Caihong Zeng

Anti-Phospholipase A2 Receptor Antibody in Membranous Nephropathy

The M-type phospholipase A2 receptor (PLA2R) is a target autoantigen in adult idiopathic membranous nephropathy (MN), but the prevalence of autoantibodies against PLA2R is unknown among Chinese patients with MN. Here, we measured anti-PLA2R antibody in the serum of 60 patients with idiopathic MN, 20 with lupus-associated MN, 16 with hepatitis B (HBV)-associated MN, and 10 with tumor-associated MN. Among patients with idiopathic MN, 49 (82%) had detectable anti-PLA2R autoantibodies using a Western blot assay; an assay with greater sensitivity detected very low titers of anti-PLA2R in 10 of the remaining 11 patients. Using the standard assay, we detected anti-PLA2R antibody in only 1 patient with lupus, 1 with HBV, and 3 with cancer, producing an overall specificity of 89% in this cohort limited to patients with secondary MN. The enhanced assay detected low titers of anti-PLA2R in only 2 additional samples of HBV-associated MN. In summary, these results suggest that PLA2R is a major target antigen in Chinese idiopathic MN and that detection of anti-PLA2R is a sensitive test for idiopathic MN.

Long-term renal survival and related risk factors in patients with IgA nephropathy: results from a cohort of 1155 cases in a Chinese adult population

BACKGROUND We sought to identify the long-term renal survival rate and related risk factors of progression to renal failure in Chinese adult patients with IgA nephropathy (IgAN) and to quantify the effects of proteinuria during the follow-up on outcome in patients with IgAN. METHODS Patients with biopsy-proven primary IgAN in the Nanjing Glomerulonephritis Registry were studied. Renal survival and the relationships between clinical parameters and renal outcomes were assessed. RESULTS One thousand one hundred and fifty-five patients were enrolled in this study. The 10-, 15- and 20-year cumulative renal survival rates, calculated by Kaplan-Meier method, were 83, 74 and 64%, respectively. At the time of biopsy, proteinuria>1.0 g/day [hazard ratio (HR) 3.2, P<0.001], estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m2 (HR 2.6, P<0.001), hypertension (HR 1.9, P<0.001), hypoproteinemia (HR 2.0, P<0.001) and hyperuricemia (HR 2.1, P<0.001) were the independent risk factors. Multivariate Cox analysis showed the time-average proteinuria (TA-P) during follow-up was the most important risk factor of renal failure. Patients with TA-P>1.0 g/day were associated with a 9.4-fold risk than patients with TA-P<1.0 g/day (P<0.001) and 46.5-fold risk than those with TA-P<0.5 g/day (P<0.001). Moreover, patients who achieved TA-P<0.5 g/day benefit much more than those with TA-P between 0.5 and 1.0 g/day (HR 13.1, P<0.001). CONCLUSIONS Thirty-six percent of Chinese adult patients with IgAN progress to end stage renal disease within 20 years. Five clinical features-higher proteinuria, hypertension, impaired renal function, hypoproteinemia and hyperuricemia-are independent predictors of an unfavorable renal outcome. The basic goal of anti-proteinuric therapy for Chinese patients is to lower proteinuria<1.0 g/day and the optimal goal is to lower proteinuria to <0.5 g/day.

Diagnosis, Pathogenesis, Treatment, and Prognosis of Hereditary Fibrinogen Aα-Chain Amyloidosis

Mutations in the fibrinogen A alpha-chain gene are the most common cause of hereditary renal amyloidosis in the United Kingdom. Previous reports of fibrinogen A alpha-chain amyloidosis have been in isolated kindreds, usually in the context of a novel amyloidogenic mutation. Here, we describe 71 patients with fibrinogen amyloidosis, who were prospectively studied at the UK National Amyloidosis Centre. Median age at presentation was 58 yr, and renal involvement led to diagnosis in all cases. Even after a median follow-up of 4 yr, clinically significant extra-renal disease was rare. Renal histology was characteristic: striking glomerular enlargement with almost complete obliteration of the normal architecture by amyloid deposition and little or no vascular or interstitial amyloid. We discovered four amyloidogenic mutations in fibrinogen (P552H, E540V, T538K, and T525fs). A family history of renal disease was frequently absent. Median time from presentation to ESRD was 4.6 yr, and the estimated median patient survival from presentation was 15.2 yr. Among 44 patients who reached ESRD, median survival was 9.3 yr. Twelve renal transplants survived for a median of 6.0 (0-12.2) yr. Seven grafts had failed after median follow up from transplantation of 5.8 yr, including three from recurrent amyloid after 5.8, 6.0, and 7.4 yr; three grafts failed immediately for surgical reasons and one failed from transplant glomerulopathy after 5.8 yr with no histological evidence of amyloid. At censor, the longest surviving graft was 12.2 yr. In summary, fibrinogen amyloidosis is predominantly a renal disease characterized by variable penetrance, distinctive histological appearance, proteinuria, and progressive renal impairment. Survival is markedly better than observed with systemic AL amyloidosis, and outcomes with renal replacement therapy are comparable to those for age-matched individuals with nondiabetic renal disease.

Triptolide protects podocytes from puromycin aminonucleoside induced injury in vivo and in vitro

Extracts of Tripterygium wilfordii Hook F have been used to treat glomerulonephritis for more than 30 years in China with dramatic antiproteinuric effects. Triptolide, a diterpene triepoxide, is one of the major active components of these extracts. To clarify its antiproteinuric effects we induced podocyte injury by puromycin aminonucleoside. Triptolide effectively reduced the proteinuria induced by puromycin in nephrotic rats without reducing the glomerular filtration rate. The antiproteinuric effect was associated with improvement in the foot process effacement, a decrease in the podocyte injury marker desmin as well as the restoration of nephrin and podocin expression and distribution. In cultured mouse podocytes triptolide pretreatment prevented the puromycin-induced disruption of the actin cytoskeleton and microfilament-associated synaptopodin while protecting nephrin and podocin expression. Triptolide suppressed reactive oxygen species generation and p38 mitogen-activated protein kinase activation while restoring RhoA signaling activity. These results show that triptolide ameliorates puromycin aminonucleoside-mediated podocyte injury in vivo and in vitro.

Downregulation of MicroRNA-30 Facilitates Podocyte Injury and Is Prevented by Glucocorticoids

MicroRNAs (miRNAs) are essential for podocyte homeostasis, and the miR-30 family may be responsible for this action. However, the exact roles and clinical relevance of miR-30s remain unknown. In this study, we examined the expression of the miR-30 family in the podocytes of patients with FSGS and found that all members are downregulated. Treating cultured human podocytes with TGF-β, LPS, or puromycin aminonucleoside (PAN) also downregulated the miR-30 family. Podocyte cytoskeletal damage and apoptosis caused by treatment with TGF-β or PAN were ameliorated by exogenous miR-30 expression and aggravated by miR-30 knockdown. Moreover, we found that miR-30s exert their protective roles by direct inhibition of Notch1 and p53, which mediate podocyte injury. In rats, treatment with PAN substantially downregulated podocyte miR-30s and induced proteinuria and podocyte injury; however, transfer of exogenous miR-30a to podocytes of PAN-treated rats ameliorated proteinuria and podocyte injury and reduced Notch1 activation. Finally, we demonstrated that glucocorticoid treatment maintains miR-30 expression in cultured podocytes treated with TGF-β, LPS, or PAN and in the podocytes of PAN-treated rats. Glucocorticoid-sustained miR-30 expression associated with reduced Notch1 activation and alleviated podocyte damage. Taken together, these findings demonstrate that miR-30s protect podocytes by targeting Notch1 and p53 and that the loss of miR-30s facilitates podocyte injury. In addition, sustained miR-30 expression may be a novel mechanism underlying the therapeutic effectiveness of glucocorticoids in treating podocytopathy.

A multicenter application and evaluation of the oxford classification of IgA nephropathy in adult chinese patients.

BACKGROUND The Oxford classification of immunoglobulin A (IgA) nephropathy (IgAN) provides a histopathologic grading system that is associated with kidney disease outcomes independent of clinical features. We evaluated the Oxford IgAN classification in a large cohort of patients from China. STUDY DESIGN Retrospective study. SETTING & PARTICIPANTS 1,026 adults with IgAN from 18 referral centers in China. Inclusion criteria and statistical analysis were similar to the Oxford study. PREDICTORS Histologic findings of mesangial hypercellularity score, endocapillary proliferation, segmental sclerosis or adhesion, crescents, necrosis, and tubular atrophy/interstitial fibrosis. Clinical features, blood pressure, estimated glomerular filtration rate (eGFR), proteinuria, and treatment modalities. OUTCOMES Time to a 50% reduction in eGFR or end-stage renal disease (the combined event); the rate of eGFR decline (slope of eGFR); proteinuria during follow-up. RESULTS Compared with the Oxford cohort, the Chinese cohort had a lower proportion of patients with mesangial hypercellularity (43%) and endocapillary proliferation (11%), higher proportion with segmental sclerosis or adhesion (83%) and necrosis (15%), and similar proportion with crescents (48%) and tubular atrophy/interstitial fibrosis (moderate, 24%; severe, 3.3%). During a median follow-up of 53 (25th-75th percentile, 36-67) months, 159 (15.5%) patients reached the combined event. Our study showed that patients with a mesangial hypercellularity score higher than 0.5 were associated with a 2.0-fold (95% CI, 1.5-2.8; P<0.001) higher risk of the combined event than patients with a score of 0.5 or lower. Patients with tubular atrophy/interstitial fibrosis of 25%-50% and >50% versus <25% were associated with a 3.7-fold (95% CI, 2.6-5.1; P<0.001) and 15.1-fold (95% CI, 9.5-24.2; P<0.001) higher risk of the combined event, respectively. Endocapillary proliferation, glomerular crescents, and necrosis were not significant. LIMITATIONS Retrospective study; the therapeutic interventions were miscellaneous. CONCLUSIONS We confirmed the associations of mesangial hypercellularity and tubular atrophy/interstitial fibrosis with kidney disease outcomes.

Rhein Improves Renal Lesion and Ameliorates Dyslipidemia in db/db Mice with Diabetic Nephropathy

Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid) is purified from rhubarb (Rheum officinale), a widely used traditional Chinese herb. In our previous studies, rhein was shown to be effective in ameliorating diabetic renal pathological changes and attenuating hyperlipidemia. Statins have also been proven to ameliorate renal pathological changes associated with diabetic nephropathy (DN) through lipid-dependent and -independent mechanisms. We here study the protective and regulatory effects of rhein on renal injury and dyslipidemia in db/db mice with DN, using simvastatin as the control, and provide information on the mechanisms by which rhein protects against renal damage from DN. The results indicated that urinary albumin excretion (UAE) was reduced after 8 weeks of treatment in the rhein group, and 12 weeks in the simvastatin group. The morphometric analysis revealed that levels of extracellular matrix (ECM) significantly decreased in the rhein group after the full treatment course, but not in the simvastatin group. The more powerful effects of rhein on decreasing transforming growth factor-beta1 (TGF-beta1) and fibronectin immunohistochemistry expression in renal tissue were also observed. And the plasma levels of cholesterol (Chol), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoE all decreased in both the rhein and the simvastatin groups. Together, our data suggested that both rhein and simvastatin regulate dyslipidemia. The powerful effect of rhein in renal protection is due to its widespread effects. Rhein is a new drug that can decrease lipid levels and protect against DN progression in a different fashion with simvastatin.

Induction therapies for class IV lupus nephritis with non-inflammatory necrotizing vasculopathy: mycophenolate mofetil or intravenous cyclophosphamide

The presence of renal noninflammatory necrotizing vasculopathy (NNV) is often associated with a severe form of lupus nephritis (LN), which is unresponsive to standard therapy. We conducted a 6-month randomized, prospective, open-label trial comparing mycophenolate mofetil (MMF) (1.5—2.0 g/day) with monthly i.v. cyclophosphamide (CTX) (0.75—1.0 g/m2) as induction therapy for class IV LN with NNV. The primary and second end points were complete remission (CR) and partial remission (PR), respectively. Of 20 patients recruited, nine were randomly assigned to MMF and 11 to CTX. The baseline characteristics between groups were not significant. CR was achieved in four patients (44.4%) receiving MMF and in none of the patients receiving CTX (P = 0.026). PR was achieved in two patients (22.2%) in the MMF group and three patients (27.2%) in the CTX group. The total remission rate (CR + PR) in the MMF and CTX group was 66.6 and 27.2%, respectively (P = 0.17). MMF was more effective than i.v. CTX in reducing proteinuria and haematuria. Adverse events were significantly less frequent with MMF than with CTX (P = 0.028). MMF was superior to i.v. CTX in inducing CR of LN with NNV and had a more favourable safety profile. Lupus (2007) 16, 707—712.

Oxford Classification of IgA nephropathy 2016: an update from the IgA Nephropathy Classification Working Group

Since the Oxford Classification of IgA nephropathy (IgAN) was published in 2009, MEST scores have been increasingly used in clinical practice. Further retrospective cohort studies have confirmed that in biopsy specimens with a minimum of 8 glomeruli, mesangial hypercellularity (M), segmental sclerosis (S), and interstitial fibrosis/tubular atrophy (T) lesions predict clinical outcome. In a larger, more broadly based cohort than in the original Oxford study, crescents (C) are predictive of outcome, and we now recommend that C be added to the MEST score, and biopsy reporting should provide a MEST-C score. Inconsistencies in the reporting of M and endocapillary cellularity (E) lesions have been reported, so a web-based educational tool to assist pathologists has been developed. A large study showed E lesions are predictive of outcome in children and adults, but only in those without immunosuppression. A review of S lesions suggests there may be clinical utility in the subclassification of segmental sclerosis, identifying those cases with evidence of podocyte damage. It has now been shown that combining the MEST score with clinical data at biopsy provides the same predictive power as monitoring clinical data for 2 years; this requires further evaluation to assess earlier effective treatment intervention. The IgAN Classification Working Group has established a well-characterized dataset from a large cohort of adults and children with IgAN that will provide a substrate for further studies to refine risk prediction and clinical utility, including the MEST-C score and other factors.

Mercury-Induced Membranous Nephropathy: Clinical and Pathological Features

BACKGROUND AND OBJECTIVES Long-term contact with mercury may induce membranous nephropathy (MN); however, the clinical pathologic features and pathogenesis of mercury-induced MN have not been investigated. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The present study retrospectively evaluated 11 cases of mercury-induced MN to analyze its causes and its clinical and pathologic features. RESULTS A total of 10 women and 1 man ages 15 to 45 years were enrolled in the present study. Mercury exposure was caused by mercury-containing pills (five patients), skin lightening cream (four patients), hair-dyeing agents (one patient), and mercury vapor (one patient). The duration of contact with mercury ranged from 2 to 60 months, and the urinary mercury concentrations were 1.5 to 50 times higher than reference values. All patients presented with proteinuria and normal renal function; three had nephrotic syndrome. Light microscopy revealed thickened glomerular basement membrane and mildly proliferative mesangial cells. Acute tubulointerstitial injury occurred in three patients. The immunofluorescence findings showed granular deposits of IgG and C3 along the glomerular capillary wall, mostly accompanied by deposits of C4 and C1q. IgG1 and IgG4 (predominantly IgG1) deposits were observed along the glomerular capillary loops. Nine patients reached complete remission in follow-up after withdrawal from mercury exposure. CONCLUSIONS Deposits of IgG1 subclasses in renal tissues indicated that the pathogenesis of mercury-induced MN differs from that of idiopathic MN. It is important that clinicians are aware that mercury exposure should be considered a possible cause of membranous nephropathy.