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*

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

Background: Diabetes mellitus (DM) has become the leading cause of chronic kidney disease (CKD). Nondiabetic renal diseases (NDRDs) have different clinicopathological features and prognosis from those of diabetic nephropathy. Our study sought to analyze the clinical and pathological features of NDRDs, in different age groups through a cross-sectional study. Methods: All patients with type 2 DM at our center who underwent renal biopsy between March 1997 and March 2017 were screened and divided into three groups by age: Group 1 (youth group), 18-44 years old; Group 2 (middle-aged group), 45-59 years old; and Group 3 (elderly group), ≥60 years old. We analyzed the clinicopathological data and risk factors by univariate and multivariate logistic regression for NDRD of the patients to identify the features of NDRD in different age groups. Results: We included 982 patients in the final analysis. Patients with NDRD accounted for 64.4% of all patients. IgA nephropathy (IgAN) was the most common pathological pattern in young patients with NDRD, accounting for 26.3%. In the middle-aged group, the two most common pathological patterns were IgAN and membranous nephropathy. Membranous nephropathy was the most common pathological pattern in elderly patients with NDRD, accounting for 29.3%. Consistent with pathological features, glomerular hematuria is a risk factor for NDRD in Group 1 (odds ratio [OR], 26.514; 95% confidence interval [CI], 2.503-280.910; P = 0.006). On the other hand, rapidly increasing proteinuria or nephrotic syndrome is a risk factor for NDRD in Group 2 (OR, 5.921; 95% CI, 2.061-17.013; P = 0.001) and Group 3 (OR, 90.409; 95% CI, 6.198-1318.826; P = 0.001). Conclusions This single-center study showed that the proportion and composition of NDRD differ among different age groups. Consistent with pathological features, some clinical indices such as hematuria and proteinuria showed different features among different age groups.
Adult ; Age Factors ; Aged ; Cross-Sectional Studies ; Diabetic Nephropathies ; pathology ; Female ; Glomerulonephritis, IGA ; pathology ; Humans ; Kidney Diseases ; pathology ; Logistic Models ; Male ; Middle Aged

Female ; Glomerulonephritis, IGA ; metabolism ; pathology ; Glomerulonephritis, Membranous ; metabolism ; pathology ; Glomerulosclerosis, Focal Segmental ; metabolism ; pathology ; Humans ; Kidney ; metabolism ; pathology ; Male ; Renal Insufficiency, Chronic ; metabolism ; pathology

PURPOSE: Smoking reportedly exerts deleterious effects on renal function; however, its effects on histology have not been clarified in patients with IgA nephropathy (IgAN). MATERIALS AND METHODS: Renal histology was evaluated in a cohort of 397 patients diagnosed with IgAN according to smoking status and dose in relation to renal function. RESULTS: Among the study cohort, which was predominantly male (88.5%), 52 patients (13%) were current smokers. These current smokers demonstrated more frequent hypertension and higher serum creatinine levels than non/ex-smokers at the time of diagnosis, which was apparent with increased smoking dose. The percentages of global glomerulosclerosis and arteriolar hyalinosis increased with increased smoking dose, whereas tubulointerstitial fibrosis or arterial intimal thickening did not. Glomerular mesangial alpha-smooth muscle actin expression were similar between current and non/ex-smokers matched for age, gender, hypertension, and histologic severity, although the number of glomerular CD68+ cells was significantly fewer in smokers. Initial serum creatinine level, estimated glomerular filtration rate (eGFR), and global glomerulosclerosis were found to be risk factors of serum creatinine doubling in both smokers and non/ex-smokers by univariate analysis during a mean follow-up of 3.8 years. CONCLUSION: In addition to dose dependent renal functional decline and hypertension, smoking contributes to renal disease progression by eliciting microvascular injury in IgAN patients.
Adult ; Aged ; Case-Control Studies ; Cohort Studies ; Creatinine/blood ; Disease Progression ; Female ; Glomerulonephritis, IGA/blood/*diagnosis/epidemiology ; Humans ; Immunohistochemistry ; Kidney/*pathology ; Kidney Function Tests ; Kidney Glomerulus/*pathology ; Male ; Middle Aged ; Risk Factors ; Smoking/*adverse effects/epidemiology

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

BACKGROUND/AIMS: The Oxford classification of immunoglobulin A nephropathy (IgAN) is a pathology-based prognostic classification system. However, further study is needed to determine its validity. We studied the relationships between the Oxford classification and established prognostic factors and renal survival. We also examined associations between electron microscopy findings and these parameters. METHODS: We reviewed and reclassified 213 patients who were diagnosed with IgAN from 1997 to 2007 using the Oxford and World Health Organization (WHO) classification systems. The patients were also categorized by a pathologist using electron microscopy findings, including foot process fusion, glomerular basement membrane thickness, and electron-dense deposits. We examined the correlations between light and electron microscopy data and known prognostic factors (e.g., age, sex, proteinuria, serum creatinine, estimated glomerular filtration rate [eGFR], and blood pressure). The same procedure was applied to renal survival. RESULTS: Patient age increased with the grades of segmental sclerosis (S) and tubular atrophy/interstitial fibrosis (T) (P < 0.05). eGFR decreased significantly with increasing mesangial hypercellularity (M) (p = 0.0034), S (p = 0.0003), endocapillary hypercellularity (E) (p = 0.0411), and T (P < 0.0001). MSET differed significantly by sex (P < 0.0001). The 24-h urine protein/creatinine ratio increased significantly with the degrees of S (p = 0.036), E (p = 0.0155), and T (p = 0.015). The serum creatinine level was significantly higher in patients with T2 than T1 or T0 (P < 0.0001). At the time of biopsy, the degree of tubular atrophy/interstitial fibrosis affected the doubling of serum creatinine or end-stage renal disease. However, the electron microscopy findings did not predict the renal outcome. CONCLUSIONS: Our study suggests that tubular atrophy/interstitial fibrosis is significantly associated with proteinuria and renal progression in IgAN.
Biopsy ; Classification ; Creatinine ; Fibrosis ; Foot ; Glomerular Basement Membrane ; Glomerular Filtration Rate ; Glomerulonephritis, IGA* ; Humans ; Kidney Failure, Chronic ; Microscopy, Electron ; Pathology* ; Prognosis ; Proteinuria ; Sclerosis ; World Health Organization

OBJECTIVETo investigate the value of serum IgA/C3 ratio in the diagnosis of IgA nephropathy and explore its relationship with the clinicopathological features of the patients.

METHODSSixty-six patients with IgA nephropathy, 111 with other glomerular diseases, and 40 healthy control subjects without kidney disease were tested for serum IgA and C3 levels using CRM470 adjusted standardized immune turbidimetric method, and the IgA/C3 ratio was calculated. According to Oxford and Lee's classification criteria, we analyzed the pathological grades of the renal biopsy samples from patients with IgA nephropathy. The ROC curve was used to assess the value of serum IgA and IgA/C3 ratio in predicting IgA nephropathy.

RESULTSPatients with IgA nephropathy had an elevated serum IgA/C3 ratio than those with other glomerular diseases and the control subjects, with an area under the ROC curve of 0.776. An elevated serum IgA/C3 ratio was not found to significantly correlate with the pathological grade of renal biopsy samples in patients with IgA nephropathy.

CONCLUSIONIn the absence of renal biopsy findings, serum IgA/C3 ratio can help in the diagnosis of IgA nephropathy.

Biopsy ; Case-Control Studies ; Complement C3 ; analysis ; Glomerulonephritis, IGA ; blood ; diagnosis ; Humans ; Immunoglobulin A ; blood ; Kidney ; pathology

BACKGROUND/AIMS: Tubulointerstitial injury plays an important role in the progression of immunoglobulin A nephropathy (IgAN), and neutrophil gelatinase-associated lipocalin (NGAL) is among the most sensitive tubular biomarkers. We investigated whether serum or urine NGAL predicts prognosis in patients with IgAN. METHODS: The present study enrolled patients with biopsy-proven IgAN from January 2005 to December 2010, whose serum and urine samples at the time of kidney biopsy were preserved by freezing. We retrospectively reviewed patient clinical data and followed patients until October 2012. Serum and urine NGAL levels were measured using an enzyme-linked immunosorbent assay kit. Renal progression was defined as an estimated glomerular filtration rate decline by > 50% or progression to end-stage renal disease. RESULTS: There were 121 patients enrolled in this study. During the median follow-up period of 41.49 months, renal progression was found in nine patients (7.4%). Serum or urine NGAL alone could not predict renal progression; however, when serum and urine NGAL levels were combined, belonging to the high NGAL group independently predicted renal progression (hazard ratio [HR], 5.56; 95% confidence interval [CI], 1.42 to 21.73; p = 0.014), along with tubular damage graded according to the Oxford classification as T2 (HR, 8.79; 95% CI, 2.01 to 38.51; p = 0.004). In addition, a Kaplan-Meier curve of renal survival showed significantly higher renal progression in patients in the high NGAL group (log rank, p = 0.004). CONCLUSIONS: In patients with IgAN, high serum and urine NGAL levels at the time of kidney biopsy predict renal progression.
Acute-Phase Proteins/*urine ; Adult ; Biomarkers/blood/urine ; Biopsy ; Chi-Square Distribution ; Disease Progression ; Enzyme-Linked Immunosorbent Assay ; Female ; Glomerular Filtration Rate ; Glomerulonephritis, IGA/*blood/complications/pathology/physiopathology/*urine ; Humans ; Kaplan-Meier Estimate ; Kidney/*metabolism/pathology/physiopathology ; Lipocalins/*blood/*urine ; Male ; Middle Aged ; Multivariate Analysis ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Proto-Oncogene Proteins/*blood/*urine ; Retrospective Studies ; Risk Factors ; Young Adult

BACKGROUND/AIMS: Neutrophil gelatinase-associated lipocalin (NGAL) is a well-known biomarker of acute kidney injury. We evaluated the value of plasma NGAL (pNGAL) as an independent predictor of prognosis in immunoglobulin A nephropathy (IgAN). METHODS: In total, 91 patients with biopsy-proven IgAN at a single center were evaluated. pNGAL was measured using a commercial enzyme-linked immunosorbent assay kit (R&D Systems). Adverse renal outcome was defined as chronic kidney disease (CKD) stage 3 or above at the last follow-up. Pearson correlation coefficient and Cox regression were used for analyses. RESULTS: The mean age of all patients (male:female, 48:43) was 35 years (range, 18 to 77). pNGAL ranged between 21.68 and 446.40 ng/mL (median, 123.97) and showed a correlation with age (r = 0.332, p = 0.001), creatinine (r = 0.336, p = 0.001), estimated glomerular filtration rate (r = -0.397, p < 0.001), uric acid (r = 0.289, p = 0.006), and the protein-to-creatinine ratio (r = 0.288, p = 0.006). During a mean follow-up period of 37.6 months, 11 patients (12.1%) had CKD stage 3 or above. In a multivariate Cox regression model, hypertension (hazard ratio [HR], 8.779; 95% confidence interval [CI], 1.526 to 50.496; p = 0.015), proteinuria > 1 g/day (HR, 5.184; 95% CI, 1.124 to 23.921; p = 0.035), and pNGAL (HR, 1.012; 95% CI, 1.003 to 1.022; p = 0.013) were independent predictors associated with adverse renal outcome. CONCLUSIONS: pNGAL showed strong correlations with other clinical prognostic factors and was also an independent predictor of adverse renal outcome. We suggest pNGAL as a potential predictor for prognosis in IgAN, while further studies are needed to confirm the clinical value.
Acute-Phase Proteins ; Adolescent ; Adult ; Aged ; Biomarkers/blood ; Biopsy ; Chi-Square Distribution ; Creatinine/blood ; Disease Progression ; Enzyme-Linked Immunosorbent Assay ; Female ; Glomerular Filtration Rate ; Glomerulonephritis, IGA/*blood/complications/pathology/physiopathology ; Humans ; Kidney/*metabolism/pathology/physiopathology ; Linear Models ; Lipocalins/*blood ; Male ; Middle Aged ; Multivariate Analysis ; Predictive Value of Tests ; Prognosis ; Proportional Hazards Models ; Proto-Oncogene Proteins/*blood ; Renal Insufficiency, Chronic/blood/etiology ; Republic of Korea ; Retrospective Studies ; Risk Factors ; Time Factors ; Young Adult