OBJECTIVE: To investigate the gut microbiota in newly diagnosed IgA nephropathy patients with chronic kidney disease (CKD) stages 1-2 and the association between the gut microbiota and the clinical risk factors of IgA nephropathy. METHODS: Fresh fecal samples were collected from nineteen newly diagnosed IgA nephropathy patients with CKD stages 1-2 and fifteen age- and sex-matched healthy controls. Fecal bacterial DNA was extracted and microbiota composition were characterized using 16S ribosomal RNA (16S rRNA) high-throughput sequencing for the V3-V4 region. The Illumina Miseq platform was used to analyze the results of 16S rRNA high-throughput sequencing of fecal flora. At the same time, the clinical risk factors of IgA nephropathy patients were collected to investigate the association between the gut microbiota and the clinical risk factors. RESULTS: (1) At the phylum level, the abundance of Bacteroidetes was significantly reduced (P=0.046), and the abundance of Actinobacteria was significantly increased (P=0.001). At the genus level, the abundance of Escherichia-Shigella, Bifidobacte-rium, Dorea and others were significantly increased (P < 0.05). The abundance of Lachnospira, Coprococcus_2 and Sutterella was significantly reduced (P < 0.05). (2) There was no significant difference in the abundance of gut microbiota between the newly diagnosed IgA nephropathy patients and the healthy control group (P>0.05), but there were differences in the structure of the gut microbiota between the two groups. The results of LEfSe analysis showed that there were 16 differential bacteria in the newly diagnosed IgA nephropathy patients and healthy controls. Among them, the abundance of the newly diagnosed IgA nephropathy patients was increased in Enterobacteriales, Actinobacteria, Escherichia-Shigella, etc. The healthy control group was increased in Bacteroidetes and Lachnospira. (3) The result of redundancy analysis (RDA) showed that Bifidobacterium was positively correlated with serum IgA levels, 24-hour urinary protein levels and the presence of hypertension. Lachnoclostridium was positively correlated with the presence of hypertension. Escherichia-Shigella was positively correlated with urine red blood cells account. Bifidobacterium was positively correlated with the proliferation of capillaries. Faecalibacterium was positively correlated with cell/fibrocytic crescents. Ruminococcus_2 was positively correlated with mesangial cell proliferation, glomerular segmental sclerosis and renal tubular atrophy/interstitial fibrosis. CONCLUSION The gut microbiota in the newly diagnosed IgA nephropathy patients with CKD stages 1-2 is different from that of the healthy controls. Most importantly, some gut bacteria are related to the clinical risk factors of IgA nephropathy. Further research is needed to understand the potential role of these bacteria in IgA nephropathy.
Humans ; Gastrointestinal Microbiome ; RNA, Ribosomal, 16S/genetics* ; Glomerulonephritis, IGA ; Bacteria/genetics* ; Risk Factors ; Renal Insufficiency, Chronic

Objective To investigate the effect of intestinal mucosal Toll-like receptor 4/nuclear factor κB (TLR4/NF-κB) signaling pathway on renal damage in pseudo-sterile IgA nephropathy (IgAN) mice. Methods C57BL/6 mice were randomly divided into experimental group (pseudosterile mouse model group), control group (IgAN mouse model group), pseudosterile mouse blank group, and normal mouse blank group. Pseudosterile mice were established by intragastric administration of quadruple antibiotics once a day for 14 days. The pseudosterile IgAN mouse model was set up by combination of oral bovine serum albumin (BSA) administration and staphylococcal enterotoxin B (SEB) injection. The pathological changes of renal tissue were observed by immunofluorescence staining and PAS staining, and the intestinal mucosa barrier damage indicators lipopolysaccharide(LPS), soluble intercellular adhesion molecule 1(sICAM-1) and D-lactate(D-LAC) were analyzed by ELISA. Biochemical analysis was used to test 24 hour urine protein, serum creatinine and blood urea nitrogen. The mRNA and protein levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor κB (NF-κB) were detected by reverse transcription PCR and Western blot analysis. Results The kidney damage of pseudosterile IgAN mice was more severe than that of IgAN mice, and the expressions of intestinal mucosal barrier damage markers (LPS, sICAM-1 and D-LAC) were significantly increased in pseudosterile IgAN mice. In addition, the expressions of TLR4, MyD88, and NF-κB level were all up-regulated in the intestinal tissues of IgAN pseudosterile mice. Conclusion Intestinal flora disturbance leads to intestinal mucosal barrier damage and induces activation of TLR4 signaling pathway to mediate renal injury in IgAN.
Animals ; Mice ; Mice, Inbred C57BL ; Glomerulonephritis, IGA ; NF-kappa B ; Toll-Like Receptor 4/genetics* ; Lipopolysaccharides ; Myeloid Differentiation Factor 88/genetics* ; Kidney ; Intestinal Mucosa ; Infertility ; Disease Models, Animal

OBJECTIVE: To evaluate the efficacy of plasma exchange therapy on crescentic IgA nephropathy (IgAN). METHODS: A retrospective analysis was performed in a cohort of patients with crescentic IgAN from January 2012 to September 2020 at 9 sites across China. Clinical and pathological data, as well as therapeutic regimens, were collected. In order to minimize the effect of potential confounders in baseline characteristics, propensity score matching using a 1 ∶1 ratio nearest neighbor algorithm was performed between the adjunctive plasma exchange therapy group and the intensive immunosuppressive therapy group. The primary outcome was end-stage of kidney disease (ESKD). Kaplan-Meier method was used to compare the difference in renal survival between the two groups. RESULTS: A total of 95 crescentic IgAN patients with acute kidney disease were included in this study, including 37 (38.9%) patients receiving adjunctive plasma exchange therapy, and 58 (61.1%) patients receiving intensive immunosuppressive therapy. In the whole cohort, the baseline eGFR was 12.77 (7.28, 21.29) mL/(min·1.73 m²), 24-hour urinary protein quantification was 5.9 (4.0, 8.9) g, and crescent percentage was 64.71% (54.55%, 73.68%). In the study, 23 patients in each group were matched after propensity score matching The median follow-up time was 7 (1, 26) months. As a whole, 29 patients (63.0%) reached ESKD, including 16 patients (69.6%) in the adjunctive plasma exchange therapy group and 13 (56.5%) patients in the intensive immunosuppressive therapy group.. There were no stastical difference between the two groups in terms of baseline eGFR [14.30 (9.31, 17.58) mL/(min·1.73 m²) vs. 11.45 (5.59, 20.79) mL/(min·1.73 m²)], 24-hour urinary protein (7.4±3.4) g vs. (6.6±3.8) g, crescent percentage 64.49%±13.23% vs. 66.41%±12.65% and the proportion of patients received steroid therapy[23 (100.0%) vs. 21 (91.3%)] (All P>0.05). Kaplan-Meier survival analysis demonstrated that there was no significant difference in renal survival rate between the two groups (Log-rank test, P=0.933). CONCLUSION The adjunctive plasma exchange therapy in addition to conventional intense immunosuppressive therapy did not additionally improve the prognosis of crescentic IgA nephropathy.
Cohort Studies ; Glomerulonephritis, IGA/pathology* ; Humans ; Kidney Failure, Chronic/therapy* ; Plasma Exchange ; Prognosis ; Retrospective Studies ; Steroids/therapeutic use*

Animals ; Glomerulonephritis, IGA/drug therapy* ; Hydroxychloroquine/therapeutic use* ; Ki-67 Antigen ; Kidney ; Rats ; Toll-Like Receptor 4/genetics* ; Vitamin D

OBJECTIVE: To systematically evaluate the efficacy and safety of steroid combined with immunosuppressants in the treatment of primary IgA nephropathy in children. METHODS: English and Chinese electronic databases were searched to include the studies on the efficacy and safety of steroid combined with immunosuppressants versus steroid alone in the treatment of primary IgA nephropathy in children. Outcome measures included proteinuria remission rate, urinary protein quantification, incidence of adverse events, estimated glomerular filtration rate, and incidence of renal dysfunction. Review Manager 5.3 software was used for data analysis. RESULTS: A total of 7 studies with 381 children were included. The children had moderate to severe proteinuria. The Meta analysis showed that compared with the steroid alone group, the steroid combined with immunosuppressants group achieved a significantly higher rate of proteinuria remission (RR=1.36, 95%CI: 1.19-1.55, P<0.001) and significantly lower urinary protein quantification (SMD=-0.82, 95%CI: -1.23 to -0.41, P<0.001). There was no significant difference in the incidence rate of adverse events between the two groups (RR=1.28, 95%CI: 0.92-1.77, P=0.14). CONCLUSIONS The current evidence shows that for children with primary IgA nephropathy who have moderate to severe proteinuria, steroid combined with immunosuppressants has a better effect than steroid alone and does not increase the incidence rate of adverse events.
Child ; Glomerular Filtration Rate ; Glomerulonephritis, IGA ; Humans ; Immunosuppressive Agents ; Proteinuria

OBJECTIVE: To study the clinical effect and safety of tacrolimus (TAC) combined with glucocorticoid (GC) versus mycophenolate mofetil (MMF) combined with GC in the treatment of primary IgA nephropathy (IgAN) in children. METHODS: A retrospective analysis was performed for the clinical data of children with primary IgAN confirmed by renal pathology between January 2012 and December 2017. These children were divided into TAC group and MMF group according to the treatment regimen. Their clinical data before treatment and at 1, 3, and 6 months of treatment were collected, and the remission status of IgAN and adverse reactions were compared between the two groups. RESULTS: A total of 43 children who met the inclusion criteria were enrolled, with 15 children in the TAC group and 28 children in the MMF group. At 1 month of treatment, there was no significant difference in the remission status between the two groups (P>0.05). At 3 and 6 months of treatment, the TAC group had a significantly better remission status than the MMF group (P<0.05). At 1 month of treatment, the TAC group had higher serum albumin levels than the MMF group (P<0.05). Both groups had a significant increase in serum albumin levels at each time point after treatment (P<0.0083) and a significant increase in the glomerular filtration rate (GFR) at 3 and 6 months of treatment (P<0.0083). There was no significant difference in the overall incidence rate of adverse reactions between the two groups (P>0.05), but fungal infection was observed in one child from the TAC group. CONCLUSIONS TAC combined with GC can effectively reduce urinary protein in children with primary IgAN, and it has a better short-term clinical effect than MMF combined with GC, with good safety.
Child ; Drug Therapy, Combination ; Glomerulonephritis, IGA ; drug therapy ; Glucocorticoids ; therapeutic use ; Humans ; Immunosuppressive Agents ; Mycophenolic Acid ; Retrospective Studies ; Tacrolimus ; therapeutic use

OBJECTIVE: To explore the value of galactose-deficient IgA1 (Gd-IgA1) in the early diagnosis of Henoch-Schönlein purpura nephritis (HSPN) in children. METHODS: A total of 67 hospitalized children who were definitely diagnosed with HSPN between January and April 2018 and 58 hospitalized children with Henoch-Schönlein purpura (HSP) were enrolled in the study. Twenty children undergoing routine physical examinations served as controls. The levels of serum and urine Gd-IgA1 were determined using ELISA. The receiver operating characteristic curve was used to analyze the value of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in the diagnosis of HSPN. RESULTS: The level of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in children with HSP or HSPN were significantly higher than those in healthy control group (P<0.01), with a significantly greater increase observed in children with HSPN (P<0.01). Serum Gd-IgA1 ≥1 485.57 U/mL and/or urine Gd-IgA1/urine creatinine ratio ≥105.74 were of favorable value in the diagnosis of HSPN. During the six-month follow-up of the 49 children with HSP, the incidence of HSPN was 47% (23/49), which included a 100% incidence in children with serum Gd-IgA1 ≥1 485.57 U/mL and a 73% incidence in children with urine Gd-IgA1/urine creatinine ratio ≥105.74. CONCLUSIONS Serum and urine Gd-IgA1 is of favorable clinical value in the early diagnosis of HSPN.
Child ; Early Diagnosis ; Galactose ; Glomerulonephritis, IGA ; Humans ; Immunoglobulin A ; Purpura, Schoenlein-Henoch

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is the most common pathological type of glomerular disease. Kidney biopsy, the gold standard for IgAN diagnosis, has not been routinely applied in hospitals worldwide due to its invasion nature. Thus, we aim to establish a non-invasive diagnostic model and determine markers to evaluate disease severity by analyzing the serological parameters and pathological stages of patients with IgAN. METHODS: A total of 272 biopsy-diagnosed IgAN inpatients and 518 non-IgA nephropathy inpatients from the Department of Nephrology of Chinese People's Liberation Army General Hospital were recruited for this study. Routine blood examination, blood coagulation testing, immunoglobulin-complement testing, and clinical biochemistry testing were conducted and pathological stages were analyzed according to Lee grading system. The serological parameters and pathological stages were analyzed. The receiver operating characteristic (ROC) analysis was performed to estimate the diagnostic value of the clinical factors. Logistic regression was used to establish the diagnostic model. RESULTS: There were 15 significantly different serological parameters between the IgAN and non-IgAN groups (all P < 0.05). The ROC analysis was performed to measure the diagnostic value for IgAN of these parameters and the results showed that the area under the ROC curve (AUC) of total protein (TP), total cholesterol (TC), fibrinogen (FIB), D-dimer (D2), immunoglobulin A (IgA), and immunoglobulin G (IgG) were more than 0.70. The AUC of the "TC + FIB + D2 + IgA + age" combination was 0.86, with a sensitivity of 85.98% and a specificity of 73.85%. Pathological grades of I, II, III, IV, and V accounted for 2.21%, 17.65%, 62.50%, 11.76%, and 5.88%, respectively, with grade III being the most prevalent. The levels of urea nitrogen (UN) (13.57 ± 5.95 vs. 6.06 ± 3.63, 5.92 ± 2.97, 5.41 ± 1.73, and 8.41 ± 3.72 mmol/L, respectively) and creatinine (Cr) (292.19 ± 162.21 vs. 80.42 ± 24.75, 103.79 ± 72.72, 96.41 ± 33.79, and 163.04 ± 47.51 μmol/L, respectively) were significantly higher in grade V than in the other grades, and the levels of TP (64.45 ± 7.56, 67.16 ± 6.94, 63.22 ± 8.56, and 61.41 ± 10.86 vs. 37.47 ± 5.6 mg/d, respectively), direct bilirubin (DB) (2.34 ± 1.23, 2.58 ± 1.40, 1.91 ± 0.97, and 1.81 ± 1.44 vs. 0.74 ± 0.57 μmol/L, respectively), and IgA (310.35 ± 103.78, 318.48 ± 107.54, 292.58 ± 81.85, and 323.29 ± 181.67 vs. 227.17 ± 68.12 g/L, respectively) were significantly increased in grades II-V compared with grade I (all P < 0.05). CONCLUSIONS The established diagnostic model that combined multiple factors (TC, FIB, D2, IgA, and age) might be used for IgAN non-invasive diagnosis. TP, DB, IgA, Cr, and UN have the potential to be used to evaluate IgAN disease severity.
Adult ; Biomarkers ; blood ; Blood Urea Nitrogen ; Cholesterol ; blood ; Creatinine ; blood ; Female ; Fibrinogen ; metabolism ; Glomerulonephritis, IGA ; blood ; diagnosis ; pathology ; Humans ; Immunoglobulin A ; blood ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; ROC Curve

OBJECTIVE: To compare the genetic architecture of susceptibility variants of IgA nephropathy (IgAN) in Chinese and Europeans. METHODS: We selected the independent genome-wide significant variants of IgAN in European population as candidate variants. Their associations, risk alleles, risk allele frequencies, odds ratios and population attributable risk scores were derived and calculated, then compared with those in the current Chinese population, including 1 194 IgAN patients and 902 controls. Using the significant variants, genetic risk scores were calculated and compared between the East Asians and the Europeans. The correlation between the genetic risk scores and clinical manifestations was also evaluated. RESULTS: There were 16 independent single nucleotide polymorphisms (SNPs) located in 11 loci showing significantly association with susceptibility to IgAN in the Europeans. 93.75% (15/16) of them also showed significant associations in the Chinese (P<0.05). The effects of all the associated SNPs were in the same direction, either risk or being protective for IgAN, between the Chinese and the Europeans. On the contrary, remarkable higher risk allelic odds ratio (P=1.94×10^-2), higher risk allele frequency (P=3.09×10^-2), and higher population attributable risk (P=3.03×10^-4) were observed for most of the associated SNPs in the Chinese than in the Europeans. Furthermore, genetic risk scores were significantly larger in the Asian populations compared with the Europeans (P=1.78×10^-163). While there was no significance among the subpopulations in both the East Asians and the Europeans. Compared with the healthy controls, the genetic risk score in the IgAN patients was significantly larger (P=3.60×10^-27). Clinical analysis showed the genetic risk score was positively associated with serum levels of IgA and IgA1, phases of chronic kidney disease and Haas grades. CONCLUSION Our study provides further evidence in the shared genetic architecture between Chinese and Europeans, while differences with respect to the effect sizes and risk allele frequencies across ethnicities, contributing partially to the differences of disease prevalence.
Asians ; Case-Control Studies ; Gene Frequency ; Genetic Predisposition to Disease ; Glomerulonephritis, IGA ; Humans ; Polymorphism, Single Nucleotide

Anti–glomerular basement membrane (GBM) nephritis is characterized by circulating anti-GBM antibodies and crescentic glomerulonephritis (GN) with deposition of IgG along the GBM. In a limited number of cases, glomerular immune complexes have been identified in anti-GBM nephritis. A 38-year-old female presented azotemia, hematuria, and proteinuria without any pulmonary symptoms. A renal biopsy showed crescentic GN with linear IgG deposition along the GBM and mesangial IgA deposition. The patient was diagnosed as concurrent anti-GBM nephritis and IgA nephropathy. Therapies with pulse methylprednisolone and cyclophosphamide administration were effective. Concurrent cases of both anti-GBM nephritis and IgA nephropathy are rare among cases of anti-GBM diseases with deposition of immune complexes. This rare case of concurrent anti-GBM nephritis and IgA nephropathy with literature review is noteworthy.
Adult ; Anti-Glomerular Basement Membrane Disease ; Antibodies ; Antigen-Antibody Complex ; Azotemia ; Basement Membrane ; Biopsy ; Cyclophosphamide ; Female ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Methylprednisolone ; Nephritis ; Proteinuria