Predictors of outcome in idiopathic rapidly progressive glomerulonephritis (IRPGN)

Crescentic glomerulonephritis in children: short-term follow-up predicts long-term outcome

Background

Crescentic glomerulonephritis (CrGN) is a relatively rare but severe condition in childhood with the clinical feature of rapidly progressive glomerulonephritis (RPGN). The aim of this study is to investigate the clinicopathological features and prognosis of CrGN in children.

Methods

We retrospectively analyzed the clinical and laboratory data, renal pathological results, treatment, and outcome of 147 CrGN in two Chinese pediatric nephrology centers.

Results

Among the 147 children, there were 22 cases of type I (15.0%), 69 cases of type II (46.9%), and 56 cases of type III (38.1%). The mean percentages of crescents in CrGN I, II, and III were 85.3%, 68.7%, and 73.6%, respectively. The children with type I CrGN presented with more severe clinical manifestations and pathological lesions. The 3-month cumulative renal survival rates of types I, II, and III CrGN were 66.3%, 93.6%, and 75.6%, respectively. The 1-year cumulative renal survival rates of types I, II, and III CrGN were 56.9%, 85.3%, and 73.1%, respectively, and the 5-year cumulative renal survival rates of types I, II, and III CrGN were 33.8%, 73.5%, and 47.1%, respectively. The Kappa Consistency Test between the 3-month and 1-year total renal survival (82.1% vs. 74.7%) of the children was 0.683 (P < 0.001), and between the 1-year and 5-year total renal-free survival (78.3% vs. 69.1%) of the children was 0.476 (P < 0.001). The Bowman's Capsule Rupture (BCR), crescent, interstitial inflammation, and interstitial fibrosis/tubular atrophy (IF/TA) score were predictors of end-stage kidney disease (ESKD) risk but BCR showed better predictive value for ESKD than interstitial inflammation score (P = 0.027) and IF/TA score (P = 0.047).

Conclusion

Patients with type I tended to have the worst renal survival rates. The three-month renal prognosis could partially reflect the 1-year renal prognosis, and the 1-year mortality rate could partially reflect the 5-year mortality rate of children with CrGN.

Prognostic analysis of crescentic glomerulonephritis with acute kidney injury: a single-center cohort with 5-year follow-up

BACKGROUND

Crescentic glomerulonephritis (CrGN) represents a severe form of glomerular injury that results in high rates of renal failure. This study aimed to investigate the influence of potential clinical and pathological factors on renal outcomes of CrGN; and the relationship between 3-month and 5-year follow-up as well.

METHODS

The cohort enrolled patients diagnosed of biopsy proven CrGN with acute kidney injury(AKI) from January 1, 2010, to January 1, 2018 in Shanghai Changzheng Hospital and followed up for 5 years.

RESULTS

A total of 56 patients were included, among whom 11 patients (19.6%) had type I, 12 (21.4%) had type II, and 33 (58.9%) had type III CrGN. Patients with type II CrGN tended to have a lower crescent score, less renal tubular damage, and lower serum creatinine than the other two types. Three-month cumulative renal survival rates of types I, II, and III CrGN were 45.5%, 66.7%, and 48.5%, respectively. Five-year cumulative renal survival rates of types I, II, and III CrGN were 27.2%, 83.3%, and 36.4%, respectively. The Kappa Consistency Test between 3-month and 5-year outcomes was 0.573(P < 0.001). Cox regression model showed that in-hospital dialysis was an indicative renal survival factor in 3 months (HR 15.670, 95% CI 2.987-82.210, P = 0.001). It also showed that the crescent score had an unfavorable effect for renal survival in 5 years (HR 1.750 95% CI 1.018-3.009, P = 0.043).

CONCLUSIONS

Clinical manifestations and outcomes varied by different CrGN types. Three-month outcomes could partially reflect the 5-year outcomes. Severity of crescents was an independent risk factor for renal survival in CrGN.

Monocytes and macrophages in ANCA-associated vasculitis

Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) are characterized by inflammation of small-to-medium-sized blood vessels and the presence of autoantibodies against cytoplasmic proteases sited in neutrophils and monocytes. Increasing evidence indicates a substantial role of monocytes and macrophages in the pathogenesis of AAV. Activated monocytes and macrophages contribute to necroinflammation in peripheral vasculitic lesions as well as to central and peripheral mechanisms of autoimmunity. The intermediate monocyte subset (CD14⁺⁺CD16⁺) is increased and monocytes show elevated expression of CD14, Toll-like receptor 2/4, MHCII and integrins, likely reflecting activation and increased monocyte extravasation. Monocytes differentiate locally predominantly into alternatively activated (M2) macrophages, which are known for cell-clearance and phagocytosis, but may ultimately lead to fibrosis. Phagocytotic function of macrophages can be impaired by surface expression of cytoplasmic proteases on apoptotic neutrophils and causes release of inflammatory cytokines and immunogenic contents, presumably resulting in a vicious circle of increased neutrophil, T and B cell activation and consequent ANCA production. Considering their crucial role in initiating necroinflammation as well as fibrogenesis, monocytes and macrophages may represent a logic first-line target for new treatment options in AAV.

Deposition of the Membrane Attack Complex in Healthy and Diseased Human Kidneys

The membrane attack complex-also known as C5b-9-is the end-product of the classical, lectin, and alternative complement pathways. It is thought to play an important role in the pathogenesis of various kidney diseases by causing cellular injury and tissue inflammation, resulting in sclerosis and fibrosis. These deleterious effects are, consequently, targeted in the development of novel therapies that inhibit the formation of C5b-9, such as eculizumab. To clarify how C5b-9 contributes to kidney disease and to predict which patients benefit from such therapy, knowledge on deposition of C5b-9 in the kidney is essential. Because immunohistochemical staining of C5b-9 has not been routinely conducted and never been compared across studies, we provide a review of studies on deposition of C5b-9 in healthy and diseased human kidneys. We describe techniques to stain deposits and compare the occurrence of deposits in healthy kidneys and in a wide spectrum of kidney diseases, including hypertensive nephropathy, diabetic nephropathy, membranous nephropathy, IgA nephropathy, lupus nephritis, C3 glomerulopathy, and thrombotic microangiopathies such as the atypical hemolytic uremic syndrome, vasculitis, interstitial nephritis, acute tubular necrosis, kidney tumors, and rejection of kidney transplants. We summarize how these deposits are related with other histological lesions and clinical characteristics. We evaluate the prognostic relevance of these deposits in the light of possible treatment with complement inhibitors.

Crescentic glomerulonephritis: what's different in South Asia? A single center observational cohort study

Background: The spectrum and outcomes of crescentic glomerulonephritis (Cr.GN) in South Asia is vastly different from that reported worldwide and there is a paucity of information. The aim of the study was to study the demography, clinical presentation, histology and predictors of longitudinal outcomes of Cr.GN in this population. Methods: An observational cohort study of renal biopsies was performed in the largest tertiary center in South India over a period of 10 years (January 2006 to December 2015) with ≥50% crescents on renal histology indicating Cr.GN. Results: A total of 8645 kidney biopsies were done; 200 (2.31%) were Cr.GN. Patients were categorized into three etiological groups: anti-glomerular basement membrane (type I), immune complex (type II), and pauci-immune (type III). Type II was the most common (96, 46.5%), followed by type III (73, 38%) and type I (31, 15.5%). Female preponderance was seen across all types. About half of all patients presented with recent onset hypertension. Type II had the highest median proteinuria (4.2 (2.1-6) g/day, p=0.06) and the median estimated glomerular filtration rate was lowest in type I (5 (4-8) ml/min/1.73m 2, p<0.001). Among type III, anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis was seen only in ~50% of patients. Nearly one third of patients with type I were also positive for ANCA making them 'double positive'. Acute glomerular insults like tuft necrosis and chronic changes as evidenced by moderate to severe interstitial fibrosis, was a predominant feature of type I. Conclusions: ANCA-negative pauci-immune vasculitis, as well as double positive Cr.GN, are reported for the first time in South-Asia. Renal survival was significantly worse in type I/III compared to type II. Types I/III, moderate to severe interstitial fibrosis and tubular atrophy, presence of oliguria/anuria and increasing percentage of crescents in renal biopsy were significant predictors of end stage kidney disease in our cohort.

Histopathological Classification-A Prognostic Tool for Rapidly Progressive Glomerulonephritis

Background: Recently proposed histopathological classification may predict patient outcome in pauci-immune glomerulonephritis. This study sought to prove that the prognostic effect could be extended to all types of rapidly progressive glomerulonephritis. Methods: Retrospective analysis of patients diagnosed with rapidly progressive glomerulonephritis between April 1999 and August 2015 was performed. Epidemiological and clinical data were collected from medical records. The descriptions of renal biopsies were reviewed and classified into focal, sclerotic, crescentic and mixed class according to classification proposed by Berden et al. The study end points were end stage renal disease (ESRD) or death. Survival analyses were modelled using Cox regression. Results: 73 renal biopsies with diagnosis of rapidly progressive glomerulonephritis were included in the study. 25 (34.2%), 16 (21.9%), 24 (32.9%) and 8 (11%) patients were assigned to focal, crescentic, mixed and sclerotic class, respectively. Thirty-two (42.5%) patients were anti-neutrophil cytoplasmic antibody (ANCA) negative, of which eight (10.9%) were anti–glomerular basement membrane antibody (anti–GBM) positive and 24 (32.8%) were negative for autoimmune antibodies. Six (8.2%) patients died within one year. Among patients who survived, median change in estimated glomerular filtration rate (eGFR) values were: −10.5 mL/min in focal, 4.2 mL/min in crescentic, −4.3 mL/min in mixed and 4.1 mL/min in sclerotic group, p > 0.05. In the Cox regression model, there was no significant predictor of patient survival whereas the sclerotic group (HR 3.679, 95% CI, 1.164–11.628, p < 0.05) and baseline eGFR of <15 mL/min (HR 4.832, 95% CI, 1.55–15.08, p < 0.01) had an unfavorable effect for renal survival. Conclusions: Predominant glomerular sclerosis and low eGFR at baseline are associated with higher risk of ESRD in cases with crescentic glomerulonephritis. Therefore, despite the origin of injury, histological classification might aid in prediction of patient outcomes in rapidly progressive glomerulonephritis.

Effect of astragalus injection on renal tubular epithelial transdifferentiation in type 2 diabetic mice

Background

Astragalus injection is used by practitioners of traditional Chinese medicine to treat diabetic nephropathy (DN). The current study was conducted to determine the effect of astragalus on tubular epithelial transdifferentiation during the progression of DN in KKAy mice, as well as to investigate the molecular mechanism underlying this effect.

Methods

Diabetic, 14-week-old, male KKAy mice were randomly divided into a model group and an astragalus treatment group, while age-matched male C57BL/6 J mice were selected as controls. The treatment group received daily intraperitoneal injections of astragalus (0.03 mL/10 g per day), while the model group received injections of an equal volume of saline. Mice were euthanized after 24 weeks. Serum samples were obtained from the animals in each group for blood glucose measurement. Kidney tissue samples were used for morphometric studies. The mRNA and protein expression levels of transforming growth factor beta 1 (TGF-β1), transforming growth factor beta receptor 1 (TGFβ-R1), alpha smooth muscle actin (α-SMA), and E-cadherin were evaluated using real-time polymerase chain reaction (PCR) and western blotting.

Results

Astragalus significantly reduced blood glucose levels; inhibited morphological changes in the kidneys of KKAy mice; reduced mRNA and protein expression levels of TGF-β1, TGFβ-R1, and α-SMA; and increased E-cadherin expression.

Conclusions

Tubular epithelial transdifferentiation plays an important role in the development of DN in diabetic mice. Administration of astragalus likely prevents or mitigates DN by suppressing tubular epithelial transdifferentiation, protecting KKAy mice from renal damage.

Crescentic glomerulonephritis in children: a single centre experience

BACKGROUND

Crescentic glomerulonephritis (CsGN) is characterized by crescents in 50% or more of glomeruli and clinically by a sudden and progressive decline in renal function.

METHODS

We evaluated the etiology, clinical features, prognostic factors and long-term outcome of CsGN. Between January 2000 and December 2010, 45 children (26 girls, 19 boys) with biopsy-proven CsGN (>50% crescents) were investigated retrospectively.

RESULTS

The mean age of the patients was 130.86±33.77 months. The mean duration of symptoms prior to diagnosis was 26±12 days (4-40 days). Most of the children had hypertension (62.2%), macroscopic hematuria (73.3%), oligoanuria (44.4%), edema (51.1%) and purpuric rash (40%) at presentation. The final clinical status of the patients was complete remission (n=21), partial remission (n=5) or chronic kidney disease (n=19). Adverse outcomes were significantly associated with a long duration between the onset of symptoms and treatment (P=0.038), the presence of oligoanuria (P=0.006), a severe decreased glomerular filtration rate (GFR <30 mL/min/1.73m²) and the need for dialysis (P=0.003) on admission, the ratio of crescents (>75%) (P=0.03), and the ratio of fibrous crescents (P=0.015).

CONCLUSION

The outcome of CsGN in children continues to be poor, and it should be treated as a renal emergency.

Role of TGF-β1/p38 MAPK pathway in hepatitis B virus-induced tubular epithelial-myofibroblast transdifferentiation

OBJECTIVE

This study is to investigate the hepatitis B virus (HBV)-induced tubular epithelial-myofibroblast transdifferentiation (TEMT) in human renal tubular epithelial HK-2 cells.

METHODS

Human proximal tubular epithelial HK-2 cells were cultured. These HK-2 cells were divided into 4 groups: the blank control group, the vector control group, the HBV-transfected group, and the inhibitor-treated group. Transfection was performed with lipofectamine. Measurements of hepatitis B e antigen (HBeAg) and hepatitis B surface antigen (HBsAg) in culture supernatant were determined by electrochemiluminescence immunoassay. Immunocytochemical staining, reverse transcription PCR (RT-PCR), and Western blot analysis were performed to detect the mRNA and protein expression levels, respectively.

RESULTS

The immunocytochemical staining showed that, the expression level of E-cadherin was dramatically decreased, while the α-SMA expression level was significantly elevated, in HBV-transfected HK-2 cells. The mRNA level of TGF-β1 and the protein level of p-p38 mitogen-activated protein kinase (MAPK) were elevated in HK-2 cells transfected with HBV. When treated with the p38 MAPK-specific inhibitor, the activation of p38 MAPK was eliminated in HBV-transfected HK-2 cells. In addition, the altered expression levels of E-cadherin and α-SMA, the increased contents of HBeAg and HBsAg in the culture supernatant, as well as the morphological changes of TEMT in HBV-transfected HK-2 cells, were all reversed by the inhibiter treatment.

CONCLUSION

HBV transfection could induce TEMT in HK-2 cells, which was mediated by the TGF-β1/p38 MAPK pathway. These findings provide new insights into the prevention and treatment of HBV-associated glomerulonephritis.

Histopathological classification of pauci-immune glomerulonephritis and its impact on outcome

Rapidly progressive renal failure is a common but severe feature of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. A histopathological classification for ANCA-associated pauci-immune glomerulonephritis was developed for prognostication of these patients. The present study aims to classify patients of pauci-immune glomerulonephritis according to this classification and its impact on outcome. Eighty-six subjects with pauci-immune glomerulonephritis between July 2006 and October 2012 were included in the study. Their renal biopsies were reviewed and classified into focal, crescentic, sclerotic and mixed class as per the new classification. The outcomes were analyzed after 6 months of treatment. Of the 86 subjects, 34 (39.53 %) were granulomatosis with polyangiitis, 36 (41.86 %) microscopic polyangiitis, 1 eosinophilic granulomatosis with polyangiitis, while the rest (17.44 %) were unclassifiable. Thirteen (15.5 %), 43 (51.2 %), 12 (14.3 %) and 16 (19 %) patients were classified as focal, crescentic, sclerotic and mixed class, respectively. The mean serum creatinine at baseline was 280.23, 659.46, 573.72 and 542.78 µmol/L in focal, crescentic, sclerotic and mixed class, respectively. The probability of improvement in renal functions at 6 months decreased from focal to crescentic to mixed to sclerotic class, while the probability of death was highest in the sclerotic class followed by the mixed class. This difference in outcome was maintained irrespective of the clinical diagnosis or the Birmingham Vasculitis Activity Score. Our study has shown that the histopathological classification can be used to predict the severity of renal dysfunction as well as the treatment outcomes in pauci-immune glomerulonephritis.

Protection of rhein on IgA nephropathy mediated by inhibition of fibronectin expression in rats

Objective:

To investigate the protective effects of rhein on IgA nephropathy (IgAN) in the rat model.

Materials and Methods:

Twenty-eight female sprague dawley rats were divided randomly into four groups, namely control, IgAN, rhein-prevented and rhein-treated. The pathologic changes on renal tissue were observed by the H and E, staining and the amount of urinary red blood cells and 24-h urinary protein excretion were measured. The glomerular deposition of immune globulin A (IgA) was measured by immunofluorescence staining. Fibronectin (FN) and α-smooth muscle actin (α-SMA) expression on renal tissue were measured via immunohistochemistry.

Results:

The model of IgAN was established according to Bovine serum albumin-Lipopolysaccharide-Carbon tetrachloride protocol, which was evidenced by histological structural lesions of glomeruli, IgA deposition and urinary measurement. Histological examination of kidney sections from both rhein-prevented group and rhein-treated group showed that glomerular hypertrophy, mesangial expansion, excessive extracellular matrix, and renal capsule dilation were markedly ameliorated compared with IgAN group. Moreover, rhein treatment significantly reduced IgA deposition in glomerulus, the volume of urinary red blood cells and 24-h urinary protein excretion. More importantly, increased FN expression in IgAN was back to normal level in rhein-prevented and rhein-treated group, which was along with the reduction of α-SMA expression in renal tissues.

Conclusions:

These findings indicate that rhein prevents the development of glomerulosclerosis and halts the progression of IgAN via inhibition of FN and α-SMA expression.

SU6668 suppresses proliferation of triple negative breast cancer cells through down-regulating MTDH expression

Background

The multiple tyrosine kinase inhibitors SU6668 have a promising therapeutic effect on the progression of hematological malignancies and some solid tumors. Here, we determined its effect on triple negative breast cancer (TNBC) cells and explored the potential molecular mechanism.

Methods

In this study, MDA-MB-231 cells were treated with SU6668 (15 μM, 30 μM) for 72 h and the change of proliferation was examined by MTT and tablet cloning. DNA ploidy was detected by flow cytometric analysis with PI staining. Double-label immunofluorescence method was used to detect the expression and distribution of MTDH proteins. VEGFR2, HIF-1α, MTDH, E-cadhrein, and SMA expressions were detected by Western bolt assay.

Results

This study showed that SU6668 inhibited the proliferation and induced polyploidization of MDA-MB-231 cells in a dose dependent form. SU6668 exposure increased the distribution of MTDH in cytoplasm and decreased its distribution in nuclei. After the treatment of SU6668, VEGFR2, HIF-1α, MTDH and SMA proteins were down-regulated, while E-cadhrein was up-regulated in MDA-MB-231 cells.

Conclusions

In conclusion, SU6668 exposure maybe induces polyploidization, inhibit EMT and influence the expression of MTDH, which suppresses the proliferation in TNBC cells. MTDH is a key signal protein in downstream of VEGF/HIF-1αpathway in MDA-MB-231 cells, which may be used as the potential target in the treatment of TNBC.

Clinical and pathological studies of IgA nephropathy presenting as a rapidly progressive form of glomerulonephritis

OBJECTIVE

IgA nephropathy (IgAN) is widely regarded as a slowly progressive disease. However, a minor population of patients present with a rapidly progressive form of glomerulonephritis (RPGN).

METHODS

We studied 25 cases of IgAN who presented with RPGN. The laboratory data, histology, and five-year prognosis after diagnostic renal biopsy were evaluated. We compared the data of these patients with those of 495 patients with the non-RPGN type. In addition, we divided the patients with the RPGN type of IgAN into a group with reduced renal function and a group with maintained renal function, and compared the data between the two groups.

RESULTS

In the 'RPGN type', the serum creatinine levels and a 24-hour urinary protein excretion were significantly higher than in the non-RPGN type. Histological examinations showed that the rates of endocapillary hypercellularity and tubular atrophy/interstitial fibrosis were significantly higher in the patients with the RPGN type. In the comparison between the groups with reduced and maintained renal functions, the former group exhibited higher levels of proteinuria, serum creatinine and crescent formation than the latter group.

CONCLUSION

The RPGN type of IgAN was significantly worse in terms of the renal survival rate at five years than the non-RPGN type. Intensive and active treatments are necessary for this minor population, according to the guideline for the management of RPGN.

Treatment of renal manifestations of ANCA-associated vasculitis

CONTEXT

Vasculitis is a clinicopathological entity characterized by inflammation and necrosis of blood vessels.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched.

RESULTS

Two major autoantigens for ANCA are myeloperoxidase (MPO) and proteinase 3 (PR3), which are proteins in the primary granules of neutrophils and in the lysosomes of monocytes. They are expressed in mature neutrophils of patients with ANCA, while absent in healthy subjects.

CONCLUSIONS

The kidney is the most commonly affected vital organ in ANCA-associated vasculitis, and patient outcomes are largely determined by the severity of renal disease at diagnosis and by its response to treatment.

von Willebrand factor antigen--a possible biomarker of disease activity in childhood central nervous system vasculitis?

OBJECTIVE

The main objective was to develop a trajectory for von Willebrand factor (vWF) antigen in childhood primary CNS vasculitis (cPACNS) after treatment and compare this with disease activity and other inflammatory markers.

METHODS

A single-centre cohort study of consecutive children diagnosed with cPACNS was performed. Demographic, clinical, laboratory, imaging and histological data were collected at diagnosis and during standardized clinic visits. Outcome measures included disease activity measured by physician global assessment and serial measures of vWF antigen. Analysis included descriptive statistics and parametric methods.

RESULTS

The study cohort consisted of 39 children diagnosed with cPACNS: 25 with angiography-negative cPACNS and 14 with angiography-positive disease. Twenty-one patients were female, median age at diagnosis was 9.8 years, and median follow-up was 18 months. All patients presented with neurological deficits. Disease activity and neurological outcome improved significantly during follow-up. vWF antigen levels were increased at diagnosis in 65% of children with cPACNS and were decreased significantly after treatment. In contrast, levels of CRP and ESR fluctuated over time. Higher vWF antigen levels at diagnosis were associated with lower measures of disease activity at 12 months.

CONCLUSION

In our study, all children with cPACNS improved over time. Changes in CRP and ESR, other laboratory tests, and MRI did not consistently reflect altered disease activity. However, vWF antigen may help clinicians to identify changes in disease activity during follow-up and predict treatment response. Controlled studies are necessary to evaluate the sensitivity and specificity of vWF antigen as a biomarker of disease activity.

Macrophages and immunologic inflammation of the kidney

Monocyte-derived tissue effector cells, macrophages, are present in large numbers in all forms of kidney disease with inflammation. Their roles in inflammation and the molecular effectors of macrophage function have been difficult to decipher. With the advent of modern genetic tools and mouse models of human disease, great insight into monocyte/macrophage biology has been forthcoming. This review places macrophage study in its historical context, defines immunologic diseases of the kidney, broadens its definition to encompass current thinking of the immune response to kidney injury, highlights key advances of the study of monocyte/macrophages in kidney diseases, and identifies new therapeutic pathways and targets that hinge around macrophage function. This article advances the case that targeting macrophage activation and phenotype is leading to new therapies in the treatment of many acute and chronic kidney diseases.