[Focusing on peritoneal dialysis adequacy]. / Adéquation en dialyse péritonéale : mise au point.

The optimal method to assess the adequacy of peritoneal dialysis therapies is controversial. Today, the adequacy must not be considered as a number or a concept assessed only by two parameters (total KT/V urea and total solute clearance) but defined by many more items. In the absence of data, based on theoretical considerations, the reanalysis of the CANUSA study showed that renal kidney function, rather than peritoneal clearance, was associated with improved survival. Residual renal function is considered as a major predictor factor of cardiovascular mortality. Results of this reanalysis were supported by the adequacy data in ADEMEX, EAPOS and ANZDATA studies. Therefore, clinical assessment plays a major role in PD adequacy. The management of fluid balance, the regular monitoring of malnutrition, the control of mineral metabolism and particularly the glucose load, considered as the "corner-stone" of the system, are the main points to be considered in the adequacy of PD patients. The essential goal is to minimize glucose load by glucose-sparing strategies in order to reduce the neoangiogenesis of the peritoneal membrane.

[A little known cause of chronic renal insufficiency in the adult: systemic tuberous sclerosis]. / Une cause mal connue d'insuffisance rénale chronique de l'adulte: la sclérose tubéreuse systémique.

BACKGROUND: Angiomyolipomas and renal cysts are commonly observed in patients with systemic tuberous sclerosis. Hemorrhagic complications related to the angiomyolipomas are well known. CASE REPORT: A 63-year old woman was hospitalized for severe chronic renal failure. Physical examination revealed skin manifestations of systemic tuberous sclerosis, which the patient had hidden to date. The radiographic work-up demonstrated complete disorganization of the renal parenchyma in both kidneys due to multiple cysts and angiomyolipomas. DISCUSSION: Chronic renal failure can be the inaugural manifestation in low-grade cases of systemic tuberous sclerosis which may go undiagnosed for years allowing progressive destruction of the kidneys.

Renal infarction and thrombosis of the infrarenal aorta in a 35-year-old man with primary antiphospholipid syndrome.

Renal manifestations of the "primary" antiphospholipid syndrome are rare. We report the case of an athletic 35-year-old man with an unremarkable medical history who suddenly developed hypertension and a renal infarction. Laboratory and radiological investigations showed a complete thrombosis of the infrarenal aorta, extensive collateral circulation arising from the superior mesenteric artery, and the primary antiphospholipid syndrome. Eight cases of renal infarction have previously been reported in the primary antiphospholipid syndrome. To our knowledge, this represents the first case of an infrarenal aortic thrombosis attributable to this syndrome.

[Nodular regenerative hyperplasia associated with primary antiphospholipid syndrome]. / Hyperplasie nodulaire régénérative associée à un syndrome primaire des antiphospholipides.

Nodular regenerative hyperplasia of the liver is characterized by diffuse nodularity of the hepatic parenchyma without fibrotic septa. It may be related to venous or arterial obstruction in the portal tract. We report a case of primary antiphospholipid syndrome associated with nodular regenerative hyperplasia in a 45-year old woman. The patient had an ischemic stroke, associated with an acute arterial ischemia of the left leg. She had high titers of serum anticardiolipin antibodies. Nodular regenerative hyperplasia of the liver was histologically confirmed and was associated with anicteric cholestasis. This case provides additional evidence that a thrombotic mechanism may play a role in the pathogenesis of nodular regenerative hyperplasia of the liver.

Uraemia is necessary for erythropoietin-induced hypertension in rats.

1. There is no experimental proof that renal insufficiency is a necessary condition for hypertension during erythropoietin treatment. 2. The present study compares the effect of 3 weeks treatment with r-hu EPO (50 i.u./kg) on systolic blood pressure (SBP), haematocrit and plasma cGMP in an animal model of chronic renal failure (remnant kidney model excision) and sham-operated rats. 3. Sub-total nephrectomy induced a significant fall in haematocrit and a significant increase in plasma creatinine levels. Treatment with r-hu EPO resulted in a significant haematocrit increase in uraemic as well as in non-uraemic rats. Despite this effect, r-hu EPO treatment had no effect on SBP in sham-operated rats. On the contrary, this treatment caused significant SBP elevation in uraemic rats; in these rats, SBP increase did not correlate with haematocrit increase. 4. Plasma cGMP concentrations were significantly higher in uraemic compared to sham-operated rats and were not modified by r-hu EPO treatment. 5. This study provides evidence that renal insufficiency in rats is a prerequisite for the development of hypertension during erythropoietin treatment.

[Vaccination against hepatitis B virus. Value of intradermal administration in dialysed patients non responsive to intramuscular approach]. / Vaccination contre le virus de l'hépatite B. Intérêt de l'administration intradermique chez les dialysés non répondeurs par voie intramusculaire.

OBJECTIVES: Approximately 16-27% of dialysis patients (DP) have no detectable antibodies after 5 intramuscular injections of hepatitis B vaccine and represent a group at high risk to contract hepatitis B virus. We report the efficacy of the intradermal route of a recombinant hepatitis B vaccine (r-HBV) in non-responsive dialysis patients in our dialysis unit. METHODS: Intradermal vaccinations were performed in 20 dialysis patients (mean age 62 years) non-responsive to the intramuscular injections (mean 6.8). Five micrograms of r-HBV (Engerix B, SK and F) were administered intradermally every two weeks (maximum 70 micrograms) until a level of anti-HBV antibodies (anti-HBs) arbitrarily choosen of > or = 230 mUI/ml was attained. Anti-HBs was determined after the fourth and subsequent intradermal injections (IMX, Abbott). RESULTS: Fourteen dialysis patients (70%) developed anti-HBs > 10 mUI/ml (geometric mean titers of 330 mIU/ml). Among these, 9 developed seroprotective levels before the fifth injection. Five patients developed anti-HBs > or = 1000 mUI/ml and 6 others developed anti-HBs > or = 230 mUI/ml. After the intradermal injections were discontinued, 11 patients were monthly monitored for at least 3 months, and 6 for one year. The geometric mean antibody level was at 3 months: 157 (n = 11), at 6 months: 122 (n = 8), at nine months: 117 (n = 6), and at 12 months: 66 mIU/ml (n = 6). The age and the sex, haemodialysis duration, albumin levels or treatment by erythropoietin did not seem to play a role in appearance of anti-HBs. CONCLUSIONS: Our experience in 20 dialysis patients shows that repeated low-dose intradermal injections resulted in long-term seroprotection in a substantial number of dialysis patients non-responsive to the intramuscular vaccinations.

[Chylous ascites in 12 patients undergoing peritoneal dialysis]. / Ascite chyleuse chez douze patients traités par dialyse péritonéale.

Chylous ascites is a rare clinical entity often secondary to a lymphoma. In peritoneal dialysis even mild chylous ascites can cause cloudiness of the peritoneal effluent and thus lead to early diagnosis. Twelve cases of chylous ascites (defined by the presence of chylomicrons) among 230 patients with chronic renal failure treated in two peritoneal dialysis centers (Limoges and Saint-Pierre de la Réunion) are reported. A malignancy was encountered in only two cases (a B-cell lymphoma and an ovarian cancer). In the other cases, a precise diagnosis was difficult to establish and was only presumed. Thus chylous effusion in seven cases seemed secondary to cirrhosis, chronic pancreatitis, systemic amyloïdosis or cardiac failure. In three cases the cause was unknown, although microtrauma due to the Tenckhoff catheter was highly suspected. Chylous ascites lasted more than two years in four cases. The long-term nutritional consequences did not justify a change in the method of dialysis.

Hypokalemic quadriplegia and respiratory arrest revealing primary Sjögren's syndrome.

We report a case of hypokalemic flaccid quadriplegia with sudden respiratory arrest in a 38-year-old woman discovered to have distal renal tubular acidosis which lead to the diagnosis of primary Sjögren's syndrome. This case is compared to 8 similar cases previously described in the literature.

[Control of vascular tone by the endothelium: the coupling active vasodilation in the kidney to renin secretion]. / Le contrôle de la vasomotricité par l'endothélium: le couplage de la vasodilatation active rénale à la sécrétion de rénine.

The vascular endothelium plays an essential role in regulating the contractility of the adjacent smooth muscle cell through its secretory and metabolic properties. One of these well known properties is the conversion of angiotensin I into angiotensin II. But the endothelium also secretes at least three compounds able to diffuse to the smooth muscle cell and exerting a paracrine action: these are the prostacyclin (PGI2), the endothelium derived relaxing factor (EDRF) and the endothelin 1. The secretion of these different vasoactive compounds by endothelial cells is triggered by mechanical events, such as the shear stress, or by the effect of several humoral factors locally released, for example from platelets. The compound NO (nitric oxide) is produced by the endothelial enzyme NO synthase from its precursor L-arginine, and is responsible for the vasodilatory and antiplatelets properties of EDRF. NO, by activating the soluble guanylate cyclase in the smooth muscle cell, is responsible for the endothelium dependent vasodilatation. We observed in an isolated perfused rat kidney that the compound L-NAME (NG-monomethyl-L-arginine methyl ester), a competitive inhibitor of NO synthase blocking the production of NO, induces renal vasoconstriction and inhibits renin release. This suggests that not only the renal vasoconstriction but also the renal vasodilatation are active processes, permanently regulated by vasoactive compounds such as EDRF. It seems also that EDRF plays an important role in maintaining the secretion of renin. It can be hypothetized that an abnormality in the release or fate of EDRF might perhaps contribute to high blood pressure, by both a direct effect on the vascular tone and an indirect effect on the release of renin, which in turn regulates also the renal and systemic hemodynamics.

Decreased renin release and constant kallikrein secretion after injection of L-NAME in isolated perfused rat kidney.

A possible role of the endothelial L-arginine/NO pathway in the control of renal hemodynamics, renin release and kallikrein secretion was studied in an isolated rat kidney model perfused in a closed-circuit. NG-nitro-L-arginine methyl ester (L-NAME, 1-50 microM), an inhibitor of nitric oxide biosynthesis, caused a dose-dependent increase in perfusion pressure (PP) and a dose-dependent decrease in renal perfusate flow. Renin release was inhibited independently of a rise in PP. L-NAME did not change the urinary kallikrein secretion. These results confirm the intervention of the L-arginine/NO pathway in the vasodilation of this isolated perfused kidney model and demonstrate the inhibitory effect of L-NAME on renin release. They suggest that nitric oxide synthesis plays a role in stimulating renin release and is not involved in the regulation of urinary kallikrein secretion.