Genome-Wide Association Analysis of Protein-Coding Variants in IgA Nephropathy.

SIGNIFICANCE STATEMENT: Genome-wide association studies have identified nearly 20 IgA nephropathy susceptibility loci. However, most nonsynonymous coding variants, particularly ones that occur rarely or at a low frequency, have not been well investigated. The authors performed a chip-based association study of IgA nephropathy in 8529 patients with the disorder and 23,224 controls. They identified a rare variant in the gene encoding vascular endothelial growth factor A (VEGFA) that was significantly associated with a two-fold increased risk of IgA nephropathy, which was further confirmed by sequencing analysis. They also identified a novel common variant in PKD1L3 that was significantly associated with lower haptoglobin protein levels. This study, which was well-powered to detect low-frequency variants with moderate to large effect sizes, helps expand our understanding of the genetic basis of IgA nephropathy susceptibility. BACKGROUND: Genome-wide association studies have identified nearly 20 susceptibility loci for IgA nephropathy. However, most nonsynonymous coding variants, particularly those occurring rarely or at a low frequency, have not been well investigated. METHODS: We performed a three-stage exome chip-based association study of coding variants in 8529 patients with IgA nephropathy and 23,224 controls, all of Han Chinese ancestry. Sequencing analysis was conducted to investigate rare coding variants that were not covered by the exome chip. We used molecular dynamic simulation to characterize the effects of mutations of VEGFA on the protein's structure and function. We also explored the relationship between the identified variants and the risk of disease progression. RESULTS: We discovered a novel rare nonsynonymous risk variant in VEGFA (odds ratio, 1.97; 95% confidence interval [95% CI], 1.61 to 2.41; P = 3.61×10 -11 ). Further sequencing of VEGFA revealed twice as many carriers of other rare variants in 2148 cases compared with 2732 controls. We also identified a common nonsynonymous risk variant in PKD1L3 (odds ratio, 1.16; 95% CI, 1.11 to 1.21; P = 1.43×10 -11 ), which was associated with lower haptoglobin protein levels. The rare VEGFA mutation could cause a conformational change and increase the binding affinity of VEGFA to its receptors. Furthermore, this variant was associated with the increased risk of kidney disease progression in IgA nephropathy (hazard ratio, 2.99; 95% CI, 1.09 to 8.21; P = 0.03). CONCLUSIONS: Our study identified two novel risk variants for IgA nephropathy in VEGFA and PKD1L3 and helps expand our understanding of the genetic basis of IgA nephropathy susceptibility.

Relationship between total testosterone, sex hormone-binding globulin levels and the severity of non-alcoholic fatty liver disease in males: a meta-analysis.

Background: In recent years, many studies have reported the relationship between non-alcoholic fatty liver disease (NAFLD) and sex hormones, especially total testosterone (TT) and sex hormone-binding globulin (SHBG). However, the relationship between sex hormones and the severity of NAFLD is still unclear. Methods: PubMed, Embase, Cochrane Library, Web of Science, WanFang, China National Knowledge Infrastructure and VIP databases were searched for relevant studies from inception to 31 August 2021. Values of weighted mean differences (WMDs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were combined by Stata 12.0 software to evaluate the relationship between TT, SHBG and the severity of NAFLD in males. Results: A total of 2995 patients with NAFLD from 10 published cross-sectional studies were included for further analysis. The meta-analysis indicated that the moderate-severe group had a lower TT than the mild group in males with NAFLD (WMD: -0.35 ng/ml, 95% CI = -0.50 to -0.20). TT and SHBG were important risk factors of moderate-severe NAFLD in males (ORTT = 0.79, 95% CI = 0.73 to 0.86; ORSHBG = 0.22, 95% CI = 0.12 to 0.39; p < 0.001). Moreover, when the analysis was limited to men older than age 50, SHBG levels were lower in those with moderate-severe disease (WMD: -11.32 nmol/l, 95% CI = -14.23 to -8.40); while for men with body mass index (BMI) >27 kg/m2, moderate-severe NAFLD had higher SHBG levels than those with mild disease (WMD: 1.20 nmol/l, 95% CI = -2.01 to 4.42). Conclusion: The present meta-analysis shows that lower TT is associated with the severity of NAFLD in males, while the relationship between SHBG and severity of NAFLD is still to be further verified.

CMIP SNPs and their haplotypes are associated with dyslipidaemia and clinicopathologic features of IgA nephropathy.

The relationship between serum lipid profiles and related clinicopathologic features of IgA nephropathy (IgAN) and c-Maf-inducing protein (CMIP) gene polymorphisms is unclear. The present study was designed to examine the effect of CMIP single-nucleotide polymorphisms (SNPs) on dyslipidaemia and clinicopathologic features of IgAN. Clinical and pathological data from patients with IgAN diagnosed at the First Affiliated Hospital of Guangxi Medical University were collected. DNA was extracted from blood samples. CMIP rs2925979 and CMIP rs16955379 genotypes were determined by PCR and direct sequencing. Among 543 patients, 281 had dyslipidaemia (51.7%). Compared with the non-dyslipidaemia group, the dyslipidaemia group exhibited higher blood pressure, blood urea nitrogen, uric acid, and body mass index; higher prevalence of oedema, haematuria, tubular atrophy, and interstitial fibrosis; and lower albumin and estimated glomerular filtration rate. In the dyslipidaemia group, the frequency of C allele carriers was higher than that of non-C allele carriers for rs16955379. Multivariate linear regression analysis showed that total cholesterol, low-density lipoprotein and high-density lipoprotein were associated with rs16955379C allele carriers. Apolipoprotein B was associated with A allele carriers of rs2925979. Linkage disequilibrium was observed between rs16955379 and rs2925979, and rs2925979G-rs16955379T was the most common haplotype. The frequencies of the four CMIP SNP haplotypes differed between dyslipidaemia and non-dyslipidaemia groups in IgAN (P<0.05, for all above). Dyslipidaemia is a common complication in IgAN patients, and those with dyslipidaemia present poor clinicopathologic features. CMIP SNPs and their haplotypes are closely correlated with the occurrence of dyslipidaemia and clinicopathologic damage in IgAN patients.

Genome-Wide Meta-Analysis Identifies Three Novel Susceptibility Loci and Reveals Ethnic Heterogeneity of Genetic Susceptibility for IgA Nephropathy.

BACKGROUND: Eighteen known susceptibility loci for IgAN account for only a small proportion of IgAN risk. METHODS: Genome-wide meta-analysis was performed in 2628 patients and 11,563 controls of Chinese ancestry, and a replication analysis was conducted in 6879 patients and 9019 controls of Chinese descent and 1039 patients and 1289 controls of European ancestry. The data were used to assess the association of susceptibility loci with clinical phenotypes for IgAN, and to investigate genetic heterogeneity of IgAN susceptibility between the two populations. Imputation-based analysis of the MHC/HLA region extended the scrutiny. RESULTS: Identification of three novel loci (rs6427389 on 1q23.1 [P=8.18×10-9, OR=1.132], rs6942325 on 6p25.3 [P=1.62×10-11, OR=1.165], and rs2240335 on 1p36.13 [P=5.10×10-9, OR=1.114]), implicates FCRL3, DUSP22.IRF4, and PADI4 as susceptibility genes for IgAN. Rs2240335 is associated with the expression level of PADI4, and rs6427389 is in high linkage disequilibrium with rs11264799, which showed a strong expression quantitative trail loci effect on FCRL3. Of the 24 confirmed risk SNPs, six showed significant heterogeneity of genetic effects and DEFA showed clear evidence of allelic heterogeneity between the populations. Imputation-based analysis of the MHC region revealed significant associations at three HLA polymorphisms (HLA allele DPB1*02, AA_DRB1_140_32657458_T, and AA_DQA1_34_32717152) and two SNPs (rs9275464 and rs2295119). CONCLUSIONS: A meta-analysis of GWAS data revealed three novel genetic risk loci for IgAN, and three HLA polymorphisms and two SNPs within the MHC region, and demonstrated the genetic heterogeneity of seven loci out of 24 confirmed risk SNPs.  These variants may explain susceptibility differences between Chinese and European populations.

Association between VDR gene FokI polymorphism and renal function in patients with IgA nephropathy.

BACKGROUND: Studies have shown that the occurrence and development of IgA nephropathy (IgAN) are genetically susceptible, but the relationship between vitamin D receptor (VDR) gene polymorphisms and renal function in IgAN patients is unclear. METHODS: We investigated the relationship between VDR FokI (rs2228570) single nucleotide polymorphism (SNP) and renal function and related clinicopathologic parameters in IgAN patients. Clinical and pathological data of 282 IgAN patients treated at the First Affiliated Hospital of Guangxi Medical University were collected, and FokI genotypes were determined by PCR and direct sequencing. Patients were divided into the renal dysfunction group and normal renal function (control) group by estimated glomerular filtration rate (eGFR) and serum creatinine level. RESULTS: Frequencies of TT genotype and T allele in the renal dysfunction group were higher than those of the control group. Blood urea nitrogen, serum phosphorus (P), proportions of mesangial cell proliferation, interstitial fibrosis/tubular atrophy and crescents in T allele carriers were higher than those in non-T allele carriers, while eGFR and 25-Hydroxyvitamin D3 were lower in T allele carriers than non-T allele carriers. Multiple linear regression analysis showed that eGFR was affected by FokI genotypes in IgAN patients. Logistics regression analysis showed that middle and elderly age, elevated P, intact parathyroid hormone and TT genotype were independent risk factors for renal dysfunction in IgAN patients; the odds ratio of carrying the TT genotype was as high as 84.77 (P < 0.05 for all). CONCLUSIONS: IgA nephropathy patients carrying the VDR FokI TT genotype have an increased risk of renal dysfunction. VDR FokI SNP is closely related to renal function, calcium-phosphate metabolism, and related pathological damage in IgAN patients.

Matrine suppresses lipopolysaccharide-induced fibrosis in human peritoneal mesothelial cells by inhibiting the epithelial-mesenchymal transition.

BACKGROUND: Peritoneal fibrosis is the primary reason that patients with end-stage renal disease (ESRD) have to cease peritoneal dialysis. Peritonitis caused by Gram-negative bacteria such as Escherichia coli (E. coli) were on the rise. We had previously shown that matrine inhibited the formation of biofilm by E. coli. However, the role of matrine on the epithelial-mesenchymal transition (EMT) in peritoneal mesothelial cells under chronic inflammatory conditions is still unknown. METHODS: We cultured human peritoneal mesothelial cells (HPMCs) with lipopolysaccharide (LPS) to induce an environment that mimicked peritonitis and investigated whether matrine could inhibit LPS-induced EMT in these cells. In addition, we investigated the change in expression levels of the miR-29b and miR-129-5p. RESULTS: We found that 10 µg/ml of LPS induced EMT in HPMCs. Matrine inhibited LPS-induced EMT in HPMCs in a dose-dependent manner. We observed that treatment with matrine increased the expression of E-cadherin (F = 50.993, P < 0.01), and decreased the expression of alpha-smooth muscle actin (F = 32.913, P < 0.01). Furthermore, we found that LPS reduced the expression levels of miR-29b and miR-129-5P in HPMCs, while matrine promoted the expression levels of miR-29b and miR-129-5P. CONCLUSIONS: Matrine could inhibit LPS-induced EMT in HPMCs and reverse LPS inhibited expressions of miR-29 b and miR-129-5P in HPMCs, ultimately reduce peritoneal fibrosis. These findings provide a potential theoretical basis for using matrine in the prevention and treatment of peritoneal fibrosis.

The association of the CMIP rs16955379 polymorphism with dyslipidemia and the clinicopathological features of IgA nephropathy.

Immunoglobulin A nephropathy (IgAN) is among the most common primary glomerular diseases. The prognosis in IgAN is affected by dyslipidemia, a risk factor for cardiovascular disease. The c-Maf inducing protein (CMIP) gene has been found to be associated with lipid metabolism. But the association between the CMIP rs16955379 single nucleotide polymorphism (SNP) and dyslipidemia or the related clinicopathological features in IgAN have not been reported thus far. The present study investigated the correlation between them. The CMIP rs16955379 SNP genotypes of 300 subjects with IgAN recruited from the First Affiliated Hospital of Guangxi Medical University were identified by polymerase chain reaction and direct sequencing. Compared with the control (normal lipid) group, the dyslipidemia group with IgAN had higher blood uric acid, serum creatinine, blood urea nitrogen and urinary protein quantity, higher proportions of mesangial cell proliferation and renal tubular atrophy/interstitial fibrosis (IFTA), and a lower estimated glomerular filtration rate and serum albumin. The frequencies of the CMIP rs16955379 SNP TT genotype and T allele in the dyslipidemia group were higher than in the control group. Triglyceride, apolipoprotein A1 (ApoA1), ApoA1/B, incidences of mesangial cell proliferation, and IFTA were higher in TT genotype carriers than in CC/CT genotype carriers. Serum lipid profiles and dyslipidemia were significantly associated with renal dysfunction and IFTA. IgAN patients with the TT genotype were more likely to have dyslipidemia, renal dysfunction and IFTA (P < 0.05 for all above). These results indicate that CMIP rs16955379 SNP may be a genetic susceptibility gene for dyslipidemia and poor renal outcome in IgAN.

Fever and prodromal infections in anti-glomerular basement membrane disease.

AIM: Anti-glomerular basement membrane (GBM) disease is an autoimmune disorder with rapidly progressive glomerulonephritis and alveolar haemorrhage. Fever symptoms and prodromal infections have been reported in many cases, but still not been elucidated. METHODS: Our study enrolled 140 consecutive patients with anti-GBM disease and retrospectively analyzed the characteristics of fever symptoms and the possible reasons. RESULTS: Among the 140 patients, 94 (67.1%) patients presented with fever (over 37.5°C) prior to admission or within 48 h of hospitalization. Among those with fever, 74 (78.7%) patients had infections, 15 (16.0%) patients had positive serum anti-neutrophil cytoplasmic antibodies, all towards myeloperoxidase, which was comparable to the patients without fever (17.4%, P = 0.830). There were 93/140 patients suffered from infections, with 47.3% in lungs and 31.2% on upper respiratory tract. In some cases, we identified the microbes of infections, including Candida albicans, Escherichia coli, Acinetobacter baumannii, Enterococcus faecalis, Klebsiella pneumoniae, Hemolytic staphylococci, Pseudomonas aeruginosa and Citrobacter braakii. Patients with fever had higher levels of serum anti-GBM antibodies (154.9 ± 58.4 vs. 106.0 ± 63.2 IU/mL, P < 0.001), higher serum creatinine (733.4 ± 402.5 vs. 580.6 ± 368.1 µmol/L, P = 0.032), higher percentage of crescents (87.0 ± 15.6 vs. 67.4 ± 37.6%, P = 0.021), and higher frequency of progression to end stage renal disease (ESRD) (80.9% vs. 60.9%, P = 0.011). CONCLUSION: We concluded that fever is a common symptom in anti-GBM disease and associates with more severe glomerulonephritis. The majority of patients at presentation had fever with respiratory tract infections, which needs further investigation to reveal their role in the pathogenesis of anti-GBM disease.

The susceptible HLA class II alleles and their presenting epitope(s) in Goodpasture's disease.

Goodpasture's disease is closely associated with HLA, particularly DRB1*1501. Other susceptible or protective HLA alleles are not clearly elucidated. The presentation models of epitopes by susceptible HLA alleles are also unclear. We genotyped 140 Chinese patients and 599 controls for four-digit HLA II genes, and extracted the encoding sequences from the IMGT/HLA database. T-cell epitopes of α3(IV)NC1 were predicted and the structures of DR molecule-peptide-T-cell receptor were constructed. We confirmed DRB1*1501 (OR = 4·6, P = 5·7 × 10-28 ) to be a risk allele for Goodpasture's disease. Arginine at position 13 (ARG13) (OR = 4·0, P = 1·0 × 10-17 ) and proline at position 11 (PRO11) (OR = 4·0, P = 2·0 × 10-17 ) on DRß1, encoded by DRB1*1501, were associated with disease susceptibility. α134-148 (HGWISLWKGFSFIMF) was predicted as a T-cell epitope presented by DRB1*1501. Isoleucine137 , tryptophan140 , glycine142 , phenylalanine143 and phenylalanine145 , were presented in peptide-binding pockets 1, 4, 6, 7 and 9 of DR2b, respectively. ARG13 in pocket 4 interacts with tryptophan140 and forms a hydrogen bond. In conclusion, we propose a mechanism for DRB1*1501 susceptibility for Goodpasture's disease through encoding ARG13 and PRO11 on MHC-DRß1 chain and presenting T-cell epitope, α134-148 , with five critical residues.

MHC Class II Risk Alleles and Amino Acid Residues in Idiopathic Membranous Nephropathy.

Epitopes of phospholipase A2 receptor (PLA2R), the target antigen in idiopathic membranous nephropathy (iMN), must be presented by the HLA-encoded MHC class II molecules to stimulate autoantibody production. A genome-wide association study identified risk alleles at HLA and PLA2R loci, with the top variant rs2187668 within HLA-DQA1 showing a risk effect greater than that of the top variant rs4664308 within PLA2R1. How the HLA risk alleles affect epitope presentation by MHC class II molecules in iMN is unknown. Here, we genotyped 261 patients with iMN and 599 healthy controls at the HLA-DRB1, HLA-DQA1, HLA-DQB1, and HLA-DPB1 loci with four-digit resolution and extracted the encoded amino acid sequences from the IMGT/HLA database. We predicted T cell epitopes of PLA2R and constructed MHC-DR molecule-PLA2R peptide-T cell receptor structures using Modeler. We identified DRB1*1501 (odds ratio, 4.65; 95% confidence interval [95% CI], 3.39 to 6.41; P<0.001) and DRB1*0301 (odds ratio, 3.96; 95% CI, 2.61 to 6.05; P<0.001) as independent risk alleles for iMN and associated with circulating anti-PLA2R antibodies. Strong gene-gene interaction was noted between rs4664308(AA) and HLA-DRB1*1501/DRB1*0301. Amino acid positions 13 (P<0.001) and 71 (P<0.001) in the MHC-DRß1 chain independently associated with iMN. Structural models showed that arginine13 and alanine71, encoded by DRB1*1501, and lysine71, encoded by DRB1*0301, facilitate interactions with T cell epitopes of PLA2R. In conclusion, we identified two risk alleles of HLA class II genes and three amino acid residues on positions 13 and 71 of the MHC-DRß1 chain that may confer susceptibility to iMN by presenting T cell epitopes on PLA2R.

Vitamin D deficiency may predict a poorer outcome of IgA nephropathy.

BACKGROUND: Experimental studies showed that 25-hydroxy-vitamin D [25(OH)D] deficiency (defined as 25-hydroxy-vitamin D < 15 ng/ml) has been associated with CKD progression. Patients with IgA nephropathy have an exceptionally high rate of severe 25(OH)D deficiency; however, it is not known whether this deficiency is a risk factor for progression of IgA nephropathy. We conducted this study to investigate the relationship between the plasma level of 25(OH)D and certain clinical parameters and renal histologic lesions in the patients with IgA nephropathy, and to evaluate whether the 25(OH)D level could be a good prognostic marker for IgA nephropathy progression. METHODS: A total of 105 patients with biopsy-proven IgA nephropathy were enrolled between 2012 and 2015. The circulating concentration of 25(OH)D was determined using serum samples collected at the time of biopsy. The primary clinical endpoint was the decline of estimated glomerular filtration rate (eGFR; a 30 % or more decline compared to the baseline). RESULTS: Mean eGFR decreased and proteinuria worsened proportionally as circulating 25(OH)D decreased (P < 0.05). The 25(OH)D deficiency was correlated with a higher tubulointerstitial score by the Oxford classification (P = 0.008). The risk for reaching the primary endpoint was significantly higher in the patients with a 25(OH)D deficiency compared to those with a higher level of 25(OH)D (P = 0.001). As evaluated using the Cox proportional hazards model, 25(OH)D deficiency was found to be an independent risk factor for renal progression [HR 5.99, 95 % confidence intervals (CIs) 1.59-22.54, P = 0.008]. CONCLUSION: A 25(OH)D deficiency at baseline is significantly correlated with poorer clinical outcomes and more sever renal pathological features, and low levels of 25(OH)D at baseline were strongly associated with increased risk of renal progression in IgAN.

Identification of new susceptibility loci for IgA nephropathy in Han Chinese.

IgA nephropathy (IgAN) is one of the most common primary glomerulonephritis. Previously identified genome-wide association study (GWAS) loci explain only a fraction of disease risk. To identify novel susceptibility loci in Han Chinese, we conduct a four-stage GWAS comprising 8,313 cases and 19,680 controls. Here, we show novel associations at ST6GAL1 on 3q27.3 (rs7634389, odds ratio (OR)=1.13, P=7.27 × 10(-10)), ACCS on 11p11.2 (rs2074038, OR=1.14, P=3.93 × 10(-9)) and ODF1-KLF10 on 8q22.3 (rs2033562, OR=1.13, P=1.41 × 10(-9)), validate a recently reported association at ITGAX-ITGAM on 16p11.2 (rs7190997, OR=1.22, P=2.26 × 10(-19)), and identify three independent signals within the DEFA locus (rs2738058, P=1.15 × 10(-19); rs12716641, P=9.53 × 10(-9); rs9314614, P=4.25 × 10(-9), multivariate association). The risk variants on 3q27.3 and 11p11.2 show strong association with mRNA expression levels in blood cells while allele frequencies of the risk variants within ST6GAL1, ACCS and DEFA correlate with geographical variation in IgAN prevalence. Our findings expand our understanding on IgAN genetic susceptibility and provide novel biological insights into molecular mechanisms underlying IgAN.

Efficacy of coenzyme Q10 in mitigating spinal cord injury-induced osteoporosis.

Spinal cord injury (SCI)­induced osteoporosis may cause mild trauma to bone and increase the risk of bone fracture. The present study aimed to investigate the efficacy of coenzyme Q (CoQ10) on SCI­induced osteoporosis in rats. SCI was induced by surgical transection of the cord at the T10­12 level. Animals were treated with CoQ10 (10 mg/kg; intragastrically) daily from 12 h after the surgery and over 10 subsequent days. At the end of the experimental period, blood was collected from the animals and femurs and tibiae were removed for evaluation using biochemical assays. Treatment with CoQ10 prevented SCI­induced bone loss by rescuing the decreased levels of bone mineral density and bone mineral content observed in the SCI rats. Furthermore, CoQ10 administration reduced bone malondialdehyde levels with a concomitant increase in superoxide dismutase levels, thus alleviating SCI­induced oxidative injury. In addition, serum inflammatory cytokine levels were markedly increased in rats post­SCI, which was attenuated by treatment with CoQ10. Finally, the osteoclast­specific genes receptor activator of nuclear factor kappa­B ligand and cathepsin K were significantly upregulated and the osteoblast­specific gene core­binding factor alpha 1 in the femur was downregulated following SCI, which was effectively restored following treatment with CoQ10. The results suggested that CoQ10 treatment may be effective in attenuating SCI­induced osteoporosis.

Prevalence and risk factors associated with chronic kidney disease in a Zhuang ethnic minority area in China.

AIM: Numerous studies have examined and reported a high prevalence of chronic kidney disease (CKD) in the general population in various countries including China. However, the situation may be different in undeveloped rural minority regions in China because of China's economic diversity. The aim of the present study was to estimate the prevalence of CKD and to analyze its associated factors in a Zhuang ethnic minority area in Southwest China. METHODS: A cross-sectional survey of a rural minority area populated by people of Zhuang ethnicity in Southwest China using multistage, cluster random sampling methods was performed. The prevalence of indicators of kidney damage and CKD were calculated and risk factors associated with the presence of CKD were analyzed. RESULTS: In total, 7588 people participated in the study. After adjustment for age and gender, the prevalence of albuminuria, haematuria and reduced estimated glomerular filtration rate were 2.7%, 3.7%, and 2.2%, respectively. After adjustment for age and gender, the prevalence of CKD was 8.3%, while recognition of the disease was 3.6%. Independent risk factors associated with CKD were age, gender, and hypertension. Risk factors independently associated with kidney damage were age, gender, hyperuricaemia, and hypertension. CONCLUSION: Our data exhibited a lower prevalence and awareness of CKD in undeveloped rural minority regions, especially exhibited a low prevalence of albuminuria. This result attributed to the low prevalence of metabolic disorders in the local region. Risk factors associated with CKD in our study is similar to surveys in other regions of China.

Effect of active vitamin D on cardiovascular outcomes in predialysis chronic kidney diseases: A systematic review and meta-analysis.

AIM: Vitamin D deficient patients present an increased risk of cardiovascular disease. We conducted this systematic review and meta-analysis to evaluate the effect of active vitamin D analogue on cardiovascular outcomes in predialysis chronic kidney disease. METHODS: Pubmed, Embase, the Cochrane Library, CNKI, and article reference lists were searched for randomized controlled trials (RCTs) that compared active vitamin D analogues with placebo or no treatment for patients with predialysis chronic kidney disease. A meta-analysis was conducted using the standard methods consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Reviewer Manager Software, ver. 5.2, was used. RESULTS: Seven RCTs (five studies with paricalcitol and two studies with calcitriol, 731 patients) were included. Compared with control groups, active vitamin D reduced the incidence of cardiovascular events (RR, 0.27; 95% CI, 0.13-0.59), induced an increase in those with proteinuria reduction (RR, 1.9; 95% CI, 1.34-2.71), but did not alter left ventricular mass index and systolic function (MD, 0.42 g/m2.7 ; 95% CI, -0.23-1.07 g/m2.7 , P = 0.21 for left ventricular mass index and MD, -0.33; 95% CI, -0.74-0.07, P = 0.1 for left ventricular ejection fraction). Neither systolic blood pressure nor diastolic blood pressure was reduced by active vitamin D (MD, 0.3 mmHg; 95% CI, -4.95-5.56 mmHg; MD, -0.24 mmHg; 95% CI: -6.21-5.72 mmHg, respectively). Increased probability of hypercalcaemia after paricalcitol therapy was found (RR, 7.85; 95% CI, 2.92-21.10). CONCLUSION: Active vitamin D reduced the incidence of cardiovascular events and induced a reduction in proteinuria, but its long-term effect on cardiac structure and function needed further confirmation. Increased probability of hypercalcaemia after paricalcitol therapy was found.

The alternative pathway of complement activation may be involved in the renal damage of human anti-glomerular basement membrane disease.

Linear deposition of IgG and complement 3 (C3) along glomerular basement membrane (GBM) is generally revealed in the kidneys of human anti-GBM disease. Our recent studies demonstrated the pathogenic role of complement activation in renal damage of this disease. However, the pathways of complement activation were still paradoxical. In this study, renal biopsy tissues from 10 patients with anti-GBM disease were used to investigate the pathways of complement activation by detecting the deposition of various complement components, including C1q, factor B, factor P (properdin), mannose-binding lectin (MBL), C3d, C4d and C5b-9, using immunohistochemistry and immunofluorescence. We found that C1q, factor B, properdin, C3d, C4d and C5b-9 were detected in all the glomeruli of our patients, along GBM with a linear and/or granular staining pattern. Furthermore, C1q, factor B and properdin co-localized well with C5b-9. The properdin also co-localized well with C3d. However, the deposition of MBL was diffusive in mesangium, GBM, Bowman's capsule and within crescents and was not co-localized with C5b-9 but partially co-localized with C4d. The intensity of factor B deposition (3.3 vs. 1.2, P<0.001) and C5b-9 deposition (3.2 vs. 1.6, P<0.001) was significantly stronger in the glomeruli with crescent formation, compared with the glomeruli without crescents. The complement system is overall activated via both the alternative pathway and classical pathway in the kidneys of human anti-GBM disease. The alternative pathway might play an important role in complement activation induced renal damage.

Benefits and harm of niacin and its analog for renal dialysis patients: a systematic review and meta-analysis.

PURPOSE: Clinical trials have shown that niacin and its analog, niacinamide, significantly reduce serum phosphate in patients undergoing dialysis. This review aimed to assess the benefits and harm of niacin and niacinamide in renal dialysis patients. METHODS: PubMed, EMBASE, and Cochrane Library were searched, without language limitation, randomized controlled trials (RCTs). Standard methods, consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, were used. Reviewer Manager software, version 5.2, was used for meta-analysis. RESULTS: Five RCTs with a sample size of 230 patients were included. The meta-analysis showed that niacin and niacinamide significantly decreased serum phosphorus levels [weight mean difference (WMD) -0.88; 95 % confidence interval (CI) -1.19 to -0.57] as well as the calcium × phosphorus product (Ca × P) (WMD -9.15; 95 % CI -13.23 to -5.08), and increased high-density lipoprotein (HDL) levels (WMD 9.30; 95 % CI 5.86-12.74) in renal dialysis patients. Niacin significantly increased the risk of flushing [relative risk (RR) 33; 95 % CI 4.71-232.12] in these patients, while the risk of thrombocytopenia was significantly increased in the niacinamide group (RR 2.82; 95 % CI 1.14-6.94). However, sensitivity analysis showed that our finding regarding thrombocytopenia should be regarded with a low degree of certainty. CONCLUSION: Niacin and its analog effectively improved phosphorus metabolism in renal dialysis patients. However, niacin can cause flushing and niacinamide probably cause thrombocytopenia. Further larger sample size and well-designed RCTs are needed.

[An epidemiology study on hypertension in the Zhuang nationality village from the Guangxi Zhuang Autonomous Region].

OBJECTIVE: To observe the risk factors and prevalence status of hypertension at the Guangxi Zhuang-rural region. METHODS: Through cross-sectional survey, Xinlan village (Ethnic-Zhuang tribe village) in Liangqing District of Nanning was chosen as survey site. Select Zhuang-ethnic villagers (age ≥ 18 years, living time ≥ 6 months per year) as survey subjects. Questionnaire survey and examinations including blood pressure measurement, blood tests, and urine test were made by trained medical professionals. Multivariate logistic regression analysis was used to analyze the risk factors of hypertension. RESULTS: Complete data were obtained in 2036 residents. The hypertension prevalence rate was 11.6% (237/2036) [12.5% (110/883) for male, 11.0% (127/1153) for female], adjusted prevalence rate was 10.7% (11.3% for male, 10.4% for female) based on the population of Guangxi in 2010. Hypertension awareness rate was 36.3% (86/237) , therapy rate was 22.8% (54/237) , and control rate was 11.0% (26/237) . Multivariate logistic regression analysis showed that age (OR = 1.06, 95%CI:1.05-1.08, P < 0.01), alcohol drinking habit (OR = 1.92, 95%CI:1.25-2.95, P < 0.01), high salt diet(OR = 1.48, 95%CI:1.04-2.10, P < 0.05), diabetes(OR = 7.03, 95%CI:1.94-25.44, P < 0.01), obesity(OR = 1.20, 95%CI: 1.15-1.25, P < 0.01) and hypertriglyceridemia(OR = 1.12, 95%CI:1.03-1.22, P < 0.01) were risk factors for hypertension in this cohort. CONCLUSIONS: Prevalence rate is slightly lower in adult of the Guangxi Zhuang-rural areas than national or Guangxi Zhuang Autonomous Region levels, but hypertension awareness, therapy and control rates in this cohort are not satisfactory. Targeted strategies are needed to improve the prevention and therapy of hypertension in this region.

Enalapril versus losartan for adults with chronic kidney disease: a systematic review and meta-analysis.

AIM: Both enalapril and losartan are effective and widely used in patients with chronic kidney disease (CKD). This review aimed to evaluate the benefits of enalapril and losartan in adults with CKD. METHODS: PubMed, EMBASE, the Cochrane Library and ClinicalTrials.gov were searched, without language limitations, for randomized controlled trials (RCT), in which enalapril and losartan were compared in adults with CKD. Standard methods, consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, were used. Reviewer Manager software, ver. 5.2, was used for meta-analysis. RESULTS: Of 318 citations retrieved, 17 RCT (14 parallel-group and three cross-over) met our inclusion criteria. The pooled analysis for parallel RCT showed that the effects of enalapril and losartan on blood pressure, renal function and serum uric acid (UA) were similar. Meta-analysis indicated that patients taking enalapril had a higher risk of dry cough (risk ratio, 2.88; 95% CI, 1.11-7.48; P=0.03). Sensitivity analysis showed good robustness of these findings. CONCLUSION: Enalapril has similar effects to losartan on systemic blood pressure, renal function and serum UA in patients with CKD, but carries a higher risk of dry cough. Larger trials are required to evaluate the effects of these medications on clinical outcomes.

Complement activation contributes to the injury and outcome of kidney in human anti-glomerular basement membrane disease.

PURPOSE: Linear or granular deposition of complement 3 (C3) along glomerular basement membrane (GBM) is generally revealed in kidneys of human anti-GBM disease. However, the mechanism of complement activation and its association with clinical features and outcomes are less clear. METHODS: We measured the plasma and urinary levels of complement components, C1q, mannose-binding lectin (MBL), factor B (Ba), C3, C3a, C4, C4a, C5, C5a and soluble C5b-9 (SC5b-9), using ELISA in 20 patients with renal biopsy proven anti-GBM disease. RESULTS: The end product of complement activation, SC5b-9, was elevated both in plasma and urine. The levels of C3 and C4 were normal in plasma, while elevated in urine. The levels of C5a and SC5b-9 were increased in plasma from 15% and 30% patients respectively, while they were raised in urine from almost all patients (100% and 92%). The levels of plasma SC5b-9 and urinary C5a were positively correlated with the serum creatinine at presentation (r=0.56, P=0.01; r=0.68, P=0.02, respectively) and the percentage of crescents in glomeruli (r=0.60, P=0.005; r=0.75, P=0.005, respectively). The plasma level of SC5b-9 was further identified as the predictor for renal failure during follow up (HR, 1.46; 95% CI, 1.12-1.90; P=0.005). CONCLUSION: Complement cascade goes to the end in human anti-GBM disease and resides mainly in kidney. It plays pathogenic role in renal injury, by the possible proinflammatory effect of C5a and/or cell lysis effect of C5b-9. C5a and C5b-9 may be useful in clinical monitoring and predicting.