[Epidemiologic study of urinary calculi in Western France]. / Etude épidémiologique des calculs urinaires dans l'Ouest de la France.

OBJECTIVES: An epidemiologic study of urinary calculi (N = 1843) was conducted in Western France: distribution according to the main chemical compounds, age and sex. Comparison with the results of a study with national recruitment (N = 10,617) and a study with regional recruitment (N = 1774). METHOD: The study involved 1843 stones characterized beforehand by morphological analysis associated with infra-red spectrophotometry (FTIR). If analysis of the composition of the stones was carried out on the totality of calculi, studies related to age and sex included only 1583 cases. Comparison of percentages was made using chi 2 test. RESULTS: The composition in main compounds of calculi was comparable with the results of other studies; minor significant compounds presented great differences, raising the problem of interpretation of the infra-red spectra of the latter. Hence, our work was directed towards the analysis of the major compounds and we showed, like most authors, that monohydrate calcium oxalate is predominant in male (46%) as well as in females (37%). Calculi average sex-ratio was 2.19 but dehydrated calcium oxalate sex-ratio was 4.42, suggesting that this compound is found mainly in men. Conversely, for the majority of phosphate stones, the sex-ratio was lower or equal to one, indicating that they predominate in women. Infectious calculi (particularly struvite calculi) appeared slightly more frequent in our population than in other studies, whereas the number of uric acid calculi was lower. This, however, remains to be confirmed. CONCLUSION: The population studied was not significantly different from the national population regarding lithiasis, except perhaps for uric acid and struvite calculi, despite specific regional differences in diet and the role of nutritional factors in lithogenesis.

Inheritance of a stable mutation in a family with early-onset disease.

Autosomal/dominant polycystic kidney disease (ADPKD) exhibits a high inter- and intrafamilial heterogeneity partly explained by the involvement of at least 3 different genes in the disorder transmission. PKD1, the major locus, is located on chromosome 16p. The occurrence of very early-onset cases of ADPKD (sometimes in utero) in a few PKD1 families or the increased severity of the disease in successive generations raise the question of anticipation. This is a subject of controversial discussion. This report deals with the molecular analysis in families with very early-onset ADPKD. The finding of the same stable mutation with such different phenotypes rules out a dynamic mutation. The molecular basis of severe childhood PKD in typical ADPKD families remains unclear; it may include segregation of modifying genes or unidentified factors and the two-hit mechanism.

Novel mutations in the duplicated region of PKD1 gene.

Autosomal dominant polycystic kidney disease (ADPKD) exhibits a genetically heterogeneous transmission involving at least three different genes. PKD1 gene linked mutations are responsible for the disease in about 85% of ADPKD cases. The search for mutations is a very important step in understanding the molecular mechanisms underlying ADPKD. We undertook this study using denaturing gradient gel electrophoresis (DGGE), after a stage of long range PCR, to scan for mutations in the duplicated region of the PKD1 gene in French ADPKD families. This allowed us to identify eight novel mutations and several polymorphisms: among the mutations, three are nonsense mutations, two are deletions in the coding sequence leading to frameshift mutations, one is a splice mutation and two are highly probable missense mutations. In this paper, we also provide a review of the mutations reported so far which are widespread throughout the gene. Although no clear hot spot for mutation is apparent, we will focus on some clustering observed.

[Symptomatic treatment of nephrotic syndrome]. / Traitement symptomatique du syndrome néphrotique.

OBJECTIVES OF SYMPTOMATIC TREATMENT: The goal is to maintain quality of life, prevent immediate complications (thromboembolic events, infection, drug reactions), prevent late complications related to atherosclerosis, and limit the progression of the chronic renal failure. THERAPEUTIC ARMAMENTARIUM: Six categories can be described. i) A reduction in proteinuria, essential for controlling the intensity of other manifestations, can be improved with a normal protein content (1 g/kg ideal weight/d) low-salt diet, strict blood pressure control, and most importantly, CEI given alone or in combination with AA2. ii) Restoration of a normal extracellular fluid (edema and high BP) can be achieved by low sodium intake and loop diuretics in fractionated increasing doses (sometimes with combination regimens). It is advisable to keep blood pressure below 125/75 mmHg. iii) Prevention of thromboembolic events (risk level dependent on urine protein output) relies on antivitamin K anticoagulants and low-molecular weight heparins. iv) Adapted prescription of protein-bound drugs. v) Lowering LDL-cholesterol, a risk factor for atherosclerosis, with an adapted diet and HMG CoA inhibitors. vi) Prevention of chronic renal failure. The development and course of chronic renal failure depend not only on the histological glomerular lesion and/or the etiology but also on supplementary glomerular and tubulointerstitial damage directly related to the degree of proteinuria. MORE THAN SYMPTOM RELIEF: Symptomatic treatment of nephrotic syndrome must be considered as an integral part of a rigorous goal-oriented therapeutic strategy.

DGGE screening of PKD1 gene reveals novel mutations in a large cohort of 146 unrelated patients.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most commonly inherited renal diseases. ADPKD is a genetically heterogeneous disorder involving at least three different genes. PKD1, the major locus mapped to chromosome 16p13.3 accounts for approximately 85% of ADPKD cases. The search for mutations is a very important step in understanding the molecular mechanisms underlying ADPKD. Despite intense screening by many groups, only a small number of mutations have been described so far. We undertook the first study using denaturing gradient gel electrophoresis (DGGE) to scan for mutations in the non-duplicated region of the PKD1 gene in a large cohort of 146 French unrelated ADPKD patients. We successfully identified novel mutations: 3 are frameshift mutations, 2 nonsense mutations, 2 missense mutations, 1 is an insertion in the frame of 9 nucleotides, 3 intronic variations and several polymorphisms. One of these mutations is the fourth de novo mutation described in this gene. We also describe a family with possible clinical anticipation. DGGE is an effective method for detecting nucleotide changes in the PKD1 gene.

Massive proteinuria as a main manifestation of primary antiphospholipid syndrome.

Renal involvement in antiphospholipid syndrome (APS) is increasingly reported. So far, massive proteinuria as the principal feature of primary APS (PAPS) has not been well documented. We describe 3 patients with PAPS and massive proteinuria. Renal biopsy was performed in all 3, and features consistent with membranous and focal segmental glomerulopathy were disclosed. These histological lesions were not yet reported in PAPS. We conclude that the spectrum of renal lesions in PAPS is diverse and that it should be considered in the differential diagnosis of patients with massive proteinuria.

Cytochrome P450 4A and 2E1 expression in human kidney microsomes.

Laurate and arachidonate omega and (omega-1)-hydroxylase activities, cytochrome P450 2E1 (CYP2E1), and CYP4A content were measured in 18 human kidney microsomal samples. The rates of laurate and arachidonate were found to be very different from those measured in human liver samples, with a laurate omega/omega-1 ratio of approximately 22 in human kidney vs 0.75 in human liver. Immunoblot analysis of the 18 human kidney microsomal samples identified 1 CYP4A electrophoretic band, but CYP2E1 was not detectable in human kidney, contrary to liver. Laurate and arachidonate omega-hydroxylase activities were significantly correlated with CYP4A content (r = 0.86 and 0.75, respectively). Polyclonal antirat CYP2E1 antibody did not affect omega-hydroxylase activity, whereas the polyclonal antirat CYP4A1 antibody inhibited it by 60%. These results suggest that, in contrast to other species, human kidney microsomes do not contain significant amounts of CYP2E1, but possess CYP4A and fatty acid omega-hydroxylase activity.

Aberrant glycosylation of IgA from patients with IgA nephropathy.

Despite the prominent role of IgA, particularly IgA1, in the pathogenesis of IgA nephropathy (IgAN), the precise role of this molecule in the process remains unclear. Four biotin-conjugated lectins in sandwich-type enzyme-linked immunosorbent assays were devised to determine the glycosylation profiles of total IgA and its subclasses. We took advantage of differential binding properties of these lectins to sugar residues to dissect the oligosaccharide chains O-linked to the hinge and those N-linked to the Fc region of total IgA and IgA subclasses in 47 patients with IgAN and an equal number of controls. The proportion of sialylated IgA1 was higher in patients compared with controls (p < 0.02), whereas IgA2 in patients appeared less well sialylated. A reduction of galactose in pathological IgA as detected by RCA-I became significant after treatment of the molecule with neuraminidase (p < 0.01). Defective galactosylation was also observed for patient IgA1 when it was probed with ECL, a lectin that has a specificity for Gal 1,4 N-acetylglucosamine groupings on N-linked oligosaccharides. The RCA and ECL results, therefore, suggest that increased sialylation on the IgA1 is on O-linked oligosaccharides in the hinge region. This was partly confirmed by a small increase in the binding of PNA to IgA1 from the patient group. This lectin binds preferentially to Gal 1,3 N-acetylgalactosamine groups that are found on O-linked oligosaccharides.

[Endovascular treatment of traumatic and iatrogenic intrarenal arterial lesions by microcoil embolization]. / Traitement endovasculaire par microspires des lésions artérielles intrarénales traumatiques et iatrogènes.

Selective embolization is the best treatment for intrarenal arterial lesions due to trauma or percutaneous procedures with non-controlled or recurrent haematuria. Three male patients, aged 20-70 (mean 49 years), were recently treated in our institution by means of arterial embolization with microcoils. Two patients presented a pseudo-aneurysm and an arterio-venous fistula secondary to percutaneous nephrolithotomy and one patient presented an isolated pseudo-aneurysm due to trauma. In the 3 cases, haematuria (associated with retroperitoneal haemhorrage in one case) was not controlled and required repeated units of blood. Embolization allowed definitive treatment of these lesions. One of our patients with a solitary functional kidney presented rapidly increasing renal failure which completely resolved after arterial embolization. We think that microcoils are the embolic agents of choice to perform endovascular treatment in this indication.

Membranous nephropathy in primary antiphospholipid syndrome: description of a case and induction of renal injury in SCID mice.

Primary antiphospholipid syndrome (PAPS) is a recently recognized clinical entity encompassing the combination of thromboembolic phenomena, thrombocytopenia and recurrent abortions in the presence of antiphospholipid antibodies. We present a patient with PAPS accompanied by renal involvement, manifested as membranous nephropathy, as proven by a renal biopsy. To investigate further the possible association between PAPS and the renal lesions we attempted to induce similar renal manifestations by transferring peripheral blood lymphocytes (PBL) from this patient to severe combined immunodeficiency (SCID) mice. The mice transfused with PBL from the affected patient exemplified antiphospholipid antibodies (aPL) following which a renal lesion consistent with the human membranous nephropathy lesion was precipitated. This study substantiates the role of aPL as possible inducers of renal damage.

HLA class II typing and idiopathic IgA nephropathy (IgAN): DQB1*0301, a possible marker of unfavorable outcome.

Previous studies have reported associations between HLA antigens and Idiopathic IgA Nephropathy (IgAN). Nevertheless most of the studies were performed by serology. Thus we decided to perform the HLA class II typing of 58 patients by molecular biology techniques. We report a small increase of DRB1*04. But the main result of our study is the identification of a strong association between HLA DQB1*0301 and IgAN patients with an unfavorable outcome.

[Results of dietary evaluation during calcium oxalate and calcium phosphate lithiasis]. / Résultats du bilan alimentaire au cours de la lithiase oxalo-phospho-calcique.

In order to better understand the role of diet in etiology of urolithiasis, 84 oxalo-phospho-calcic-lithiasic patients (52 men, 32 women) have been studied by a nutritional week-interview and by urinary and blood testing. Diet data were compared to an ideal standard. Total caloric intake was 2428 +/- 651 calories/d; this intake is high in 7% women and 40% men. 79% out of patients are fat. Protidic intake is 87 +/- 21 g/d higher than 1 g/kg/d in 84.5% of patients. Lipids are high in 38.9 +/- 7%, glucid are low in 45.3 +/- 7%. Calcium intake is 934 +/- 406 mg/d, sodium intake is 12.9 + 3 g/d. Water intake is 2305 +/- 759 ml/d. Different groups of patients are studied: a) 21 patients with mean age of 43 +/- 12 years have recurrent lithiasis (R). This group is compared to 48 patients with 37 +/- 44 years who have a single lithiasis. Half of (R) patients have hypercalciuria, hyperphosphaturia and hyperoxaluria. Diet study is no different between these two groups. b) Other groups are studied: 21 have hyperophosphaturia (HPU) without hypophosphoremia and they have hypercalciuria, hyperuraturia and high urinary urea; diet shows higher glucicid and potassium intake than group with normal phosphaturia; 23 have hypercalciuria (HCU) and high uraturia and phosphaturia: diet study shows no difference with a group with normal calciuria. 21 have hyperoxaluria (HOU): diet study of a normal oxaluric group shows higher lipid intake, lower glucidic and calcium intake; 22 have hyperuraturia (HAU) and higher urinary urea, sodium and potassium than normouraturia group: in this group potassium intake is higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of interleukin-4 to isotypic distribution of anti-double-stranded DNA antibodies in systemic lupus erythematosus.

IgG subclasses of anti-double-stranded DNA antibodies were determined in 182 patients with systemic lupus erythematosus. All isotypes were detected, but IgG1 and IgG3 were predominant (62 and 51% of the cases, respectively). An average of 64 +/- 27% was IgG1, 16 +/- 22% IgG2, 16 +/- 19% IgG3 and 4 +/- 10% IgG4. The rank order or frequency was IgG1, IgG3, IgG2 and IgG4 in patients with musculoskeletal involvement; IgG1, IgG2, IgG3 and IgG4 in those with renal complications; IgG3, IgG1, IgG2 and IgG4 in those with cutaneous involvement; and IgG1, IgG3, IgG2 and IgG4 in those with hematological manifestations. Interleukin-4 (IL-4) was detectable in 17 of 36 selected patients, as opposed to 1 of 40 normal controls. The percentage of the total autoantibody contributed by IgG1 was significantly higher (p < 0.03) in these patients than in the remainder with undetectable levels of IL-4.

[Chronic lead nephropathy. Epidemiology and diagnosis]. / Néphropathie saturnine chronique. Epidémiologie et diagnostic.

Chronic lead nephropathy has recently been rediscovered. Its usual manifestations are hypertension, gout and renal impairment. Retrospective epidemiological data suggest that prolonged exposure to lead increases the risk of hypertension and nephropathy. An increase in EDTA-induced urinary lead concentration (above 600 micrograms/72 hours), perfectly representative of lead concentration in bone, has been found with a 5 to 12 percent prevalence in chronic renal impairment irrespective of its cause. The origin of lead impregnation and its influence on the course of the renal disease have not yet been elucidated.

Nephrocalcinosis in Sjögren's syndrome: a late sequela of renal tubular acidosis.

Sjögren's syndrome (SS) is an autoimmune exocrinopathy that develops into systemic autoimmune disease in 25% of patients, leading to general complications, one of which is kidney involvement. It presents mainly as interstitial nephritis, disclosed by hyposthenuria, distal renal tubular acidosis (RTA) and diabetes insipidus. We here describe five cases of SS with type-1 RTA (hyperchloraemic metabolic acidosis with an anion gap and alkaline urine pH) who developed nephrolithiasis, nephrocalcinosis and renal insufficiency. Hypercalciuria due to acidosis was the main nephrocalcinosis-prone factor in four patients; four subjects displayed diminished renal concentrating capacity, and two had hypokalaemia.