall, as shown by double immunolocalization experiments, by quantitative analysis of the amount of radiolabelled complexes bound per g of kidney, and by blocking experiments with the corresponding carbohydrate. Rats injected with amounts of those complexes as low as 500 micrograms developed, one hour later, a focal and segmental proliferative glomerulonephritis characterized by the deposition of injected complexes and of rat C3 and rat fibrin/fibrinogen in most glomeruli; focal thrombosis and small areas of necrosis in 10 to 15% of glomeruli, confined to the periphery of a single lobule of the tuft and segmental infiltration of these glomeruli by polymorphonuclear leucocytes and platelets. At the same time, many mesangial cells exhibited a hyperactive appearance, and red blood cells were noted in tubular lumens. In contrast, rats similarly injected with either monomeric IgA-ConA complexes, multimeric or secretory IgA-peanut agglutinin complexes or polymeric or monomeric IgA aggregates of comparable apparent molecular weight did not develop obvious glomerular lesions within one hour. The data indicate that performed polymeric IgA-ConA complexes can specifically bind to glomerular structures in vivo and trigger acute glomerular lesions locally, analogous to those observed in some glomerular diseases associated with a cryoglobulinaemia.

[Acute experimental glomerulonephritis induced by the glomerular deposition of circulating polymeric IgA-concanavalin A complexes]. / Glomérulonéphrite aiguë expérimentale induite par le dépôt glomérulaire de complexes circulants IgA polymérique-concanavaline A.

The perfusion of polymeric IgA (pIgA)--or secretory IgA (sIgA)--Concanavalin A (ConA) non-immune complexes (apparent Mol.Wt greater than 10(3) Kd) into the aorta of rats led to a dose-dependent and a mannose-dependent deposition of both IgA and lectin into the glomeruli. Rats injected with amounts of those complexes as low as 500 micrograms developed, one hour later, a focal and segmental proliferative glomerulonephritis characterized by: a) the deposition in the mesangial area of most glomeruli of injected complexes and of rat C3; b) small areas of fibrinoïd necrosis in 10 to 15% of glomeruli, confined to the periphery of a single lobule of the tuft; c) a segmental infiltration of those glomeruli by polymorphonuclear leucocytes, mononuclear phagocytes and platelets; d) a hyperactive aspect of mesangial cells; e) the presence of red blood cells in tubular lumens. By contrast, no glomerular lesions were obvious in rats similarly injected either with monomeric IgA (mIgA)-ConA, pIgA-peanut agglutinin (PNA) or sIgA-PNA complexes or with heat-aggregated pIgA or mIgA. The data indicate that preformed polymeric IgA-ConA complexes can specifically bind to glomerular structures in vivo and locally trigger, as antigen-antibody complexes, an acute inflammatory reaction resulting in glomerular lesions similar to those observed in Henoch-Schönlein purpura nephritis.

Urinary excretion of neutral proteinases in nephrotic rats with a glomerular disease.

A proliferative glomerulonephritis was induced in rats pre-immunized with rabbit IgG by injecting intravenously a sub-nephrotoxic dose of rabbit anti-glomerular basement membrane (GBM) IgG (A rats). Most rats (80%) developed a severe proteinuria (greater than 100 mg/24 hr) within two to five days after the injection of anti-GBM IgG. At the same time, microscopic examination of the kidneys revealed a glomerular infiltration by mononuclear phagocytes and a prominent decrease in the intensity of the colloidal iron reaction in glomeruli. A non-proliferative glomerular disease was induced in another group of rats (B rats) by intraperitoneal administration of aminonucleoside of puromycin. A marked proteinuria (greater than 100 mg/24 hr) occurred after six days in 90% of animals. Histochemical studies then revealed a decrease in staining intensity of glomeruli for polyanion. No glomerular hypercellularity was noted. In normal rats and in non-proteinuric A or B rats, the 24 hour urinary excretion of neutral proteinases ranged from 1.4 to 7.8 units (mean value +/- SEM, 4.69 +/- 0.60, N = 11), that of laminin ranged from 100 to 3,900 ng (mean value +/- SEM, 1,154 +/- 325, N = 10), and that of type IV collagen ranged from 160 to 420 ng (mean value +/- SEM, 306 +/- 26.5 ng, N = 8). In proteinuric rats from groups A (N = 11) and B (N = 9), the 24 hour urinary excretion of neutral proteinases significantly increased (mean values +/- SEM, 38.55 +/- 8.66 U for A rats and 42.17 +/- 7.92 U for B rats) and ran parallely with that of proteins, laminin and type IV collagen.(ABSTRACT TRUNCATED AT 250 WORDS)

Electron microscopic studies in a long-term follow-up of a case of congenital nephrotic syndrome.

A boy presenting with a severe congenital nephrotic syndrome diagnosed by histological analysis at the age of 3 weeks was biopsied again 7 years later. The ultrastructural glomerular basement membrane abnormalities depicted in the first biopsy were no longer present in the second one. The number of completely hyalinized glomeruli was not significantly decreased. The GFR remained normal, but a moderate persistent, non-selective proteinuria (800 mg/24 h) was noted without oedema. The patient however developed a progressive perceptive deficit of hearing.