We performed a genome-wide association study of IgA nephropathy (IgAN), a major cause of kidney failure worldwide. Discovery was in 1,194 cases and 902 controls of Chinese Han ancestry, with targeted follow-up in Chinese and European cohorts comprising 1,950 cases and 1,920 controls. We identified three independent loci in the major histocompatibility complex (MHC), a common deletion of CFHR1 and CFHR3 at Chr. 1q32 and a locus at Chr. 22q12 that each surpassed genome-wide significance (p-values for association between 1.59 × 10−26 and 4.84 × 10−9 and minor allele odds ratios of 0.63–0.80). These five loci explain 4–7% of the disease variance and up to a 10-fold variation in interindividual risk. Many of the IgAN–protective alleles impart increased risk of other autoimmune or infectious diseases, and IgAN risk allele frequencies closely parallel the variation in disease prevalence among Asian, European and African populations, suggesting complex selective pressures.

We performed a genome-wide association study (GWAS) of IgA nephropathy (IgAN), the most common form of glomerulonephritis, with discovery and follow-up in 20,612 individuals of European and East Asian ancestry. We identified six novel genome-wide significant associations, four in ITGAM-ITGAX, VAV3 and CARD9 and two new independent signals at HLA-DQB1 and DEFA. We replicated the nine previously reported signals, including known SNPs in the HLA-DQB1 and DEFA loci. The cumulative burden of risk alleles is strongly associated with age at disease onset. Most loci are either directly associated with risk of inflammatory bowel disease (IBD) or maintenance of the intestinal epithelial barrier and response to mucosal pathogens. The geo-spatial distribution of risk alleles is highly suggestive of multi-locus adaptation and the genetic risk correlates strongly with variation in local pathogens, particularly helminth diversity, suggesting a possible role for host-intestinal pathogen interactions in shaping the genetic landscape of IgAN.

BackgroundA cyclic corticosteroid-cyclophosphamide regimen is the first-line therapy for membranous nephropathy. Compared with this regimen, rituximab therapy might have a more favorable safety profile, but a head-to-head comparison is lacking.MethodsWe randomly assigned 74 adults with membranous nephropathy and proteinuria >3.5 g/d to rituximab (1 g) on days 1 and 15, or a 6-month cyclic regimen with corticosteroids alternated with cyclophosphamide every other month. The primary outcome was complete remission of proteinuria at 12 months. Other outcomes included determination of complete or partial remission at 24 months and occurrence of adverse events.ResultsAt 12 months, six of 37 patients (16%) randomized to rituximab and 12 of 37 patients (32%) randomized to the cyclic regimen experienced complete remission (odds ratio [OR], 0.4; 95% CI, 0.13 to 1.23); 23 of 37 (62%) receiving rituximab and 27 of 37 (73%) receiving the cyclic regimen had complete or partial remission (OR, 0.61; 95% CI, 0.23 to 1.63). At 24 months, the probabilities of complete and of complete or partial remission with rituximab were 0.42 (95% CI, 0.26 to 0.62) and 0.83 (95% CI, 0.65 to 0.95), respectively, and 0.43 (95% CI, 0.28 to 0.61) and 0.82 (95% CI, 0.68 to 0.93), respectively, with the cyclic regimen. Serious adverse events occurred in 19% of patients receiving rituximab and in 14% receiving the cyclic regimen.ConclusionsThis pilot trial found no signal of more benefit or less harm associated with rituximab versus a cyclic corticosteroid-cyclophosphamide regimen in the treatment of membranous nephropathy. A head-to-head, pragmatic comparison of the cyclic regimen versus rituximab may require a global noninferiority trial.Clinical Trial registry name and registration number:Rituximab versus Steroids and Cyclophosphamide in the Treatment of Idiopathic Membranous Nephropathy (RI-CYCLO), NCT03018535

Objective-To better understand the role of lecithin:cholesterol acyltransferase (LCAT) in lipoprotein metabolism through the genetic and biochemical characterization of families carrying mutations in the LCAT gene. Methods and Results-Thirteen families carrying 17 different mutations in the LCAT gene were identified by Lipid Clinics and Departments of Nephrology throughout Italy. DNA analysis of 82 family members identified 15 carriers of 2 mutant LCAT alleles, 11 with familial LCAT deficiency (FLD) and 4 with fish-eye disease (FED). Forty-four individuals carried 1 mutant LCAT allele, and 23 had a normal genotype. Plasma unesterified cholesterol, unesterified/total cholesterol ratio, triglycerides, very-low-density lipoprotein cholesterol, and pre-␤ high-density lipoprotein (LDL) were elevated, and high-density lipoprotein (HDL) cholesterol, apolipoprotein A-I, apolipoprotein A-II, apolipoprotein B, LpA-I, LpA-I:A-II, cholesterol esterification rate, LCAT activity and concentration, and LDL and HDL 3 particle size were reduced in a gene-dose-dependent manner in carriers of mutant LCAT alleles. No differences were found in the lipid/lipoprotein profile of FLD and FED cases, except for higher plasma unesterified cholesterol and unesterified/total cholesterol ratio in the former. Conclusion-In a large series of subjects carrying mutations in the LCAT gene, the inheritance of a mutated LCAT genotype causes a gene-dose-dependent alteration in the plasma lipid/lipoprotein profile, which is remarkably similar between subjects classified as FLD or FED. Key Words: familial lecithin:cholesterol acyltransferase deficiency Ⅲ fish eye disease Ⅲ high-density lipoproteins Ⅲ lecithin:cholesterol acyltransferase Ⅲ mutation T he lecithin:cholesterol acyltransferase (LCAT) (phosphatidylcholine:sterol-O-acyltransferase; EC 2.3.1.43) enzyme is responsible for the synthesis of cholesteryl esters (CE) in plasma. 1 Through this action, LCAT plays a central role in the formation and maturation of high-density lipoproteins (HDL), and in the intravascular stage of reverse cholesterol transport, the major mechanism by which HDL modulate the development and progression of atherosclerosis. A defect in LCAT function would be expected to enhance atherosclerosis by interfering with this process.The human LCAT gene encompasses 4.2 kilobases and is localized in the q21-22 region of chromosome 16. Methods SubjectsProbands with primary hypoalphalipoproteinemia (HALP), defined by a plasma HDL-C level below the fifth percentile for the age-and sex-matched general population, were identified by Lipid Clinics and Departments of Nephrology throughout Italy. Plasma samples were analyzed for total and unesterified cholesterol; in 18 unrelated index cases, the results were suggestive of a defect in the LCAT gene. Genetic analysis revealed that 13 of 18 index cases carried at least 1 mutant LCAT allele. Relatives of the 13 probands were invited to participate in the study. All subjects gave an informed consent. Blood samples were collected after an overni...

Background-Mutations in the LCAT

Italy was the first Western country to face the COVID-19 pandemic. Here we report the results of a national survey on kidney transplantation activity in February and March 2020, and the results of a three-round Delphi consensus promoted by four scientific societies: the Italian Society of Organ Transplantation, the Italian Society of Nephrology, the Italian Society of Anesthesia and Intensive Care, and the Italian Group on Antimicrobial Stewardship. All 41 Italian transplant centers were invited to express their opinion in the Delphi rounds along with a group of seven experts. The survey revealed that, starting from March 2020, there was a decline in kidney transplantation activity in Italy, especially for living-related transplants. Overall, 60 recipients tested positive for SARS-CoV2 infection, 57 required hospitalization, 17 were admitted to the ICU, and 11 died. The online consensus had high response rates at each round (95.8%, 95.8%, and 89.5%, respectively). Eventually, 27 of 31 proposed statements were approved (87.1%), 12 at the first or second round (38.7%), and 3 at the third (9.7%). Based on the Italian experience, we discuss the reasons for the changes in kidney transplantation activity during the COVID-19 pandemic in Western countries. We also provide working recommendations for the organization and management of kidney transplantation under these conditions.

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peritoneal fluid makes a reduction of phosphate dietary Phosphate metabolism in chronic renal failure intake impractical, the protein content of the diet being strictly linked to that of phosphate. Even though hypophosphataemia has been reportedWeekly phosphate removal in CAPD has been occasionally in chronic renal failure patients on dialysis reported to be ~70 mmol, with 4×2 l exchanges per treatment [1,2], phosphate (Pi) retention, often associday [12]. This value is quite similar to that found in ated with increased serum Pi, is the most common 35 of our CAPD patients (65.5±40.6 mmol/week), finding in this clinical setting. Pi retention is secondary and is ~20 mmol per week less than in haemodialysis to reduced or null renal excretion, and dialysis removal (HD) (84.3±19.1 mmol/week). However, in our is often, but not always, insufficient as compared with CAPD patients, urinary excretion (48.8±21.4) suba variably reduced intestinal absorption of Pi [3][4][5].stantially contributes to Pi balance, representing ~40% The main metabolic consequences of phosphate of the total Pi removed, while in most HD patients retention have been related to: (i) a possible direct [6 ] this route of Pi excretion is negligible. We found that and indirect (mediated by calcium and calcitriol reducurinary Pi excretion was linearly related to glomerular tion) [7,8] stimulation of parathyroid hormone; (ii) a filtration rate (GFR) values, evaluated as the mean direct involvement in extraosseous calcifications [9]; of creatinine and urea clearances in our CAPD and (iii) a detrimental effect on renal function [10], that can still be maintained at a significant level in patients (uPi mmol/day=−1.11+1.39×GFR; r=0.91, continuous ambulatory peritoneal dialysis (CAPD) P<0.001), stressing the importance of the preservation patients.of residual renal function in maintaining a good Before addressing the problem of Pi removal by metabolic balance in CAPD. dialysis treatment, it might be useful to recall some When we considered the factors affecting the dialytic points on Pi body distribution. Of the more than 650 g removal of phosphate in our CAPD patients by means of Pi contained in a medium-sized man, ~85% is of a multiple regression analysis ( Table 1), we found contained in bone, 14% in the cells and only 1% or that plasma Pi concentration plays the main role. less is in the plasma. It is also important to bear in Another important factor is represented by the glucose mind that the bulk of intracellular Pi is represented by concentration in the dialysate, and its influence on organic phosphate (nucleoside phosphate compounds, Pi removal was independent of ultrafiltration rate. phosphorylated enzymes, 2,3-diphosphoglycerate, pho-Finally, Pi removal by peritoneal dialysis was greatly sphocreatine, etc.) at 10-100 times the concentration affected by dialysate volume, with a calculated removal of inorganic phosphate with which it is in equilibrium. of ~95 mmol/week at a dialysate volume of 12 l per The inorganic intracellular phosphate is in turn...