OBJECTIVES: To explore the value of serum cystatin C (CysC) levels in evaluating renal prognosis in IgA nephropathy (IgAN) patients. METHODS: We retrospectively collected the clinical data of IgAN patients diagnosed by renal biopsy at Guangdong Provincial People's Hospital from January, 2014 to December, 2018. Based on baseline serum CysC levels, the patients were divided into high serum CysC (>1.03 mg/L) group and normal serum CysC (≤1.03 mg/L) group. The composite endpoint for poor renal prognosis was defined as ≥50% decline in estimated glomerular filtration rate (eGFR) and/or progression to end-stage renal disease (ESRD). Lasso regression, multivariate Cox regression and Kaplan-Meier survival analysis were used to identify the risk factors and compare renal survival rates between the two groups. Smooth curves fitting and threshold effect analysis were used to explore the relationship between serum CysC levels and the outcomes. A nomogram model was constructed and its predictive performance was evaluated using concordance index, calibration curve, receiver operating characteristic (ROC) curve and the area under curve (AUC). RESULTS: A total of 356 IgAN patients were enrolled, who were followed up for 4.65±0.93 years. The composite endpoint occurred in 74 patients. High serum CysC was identified as an independent risk factor for poor renal prognosis in IgAN (HR=2.142, 95% CI 1.222 to 3.755), and the patients with high serum CysC levels had a lower renal survival rate (Log-rank χ²=47.970, P<0.001). In patients with serum CysC below 2.12 mg/L, a higher CysC level was associated with an increased risk of poor renal prognosis (β=3.487, 95% CI: 2.561-4.413, P<0.001), while above this level, the increase of the risk was not significant (β=0.676, 95% CI: -0.642-1.995, P=0.315). The nomogram model based on serum CysC and 3 other independent risk factors demonstrated good internal validity with a concordance index of 0.873 (95% CI: 0.839-0.907) and an AUC of 0.909 (95% CI: 0.873-0.945). CONCLUSIONS Serum CysC levels are associated with renal prognosis in IgAN patients, and high serum CysC an independent risk factor for poor renal prognosis.
Humans ; Glomerulonephritis, IGA/diagnosis* ; Cystatin C/blood* ; Prognosis ; Risk Factors ; Retrospective Studies ; Glomerular Filtration Rate ; Kidney Failure, Chronic ; Male ; Female ; Adult ; Nomograms ; Middle Aged

IgA nephropathy (IgAN) is the most common primary glomerular disease in China and a leading cause of end-stage renal disease (uremia) in young adults. The diagnosis, prognostic assessment, and treatment strategies for IgAN and IgA vasculitis with nephritis (IgAVN) have been comprehensively evaluated by the Scientific Committee of the China IgA Nephropathy Network (IIgANN-China) and the Chinese Preventive Medicine Association's Committee for the Prevention and Control of Kidney Diseases based on recent literature and evidence-based medicine. As a result, clinical practice guidelines specifically tailored to Chinese patients have been developed. These guidelines introduce an integrated therapeutic framework that incorporates risk-stratified treatment, targeting both immune-mediated renal injury and chronic kidney disease progression, as well as stage-specific treatment, including both the induction and maintenance phases. The aim is to provide standardized guidance and practical recommendations for the clinical management of IgAN and IgAVN in China.
Humans ; Glomerulonephritis, IGA/diagnosis* ; China ; Adult ; Vasculitis/complications* ; Practice Guidelines as Topic ; Immunoglobulin A ; Prognosis ; Nephritis/therapy*

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

PURPOSE: To classify the results of renal biopsy in pediatric patients and to compare pathological findings with clinical features. METHODS: This study included data of 318 children who underwent renal biopsy at our hospital between December 1987 and November 2014. Biopsy specimens were examined histopathologically using light, immunofluorescence, and electron microscopy. RESULTS: Asymptomatic urinary abnormalities was the most common clinical diagnosis (35.9%), followed by nephrotic syndrome (29.3%), and acute glomerulonephritis (18.0%). Glomerular disease was identified in 98.1% of the renal biopsy specimens. The most common primary cause of glomerulonephritis was IgA nephropathy, with gross hematuria in 61.9% of the patients, hypertension in 14.2%, proteinuria >1.0 gm/24-hr in 33.3%, and impaired renal function in 3.6% patients. CONCLUSION: The most common clinical diagnosis was asymptomatic urinary abnormalities, with primary glomerular disease being the most common renal biopsy finding, and IgA nephropathy the most common histopathological lesion. This study provides a 27-year overview of pediatric renal disease at our center and underlines the importance of renal biopsy for accurate diagnosis and proper management.
Biopsy* ; Child* ; Diagnosis ; Fluorescent Antibody Technique ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Humans ; Hypertension ; Microscopy, Electron ; Nephrotic Syndrome ; Proteinuria

A 37-year-old male patient was admitted with generalized edema as the main symptom. A blood test confirmed hypoalbuminemia and hyperlipidemia, and a urine test confirmed severe albuminuria. A renal biopsy was conducted, which revealed a diagnosis of minimal change disease. Although the patient experienced complete remission of minimal change nephrotic syndrome after oral prednisolone and cyclophosphamide treatment, he is readmitted due to bilateral leg edema 5 years later since minimal change nephrotic syndrome was completely cured. The patient is diagnosed with IgA nephropathy. Although the exact mechanisms of IgA nephropathy in this patient remain unclear, this case represents an extremely rare development, and is separate from the remission of minimal change nephrotic syndrome.
Adult ; Albuminuria ; Biopsy ; Cyclophosphamide ; Diagnosis ; Edema ; Glomerulonephritis, IGA* ; Hematologic Tests ; Humans ; Hyperlipidemias ; Hypoalbuminemia ; Immunoglobulin A* ; Leg ; Male ; Nephrosis, Lipoid* ; Nephrotic Syndrome ; Prednisolone

C1q nephropathy is a rare glomerular disease, defined by characteristic mesangial C1q immune deposition seen in immunofluorescence microscopy with no serological evidence of systemic lupus erythematosus. C1q nephropathy can be diagnosed with a subsequent biopsy, as with IgA nephropathy. There are some cases with an initial diagnosis of hematuria and proteinuria with minimal disease changes, focal segmental glomerulonephritis, and mesangial proliferative glomerulonephritis, but lacking C1q nephropathy, in which C1q deposition on immunofluorescence subsequently develops. We report a case that was diagnosed as diffuse mesangial proliferative glomerulonephritis, but a subsequent biopsy showed C1q nephropathy, with C1q deposition in both immunohistochemistry and electron microscopy (EM). We treated the C1q nephropathy with methylprednisolone and confirmed the disappearance of C1q depositions by both immunohistochemistry and EM in a follow-up biopsy.
Biopsy ; Complement C1q ; Diagnosis ; Fluorescent Antibody Technique ; Follow-Up Studies ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Immunohistochemistry ; Lupus Erythematosus, Systemic ; Methylprednisolone ; Microscopy, Electron ; Microscopy, Fluorescence ; Proteinuria

Bartter syndrome (BS) I-IV is a rare autosomal recessive disorder affecting salt reabsorption in the thick ascending limb of the loop of Henle. This report highlights clinicopathological findings and genetic studies of classic BS in a 22-year-old female patient who presented with persistent mild proteinuria for 2 years. A renal biopsy demonstrated a mild to moderate increase in the mesangial cells and matrix of most glomeruli, along with marked juxtaglomerular cell hyperplasia. These findings suggested BS associated with mild IgA nephropathy. Focal tubular atrophy, interstitial fibrosis, and lymphocytic infiltration were also observed. A genetic study of the patient and her parents revealed a mutation of the CLCNKB genes. The patient was diagnosed with BS, type III. This case represents an atypical presentation of classic BS in an adult patient. Pathologic findings of renal biopsy combined with genetic analysis and clinicolaboratory findings are important in making an accurate diagnosis.
Adult* ; Atrophy ; Bartter Syndrome* ; Biopsy ; Diagnosis ; Extremities ; Female ; Fibrosis ; Glomerulonephritis, IGA ; Humans ; Hyperplasia ; Hypokalemia ; Loop of Henle ; Mesangial Cells ; Parents ; Proteinuria* ; Young Adult

BACKGROUND/AIMS: Immunoglobulin A nephropathy (IgAN) is a generally progressive disease, even in patients with favorable prognostic features. In this study, we aimed to investigate the antiproteinuric effect and tolerability of low-dose valsartan (an angiotensin II receptor blocker) therapy in normotensive IgAN patients with minimal proteinuria of less than 0.5 to 1.0 g/day. METHODS: Normotensive IgAN patients, who had persistent proteinuria with a spot urine protein-to-creatinine ratio of 0.3 to 1.0 mg/mg creatinine, were recruited from five hospitals and randomly assigned to either 40 mg of valsartan as the low-dose group or 80 mg of valsartan as the regular-dose group. Clinical and laboratory data were collected at baseline, and at 4, 8, 12, and 24 weeks after valsartan therapy. RESULTS: Forty-three patients (low-dose group, n = 23; regular-dose group, n = 20) were enrolled in the study. Proteinuria decreased significantly not only in the regular-dose group but also in the low-dose group. The change in urine protein-to-creatinine ratio at week 24 was -41.3% +/- 26.1% (p < 0.001) in the regular-dose group and -21.1% +/- 45.1% (p = 0.005) in the low-dose group. In the low-dose group, blood pressure was constant throughout the study period, and there was no symptomatic hypotension. In the regular-dose group, blood pressure decreased at weeks 8 and 12. No significant change in glomerular filtration rate, serum creatinine level, or serum potassium level was observed during the study period. CONCLUSIONS: Our results suggest that low-dose valsartan can significantly reduce proteinuria without causing any intolerability in normotensive IgAN patients with minimal proteinuria.
Adult ; Angiotensin II Type 1 Receptor Blockers/*administration & dosage/adverse effects ; Biomarkers/urine ; Blood Pressure ; Creatinine/urine ; Female ; Glomerulonephritis, IGA/diagnosis/*drug therapy/physiopathology/urine ; Humans ; Male ; Middle Aged ; Prospective Studies ; Proteinuria/diagnosis/*drug therapy/physiopathology/urine ; Republic of Korea ; Time Factors ; Treatment Outcome ; Valsartan/*administration & dosage/adverse effects

The increasing interest in healthcare and health screening events is revealing additional cases of asymptomatic isolated microscopic hematuria (IMH). However, a consensus of the evaluation and explanation of the IMH prognosis is controversial among physicians. Here, we present the natural course of IMH together with the pathological diagnosis and features to provide supportive data when approaching patients with IMH. We retrospectively evaluated 350 patients with IMH who underwent a renal biopsy between 2002 and 2011, and the pathological diagnosis and chronic histopathological features (glomerulosclerosis, interstitial fibrosis, and tubular atrophy) were reviewed. Deterioration of renal function was examined during follow up. The patients with IMH were evaluated for a mean of 86 months. IgA nephropathy was the most common diagnosis in 164 patients (46.9%). Chronic histopathological changes were observed in 166 (47.4%) but was not correlated with proteinuria or a decline in renal function. Ten patients developed proteinuria, and all of them had IgA nephropathy. Three patients progressed to chronic kidney disease with an estimated glomerular filtration rate < 60 mL/min/1.73 m2 but none progressed to end stage renal disease. In conclusion, IMH had a generally benign course during 7-years of observation, although IgA nephropathy should be monitored if it progresses to proteinuria. Future prospective randomized studies may help conclude the long-term prognosis and lead to a consensus for managing IMH.
Adolescent ; Adult ; Biopsy ; Female ; Glomerular Filtration Rate ; Glomerulonephritis, IGA/diagnosis ; Hematuria/*diagnosis/pathology ; Humans ; Kidney/*pathology/physiology ; Kidney Failure, Chronic/diagnosis ; Male ; Middle Aged ; Prognosis ; Proteinuria/diagnosis ; Retrospective Studies ; Young Adult