Prevalence of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis and Spatial Association With Quarries in a Region of Northeastern France: A Capture-Recapture and Geospatial Analysis.

OBJECTIVE: Silica is an environmental substance strongly linked with autoimmunity. The aim of this study was to assess the prevalence of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and renal limited vasculitis, in a northeastern region of France and to evaluate whether there was a geospatial association between the localization of quarries in the region and the prevalence of these AAVs. METHODS: Potential AAV patients were identified using 3 sources: hospital records, immunology laboratories, and the French National Health Insurance System. Patients who resided in the Alsace region of France as of January 1, 2016 and who fulfilled the American College of Rheumatology criteria for GPA or the 2012 Chapel Hill Consensus Conference definitions for GPA or MPA were included. Incomplete case ascertainment was corrected using a capture-recapture analysis. The spatial association between the number of cases and the presence of quarries in each administrative entity was assessed using regression analyses weighted for geographic region. RESULTS: Among 910 potential AAV patients, we identified 185 patients fulfilling inclusion criteria: 120 patients with GPA, 35 patients with MPA, and 30 patients with renal limited vasculitis. The number of cases missed by any source as estimated by capture-recapture analysis was 6.4 (95% confidence interval [95% CI] 3.6-11.5). Accordingly, the estimated prevalence in Alsace in 2016 was 65.5 GPA cases per million inhabitants (95% CI 47.3-93.0), 19.1 MPA cases per million inhabitants (95% CI 11.3-34.3), and 16.8 renal limited vasculitis cases per million inhabitants (95% CI 8.7-35.2). The risk of AAV was significantly increased in communities with quarries (odds ratio 2.51 [95% CI 1.66-3.80]), and geographic-weighted regression analyses revealed a significant spatial association between the proximity to quarries and the number of GPA cases (P = 0.039). In analyses stratifying the AAV patients by ANCA serotype, a significant association between the presence of quarries and positivity for both proteinase 3 ANCAs (P = 0.04) and myeloperoxidase ANCAs (P = 0.03) was observed. CONCLUSION: In a region with a high density of quarries, the spatial association between the presence of and proximity to quarries and the prevalence of AAVs supports the idea that silica may have a role as a specific environmental factor in this disease.

Metabolic syndrome in haemodialysis patients: prevalence, determinants and association to cardiovascular outcomes.

BACKGROUND: In the general population, metabolic syndrome (MetS) is predictive of major adverse cardiovascular events (MACE). Waist circumference (WC), a component of the MetS criteria, is linked to visceral obesity, which in turn is associated with MACE. However, in haemodialysis (HD) patients, the association between MetS, WC and MACE is unclear. METHODS: In a cross-sectional study of 1000 HD patients, we evaluated the prevalence and characterised the clinical predictors of MetS. The relationship between MetS and its components, alone or in combination, and MACE (coronary diseases, peripheral arteriopathy, stroke or cardiac failure), was studied using receiver operating characteristics (ROC) curves and logistic regression. RESULTS: A total of 753 patients were included between October 2011 and April 2013. The prevalence of MetS was 68.5%. Waist circumference (> 88 cm in women, 102 cm in men) was the best predictor of MetS (sensitivity 80.2; specificity 82.3; AUC 0.80; p <  0.05). In multivariate analysis, MetS was associated with MACE (OR: 1.85; 95CI 1.24-2.75; p <  0.01), but not WC alone. There was a stronger association between the combination of abdominal obesity, hypertriglyceridaemia and low high-density lipoprotein cholesterol with MACE after exclusion of impaired fasting glucose and hypertension. CONCLUSIONS: MetS is frequent and significantly associated with MACE in our haemodialysis cohort and probably in other European dialysis populations as well. In HD patients, a new simplified definition could be proposed in keeping with the concept of the "hypertriglyceridaemic waist".

[The recommendations of nephrologist are poorly followed by the primary care physician. The example of vaccination against hepatitis B]. / Les recommandations des néphrologues sont peu suivies par les médecins traitants. L'exemple de la vaccination contre l'hépatite B.

The relationship between specialist physician and primary care physician (PCP) has been poorly evaluated in France. We have studied the application of a specialist's recommendation by the PCP. Vaccination against hepatitis B in patients with chronic renal failure was the follow-up marker. After consultation, the nephrologist wrote in his report to the PCP that the vaccination was recommended. At the next nephrological consultation, the patient was asked if the PCP had proposed vaccination. The clinical, biological characteristics and history of the patients were recorded as well as number and location of the PCP consultations. Five nephrology centers recruited 315 patients. In 61.6% (194/315) of the cases, the vaccination was not proposed by the PCP. Only the estimated GFR (lowest in vaccinated patients, 29.5 vs. 34.5mL/min/1.73m2), the delay between the two consultations of the nephrologist (shorter in vaccinated patients, 18.7 vs. 22.9 weeks) and the nephrologist's practice center (17.5 to 52% vaccination rate) are statistically significant in univariate analysis. In multivariate analysis, only the center effect persists. The lack of vaccination was argued by a letter from the PCP in 2 cases (1%). In the absence of a direct questioning of the PCP, the reasons for not following the recommendation remain unexplained. Overall, the recommendation of the nephrologist was little followed. Our study can contribute to the reflection on the shared follow-up of patients suffering from chronic diseases.

[Compliance and leaflet's reading, which link and which media? Results from a French population with chronic kidney disease]. / Observance et lecture des notices, quel lien et quels médias ? Résultats d'une population avec maladie rénale chronique.

Leaflets inside drug boxes are complex and often poorly understood. Patients consulting in nephrology are mostly old and often suffer from multiple comorbidities. As so, they are often subject to various contra-indications and drug interactions. This paper aims to evaluate if patients actually read leaflets or other medical information on others medias such as Internet and whether this could, potentially, interfere with their observance. Results showed that leaflets were read by 65.1% of patients, leading to 12% of withdrawal or not taking drugs. Furthermore, compliance to medical guidance was deemed e-read by 65.1% of patients, leading to 12% of withdrawal or not taken drugs. Furthermore, this study showed no clear profile for non-compliant patients. Even the youngest patients (under 50 years old) have had a good compliance, with not more withdrawal or not taking pills. Nonetheless, youngest patients used more often to consult alternative medias and did not read much of the leaflets' information. Patients who were reading leaflets however, tended to search further information on other medias. This situation would create new challenges in health care, as it seems that data available on new medias are not systematically validated or adapted to the needs of the patients.

Oral antidiabetics use among diabetic type 2 patients with chronic kidney disease. Do nephrologists take account of recommendations?

BACKGROUND: There is an increasing prevalence of diabetes type 2 and chronic kidney disease, challenging appropriate prescribing of oral anti-diabetic drugs (OADs). METHODS: We have described the practice patterns of 13 nephrologists in 4 centers, in a cohort of 301 consecutive adult type 2 diabetic patients. Among oral anti-diabetic prescriptions, we have detailed drugs dosage for each subject, with 3 different formulae for estimating glomerular filtration rate (GFR) and its adequation according to the latest ERBP recommendations (2015). As individuals were mostly obese in this work, we also compare adequacy rates using both standard indexed CKD-EPI formula and CKD-EPI formula de-indexed from body surface area. RESULTS: Using the CKD-EPI formula as the reference method for estimating GFR, 53.5% of patients were outside the recommendations, mostly for metformin (30% of the whole cohort) and for sitagliptin (17.9% of the whole cohort). With Cockcroft and Gault formula, 38.2% of persons were outside recommendations and 45.9% (p<0.001) with CKD-EPI de-indexed. Among individuals consulting a nephrologist for the first time (n=90), 61.1% were outside recommendations (p=0.1). Among those persons under diabetologist supervision (n=103), 63.1% were outside recommendations (p=0.09), and were taking significantly more often metformin and insulin. CONCLUSION: We have found a substantial number of inadequate OAD prescriptions in type 2 diabetic patients with chronic kidney disease. The proportion of individuals outside guidelines was strongly affected by the method used for estimating GFR and by the type of practice, i.e., specialists versus general practitioners.

Continuous glucose monitoring in hemodialyzed patients with type 2 diabetes: a multicenter pilot study.

AIMS: Hemodialyzed patients with diabetes face an increased cardiovascular risk. Optimal glycemic control can reduce morbidity and mortality, but it is difficult to achieve because of the alternation between dialysis and non-dialysis periods. This study evaluated the contribution of continuous glucose monitoring (CGM) to the management of insulin regimen. METHODS: In this pilot prospective multicenter study, we performed CGM (Navigator®, Abbott, Rungis, France) for a total of 54 hours at baseline and for a 3-month follow-up period in a group of 28 hemodialyzed patients with type 2 diabetes treated by a basal-bolus detemir plus aspart insulin regimen. Insulin therapy was adapted to the CGM values. HbA1c and CGM parameters collected over the 3-month treatment period were compared using MANOVA for repeated measures. RESULTS: After 3 months, HbA1c significantly decreased from 8.4 ± 1.0% (65 ± 1 mmol/mol) to 7.6 ± 1.0% (60 ± 11 mmol/mol; p < 0.01). Similarly, mean CGM glucose values significantly decreased from 9.9 ± 1.9 to 8.9 ± 2.1 mmol/L (p = 0.05). The frequency of glucose values > 10 mmol/L significantly decreased from 41.3 ± 21.9% to 30.1 ± 22.4% (p < 0.05), without a significant increase in the frequency of glucose values < 3.3 mmol/L. Insulin requirements significantly increased from 70 ± 51 IU/d to 82 ± 77 IU/d (p < 0.001), without significant changes in body weight. CONCLUSIONS: CGM-adapted insulin regimen improves glycemic control without increasing hypoglycemic events in hemodialyzed diabetic patients. CGM could be a useful tool for the management of insulin therapy in these patients. These results need to be confirmed by long-term studies with larger sample sizes.

Parathyroid hormone-related protein is a mitogenic and a survival factor of mesangial cells from male mice: role of intracrine and paracrine pathways.

Glomerulonephritis is characterized by the proliferation and apoptosis of mesangial cells (MC). The parathyroid-hormone related protein (PTHrP) is a locally active cytokine that affects these phenomena in many cell types, through either paracrine or intracrine pathways. The aim of this study was to evaluate the effect of both PTHrP pathways on MC proliferation and apoptosis. In vitro studies were based on MC from male transgenic mice allowing PTHrP-gene excision by a CreLoxP system. MC were also transfected with different PTHrP constructs: wild type PTHrP, PTHrP devoid of its signal peptide, or of its nuclear localization sequence. The results showed that PTHrP deletion in MC reduced their proliferation even in the presence of serum and increased their apoptosis when serum-deprived. PTH1R activation by PTHrP(1-36) or PTH(1-34) had no effect on proliferation but improved MC survival. Transfection of MC with PTHrP devoid of its signal peptide significantly increased their proliferation and minimally reduced their apoptosis. Overexpression of PTHrP devoid of its nuclear localization sequence protected cells from apoptosis without changing their proliferation. Wild type PTHrP transfection conferred both mitogenic and survival effects, which seem independent of midregion and C-terminal PTHrP fragments. PTHrP-induced MC proliferation was associated with p27(Kip1) down-regulation and c-Myc/E2F1 up-regulation. PTHrP increased MC survival through the activation of cAMP/protein kinase A and PI3-K/Akt pathways. These results reveal that PTHrP is a cytokine of multiple roles in MC, acting as a mitogenic factor only through an intracrine pathway, and reducing apoptosis mainly through the paracrine pathway. Thus, PTHrP appears as a probable actor in MC injuries.

[Hematologic malignant complications after transplantation]. / Complications hématologiques malignes, en particulier lymphoprolifératives, après transplantation.

Post-transplant hemopathies are a serious complication of organ transplantation. They include several entities: non-hodgkin lymphoma, Hodgkin disease and myeloma. The pathophysiology, clinical and histological features, treatment and evolution of these diseases are different, but share some similarities. Among factors involved in lymphomagenesis, the role of Epstein Barr virus and immunosuppression are central. EBV primo-infection or reactivation together with a deep depression of T-cell immunity is at particular risk of lymphoma development. The clinical expression and outcome of lymphomas are varied. Assays for EBV replication quantification have been developed leading to immunosuppression decreasing and antiviral therapy when the replication increases. Treatment of post-transplant lymphoproliferations consists mainly in immunotherapy and chemotherapy. Hodgkin disease and myeloma are rare after transplantation; their management is close to the one of immunocompetent patients. The recurrence of myeloma, amyloidosis or light chain deposition disease seems frequent after transplantation and only patients with disappearance of monoclonal component should be proposed for transplantation. On the opposite, the risk of recurrence appears lower for Hodgkin disease; therefore the transplantation of patients with a history of Hodgkin disease looks possible.

Bardet-Biedl syndrome highlights the major role of the primary cilium in efficient water reabsorption.

Studies of the primary cilium, now known to be present in all cells, have undergone a revolution, in part, because mutation of many of its proteins causes a large number of diseases, including cystic kidney disease. Bardet-Biedl syndrome (BBS) is an inherited ciliopathy characterized, among other dysfunctions, by renal defects for which the precise role of the cilia in kidney function remains unclear. We studied a cohort of patients with BBS where we found that these patients had a urinary concentration defect even when kidney function was near normal and in the absence of major cyst formation. Subsequent in vitro analysis showed that renal cells in which a BBS gene was knocked down were unciliated, but did not exhibit cell cycle defects. As the vasopressin receptor 2 is located in the primary cilium, we studied BBS-derived unciliated renal epithelial cells and found that they were unable to respond to luminal arginine vasopressin treatment and activate their luminal aquaporin 2. The ability to reabsorb water was restored by treating these unciliated renal epithelial cells with forskolin, a receptor-independent adenylate cyclase activator, showing that the intracellular machinery for water absorption was present but not activated. These findings suggest that the luminal receptor located on the primary cilium may be important for efficient transepithelial water absorption.

Bardet-Biedl syndrome: a study of the renal and cardiovascular phenotypes in a French cohort.

BACKGROUND AND OBJECTIVES: Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive ciliopathy with a wide spectrum of clinical features including obesity, retinitis pigmentosa, polydactyly, mental retardation, hypogonadism, and renal abnormalities. The molecular genetic profile of BBS is currently being investigated after the recent identification of 14 BBS genes involved in primary cilia-linked disease. This study aims to characterize the renal and cardiovascular presentations and to analyze possible relationships between genotypes and clinical phenotypes. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS: This clinical study was performed in a national cohort of 33 BBS patients, 22 men and 11 women, all aged >16 years (mean age 26.3 years). RESULTS: Renal abnormalities, including impairment of renal function and signs of chronic interstitial nephropathy of dysplastic nature, were documented in 82% of the patients. Cardiovascular evaluations revealed that this group of young patients had significant cardiovascular risk factors. Hypertension was found in >30% of the patients and hyperlipidemia in >60%, and almost 50% had other metabolic abnormalities. Overt diabetes was present in only 6%. With regard to genotype-phenotype correlation, patients with a mutation in the BBS6, BBS10, or BBS12 gene (10 of 33 patients) had more severe renal disease. CONCLUSIONS: Our study results confirm the frequent occurrence of renal involvement in patients with BBS, underscore the high risk of cardiovascular disease in these patients, and provide new information on a possible genotype-phenotype correlation.