Association between the AKT1 single nucleotide polymorphism (rs2498786, rs2494752 and rs5811155) and microscopic polyangiitis risk in a Chinese population.

Microscopic polyangiitis (MPA) is an autoimmune disease, characterized by ANCA in blood and necrotizing inflammation of small and medium-sized vessels, one of the three clinical phenotypes of ANCA-associated vasculitis (AAV). Autophagy has been confirmed to be involved in the pathogenesis of AAV. AKT1 is one of the autophagy-regulated proteins. Its single nucleotide polymorphisms (SNPs) are associated with multiple immune-related diseases, but there are rarely studies in AAV. The incidence rate of AAV has a notable geographic difference, and MPA is predominant in China. The aim of this study was to investigate the association between AKT1 SNP and MPA risk. Genotypes of 8 loci in AKT1 were evaluated by multiplex polymerase chain reaction (PCR) and high-throughput sequencing in 416 people, including 208 MPA patients and 208 healthy volunteers from Guangxi in China. Additionally, data of 387 healthy volunteers from China were obtained from the 1000Genomes Project on public database. Differences were observed between the loci (rs2498786, rs2494752, and rs5811155) genotypes in AKT1 and MPA risk (P = 7.0 × 10-4, P = 3.0 × 10-4, and P = 5.9 × 10-5, respectively). A negative association was detected in the Dominant model (P = 1.2 × 10-3, P = 2.0 × 10-4 and P = 3.6 × 10-5, respectively). A haplotype (G-G-T) was associated with MPA risk negatively (P = 7.0 × 10-4). This study suggests that alleles (rs2498786 G, rs2494752 G and rs5811155 insT) are protective factors for MPA and alleles (rs2494752 G and rs5811155 insT) for MPO-ANCA in patients with MPA. There is a haplotype (G-G-T), which is a protective factor for MPA. It suggests that the role of AKT1 in MPA/AAV needs further study to provide more intervention targets for MPA/AAV.

Analysis of rs1864182 and rs1864183 variants in ATG10 gene and antineutrophil cytoplasmic autoantibody-associated vasculitis in Chinese Guangxi population.

OBJECTIVES: To investigate the association of autophagy-associated gene 10 (ATG10) gene polymorphisms (rs1864182 and rs1864183) with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) in Chinese Guangxi population. METHODS: The single nucleotide polymorphisms (SNPs) of ATG10 rs1864182 and rs1864183 in 395 participants (195 AAVs and 200 healthy controls) were genotyped. Generalized multiple dimensionality reduction (GMDR) was used to analyze the SNP-SNP interactions among two SNPs of ATG10 gene and other SNPs of autophagy gene previously studied by our research team. RESULTS: In this study, we found that the two ATG10 SNPs were not associated with AAV risk in Chinese Guangxi population. However, there were statistically significant differences in the incidence of hemoptysis, hematuria, and proteinuria among the three genotypes of ATG10 rs1864182 and rs1864183 (p < 0.05). Moreover, permutation test of GMDR suggested that immunity-related GTPase M(IRGM) rs4958847, autophagy-associated gene 7 (ATG7) rs6442260, ATG7 rs2594966, ATG10 rs1864183, protein kinase B(AKT2) rs3730051, and AKT2 rs11552192 might interact with each other in the process of developing AAV (p < 0.05). CONCLUSIONS: Our results indicated that there existed no association between ATG10 SNPs and AAV, and SNP-SNP interactions among IRGM rs4958847, ATG7 rs6442260, ATG7 rs2594966, ATG10 rs1864183, AKT2 rs3730051, and AKT2 rs11552192 may confer AAV risk in the Chinese Guangxi population.

The therapeutic effect of plasma exchange on ANCA-associated vasculitis: A meta-analysis.

AIMS: The therapeutic effect of plasma exchange (PLEX) combined with conventional treatment in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) remains controversial. MATERIALS AND METHODS: We searched PubMed, Embase, Cochrane Library, and China National Knowledge Infrastructure for randomized controlled trials (RCTs) and cohort studies that compared PLEX added to conventional therapy with conventional therapy only in active AAV. RESULTS: 19 studies were included for the meta-analysis. Compared with the conventional therapy group, the PLEX group had a significantly reduced risk of end-stage renal disease (ESRD) at 3 months (odds ratio (OR) = 0.32, 95% confidence interval (CI) = 0.16 - 0.66, p = 0.002, I2 = 0%), and the ANCA titerwas also decreased (OR = 40.99, 95% Cl = 23.56 - 58.43, p < 0.00001, I2 = 42%). The plasma and non-plasma exchange groups had no substantial differences in terms of short- and long-term outcomes, including all-cause mortality, ESRD risk at 12 months and 5 years, remission rate, serum creatine levels, or serious adverse events. CONCLUSION: PLEX therapy was not associated with favorable long-term outcomes, although the results showed benefits in the incidence of ESRD rate at 3 months and ANCA titers in patients with AAV. No advantage of PLEX added to conventional therapy on mortality and complete remission was observed in patients with diffuse alveolar hemorrhage. Further high-quality multicenter RCTs with a high number of participants are required to assess the potential efficacy of PLEX in active AAV.

MTOR gene polymorphism may be associated with microscopic polyangiitis susceptibility in a Guangxi population of China.

OBJECTIVE: Microscopic polyangiitis (MPA) onset is affected by genetic predisposition. Autophagy plays a certain role in antineutrophil cytoplasmic antibody-associated vasculitis developing. A key factor in autophagy regulating, the genetic polymorphism of MTOR gene is essential. The objective was to explore the associations between MTOR gene polymorphism and MPA susceptibility in a Guangxi population of China. METHODS: A sum of 208 MPA cases and 209 healthy volunteers from Guangxi in this case-control study, four important single nucleotide polymorphism (SNP) loci of MTOR gene including rs3806317, rs1064261, rs1883965 and rs2295080 were examined. Multiplex polymerase chain reaction combined with high-throughput sequencing was performed. Subgroup analysis was evaluated by gender and ethnicity. Linkage disequilibrium and haplotype analysis were tested. Multi-SNPs interaction among mTOR signaling pathway was assessed. RESULTS: For rs2295080, homozygous mutant GG genotype was associated with a decreased susceptibility of MPA in recessive model (OR = 0.38, 95%CI: 0.14-1.00, p = 0.040), particularly in the subgroup of female (OR = 0.16, 95%CI: 0.03-0.74, p = 0.006) and Han population (OR = 0.32, 95%CI: 0.10-1.00, p = 0.034). Individual carrying G allele was linked with decreasing MPA susceptibility in Han population of Guangxi (OR = 0.65, 95%CI: 0.44-0.97, p = 0.036). In haplotype analysis, the haplotype AAT was correlated with increasing susceptibility of MPA (OR = 1.347, 95%CI: 1.004-1.807, p = 0.046). Moreover, in the multi-SNPs interaction analysis, the six-locus model was identified as the best interaction model (p < 0.05). CONCLUSION: These findings suggest that rs2295080 polymorphism of MTOR gene may be associated with MPA susceptibility in a Guangxi population of China and G allele might be an important protective factor.

Using iron-based phosphate binders in phosphate reduction and anemia improvement in patients receiving dialysis: a meta-analysis of randomized controlled trials.

PURPOSE: A study was conducted to determine whether iron-based phosphate binders (IBPBs) need to be preferred for hyperphosphatemia and anemia management in patients on dialysis. METHODS: For this meta-analysis, we searched PubMed, Embase, and Cochrane Central Register of Controlled Trials for randomized controlled trials that evaluated the efficacy and safety of IBPBs in decreasing phosphate and correcting anemia in dialysis patients. RESULTS: Nineteen trials comprising 4719 participants were included. Compared with placebo, serum phosphate decreased significantly after treatment with ferric citrate (FC), fermagate (one study), and SBR759 (one study). Hemoglobin increased significantly after treatment with FC and sucroferric oxyhydroxide (PA21). In addition, FC and PA21 reduced serum intact parathyroid hormone (iPTH) and increased ferritin and transferrin saturation, but SBR759 did not. Compared with active treatment, the non-inferiority of IBPBs in reducing serum phosphate and iPTH was demonstrated. FC significantly improved serum hemoglobin and iron-related parameters and decreased the use of intravenous iron and erythropoiesis-stimulating agent, whereas PA21 did not increase serum hemoglobin level. The incidences of infection and hospitalization were similar between the two groups, with FC having a higher risk of diarrhea than the placebo and active treatments. CONCLUSION: FC was associated with the control of hyperphosphatemia and the improvement of anemia. However, PA21 did not show superiority for alleviating anemia compared with the active treatment. Other IBPBs, such as fermagate and SBR759, remained poorly understood due to the limited number of studies. Further trials are required to assess the effect of IBPBs on the risk of cardiovascular events and all-cause mortality.

Gene polymorphisms in ULK1 and PIK3CA are associated with the risk of microscopic polyangiitis in the Guangxi Zhuang Autonomous Region in China.

BACKGROUND: Microscopic polyangiitis (MPA) is a systemic autoimmune disease characterized by inflammation of small- and medium-sized blood vessels. Autophagy-related protein polymorphisms are involved in autoimmune disease. The aim of this study was to evaluate the effects of single-nucleotide polymorphisms (SNPs) in the ULK1 and PIK3CA genes on the risk of MPA. METHOD: A total of 208 patients with MPA and 211 controls in the Guangxi Zhuang Autonomous Region were recruited and analyzed. The SNPs selected were detected by polymerase chain reaction and high-throughput sequencing. The differences in allele and genotype frequency, various genetic models, and stratification analyses were evaluated, haplotype evaluation was performed after linkage disequilibrium analysis, and the interaction between gene alleles was analyzed. RESULTS: A statistically significant difference was detected in the genotypic distribution of two SNPs between the two groups: ULK1 rs4964879 (p = 0.019) and PIK3CA rs1607237 (p = 0.002). The results of the genetic models revealed that ULK1 rs4964879 and rs9481 were statistically significantly associated with an increased risk of MPA, whereas PIK3CA rs1607237 was associated with a reduced risk. The association between SNPs and MPA risk was affected by age, sex, and ethnicity. The ULK1 haplotype (G-T-A-C-G-A) and PIK3CA haplotype (T-G) were associated with a reduced risk of MPA, while the PIK3CA haplotype (C-G) was associated with an increased risk. CONCLUSION: In this study, polymorphisms in the autophagy-related genes ULK1 and PIK3CA and their association with MPA were examined. The results showed that the polymorphisms in ULK1 (rs4964879 and rs9481) and PIK3CA (rs1607237) were significantly associated with MPA risk in the Guangxi population. However, the molecular mechanisms are still unclear; basic science research and studies with larger samples are needed to confirm our conclusions and explore the underlying mechanisms.