Whole exome sequencing reveals novel COL4A3 and COL4A4 mutations and resolves diagnosis in Chinese families with kidney disease.

BACKGROUND: Collagen IV-related nephropathies, including thin basement membrane nephropathy and Alport Syndrome (AS), are caused by defects in the genes COL4A3, COL4A4 and COL4A5. Diagnosis of these conditions can be hindered by variable penetrance and the presence of non-specific clinical or pathological features. METHODS: Three families with unexplained inherited kidney disease were recruited from Shanghai, China. Whole exome sequencing (WES) was performed in the index case from each family and co-segregation of candidate pathogenic mutations was tested by Sanger sequencing. RESULTS: We identified COL4A4 missense variants [c.G2636A (p.Gly879Glu) and c.C4715T (p.Pro1572Leu)] in the 21-year-old male proband from family 1, who had been diagnosed with mesangial proliferative nephropathy at age 14. COL4A4 c.G2636A, a novel variant, co-segregated with renal disease among maternal relatives. COL4A4 c.C4715T has previously been associated with autosomal recessive AS and was inherited from his clinically unaffected father. In family 2, a novel COL4A3 missense mutation c.G2290A (p.Gly997Glu) was identified in a 45-year-old male diagnosed with focal segmental glomerulosclerosis and was present in all his affected family members, who exhibited disease ranging from isolated microscopic hematuria to end stage renal disease (ESRD). In family 3, ESRD occurred in both male and females who were found to harbor a known AS-causing COL4A5 donor splice site mutation (c.687+1G>A). None of these variants were detected among 100 healthy Chinese individuals. CONCLUSION: WES identified 2 novel and 2 known pathogenic COL4A3/COL4A4/COL4A5 mutations in 3 families with previously unexplained inherited kidney disease. These findings highlight the clinical range of collagen IV-related nephropathies and resolved diagnostic confusion arising from atypical or incomplete clinical/histological findings, allowing appropriate counselling and treatment advice to be given.

Imbalance of regulatory T cells to Th17 cells in IgA nephropathy.

BACKGROUND: Dysregulation of CD4 (+) T cell subsets participates in the pathogenesis of IgA nephropathy (IgAN). FoxP3 (+) regulatory T cells (Treg) and Th17 cells are two novel subsets of CD4 (+) T cells. This study aims to investigate Treg/Th17 balance in IgAN patients. METHODS: Peripheral frequencies of Th17 and Treg functional subsets - CD45RA (+) FoxP3(low) resting Treg (rTreg) and CD45RA(-)FoxP3(high) activated Treg (aTreg) were assessed in 63 adult IgAN patients. Expression of transcription factors (FoxP3 and RORγt) and related cytokines of Treg and Th17 were analysed. Renal expression of FoxP3 and IL-17A were detected by immunohistochemistry. RESULTS: Compared with normal controls, IgAN patients had decreased frequency of CD45RA(-)FoxP3(high) aTreg subset (p < 0.05), increased frequency of Th17 (p < 0.05) and decreased ratio of Treg/Th17 (p < 0.05). Frequency of aTreg subset correlated with SBP(r = - 0.57, p < 0.05), DBP (r = - 0.50, p < 0.05), eGFR (r = 0.68, p < 0.05) and 24 h proteinuria (r = - 0.58, p < 0.05). RORγtmRNA/FoxP3mRNA ratio increased in IgAN (p < 0.05). Serum IL-17A, IL-21, IL-23, IL-1ß and IL-6 elevated while IL-10 decreased in IgAN (p < 0.05), and serum IL-17A correlated with 24 h proteinuria (r = 0.35, p < 0.05). Serum TGF-ß1 wasn't different between the two groups. Renal interstitial infiltration of FoxP3 (+) mononuclear cells were observed in IgAN patients, particularly prominent in those with > 25% tubular atrophy/interstitial fibrosis. Tubular IL-17A expression was found in 34 out of 63 IgAN patients. Compared with 29 patients without IL-17A expression, these patients had lower renal function, greater proteinuria, and more severe tubulointerstitial damage. CONCLUSIONS: Imbalance of Treg/Th17 found in IgAN may play a role in disease pathogenesis and progression.

Micro RNA-155 inhibitor as a potential therapeutic strategy for the treatment of acute kidney injury (AKI): a nanomedicine perspective.

In this study, we have prepared miR-155 inhibitor-loaded liposome vesicles for the effective treatment of acute kidney injury. The efficacy of liposomal miR-155 inhibitor in the expression of miR-155, mortality in animals, the expression of TNF-α-IL6, and the expression of SOCS1-STAT1 were evaluated. The loading of miR-155 inhibitor into liposomes conferred the much needed colloidal stability and efficient delivery to the renal tissues. The study clearly shows that miR-I-LV significantly decreases the expression of miR-155 in kidneys compared to LPS. Administration of miR-I-LV remarkably reduced the pathological concerns of the kidneys with a marked decrease in inflammatory cell infiltration. Scrambled miR-155 did not have any effect on the expression of these markers; however miR-I-LV showed a remarkable ability to decrease the expression of TNF-α and IL-6 in kidney tissues indicating an ability to treat acute kidney infections. Overall, administration of miR-155 inhibitor effectively alleviated LPS-induced kidney injury by significantly suppressing TNF-α and IL-6 in kidney tissue and by remarkably increasing the expression of mRNA of SOCS1 and STAT1. The present results suggest that miR-155 inhibitor could be used in an effective targeting strategy for the treatment of acute kidney injury (AKI).

Effects of mineralocorticoid receptor antagonists on the progression of diabetic nephropathy.

AIMS/INTRODUCTION: We aimed to evaluate the potential benefits and adverse effects of adding a mineralocorticoid receptor antagonist (MRA) to angiotensin-converting enzyme inhibitors (ACEI) and/or angiotensin receptor blockers (ARB), as standard treatment in patients with diabetic nephropathy. MATERIALS AND METHODS: We scanned the Embase, PubMed and Cochrane Central Register of Controlled Trials databases for human clinical trials published in English until June 2016, evaluating renal outcomes in patients with diabetic nephropathy. RESULTS: A total of 18 randomized controlled trials involving 1,786 patients were included. Compared with ACEI/ARB alone, co-administration of MRA and ACEI/ARB significantly reduced urinary albumin excretion and the urinary albumin-creatinine ratio (mean difference -69.38, 95% confidence intervals -103.53 to -35.22, P < 0.0001; mean difference -215.74, 95% confidence intervals -409.22 to -22.26, P = 0.03, respectively). A decrease of blood pressure was also found in the co-administration of MRA and ACEI/ARB groups. However, we did not observe any improvement in the glomerular filtration rate. There was a significant increase in the risk of hyperkalemia on the addition of MRA to ACEI/ARB treatment (relative risk 3.74, 95% confidence intervals 2.30-6.09, P < 0.00001). CONCLUSIONS: These findings suggest that co-administration of MRA and ACEI/ARB has beneficial effects on renal outcomes with increasing the incidence of hyperkalemia.

Combination therapy with lamivudine and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker for hepatitis B virus-associated glomerulonephritis with mild to moderate proteinuria: a clinical review of 38 cases.

PURPOSE: The treatment of HBV-associated glomerulonephritis (HBV-GN) is still a challenge in clinical practice now. The objective of this study was to report the pathological characteristics of HBV-GN presenting with mild to moderate proteinuria and to evaluate the therapeutic efficacy of lamivudine (LAM) in combination with angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) as compared to ACEI/ARB monotherapy. METHODS: We conducted a retrospective observational study in HBV-GN patients between 2005 and 2014. The patients were classified into two groups: Group 1 included patients treated with LAM plus ACEI/ARB (n = 20), and group 2, patients treated with ACEI/ARB alone (n = 18). Their clinical and pathological characteristics were collected; we analyzed the therapeutic responses and assessed the correlation between renal and liver pathologies. RESULTS: Our results showed that the most common type of HBV-GN was IgA nephropathy. LAM plus ACEI/ARB therapy was better in reducing 24-h urinary protein excretion, alanine aminotransferase, and aspartate aminotransferase levels, while maintaining the level of kidney function. The proportion of patients who achieved remission (CR + PR) was higher in the LAM plus ACEI/ARB group than in the ACEI/ARB monotherapy group (χ 2 = 5.371, P = 0.035). CONCLUSION: In the HBV-GN patients with mild to moderate proteinuria, LAM plus ACEI/ARB not only improved liver function but also better reduced 24-h proteinuria.

Increased CD45RA+ FoxP3(low) regulatory T cells with impaired suppressive function in patients with systemic lupus erythematosus.

BACKGROUND: The role of naturally occurring regulatory T cells (Treg) in the control of the development of systemic lupus erythematosus (SLE) has not been well defined. Therefore, we dissect the phenotypically heterogeneous CD4(+)FoxP3(+) T cells into subpopulations during the dynamic SLE development. METHODLOGY/PRINCIPAL FINDINGS: To evaluate the proliferative and suppressive capacities of different CD4(+) T cell subgroups between active SLE patients and healthy donors, we employed CD45RA and CD25 as surface markers and carboxyfluorescein diacetatesuccinimidyl ester (CFSE) dilution assay. In addition, multiplex cytokines expression in active SLE patients was assessed using Luminex assay. Here, we showed a significant increase in the frequency of CD45RA(+)FoxP3(low) naive Treg cells (nTreg cells) and CD45RA(-)FoxP3(low) (non-Treg) cells in patients with active SLE. In active SLE patients, the increased proportions of CD45RA(+)FoxP3(low) nTreg cells were positively correlated with the disease based on SLE disease activity index (SLEDAI) and the status of serum anti-dsDNA antibodies. We found that the surface marker combination of CD25(+)CD45RA(+) can be used to defined CD45RA(+)FoxP3(low) nTreg cells for functional assays, wherein nTreg cells from active SLE patients demonstrated defective suppression function. A significant correlation was observed between inflammatory cytokines, such as IL-6, IL-12 and TNFα, and the frequency of nTreg cells. Furthermore, the CD45RA(+)FoxP3(low) nTreg cell subset increased when cultured with SLE serum compared to healthy donor serum, suggesting that the elevated inflammatory cytokines of SLE serum may promote nTreg cell proliferation/expansion. CONCLUSIONS/SIGNIFICANCE: Our results indicate that impaired numbers of functional CD45RA(+)FoxP3(low) naive Treg cell and CD45RA(-)FoxP3(low) non-suppressive T cell subsets in inflammatory conditions may contribute to SLE development. Therefore, analysis of subsets of FoxP3(+) T cells, using a combination of FoxP3, CD25 and CD45RA, rather than whole FoxP3(+) T cells, will help us to better understand the pathogenesis of SLE and may lead to the development of new therapeutic strategies.

Combination of maintenance hemodialysis with hemoperfusion: a safe and effective model of artificial kidney.

OBJECTIVE: To investigate whether the combination of maintenance hemodialysis (MHD) with hemoperfusion (HP) could improve the clearance rate of middle and large molecule uremic toxins so as to improve the quality of life of MHD patients and reduce their mortality rate. METHODS: This study was a prospective, randomized, controlled clinical trial. 100 MHD patients were selected and then randomly divided into two groups after four weeks of run-in period. Group 1 received HD alone 2 times a week and the combined treatment of HD with HP (HD+HP) once a week, whereas Group 2 was given HD alone 3 times a week. This study was followed up for a mean of 2 years. The primary outcome was the death of patients. Secondary end points included normal clinical data, leptin, high sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), ß(2) microglobulin (ß(2)-MG), immunoreactive parathyroid hormone (iPTH), tumor necrosis factor-α (TNF-α) and the index of dimensions of Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36 Chinese Edition ). RESULTS: At the end of the two-year observation, the serum concentration of leptin, hsCRP, iPTH, IL-6, ß(2)-MG and TNF-α, systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), cardiothoracic ratio, left ventricular mass index (LVMI), the EPO doses and the types of antihypertensive drugs used were lower with Group 1 than with Group 2 (p<0.05); Group 1 had higher hemoglobin (Hb), ejection fraction (EF), and body mass index (BMI) (p<0.05). No statistical difference between the two groups was observed in terms of serum albumin, serum iron (SI), total iron binding capacity (TIBC), cardiac output (CO), Kt/V, early/atrial mitral inflow velocities (E/A) (p>0.05). Besides, the SF-36 indicated that the total score of overall dimentions of Group 1 was higher than Group 2 (p<0.05) and the quality of life of Group 1 was evidently better than Group 2. The Kaplan-Meier Survival Curves for the 2-year observation period showed that patients in Group 1 had obvious survival advantage while Log-rank test results showed p<0.05. No serious adverse incidents occurred during the HD+HP treatment. CONCLUSIONS: HD+HP was superior to HD in regularly eliminating middle and large molecule uremic toxins accumulated in the body. These findings suggest a potential role for HD+HP in the treatment to improve the quality of life and survival rate of MHD patients.