Bacterial superantigen enhances cytokine production by T-helper lymphocyte subset-2 cells and modifies glomerular lesions in experimental immunoglobulin a nephropathy

Background The purpose of this study was to examine the effects of bacterial suporantigens, which can derange the immune response and contribute to the renal lesions of immunoglobulin A (lgA) nephropathy. Methods Twenty-five micrograms of a bacterial superantigen, staphylococcal enterotoxin B (SEB), was injected into IgA nephropathy-prone ddY mice intrathymically when they reached 6 weeks of age. Evaluation included measurement of albumin excretion in urine, immunoglobulin concentration, and lymphokine production in vitro, as well as analysis of T-cell receptor expression in splenic T-cell subsets and examination of renal histology by light and fluorescence microscopy. Results At 40 weeks of age, the serum level of IgA in these mice was substantially increased and the number of Vβ8⁺ CD4⁺splenic T-cells was significantly decreased compared with measurements in untreated controls. Both control and SEB-treated mice excreted less than 30 μg/mL of urinary albumin. In mice given SEB, the amount of interleukin 2 (IL-2) and tumor necrosis factor-α (T helper 1 [Th1]-type cytokines) produced by the in vitro-stimulated lymphocytes significantly decreased. whereas that of interleukin 4 (IL-4) and interleukin 6 (IL-6) (Th2-type cytokines) markedly increased compared with measurements in control mice. At 40 weeks of age, mice given SEB showed marked glomerular hypercellularity and enhanced glomerular C3 deposition by renal histology, compared with control mice. Conclusion These results suggest that bacterial superantigen SEB may modify glomerular lesions through activating Th2 cells, while inducing deletion of Th1 cells in this experimental model.     

Acute reversible renal failure with macroscopic haematuria in IgA nephropathy

Macroscopic haematuria is common in IgA nephropathy, but itssignificance and influence on prognosis remains uncertain. Wecompared the clinical and pathological features of 11 adultpatients with primary IgA nephropathy who had had a renal biopsyduring or shortly after a bleeding episode. Six patients developedtransient acute renal failure (ARF) (group 1) and five did not(group 2). Patients of group 1 had a higher percentage of tubularred-blood-cell (RBC) casts (P<0.05) and of glomerular crescents(P<0.001). However, crescents were focal and involved lessthan 50% of glomeruli. Acute tubular necrosis was only presentin patients of group 1, and ARF was attributed to the acutetubular changes rather than to the glomerular lesions. Despitea prolonged duration of ARF (mean: 38 days), further outcomedid not differ in patients of both groups. We suggest that acutetubular damage and/or tubular obstruction by RBC casts shouldbe considered in any patient who develops ARF soon after a haematuricepisode.     

Role of cytokines in the progression of renal damage in IgA nephropathy

Summary: IgA nephropathy, or Berger's disease (IgAN), is a worldwide disease which is characterized by a slowly progressive loss of renal function accompanied by decreasing kidney size with the development of glomerulosclerosis and interstitial fibrosis. Immunologic and non-immunologic factors are implicated in the progression of renal damage, since they are potent inducers in stimulating glomerular, tubular and interstitial cells and non-resident cells to produce free oxygen radicals, cytokines, growth factors, chemokines, etc. Recent data from our laboratory and other groups, synthesized in this review, have demonstrated the remarkable involvement of these humoral factors in the progression of renal damage in IgAN patients. Therefore, prospective therapeutic approaches have been suggested in blocking the inflammatory mediators during the pathophysiologic sequelae of immune and non-immune mechanisms which may intervene in the outcome of the disease.     

Clinical remission and pathological progression after tonsillectomy in a renal transplant patient with recurrent IgA nephropathy

Abstract:  We discuss a renal transplant patient with recurrent IgA nephropathy (IgAN) before and after tonsillectomy. A 36-year-old man started on hemodialysis support in 1996 due to biopsy-proven IgAN, living related renal transplantation was then performed in 1997. Six years after transplantation, the patient presented with microhematuria and proteinuria. Graft biopsy for these urinary abnormalities showed recurrent IgAN. Tonsillectomy was subsequently performed in December 2003, proteinuria remitted 6 months after the tonsillectomy and microhematuria disappeared three years later. Protocol graft biopsy was subsequently performed twice, at 2 yr after the tonsillectomy (2005) and 4 yr after (2008). Comparing the findings of the pre-tonsillectomy biopsy and the two post-tonsillectomy biopsies, an increase in mesangial cells and matrix in 2005, and an expansion of the mesangial matrix and proliferation of mesangial interposition in 2008. In addition, global sclerosis of glomeruli increased over time, the area of tubulointerstitial damage has extended as well. While the tonsillectomy led to clinical remission of recurrent IgAN, the chronicity progressed on these protocol biopsies. This is the first report of the efficacy and the limitations of tonsillectomy in a case of recurrent IgAN in a transplant patient.     

Clinical and pathological analysis of IgA nephropathy with chronic renal failure

Objective: To investigative clinical and pathological characteristics of IgA nephropathy with chronic renal failure.

Method: Clinical and pathological findings from 65 cases of IgA nephropathy with chronic renal failure were reviewed. Pathological characteristics of all the cases were analyzed according to WHO definition and Oxford Classification. Evaluating the severity of pathological lesions by the Katafuchi R semiquantitative scoring system, and analyzing their relationship with clinical indexes of renal function.

Results: Of all 65 cases the male and female ratio was 1.4, and the mean age was 37?±?13 years old. Levels of systolic pressure, mean arterial pressure (MAP), blood urea nitrogen (BUN), serum creatinine (Scr), uric acid (UA), album (Alb), serum IgG and 24?h urinary protein were related with eGRF level (p < 0.05, respectively). The most common pathological type was proliferative sclerosis glomerulonephritis (PSGN) and M1S1E0T0 according to WHO definition and Oxford Classification, respectively, and most of the 65 cases had glomerulosclerosis. Simple IgA deposition was the most common immunopathologic type. Of all the cases, 44.6% accompanied with C3 while 4.6% with C1q. Further analysis revealed there were no relationships between severity of pathological lesion and levels of clinical indexes (Scr and eGRF) (p?>?0.05).

Conclusion: IgA nephropathy with chronic renal failure usually occurred in young adults, and it had severe clinical condition and pathological changes, while there was no significant relationship between them.     

The spectrum of acute renal failure in IgA nephropathy

Background: Acute renal failure rarely complicates the course of IgA nephropathy. In this study, we have tried to define the mode of presentation, the spectrum of morphology, and the prognostic factors for renal outcome. Methods: Twenty patients with biopsy-proven IgA nephropathy who developed acute renal failure were identified from 2000 to 2009 at a medical center in Taiwan. The patients' records were retrospectively reviewed with respect to clinical presentation, morphology of renal biopsy, and outcomes. Results: On histology, glomerular crescents were present in 11 patients (55%), acute tubular necrosis was identified in 11 patients (55%), acute interstitial nephritis was seen in 4 patients (20%), and extensive tubular red blood cell casts were present in 4 patients (20%). At the end of follow-up, 2 patients (10%) had died, 11 patients (55%) were in remission, and 7 patients (35%) developed end-stage renal disease. The prognostic factors for renal outcome were peak serum creatinine, dialysis support requirement, morphology (prominent glomerular/tubular injury), percentage of glomeruli affected by crescents, and interstitial infiltration (p = 0.04, <0.001, 0.013, 0.05, 0.02, respectively). Conclusions: Our findings suggested that there were four pathogenic mechanisms involved in IgA nephropathy with acute renal failure including (1) crescentic IgA nephropathy; (2) acute tubular necrosis associated with microhematuria and red blood cell casts occluding tubules; (3) acute tubular necrosis not related to microhematuria; and (4) acute interstitial nephritis, apparently induced by drugs. In general, patients with prominent tubular injury had a much higher remission rate than patients with prominent glomerular injury.     

IgA serology in recurrent and non-recurrent IgA nephropathy after renal transplantation

BACKGROUND: This study investigated whether abnormal circulation of macromolecularIgA and IgA with altered glycosylation or electrical chargeplays a role in the recurrence of IgA nephropathy (IgAN) aftertransplantation. STUDY DESIGN: A total of 92 renal transplant patients were enrolled; 52 IgANpatients and 40 with other non-IgAN. The IgAN group included10 patients showing IgA mesangial deposits in the grafted kidneys(recurrent group) and 10 who did not (immunohistochemicallyproven non-recurrent group). In addition another 22 IgAN transplantpatients were clinically free of recurrent disease. METHODS: The analyses included macromolecular IgA (IgAIC) detected bythe conglutinin assay (K), heavy IgA precipitated in 2.5% polyethyleneglycol (PEG), IgA-fibronectin aggregates (IgA/F Aggr), mixedIgA/IgGIC, IgA binding to mesangial matrix components (fibronectin,laminin, type IV collagen) or polycations (poly-L-lysine) andIgA with altered glycosylation (Jacalin-binding assay). RESULTS: After transplantation, IgAN patients displayed significantlyhigher mean levels for each variable measured than non-IgAN(ANOVA, P <0.05). By stepwise regression analysis, the bindingof IgA to fibronectin had the highest coefficient. By comparingdata in recurrent and clinically non-recurrent IgAN, we observedthat two groups could be distinguished by the results of thetwo assays for macromolecular IgA (conglutinin IgAIC and IgA-fibronectinaggregates) and IgA with increased affinity for type IV collagen(P <0.05). When the selected group of immunohistochemicallyproven non-recurrent IgAN was compared to the recurrent one,a statistically significant difference was found only for thebinding of IgA to type IV collagen (P<0.05). Data from thistest were significantly related with proteinuria (P<0.05)and microscopic haematuria (P <0.04). CONCLUSION: Even though the IgA serology of renal transplant IgAN patientsshows peculiar features and recurrent and non-recurrent IgANdiffer in many aspects, the prevalence of positive data in thetwo groups had no predictive value. This suggests that the recurrenceof IgAN is modulated by factors affecting the interaction betweencirculating abnormal IgA and mesangial cells and/or matrix.     

Vitamin E in renal therapeutic regimens

Administration of vitamin E in children with immunoglobulin A (IgA) nephropathy, focal segmental glomerulosclerosis (FSGS) and type I diabetes demonstrated potential towards ameliorating progression. Oral vitamin E therapy reduced endothelial dysfunction, lipid peroxidation and oxidative stress in patients with chronic kidney failure (CKF). Moreover, the use of vitamin E-bonded hemodialyzers reduced atherosclerotic changes, erythropoietin dosage and muscular cramps in patients on hemodialysis (HD). However, several controlled clinical trials failed to document beneficial effects on the study subjects’ cardiovascular and renal outcomes. A recent report of increased all-cause mortality in adult patients receiving high dose vitamin E therapy has caused considerable concern and debate. These issues regarding the efficacy and safety of vitamin E in renal therapeutic regimens will be reviewed in this article.     

Reflux nephropathy: the glomerular lesion and progression of renal failure

Reflux nephropathy is the cause of 5%–10% of dialysed end-stage renal failure. Once scarring has occurred, the prognosis depends on the severity of initial damage and the presence of proteinuria, which reflects the development of glomerulosclerosis. It is independent of ongoing reflux or infection. Histological appearances highly suggestive of reflux nephropathy can occur in radiologically normal kidneys. Duplex Doppler scans of ureteric orifices suggest these patients may have lateral insertion, suggesting past reflux. Glomerular hypertrophy correlates well with reduced renal function and severe renal scarring, but poorly with focal and segmental glomerulosclerosis, which correlates with proteinuria. Increasing attention is being paid to the tubulointerstitium and the relationships between the cellular infiltrates (mainly T4 cells) and glomerular, tubular and vascular damage. Control of hypertension, hyperphosphataemia and a low-protein diet are the only currently widely accepted treatments for slowing progression.Presented at the Festschrift for Professor R. H. R. White on March 6, 1992, Birmingham, UK     

Contribution of cellular infiltration to the progression of IgA nephropathy: A longitudinal, immunocytochemical study on repeated renal biopsy specimens

Summary: A retrospective immunocytochemical study was performed on repeated renal biopsy specimens from 47 patients with IgA nephropathy, 23 of whom received steroid therapy after the initial biopsy. Immune cells in renal tissues were detected by the immunoperoxidase method using monoclonal antibodies against common leukocyte antigens, T cells, B cells and monocytes/macrophages.
Overall, glomerular infiltration of total leukocytes and monocytes/macrophages was significantly correlated with proteinuria. Interstitial infiltration of total leukocytes, T cells and monocytes/macrophages was significantly correlated with histological injury and renal dysfunction. In the steroid-treated group (group S), urinary protein and glomerular infiltration of total leukocytes and macrophages were significantly reduced at the follow-up biopsy, while these parameters remained unchanged in the nonsteroid-treated group (group N). In group S, interstitial infiltration of almost all of the various cell types, histological renal damage and renal function remained unchanged at the follow-up biopsy, while group N showed a significant increase in the number of interstitial total leukocytes, T cells and macrophages and showed a significant progression of histological renal injury.
These findings suggest that glomerular immune cells, especially monocytes/macrophages, are involved in inducing proteinuria and interstitial immune cells are involved in renal deterioration. Furthermore, steroid therapy appears to reduce urinary protein and prevent the progression of tissue injury through suppression of renal infiltration of these inflammatory cells.     

华法令能延缓糖尿病肾病患者的肾功能衰竭进展

目的：探讨华法令（warfarin)对糖尿病肾病的临床疗效。方法：32例2型糖尿病肾病（DN）患者,以肾小球内凝血指数（ICI）＜0．5或＞1．0和是否应用warfarin治疗分为4组：低指数非应用（LNW）组6例,低指数应用（LW）组6例;高指数非应用（HNW）组11例,高指数应用（HW）组9例。酶联免疫吸附法检测治疗前后凝血、纤溶指标,并检测尿蛋白、肾功能变化。结果：ICI1．0以上的DN患者较ICI0．5以下者有更强的凝血、纤溶活性,并且肾功能衰竭进展迅速。warfarin治疗能明显改善DN患者的凝血状态,延缓肾功能衰竭进展,但无降低尿蛋白作用。结论：DN患者的凝血、纤溶异常可加重其肾功能恶化。warfarin治疗能明显改善凝血异常,延缓肾功能衰竭进展。     

Neutrophils in IgA nephropathy

Summary: Neutrophil participation is prominent in proliferative forms of glomerulonephritis. They are recruited by antibody-mediated chemoattractant complement fragments. Monocyte and endothelial derived cytokines or adhesion molecules may also recruit these cells. In most situations of inflammation, neutrophils induce injury by the release of reactive oxygen radicals and their production of lysosomal proteolytic enzymes. the clinical importance of neutrophils in mediating glomerular injury in IgA nephropathy (IgAN) has often been downplayed, although it has been recognized that IgA is involved in the initiation of intracellular oxidative metabolism in normal neutrophils. That disordered neutrophil activation could be relevant to the pathogenesis of IgAN seems likely from their prominent infiltration in glomerular capillaries in the acute phase of primary IgAN, increased expression of complement 3 receptors on neutrophils from patients with IgAN, and increased oxidative metabolism of neutrophils in these patients. Furthermore, recent data revealed heat-aggregated forms of IgA prepared from patients with IgAN exert an up-regulatory effect on calcium mobilization, inositol triphosphate production, and oxidative metabolism in human neutrophils. Interestingly, the plasma level of E-selectin, mainly derived from activated vascular endothelial cells upon interaction with neutrophil, was elevated following synpharyngitic macrohaematuria in patients with IgAN. There was also a significant stepwise increase in circulating E-selectin associated with increased histopathologic severity in these patients. These data tend to support the notion that neutrophils could be activated in IgAN despite lack of acute clinical exacerbation and may potentially be participating in the inflammatory process of glomerular and interstitial injury.     

Novel mechanisms of tubulointerstitial injury in IgA nephropathy: a new therapeutic paradigm in the prevention of progressive renal failure

IgA nephropathy (IgAN) runs a highly variable clinical course with frequent involvement of tubulointerstitial damage. Notably, renal progression correlates more closely with the severity of tubulointerstitial lesions than with the degree of glomerular lesions In IgAN. Mesangial IgA deposition induces local release of cytokines, complement, and angiotensin II leading to glomerular inflammation. It remains unclear how mesangial IgA deposition leads to tubulointerstitial injury in IgAN. Moreover, IgA deposits are rarely detected in renal interstitium in IgAN. We hypothesize that mediators released from mesangial cells triggered by IgA deposition leads to activation of proximal tubular epithelial cells. Our preliminary findings implicate a glomerulotubular cross talk with mediators released from the mesangium contributing to the pathogenesis of tubulointerstitial damage in IgAN. We have also found the expression of angiotensin II subtype-1 receptor or angiotensin II subtype-2 receptor in proximal tubular epithelial cells differs from that of mesangial cells. One potential therapeutic approach is to counterbalance the growth-stimulatory effects of angiotensin II through subtype-1 receptor in tubular epithelial cells by subtype-2 receptor-mediated apoptosis and growth inhibition. These novel findings may provide clinicians new therapeutic approach for selective blockade of the RAS in IgAN.     

氧自由基、炎症因子在结石患者肾小管损伤中的作用

目的探讨氧自由基和炎症因子共同作用促进肾结石形成。方珐选择40例肾结石患者（志愿者）和健康无结石志愿者30例，分别留尿生化分光光度法测NAG、7-GT、Cr、SOD、MDA和NO，放免法测Bz—MG和TNFa。结果结石组尿中反映肾脏损伤的特异性指标NAG、rGT和Bz—MG显著升高，两组之间存在统计学差异（P〈O．05）。结石组血中损伤相关因子TNF—a和MDA值高于健康对照组，两组之间有显著性差异（P〈0．05）；血中保护相关因子SOD值显著低于健康对照组（P〈0．05）。培论尿路结石患者尿中Bz—MG、7-GT和NAG水平显著升高，表明尿路结石形成过程中的确导致肾小管功能损伤，而且其升高可能与氧化损伤和局部炎症反应有关。     

Pre-transplant course and risk of kidney transplant failure in IgA nephropathy patients

Bjørneklett R, Vikse BE, Smerud HK, Bostad L, Leivestad T, Hartmann A, Iversen BM. Pre‐transplant course and risk of kidney transplant failure in IgA nephropathy patients.
Clin Transplant 2011: 25: E356–E365. © 2011 John Wiley & Sons A/S. Abstract: Background: There is lack of knowledge to what degree clinical/morphological presentation and course of IgA nephropathy (IgAN) prior to end‐stage renal disease are risk factors for graft loss after kidney transplantation. Material and Methods: Patients with IgAN between 1988 and 2006 (registered in the Norwegian Kidney Biopsy Registry) who later received a kidney transplant (registered in the Norwegian Renal Registry) were included. The cohort was followed up regarding death‐censored graft loss throughout 2008. Graft survival with a rapid progressive (RP) vs. a slow progressive (SP) course of pre‐Tx IgAN (annual GFR > or <30 mL/min/1.73 m²) was studied. Results: Among 106 included patients, there were 14 graft losses giving a graft loss rate of 1.9/100 patient years. Follow‐up until the first kidney transplant was 6.9 ± 4.4 (range 0.1–19) yr. Patients with pre‐Tx RP had a higher graft loss rate compared with SP patients (6.3 vs.1.3/100 patient years, p < 0.001). Graft loss rate with living‐related donor (LRD) was similar to unrelated donor (UD) grafts. Most RP patients had received LRD grafts, and in SP patients, graft survival with LRD grafts was better than UD grafts (0.3 vs.2.1/100 patient years, p = 0.055). Conclusions: A rapid pre‐transplant course is a strong risk factor for transplant failure in patients with IgAN.     

Proteinuria patterns and their association with subsequent end-stage renal disease in IgA nephropathy.

BACKGROUND: Proteinuria (UP) >1.0 g/24 h at diagnosis is a well-known indicator of progressive renal disease in patients with IgA nephropathy (IgAN). To determine if persistent UP is a more sensitive marker for later progression of IgAN, the hypothesis was tested that the prior level and trend (slope) in UP for 1 year was better at predicting later end-stage renal disease (ESRD) (dialysis or transplant) than a current 24-h UP, serum creatinine (SC), SC slope, hypertension, or total glomerular histopathological score on index renal biopsy in an observational study of 154 high-risk patients enrolled in two clinical trials (IgAN 1, IgAN 2). METHODS: Measurements of 24-h UP and SC were made at time 0, 6 weeks, 6 months and 1 year in all patients, who were then followed for an additional 5.76 years and 1.63 years in the two studies, respectively. The Cox proportional hazards model was used to identify predictors of ESRD following the 1-year visit. RESULTS: Adjusting only for randomized treatment, nearly all UP variables (number of high readings, 1-year level, slopes), SC at 1 year, and SC trends (slopes) over the prior year were significantly associated with subsequent ESRD (all P values <0.05) in both studies. However, among the UP variables, the 1-year readings had the strongest association with ESRD in IgAN 1 (hazard ratio (HR), 95% CI, for a 1g increase: 1.5, 1.2,1.9), and the second strongest association (similar to UP trends) in IgAN 2 (1.4, 1.2,1.6). Males had lower rates of ESRD in both studies (IgAN 1 HR: 0.5, 0.2,1.2, P=0.11; IgAN 2 HR: 0.2, 0.1,0.6, P=0.002). In the multivariate analyses that examined all clinical and histological variables, 1-year levels of 24-h UP and SC, and female gender were independently associated with subsequent ESRD. CONCLUSION: In a high-risk patient with IgAN, the current 24-h UP and SC measurements are as good predictors of subsequent ESRD as UP and SC trends and levels over the prior year. Additionally, it appears that females have poorer outcomes than males.