Nonasthmatic Churg-Strauss syndrome superimposed on chronic pyelonephritis: a case report

Churg–Strauss syndrome (CSS) is a granulomatous small-vessel vasculitis. Asthma is seen in the majority of patients with CSS, but atypical nonasthmatic forms of CSS are also being recognized. We herein describe a 67-year-old woman with a history of chronic pyelonephritis and drug allergy reactions who was admitted to our hospital because of worsening renal function preceded by fever, purpura, sinusitis, and a positive urine culture that confirmed a urinary infection. She was initially treated with pipemidic acid for 7 days, followed by clarithromycin for sinusitis. Laboratory tests on admission showed an absolute eosinophil count of 1750 cells/µL and serum creatinine concentration of 4.72 mg/dL. Urine and blood cultures showed no growth. Kidney biopsy revealed crescent formations with diffuse interstitial fibrosis and foci of eosinophil infiltration. An atypical form of CSS was diagnosed based on tissue eosinophilia, peripheral eosinophilia, and sinusitis. Intravenous methylprednisolone and cyclophosphamide pulse therapy together with hemodialysis treatment improved the patient’s clinical condition but did not resolve the kidney damage. The onset of an atypical form of CSS in our patient manifested as symptoms and signs mimicking those of chronic pyelonephritis and drug allergy reactions. The patient’s chronic kidney disease finally progressed to dialysis dependence.

PRMT1 expression in renal cell tumors- application in differential diagnosis and prognostic relevance

BACKGROUND

Protein arginine methyltransferase-1 (PRMT1) is associated with the progression of various tumor types and the process of epithelial to mesenchymal transition (EMT). However, the expression of PRMT1 in renal cell tumors (RCT) is unknown.

METHODS

We evaluated PRMT1 immunohistochemical (IHC) expression on tissue microarray (TMA) of 208 specimens of RCT, including clear cell renal cell carcinomas (ccRCC), papillary RCC type I and II (pRCC I and II), chromophobe RCC (chRCC), renal oncocytomas (RO), collecting duct carcinomas - Bellini (CDC) and multilocular cystic renal cell neoplasms of low malignant potential (MLCRN-LMP). Moreover, a subset of ccRCC, pRCC, chRCC, RO were also studied using conventional sections. PRMT1 expression in tumor tissue was compared to the IHC expression of EMT-related transcription factors (ZEB1, RUNX1, and TWIST1) and cell surface markers (ß-catenin, N- and E-cadherin). Additionally, qRT-PCR expression of PRMT1 in ccRCC, pRCC, and chRCC was evaluated and the results were compared to the mRNA PRMT1 transcript profiling data in The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) cohort.

RESULTS

PRMT1 immunoreactivity was observed in the majority of ccRCC, RO, all MLCRN-LMP, but in a minority of chRCC (p = 0.044), and it was associated with low grade and low stage ccRCC (p = 0.014; p = 0.044, respectively). ZEB1 immunoreactivity was noted in all RO, in minority of chRCC and neither of MLCRN-LMP (p < 0.001). The majority of PRMT1-negative ccRCC was negative to ZEB1 and showed cytoplasmic expression of TWIST1 (p = 0.028; p < 0.001, respectively). PRMT1 positive ccRCC mostly expressed RUNX1 (p = 0.019). PRMT1 and ZEB1 expression were associated with better cancer-specific survival in patients with ccRCC (p = 0.029; p = 0.009, respectively). In multivariate analysis, ZEB1 expression was an independent prognostic factor for cancer-specific survival (hazard ratio [HR], 0.367; p = 0.026). Significant IHC heterogeneity was observed in PRMT1, ZEB1 and TWIST1 expression (p < 0.001). Homogenous loss of PRMT1 was associated with high grade and high stage ccRCC, while the homogenous loss of PRMT1 and ZEB1 was more frequent in patients who died of ccRCC (p = 0.017; p = 0.040; p = 0.044; p = 0.009, respectively). Relative mRNA-PRMT1 expression in both cohorts was down-regulated in tumor tissue compared to non-tumor parenchyma (p = 0.009). Unlike in our samples, mRNA-PRMT1 expression in the TCGA cohort was not correlated to ccRCC tumor stage or grade. PRMT1, ZEB1, and TWIST1 expression were not associated with EMT related aberrant ß-catenin expression, a gain of N-cadherin or loss of E-cadherin expression. Only RUNX1 was associated with a gain of N-cadherin (p = 0.003).

CONCLUSIONS

IHC expression of PRMT1 may be characteristic for low grade and low stage ccRCC, while the homogenous loss of PRMT1 may be significant for high grade and high stage ccRCC. Both, PRMT1 and/or ZEB1 expression, could be associated with better survival of the patients with ccRCC.

Modulation of NCAM/FGFR1 signaling suppresses EMT program in human proximal tubular epithelial cells

Neural cell adhesion molecule (NCAM) and fibroblast growth factor receptor 1 (FGFR1) cross-talk have been involved in epithelial-to-mesenchymal transition (EMT) process during carcinogenesis. Since EMT also contributes to maladaptive repair and parenchymal damage during renal fibrosis, we became encouraged to explore the role of NCAM/FGFR1 signaling as initiating or driving forces of EMT program in cultured human proximal tubular epithelial cells (TECs). TECs stimulated with TGF-β1 (10ng/mL) was used as an established in vitro EMT model. TGF-β1 downstream effectors were detected in vitro, as well as in 50 biopsies of different human kidney diseases to explore their in vivo correlation. NCAM/FGFR1 signaling and its modulation by FGFR1 inhibitor PD173074 (100nM) were analyzed by light microscopy, immunolabeling, qRT-PCR and scratch assays. Morphological changes associated with EMT appeared 48h after TGF-ß1 treatment and was clearly apparent after 72 hours, followed by loss of CDH1 (encoding E-Cadherin) and transcriptional induction of SNAI1 (SNAIL), SNAI2 (SLUG), TWIST1, MMP2, MMP9, CDH2 (N-Cadherin), ITGA5 (integrin-α5), ITGB1 (integrin-β1), ACTA2 (α-SMA) and S100A4 (FSP1). Moreover, at the early stage of EMT program (24 hours upon TGF-β1 exposure), transcriptional induction of several NCAM isoforms along with FGFR1 was observed, implicating a mechanistic link between NCAM/FGFR1 signaling and induction of EMT. These assumptions were further supported by the inhibition of the EMT program after specific blocking of FGFR1 signaling by PD173074. Finally, there was evidence for an in vivo TGF-β1 pathway activation in diseased human kidneys and correlation with impaired renal excretory functions. Collectively, NCAM/FGFR1 signaling appears to be involved in the initial phase of TGF-ß1 initiated EMT which can be effectively suppressed by application of FGFR inhibitor.

Does the pathohistological pattern of renal biopsy change during time?

Biopsy registries are one of the most important sources of accurate epidemiological data and the clinical presentation of renal diseases. A detailed analysis of clinicopathologic correlations over a period of 20 years (1987-2006) was performed earlier by our centre. The aim of this study was to check the current state and to register possible changes in clinicopathologic findings recorded under better socioeconomical circumstances and new management. Records of 665 renal biopsies performed at our institution were prospectively followed from 2007 to 2014. The results were compared with our previously published data. The average annual incidence of renal biopsies increased by 10% and included more elderly patients. Nephrotic syndrome (NS) remained the most common clinical indication for biopsy, while acute kidney injury participated more frequently than in the previous study (p < 0.001). Membranous nephropathy (MN) was still the most common cause of NS. Primary glomerulonephritis (PGN) remained the most prevalent disease, while MN was the most prevalent PGN. In comparison with the earlier period, MN was a more common diagnosis (p = 0.002), while the prevalence of mesangioproliferative non-IgA nephropathy decreased significantly during the time (p = 0.012). LN remained the most frequent secondary glomerulonephritis. The pathohistological pattern of renal biopsy remained largely unchanged during time. However, acute kidney injury was more frequently an indication for biopsy in the current study. The significant increase of biopsied elderly patients is due to the rise in their relative numbers in our population.

Combined Angiotensin II Type-1 Receptor Blockade and Superoxide Anion Scavenging Affect the Post-Ischemic Kidney in Hypertensive Rats

Ischemic acute kidney injury is characterized by renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and overproduction of angiotensin II and reactive oxygen species. Considering this complexity, the aim of our study was to investigate the effects of angiotensin II type-1 receptor blocker - Losartan and superoxide anion scavenger - Tempol, in a combined treatment on acute kidney injury in postischemic hypertensive rats.

The experiment was performed in anesthetized, adult male spontaneously hypertensive rats. The right kidney was removed and the left renal artery was occluded for 40 minutes. Experimental groups received combined treatment (Losartan + Tempol) or saline in the femoral vein 5 minutes before, during and 175 minutes after clamp removal.

Hemodynamics and biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. Histological examination was performed by optical microscopy.

Combined treatment improves renal haemodynamics parameters which were exacerbated due to acute kidney injury. Acute kidney injury significantly decreased creatinine and urea clearance and increased lipid peroxidation in the plasma. Treatment with Losartan and Tempol induced a significant increase of creatinine and urea clearance. Lipid peroxidation in the plasma decreased and glutathione peroxidase enzyme activity in the erythrocytes increased after Losartan + Tempol treatment. This combined treatment reduced cortico-medullary necrosis and tubular dilatation in the kidney.

Our results indicate that synergism of Losartan and Tempol treatment could have beneficial effects on blood pressure and kidney function, during postischemic acute kidney injury development in experimental hypertension.

Granulomatous interstitial nephritis associated with influenza A: H1N1 infection--A case report

INTRODUCTION

The causes of acute tubulointerstitial nephritis can be grouped into four broad categories: medications, infections, immunologic diseases, or idiopathic processes. Here we report a 17-year-old female who developed acute kidney injury (AKI) due to granulomatous interstitial nephritis (GIN) associated with influenza A: H1N1 infection.

CASE OUTLINE

The illness presented after two weeks of respiratory tract infection, skin rash and hypermenorrhea. On admission the patient was febrile, with bilateral pedal edema, macular skin rash, and auscultatory finding that suggested pneumonia. Laboratory investigations showed normocytic anemia, azotemia, hematuria and proteinuria. Renal ultrasound was normal. Antinuclear antibodies, antineutrophil cytoplasmic antibodies, lupus anticoagulant, antiphospholipid antibodies were negative with normal complement. Urine cultures including analysis for Mycobacterium tuberculosis were negative. The diagnosis of influenza A: H1N1 infection was made by positive serology. A kidney biopsy showed interstitial nephritis with peritubular granulomas. Glomeruli were normal. Staining for immunoglobulins A, M, G, and F was negative. The girl was treated with oseltamivir phosphate (Tamiflu; Genentech, Inc., South San Francisco, CA, USA) for five days, as well as with tapered prednisone after a starting dose of 2 mg/kg. The treatment resulted in a complete remission during two years of follow-up.

CONCLUSION

We present a severe but reversible case of GIN and AKI associated with influenza A: H1N1 infection. Although a causal effect cannot be confirmed, this case suggests that influenza A: H1N1 should be considered in the differential diagnosis of GIN manifested with AKI in children.

Variable Expression of Neural Cell Adhesion Molecule Isoforms in Renal Tissue: Possible Role in Incipient Renal Fibrosis

Rare neural cell adhesion molecule (NCAM) positive cells have been previously described within the normal human adult kidney interstitium, speculating that they could increase in the interstitium with incipient interstitial renal fibrosis (IRF). In the present study, among 93 biopsy samples of various kidney diseases, NCAM⁺ interstitial cells were detected in 62.4% cases. An increased number of NCAM⁺ cells was significantly observed only in incipient IRF compared to normal renal tissues and advanced IRF stages (p<0.001), independently of underlying diseases (p = 0.657). All three major NCAM isoforms’ RT-PCR bands were visible either in normal or in kidneys with incipient IRF, albeit their mRNA expression levels measured by qRT-PCR were different. Applying qRT-PCR on pure NCAM⁺ cells population, obtained by laser capture microdissection, significant mRNA over-expression of NCAM^140kD isoform was found in NCAM⁺ cells within incipient IRF (p = 0.004), while NCAM^120kD and NCAM^180kD isoforms were not changed significantly (p = 0.750; p = 0.704; respectively). Simultaneously, qRT-PCR also showed significant αSMA (p = 0.014) and SLUG (p = 0.004) mRNAs up-regulation within the NCAM⁺ cells of incipient IRF, as well as highly decreased matrix metalloproteinases (MMP) -2 and -9 mRNAs (p = 0.028; p = 0.036; respectively). However, using double immunofluorescence MMP-9 could still be detectable on the protein level in rare NCAM⁺ cells within the incipient IRF. Further characterization of NCAM⁺ cells by double immunofluorescent labeling revealed their association with molecules involved in fibrosis. Fibroblast growth factor receptor 1 (FGFR1) and α5β1 integrin were extensively expressed on NCAM⁺ cells within the incipient IRF areas, whereas human epididymis protein-4 (HE4) was found to be present in few NCAM⁺ cells of both normal and interstitium with incipient fibrosis. Heterogeneity of NCAM⁺ interstitial cells in normal and incipient IRF, concerning molecules related to fibrosis and variable expression of NCAM isoforms, could suggest diverse role of NCAM⁺ cells in homeostasis and in regulation of renal fibrosis in diseased kidneys.

Glomerular nestin expression: possible predictor of outcome of focal segmental glomerulosclerosis in children

BACKGROUND

A high prevalence of chronic kidney disease among children with focal segmental glomerulosclerosis (FSGS) leads to a permanent quest for good predictors of kidney dysfunction. Thus, we carried out a retrospective cohort study in order to examine known clinical and morphological predictors of adverse outcome, as well as to investigate glomerular nestin expression as a potential new early predictor of kidney dysfunction in children with FSGS. Relationships between nestin expression and clinical and morphological findings were also investigated.

METHODS

Among 649 renal biopsy samples, obtained from two children's hospitals, FSGS was diagnosed in 60 children. Thirty-eight patients, who met the criteria for this study, were followed up for 9.0 ± 5.2 years. Using Kaplan-Meier and Cox's regression analysis, potential clinical and morphological predictors were applied in two models of prediction: after disease onset and after the biopsy.

RESULTS

The present study revealed the following significant predictors of kidney dysfunction: patients' ages at disease onset, as well as age at biopsy, resistance to corticosteroid treatment, serum creatinine level, urine protein/creatinine ratio, vascular involvement, tubular atrophy, interstitial fibrosis, and decreased glomerular nestin expression.

CONCLUSIONS

The most important finding of our study is that nestin can be used as a potential new early morphological predictor of kidney dysfunction in childhood onset of FSGS, since nestin has been obviously decreased in both sclerotic and normal glomeruli seen by light microscopy.

Losartan improved antioxidant defense, renal function and structure of postischemic hypertensive kidney

Ischemic acute renal failure (ARF) is a highly complex disorder involving renal vasoconstriction, filtration failure, tubular obstruction, tubular backleak and generation of reactive oxygen species. Due to this complexity, the aim of our study was to explore effects of Angiotensin II type 1 receptor (AT1R) blockade on kidney structure and function, as well as oxidative stress in spontaneously hypertensive rats (SHR) after renal ischemia reperfusion injury. Experiments were performed on anaesthetized adult male SHR in the model of ARF with 40 minutes clamping the left renal artery. The right kidney was removed and 40 minutes renal ischemia was performed. Experimental groups received AT1R antagonist (Losartan) or vehicle (saline) in the femoral vein 5 minutes before, during and 175 minutes after the period of ischemia. Biochemical parameters were measured and kidney specimens were collected 24h after reperfusion. ARF significantly decreased creatinine and urea clearance, increased LDL and lipid peroxidation in plasma. Treatment with losartan induced a significant increase of creatinine and urea clearance, as well as HDL. Lipid peroxidation in plasma was decreased and catalase enzyme activity in erythrocytes was increased after losartan treatment. Losartan reduced cortico-medullary necrosis and tubular dilatation in the kidney. High expression of pro-apoptotic Bax protein in the injured kidney was downregulated after losartan treatment. Our results reveal that angiotensin II (via AT1R) mediates the most postischemic injuries in hypertensive kidney through oxidative stress enhancement. Therefore, blockade of AT1R may have beneficial effects in hypertensive patients who have developed ARF.

NCAM and FGFR1 coexpression and colocalization in renal tumors

Neural cell adhesion molecule (NCAM) and fibroblast growth factor receptor (FGFR) have a role in epithelial-mesenchymal transformation during tumor genesis. Interplay between both molecules activates FGFR signaling and it could be responsible for tumor development. Renal epithelial tumors were analyzed for FGFR1 and NCAM coexpression by immunohistochemistry and for colocalization of these molecules on the particular tumor cells by triple immunofluorescence. Detection of NCAM isoforms in renal tumors was evaluated by RT-PCR. Applying immunohistochemistry we revealed that the majority of analyzed renal neoplasms, including renal cell carcinoma (RCC) and oncocytoma coexpressed NCAM and FGFR1. Triple immunofluorescent technique confirmed that both markers are commonly colocalized on the same tumor cells. Interestingly, it seemed that different position of NCAM and FGFR1 expression on renal tumor cells is related to renal tumor type or grade: exclusively membranous FGFR1/NCAM expression occurred in low grade clear cell RCC (cRCC); cytoplasmatic and membranous expression was present in high grade cRCC and other RCC types; oncocytoma showed only cytoplasmatic staining of both markers. NCAM-140 and NCAM-120 were detected in almost all analyzed renal neoplasms. Expression of both molecules on different cell compartments in various kidney tumors indicated that NCAM/FGFR1 interaction could play distinct roles in renal tumor genesis.

Pulmonary renal syndrome in a child with coexistence of anti-neutrophil cytoplasmic antibodies and anti-glomerular basement membrane disease: case report and literature review

BACKGROUND

Pulmonary renal syndrome (PRS), denoting the presence of diffuse alveolar hemorrhage and glomerulonephritis as manifestations of systemic autoimmune disease, is very rare in childhood. The coexistence of circulating anti-neutrophil cytoplasmic antibody (ANCA) and anti-glomerular basement membrane (GBM) disease in children affected by this syndrome is exceptional, with unfavorable outcome in five out of seven patients reported to date. We describe a child with PRS associated with both circulating anti-myeloperoxidase (anti-MPO) ANCA and anti-GBM disease on renal biopsy who was successfully treated with immunosuppressive therapy.

CASE PRESENTATION

A 10-year old girl presented with fever, fatigue, malaise, and pallor followed by hemoptysis and severe anemia. Diffuse alveolar hemorrhage was revealed on fiberoptic bronchoscopy. Renal findings consisted of microscopic hematuria, moderate proteinuria, and anti-GBM disease on renal biopsy. ANCA with anti-MPO specificity were present whereas anti-GBM antibodies were on borderline for positivity. Methyl-prednisolone pulses followed by prednisone led to cessation of hemoptysis, marked improvement of lung fuction, and normal finding on chest x-ray within 10 days. An immunosuppressive regimen was then given consisting of prednisone daily for 4 weeks with subsequent taper on alternate day, i.v. cyclophosphamide pulses monthly for 6 doses, followed by mycophenolate mofetil that resulted in normal lung function tests, hemoglobin concentration, and anti-MPO level within four subsequent weeks. During 10-months of follow-up she remained well, her blood pressure and renal function tests were normal, and proteinuria and hematuria gradually resolved.

CONCLUSION

We report a child with an exceptionally rare coexistence of circulating ANCA and anti-GBM disease manifesting as PRS in whom renal disease was not the prominent part of clinical presentation, contrary to other reported pediatric patients. A review of literature on disease with double positive antibodies is also presented. Evaluation of a patient with PRS should include testing for presence of different antibodies. An early diagnosis and rapid institution of aggressive immunosuppressive therapy can induce remission and preserve renal function. Renal prognosis depends on the extent of kidney injury at diagnosis and appropriate treatment.

Differential expression of KCNQ1 K+ channel in tubular cells of frog kidney

The aim of this study was to evaluate KCNQ1 K⁺ channel expression in the frog kidney of Rana esculenta. KCNQ1 K⁺ channel, also known as KvLQT1, is the pore forming α-subunit of the I_Ks K⁺ channel, a delayed rectifier voltage-gated K⁺ channel, which has an important role in water and salt transport in the kidney and gastrointestinal tract. The expression of KCNQ1 K⁺ channel along tubular epithelium differs from species to species. In the present study the expression of KCNQ1 K⁺ channel in the frog kidney has been demonstrated by immunohistochemistry. The presence of KCNQ1 K⁺ channel was demonstrated in the epithelial cells of distal convoluted tubule and collecting duct. However, the pattern of expression of KCNQ1 K⁺ channel differs between distal convoluted tubules and collecting duct. All epithelial cells of distal convoluted tubules revealed basolateral expression of KCNQ1 K⁺ channel. On the contrary, only the single cells of collecting duct, probably intercalated cells, showed diffuse cell surface staining with antibodies against KCNQ1 K⁺ channel. These findings suggest that KCNQ1 K⁺ channel has cell-specific roles in renal potassium ion transport.

Comparative effects of L-arginine and vitamin C pretreatment in SHR with induced postischemic acute renal failure

Postischemic acute renal failure is worsened when occurs in a various conditions with impaired nitric oxide (NO) synthesis, such as arterial hypertension. Reoxygenation itself increases ischemic injury through the massive production of oxygen-free radicals. Therefore, we have directed our investigations to effects of both NO donor and antioxidant treatment on course of acute renal failure in experimental hypertension. Experiments were performed in anesthetized, adult male spontaneously hypertensive rats. In ARF groups the right kidney was removed, and rats were subjected to renal ischemia by clamping the left renal artery for 40 min. Experimental group received NO donor L-arginine (2 g/kg b.m.) (LArg group), or oxidant scavenger vitamin C (100 mg/kg b.m.) (Vit C group) during 3 days before the period of ischaemia. All parameters were measured 24 h after reperfusion. The mean arterial pressure was markedly reduced and renal vascular resistance significantly dropped in the ARF+L-Arg group vs. ARF group. Tubular injuries were similar between the ARF+L-Arg and ARF groups. Intensity of tubular necrosis and dilatation was markedly reduced in ARF+Vit C group in comparison to ARF. L-arginine failed to reduce tubular injury, despite its evident improvement of systemic and renal haemodynamic, thus NO seems to act as a double-egged sword, but reduction of tubular injury promotes vitamin C as an effective chemoprotectant against ishemia-reperfusion tubular injury in hypertension.

Bosentan and losartan ameliorate acute renal failure associated with mild but not strong NO blockade

BACKGROUND

Acute renal failure (ARF) is a devastating illness, especially when it occurs in various conditions with impaired nitric oxide (NO) synthesis, such as arterial hypertension, heart failure and some renal diseases. We have directed our investigations to effects of both angiotensin II (AII) and endothelin (ET) receptor blockade associated with mild or strong NO deficiency on haemodynamic, biochemical and morphological parameters in experimental post-ischaemic ARF.

METHODS

In this study, we used bosentan (dual, ETA/ETB-receptor antagonist), losartan (non-peptide, competitive antagonist of type I AII receptor), and NG-nitro-L-arginine methyl ester (L-NAME), inhibitor of NO synthesis. Experiments were performed in anaesthetized, adult male Wistar rats. The right kidney was removed and the renal ischaemia was performed by clamping the left renal artery for 45 min. Experimental groups received receptor antagonists (bosentan or losartan) or vehicle (saline) in the femoral vein 20 min before, during and 20 min after the period of ischaemia. L-NAME was given as i.v. bolus before each antagonist infusion. All parameters were measured 24 h after reperfusion.

RESULTS

Our results showed that strong NO blockade overcame effects of both ET and AII receptor blockade in experimental post-ischaemic ARF. In addition, the AII receptor blockade had a harmful effect on this condition, probably due to disturbed autoregulatory renal function. On the other hand, ET and AII receptor blockade in mild NO blockade associated with reperfusion injury, improves the most haemodynamic, biochemical and morphological parameters.

CONCLUSIONS

We concluded that experimental post-ischaemic ARF is neither AII nor ET mediated in case of strong NO blockade, but, in more realistic conditions of mild NO deficiency, these peptides represent significant players whose receptor blockade expressed relevant therapeutic potential.

Neural cell adhesion molecule expression on renal interstitial cells

BACKGROUND

At early stages of kidney development, the neural cell adhesion molecule (NCAM) is highly expressed on cells of the metanephrogenic mesenchyme. During maturation of the fetal kidney, NCAM gradually disappears. So far, it has been widely accepted that NCAM in the adult kidney is only expressed by nerves, and not by other cell types.

METHODS

NCAM expression was analysed in human adult healthy and diseased kidneys by immunohistochemistry and western blot analysis. NCAM+ renal interstitial cells were further characterized by double immunofluorescent staining using antibodies against neurofilaments, alpha smooth muscle actin, vimentin, alpha5beta1 integrin, CD68, CD11c, HLA-DR and the potential progenitor cell markers CD34, CD117, CD133, CD24, nestin and cadherin-11.

RESULTS

In adult human kidneys, NCAM expression is restricted to rare interstitial cells with dendritic morphology, which are neurofilament-negative and predominantly localized on the corticomedullary junction. They are also negative for fibroblast cell markers, but co-express the haematopoietic stem cell markers CD34 and CD133. The number of NCAM+ interstitial cells increased in the initial phases of interstitial fibrosis. Western blot analysis of renal tissues with incipient interstitial fibrosis tissues showed the expression of the 140 kDa NCAM isoform.

CONCLUSIONS

These data indicate that a rare subpopulation of NCAM+ interstitial cells could represent renal progenitors, and that NCAM+ interstitial cells can participate in the initial phase of interstitial fibrosis.

Relative roles of endothelin-1 and angiotensin II in experimental post-ischaemic acute renal failure

BACKGROUND

The relative roles of endothelin (ET)-1 and angiotensin (ANG) II in post-ischaemic acute renal failure (ARF) have not been fully established so far. With the aim of contributing to this goal, we assessed in this study the effect of ANG II and ET-1 blockade on the course of post-ischaemic-ARF.

METHODS

Anaesthetized Wistar rats received i.v. either bosentan (a dual ET receptor antagonist; 10 mg/kg body weight) or losartan [ANG II type 1 (AT(1)) receptor antagonist; 5 or 10 mg/kg body weight] or both, 20 min before, during and 20 min after ischaemia. Rats in the control group received the vehicle via the same route. Survival and renal function were monitored up to 8 days after the ischaemic challenge, while haemodynamic parameters were measured 24 h after ARF.

RESULTS

Our results demonstrate that bosentan treatment has a more beneficial effect on experimental ARF than losartan. The survival rate was remarkably higher in bosentan-treated rats than in both rat groups treated with losartan. In the ARF group treated with bosentan, renal blood flow (RBF) was increased by 129% in comparison with the untreated ARF group, whereas in the losartan-treated ARF groups, RBF was only approximately 35 or 38% higher than in control ARF rats. The glomerular filtration rate was markedly higher in bosentan-treated rats than in all other ARF groups on the first and second day after ischaemia. Tubular cell injury was less severe in bosentan-treated rats than in the control ARF rats, but in losartan-treated groups it was similar to that in the ARF group. Concurrent blockade of both ET and AT(1) receptors did not improve ARF because this treatment induced a marked decrease in blood pressure.

CONCLUSIONS

These results suggest that ET-1 blockade is more efficient in improving the early course of post-ischaemic renal injury than ANG II inhibition, and that blockade of ET-1 might be effective in prophylaxis of ischaemic ARF.

[Aging and hypertension as factors of progressive renal failure]

INTRODUCTION

This study evaluated the effects of aging on renal hemodynamic, biochemical and histological parameters in spontaneously hypertensive rats.

MATERIAL AND METHODS

Systolic blood pressure was measured in male SHR (adult--adSHR and aged--agSHR) during four weeks, indirectly, once a week At the end of the experiment 24 h urine samples were collected and hemodynamic measurements were performed. Animals were sacrificed and blood samples were collected for biochemical analysis. The left kidney was histopathologically examined.

RESULTS AND DISCUSSION

Our results show that there is no difference in systolic blood pressure between adult and aged SH rats. Renal blood flow was significantly decreased (0.68+/-0.08 vs. 0.99+/-0.007 ml/min/100 g b.w.), while renal vascular resistance increased by 28.90% in aged gSH rats. Plasma creatinine (Pcr) level was decreased in agSHR compared to adSHR (p<0.001). There was no difference in creatinine clearance, because urine volume was significantly increased in the aged rats (p<0.001). Protein excretion (Pex) and filtration fraction were significantly increased in aged rats compared to adult rats (Pex: p<0.001, and FF: p<0.05). The degree of focal-segmental glomerulosclerosis measured by a semiquantitative histological technique was significantly increased in the aged rats compared to adult. Sporadic focal tubular atrophy and dilatation with periodic acid-schiff positive material were present in the aged group. Also there were changes in structure of afferent arterioles and small vessels with myointimal proliferation and reduced lumen diameter. There were no changes in lumen diameter of large renal vessels. Histopathological score of adult rats showed only minimal changes in vessel structure.

CONCLUSION

These results show that aging, and long-term high arterial blood pressure are risk factors associated with hemodynamic changes in renal arteries and kidney vessels, advancement of glomerulosclerosis and tubular injury, and therefore may contribute to progression of renal failure and eventually cause end stage renal disease.

[Corticoid-sensitive nephrotic syndrome in children with myelodysplastic syndromes]

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated with steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented also hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementamia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient haematological improvement occurred. Relapse subsequently occurred that was manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease but haematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, two years after the onset of MDS. Patient 2, who had refractory anaemia with clonal monosomy 19, manifested bowel disease, hepatosplenomegaly, anaemia and non-organic specific autoantibodies. Prednisone led to both clinical and haematological remission. Haematologic disease relapsed 12 months later, when nephrotic-range proteinuria, haematuria and mild azotaemia were also found. Corticosteroid treatment led to long-lasting renal and haematologic remission, maintained by a small dosage of prednisone. In both patients, renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with either acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis and AL amyloidosis, were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS; (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.

[Lupus nephritis in children and adolescents: clinical and morphologic aspects and clinico-morphologic correlations]

In 53 children and adolescents (47 males, 6 females) with lupus nephritis, clinical features at the time of renal biopsy were analyzed and correlated with pathohistological findings. The mean age at the time of diagnosis of systemic lupus was 12.9 +/- 2.6 (SD) years; the mean ages at the time of diagnosis of lupus nephritis and renal biopsy were 13.5 +/- 2.6 and 13.6 +/- 2.5 years, respectively. The most frequent clinical and laboratory features of lupus nephritis at the time of biopsy were proteinuria (100% of patients), haematuria (88%), nephrotic syndrome (38%), hypertension (32%), and decreased glomerular filtration rate (26%). On initial biopsy, the most frequent finding was diffuse proliferative glomerulonephritis (in 64.1%), followed by "mesangiopathy" (20.8%), minimal changes (7.5%), membranous nephropathy (5.8%), and focal proliferative nephritis (1.9%). Nephrotic syndrome, hypertension, decreased glomerular filtration rate, and haematuria were significantly associated with WHO classes IV and III of lupus nephritis.

[Lupus nephritis in children and adolescents: therapy, clinical course and prognosis]

In 53 children and adolescents (47 males, 6 females) with lupus nephritis, clinical features at the time of renal biopsy were analyzed and correlated with pathohistological findings. Therapeutic regimens used and the renal status at the end of follow-up are presented, and factors significantly associated with adverse outcome are analyzed. The mean age at the time of diagnosis of systemic lupus was 12.9 +/- 2.6 (SD) years, the mean ages at the time of diagnosis of lupus nephritis and renal biopsy were 13.5 +/- 2.6 and 13.6 +/- 2.5 years, respectively. The patients having WHO classes I and II of lupus nephritis were treated with prednisone and/or azathioprine; those with WHO classes IV and III were treated with cyclophosphamide (25) or with corticosteroids (5) or with corticosteroids and azathioprine (4), five of them were also treated with plasmapheresis; the patients with WHO class V were treated with prednisone and azathioprine or cyclosporine. Repeated renal biopsies were performed in 12 patients: worsening of morphological lesions was found in four patients, improvement in two and no change was observed in six patients (all with WHO class IV). At the end of follow-up lasting from 0.1 to 14.6 years (mean 4.8 +/- 3.2 years) 80% of patients were in complete (49%) or partial (30%) remission, in 8% of patients the renal disease was clinically active, and in 13% of patients the adverse outcome was noted: one patient died in the first month after diagnosis from extrarenal complications, two patients were in preterminal and the other four in terminal renal failure. Adverse outcome was significantly associated with the presence of nephrotic syndrome at the time of biopsy and with class IV nephritis. The five-year patient's survival rate was 98.1%. The five-year kidney survival rate was 88.6% and 82.4% for the whole group and for the subgroup of patients having classes III and IV nephritis, respectively.

Glomerular involvement in myelodysplastic syndromes

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented with hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementemia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient hematological improvement occurred. Relapse subsequently occurred that manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease, but hematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, 2 years after the onset of the MDS. Patient 2, who had refractory anemia with clonal monosomy 19, presented with bowel disease, hepatosplenomegaly, anemia and non-organ-specific autoantibodies. Prednisone led to both clinical and hematological remission. The hematologic disease relapsed 12 months later, when nephrotic-range proteinuria, hematuria and mild azotemia were also found. Corticosteroid treatment led to long-lasting renal and hematologic remission, maintained by a small dosage of prednisone. In both patients, renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis, and AL amyloidosis were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS and (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.

Immunohistochemical analysis of HLA class II antigens and tumor infiltrating mononuclear cells in renal cell carcinoma: correlation with clinical and histopathological data

Cryostat sections of 37 renal cell carcinomas (RCC)--25 clear cell type, 10 granular and 2 chromophobe--were studied with indirect immunoperoxidase method applying monoclonal antibodies (MoAb) to HLA-DR, -DP and -DQ antigens for analysis of HLA class II antigens, and anti-CD14, -CD3, -CD4 and -CD8 MoAb for tumor infiltrating mononuclear cells (TIM). Number of positive cells was estimated semiquantitatively and results of immunohistochemical investigation were correlated with clinical (patient age and sex, tumor size and TNM stage) and histopathological (cytology, histology, grade) characteristics of RCC. All RCC expressed HLA-DR, 92% -DQ and 73% -DP antigens with level of expression in hierarchy- DR>-DQ>-DP, but no statistically important correlation could be established with any of the histopathological or clinical parameters analyzed. Monocytes were more abundant than T lymphocytes and CD4+ than CD8+ T cells, whereas tumors with T lymphocyte predominance and approximately equal number of CD4+ and CD8+ T cells had greatest average diameter. Inadequate activation of T lymphocytes by tumor cells (despite capability of antigen presentation) could be the reason for association of parameters which indicates more aggressive tumor behavior with aberrant HLA class II antigen expression on RCC.

L-arginine reduces tubular cell injury in acute post-ischaemic renal failure

BACKGROUND

The pathophysiology of renal ischaemia, resulting in tubular cell injury and leading to acute renal failure (ARF), remains unclear. An ever-increasing number of investigations focus on a possible role of nitric oxide (NO) in regulating circulation during ARF. In this context, we investigated the influence of chronic stimulation or inhibition of NO synthesis, or both, on haemodynamic parameters, histology and plasma renin activity (PRA) after ischaemia-reperfusion injury of rat kidneys.

METHODS

Experiments were performed on adult, male Wistar rats. Before induction of ARF, a group of animals was treated with a NO synthesis inhibitor (L-NAME) and another group was treated with a precursor of NO synthesis (L-arginine). The animals received those substances for 4 weeks. Control groups received the same amount of tap water for 4 or 8 weeks and were divided into groups with ARF (4 weeks--ARF group and 8 weeks ARF group) and a sham-operated group. Another group of rats was treated first with L-NAME and then with L-arginine in their drinking water, for 4 weeks for each of these two substances. All parameters were evaluated 24 h after the induction of ischaemic ARF or the sham operation.

RESULTS

Our results show that such long-term stimulation of NO release by L-arginine improved renal haemodynamics in the ischaemic form of ARF. Renal blood flow (RBF) increased by 96% in the L-arginine-treated rats with ARF compared with the group with ARF alone. Inhibition of NO synthesis worsens renal haemodynamics after ARF. However, this aggravation can be reversed by L-arginine. The rate of water reabsorption was reduced in all groups with ARF, but this reduction was least in the group treated with L-arginine. The rate of Na+ reabsorption was reduced in all groups 24 h after renal ischaemia, but a significant decrease was observed after the inhibition of NO synthesis. Histological examination of the kidney specimens showed that morphological changes were least in the rats treated with L-arginine, when compared with all other groups with ARF. Nevertheless, the lesions were most prominent in the L-NAME+ARF group. In this group, the areas of corticomedullar necrosis were more widespread in comparison with other groups, especially the L-arginine group where only swelling of the proximal tubular cells was observed. Treatment with L-NAME was not accompanied by any significant alteration in the plasma concentration of angiotensin I (ANG I), while in the group treated with L-arginine ANG I had a tendency to decrease.

CONCLUSIONS

Acute post-ischaemic renal failure may be alleviated by administering the NO substrate (L-arginine). NO acts cytoprotectively on tubular epithelial cells in ischaemia--reperfusion injury of rat kidney. Evidence of this comes from both histopathological findings and increased tubular water and sodium reabsorption. However, inhibition of NO synthesis (provoked by L-NAME) worsens renal haemodynamics and aggravates morphological changes after ARF. These aggravations can, however, be reversed by L-arginine.

[Adhesion molecules in kidney diseases (part II)]

Different adhesion molecules are involved in the maintenance of tissue architecture, morphogenesis, immunosurveillance, inflammation, tumour growth, etc. Thus, this review will be directed to the role of cadherins, selectins, integrins and members of the immunoglobuline supergene family in the pathogenesis of glomerulonephritis, acute renal failure, reaction of renal rejection, development of renal tumours, their invasion and metastases. A better understanding of the role of adhesion molecules in nephropathology may provide new aspects of treatment of different forms of renal diseases including tumours.

[Adhesion molecules in kidney diseases (part I)]

Adhesive molecules are (glyco)proteins of the cellular membranes. All of them have their extramembranous, transmembranous and intracytoplasmatic parts. As receptor molecules, their extracellular parts bind the specific ligand. The ligand can be found on the surface of the other cell or in the extracellular matrix (basal membranes). The following families of adhesion molecules are: cadherins, selectins, integrins and members of immunoglobuline supergene family. Different members of the same family could have different times (in ontogenesis, in adult form) and space distribution (in different tissues, different tissue structures). The contact between the cells and basal membranes with these molecules is important for cell division, maintaining the tissue architecture, polarization and function of cells, migration of cells, endo- and exo-cytosis as well as for maintaining the structure and function of basal membranes. As above stated all this is important in the occurrence morphogenesis, haemostasis, inflammation, malignant cell transformation and metastasis. This knowledge is important for the better understanding of renal diseases.

[Electron microscopic analysis of eosinophilic renal cell carcinoma]

Renal cell carcinoma with cytoplasmic eosinophilic globules visualized on routine histologic preparations was analyzed. Eosinophilic globules in cytoplasm of the cells in renal cell carcinoma are very rate and till today we have not heard or found in the literature an attempt to analyze and describe them and that was the aim of our study. By electron microscopy, the globules most closely resembled non-membrane bound filamentous material that normally constitutes the cytoskeleton of normal and neoplastic renal epithelium.

[Ultrastructural changes in transplantation glomerulopathy]

Twenty-eight biopsy specimens were obtained from patients 3-95 months after kidney transplantation and studied by light, electron and in some cases also by immunofluorescence microscopy. Electron microscopic studies showed that the most frequent glomerular lesion was widening of lamina rata interna which is accompanied with subendothelial accumulation of finely granular material, formation of new subendothelial basement membrane and deposition of microfibrils and fine filaments. The mesangial changes were mainly those of mesangiolysis and mesangial sclerosis with deposition of mesangial matrix and microfibrils, but little cellular proliferation. Fragmented red blood cells were seen in nearly half of the patients. Arterial intimal thickening and occasionally also thrombosis produced ischaemic changes in the kidney and in the glomeruli and contributed to the process of transplant rejection.

[Intercellular adhesion molecule-1 expression in renal cell carcinoma]

The presence of intercellular adhesion molecule-1 (ICAM-1) was analyzed using indirect immunoperoxidase technique in frozen sections of 27 renal cell carcinomas (RCC)--18 clear cell, 6 granular, 2 chromophobe and 1 sarcomatoid. Great variations in ICAM-1 expression were observed in clear and granular cell RCC, without correlation with mononuclear (lympho-monocytic) cell infiltration. Sarcomatoid type displayed widespread ICAM-1 distribution and intense mononuclear infiltrate, while chromophobic RCC, despite better prognosis, expressed ICAM-1 weakly and focally, almost without mononuclear infiltrate. With such results, no relation between ICAM-1 expression on tumor cells and behavior of various RCC types could be established and possible explanations are: different histogenesis of some RCC (chromophobe), nonspecific upregulation of ICAM-1 as a result of ischaemic-necrotic processes, or negative effect of ICAM-1 expression on complement action.

[Association of liver cirrhosis, hepatitis B virus infection and hepatocellular carcinoma--immunohistochemical study]

In order to assess frequency and importance of the presence of alpha fetoprotein (AFP) and AlAChy as well as hepatitis B virus (HBV) infection antigens in the tissue of hepatocellular carcinoma (HCC) and in the liver tissue outside a tumour, there have been performed retrospective light-microscopic and immunohistochemical examinations of the liver tissue in 65 cases of HCC (39 autopsy and 26 biopsy cases). The finding of AlAChy in 100% of autopsy cases of HCC and 80.7% of biopsy cases of HCC compared with the presence of AFP in 33% of autopsy and 61.5% of biopsy cases point out that AlAChy is a more sensitive marker than AFP in diagnosing HCC. The presence of HBV infection antigens in 43.5% of autopsy cases and 23.5% of biopsy cases of HCC point to an important role of HBV infection in development of HCC in the studied population.