[Show abstract][Hide abstract] ABSTRACT: Dual renin-angiotensin system blockade with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers has been advocated to minimize proteinuria. However, recent trials have questioned the renal safety of this approach. Our understanding on the molecular effects of dual blockade in humans is incomplete.
We present a patient with corticoid resistant nephrotic syndrome who developed marked juxtaglomerular apparatus hyperplasia and renin expression in the context of dual angiotensin system blockade.
Although renin may have profibrotic effects mediated by (pro)renin receptor activation, this report raises questions on the potential consequences of local renin activation on chronic kidney disease in patients with dual angiotensin blockade.
[Show abstract][Hide abstract] ABSTRACT: Acute interstitial nephritis is an infrequent cause of early allograft dysfunction. Prophylactic trimethoprim sulfamethoxazole (cotrimoxazole) is frequently prescribed early in the course of kidney transplantation. Herein we have reported a case of delayed graft function associated with eosinophilia in which the renal biopsy showed interstitial mononuclear infiltrates with abundant eosinophils. An initial methylprednisolone course failed to lower the serum creatinine, but renal function and eosinophilia persistently improved following cotrimoxazole withdrawal and a second course of steroids. Cotrimoxazole acute interstitial nephritis is an infrequent but treatable cause of kidney allograft dysfunction, which should be included in the differential diagnosis of delayed renal allograft function.
[Show abstract][Hide abstract] ABSTRACT: Macroscopic haematuria of glomerular origin has been associated with acute kidney injury. We report a patient with IgA nephropathy, macroscopic haematuria and acute kidney injury. Systemic anticoagulation may have aggravated haematuria. There was extensive interstitial and intratubular red blood cell extravasation, and interstitial haemosiderin deposits. The abundant presence of macrophages expressing the haemoglobin scavenger receptor CD163 and of cells stained for oxidative stress markers (NADPH-p22 phox and heme-oxigenase-1) in areas of interstitial haemorrhage and red blood cell cast-containing tubules provided evidence for a role for free haemoglobin in tubulointerstitial renal injury in human glomerular disease.
[Show abstract][Hide abstract] ABSTRACT: Twenty-six cases of high-grade lymphomas with activation markers (CD30) classified and immunophenotyped according to the Kiel classification were studied to determine their fine structural features. Transmission electron microscopy showed in 17 cases anaplastic nuclear and cytoplasmic changes identical to those observed in Hodgkin's disease, it being impossible to determine by the morphology a B, T, or null nature. Four high-grade B-centroblastic and immunoblastic cases and five T-pleomorphic cases showed nuclear changes and cytoplasmic differentiation that suggested a T or B nature. An immunogold-labeling technique showed CD30-positive particles primarily in the Golgi complex and occasionally in the cell membrane.
[Show abstract][Hide abstract] ABSTRACT: Leishmania infection may be associated with immunecomplex-mediated glomerular injury. Contrary to immune-competent individuals, leishmaniasis in HIV patients is a chronic, relapsing disease. Despite the increasing frequency of the Leishmania/ HIV co-infection, there is a paucity of information on the effects of such co-infection in the kidney. We present a patient with AIDS and refractory, relapsing visceral leishmaniasis who developed nephrotic syndrome associated with renal involvement by Leishmania in the absence of immunecomplex glomerular deposition. For the first time, the relapsing nature of renal injury in this context is documented.
[Show abstract][Hide abstract] ABSTRACT: Recurrent acute postinfectious glomerulonephritis is infrequent in childhood and exceptional in adults. The factors that determine recurrence are poorly understood. Selective IgA deficiency is characterized by an increased incidence of gastrointestinal and respiratory infections. The case of a 33-year-old man with a history of repetitive sinopulmonary infections and diagnosed with selective IgA deficiency is described. He suffered 2 episodes of postinfectious glomerulonephritis within a 15-year period. Selective IgA deficiency may have predisposed to the development of recurrent postinfectious glomerulonephritis
[Show abstract][Hide abstract] ABSTRACT: Parathyroid hormone-related protein (PTHrP) is shortly upregulated in acute renal injury, but its pathophysiologic role is unclear. Investigated was whether PTHrP might act as a profibrogenic factor in mice that do or do not overexpress PTHrP in the proximal tubule after folic acid (FA) nephrotoxicity, a model of acute renal damage followed by partial regeneration and patchy tubulointerstitial fibrosis. It was found that constitutive PTHrP overexpression in these animals conveyed a significant increase in tubulointerstitial fibrosis, associated with both fibroblast activation (as alpha-smooth muscle actin staining) and macrophage influx, compared with control littermates at 2 to 3 wk after FA damage. Cell proliferation and survival was higher (P<0.01) in the renal interstitium of PTHrP-overexpressing mice than in control littermates within this period after injury. Moreover, the former mice had a constitutive Bcl-XL protein overexpression. In vitro studies in renal tubulointerstitial and fibroblastic cells strongly suggest that PTHrP (1-36) (100 nM) reduced FA-induced apoptosis through a dual mechanism involving Bcl-XL upregulation and Akt and Bad phosphorylation. PTHrP (1-36) also stimulated monocyte chemoattractant protein-1 expression in tubuloepithelial cells, as well as type-1 procollagen gene expression and fibronectin (mRNA levels and protein secretion) in these cells and renal fibroblastic cells. Our findings indicate that this peptide, by interaction with the PTH1 receptor, can increase tubulointerstitial cell survival and seems to act as a proinflammatory and profibrogenic factor in the FA-damaged kidney.
Journal of the American Society of Nephrology 06/2006; 17(6):1594-603. DOI:10.1681/ASN.2005070690 · 9.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Parathyroid hormone-related protein (PTHrP), a mitogenic factor for renal cells, is overexpressed in acute renal failure (ARF). Recent data support an association between PTHrP and the renin-angiotensin system in the damaged kidney. The effects of angiotensin II (Ang II) inhibitors (quinapril, enalapril, and/or losartan) on PTHrP and the PTH1 receptor (PTH1R) expression in rats with either folic acid (FA)- or gentamicin-induced ARF were analyzed. The decreased renal function and the PTHrP upregulation and PTH1R downregulation induced by the nephrotoxins were inhibited by the Ang II blockers. In tubuloepithelial cells NRK-52E, the rapid (10 min) increase in PTHrP mRNA by FA, associated with a perinuclear relocalization of Ang II/AT1 receptor, was inhibited by losartan but not candesartan, which traps Ang II receptors at the cell surface. Maximal PTHrP protein overexpression by FA (at 24 to 72 h)-or by exogenous Ang II-was abolished by both Ang II antagonists. PTHrP upregulation by FA was preceded by increased extracellular signal-regulated kinase (ERK) phosphorylation and inhibited by the ERK inhibitor PD098059. FA also activated cAMP response element-binding (CREB) protein, and this was prevented by losartan in these cells. Moreover, PTHrP mRNA overexpression by either FA or Ang II occurred in NRK 52E that were transfected with a CREB construct but not the dominant-negative CREB133 construct. These findings demonstrate that the decreased renal function and PTHrP overexpression in nephrotoxin-damaged kidney depends on renin-angiotensin system. In this setting, intracellular Ang II/AT1 receptor recycling seems to be related to PTHrP induction through ERK and CREB activation in tubuloepithelial cells.
Journal of the American Society of Nephrology 05/2005; 16(4):939-49. DOI:10.1681/ASN.2004040328 · 9.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Cidofovir is an antiviral drug with activity against a wide array of DNA viruses including poxvirus. The therapeutic use of cidofovir is marred by a dose-limiting side effect, nephrotoxicity, leading to proximal tubular cell injury and acute renal failure. Treatment with cidofovir requires the routine use of prophylactic measures. A correct knowledge of the cellular and molecular mechanisms of cidofovir toxicity may lead to the development of alternative prophylactic strategies. We recently cared for a patient with irreversible acute renal failure due to cidofovir. Renal biopsy showed tubular cell apoptosis. Cidofovir induced apoptosis in primary cultures of human proximal tubular cells in a temporal (peak apoptosis at 7 days) and concentration (10-40 microg/ml) pattern consistent with that of clinical toxicity. Apoptosis was identified by the presence of hypodiploid cells, by the exposure of annexin V binding sites and by morphological features and was associated with the appearance of active caspase-3 fragments. Cell death was specific as it was also present in a human proximal tubular epithelial cell line (HK-2), but not in a human kidney fibroblast cell line, and was prevented by probenecid. An inhibitor of caspase-3 (DEVD) prevented cidofovir apoptosis. The survival factors present in serum, insulin-like growth factor-1 and hepatocyte growth factor, were also protective. The present data suggest that apoptosis induction is a mechanism contributing to cidofovir nephrotoxicity. The prophylactic administration of factors with survival activity for tubular epithelium should be further explored in cidofovir renal injury.
[Show abstract][Hide abstract] ABSTRACT: The role of infiltrating cells (I.C.), commonly observed in the adenoma interstitial tissue, is unknown. We tested the hypothesis that I.C. are related with BPH progression by: phenotypically characterising these cells; quantifying the expression of lymphokines and growth factors; investigating the response to Permixon (P) in a clinical study. Permixon is a lipido sterolic extract of Serenoa repens possessing pharmacological activities and widely used in the treatment of men with BPH.
A multicenter open pilot study of two parallel groups on BPH patients was carried out. They were randomized to receive either oral Permixon (P) 160 mg bid for three months or to be followed for 3 weeks without any treatment before surgery (control group C). Strict inclusion and exclusion criteria were applied to conform homogeneous groups, avoiding interferences of inflammatory drugs or others. Baseline clinical profile was almost identical in both groups in terms of age (65.7+/-5.1 vs. 67.1+/-5.8 years), IPSS (19.8+/-6.1 vs. 19.0+/-5.8), prostate volume (64.8+/-18.9 vs. 71.5+/-29.3cc), Q(max) (9.6+/-3.2 vs. 10.6+/-2.6 ml/s), and Q(L) (4.0+/-1.1 vs. 3.5+/-0.7). Surgery was ultimately performed on 29 patients (17C, 12P) by TURP or retropubic adenomectomy. Adenoma samples were routinely stained with HE and later prepared for immunohistochemical studies using CD3, CD20 and CD68 antibodies. Counting of positives cells, lymphoid aggregates and foci were done using EnVision technique and the Tech Mate processor. Cytokines, growth factors and eicosanoids were determined by Elisa kits following the manufactured recommendation.
HISTOLOGICAL: A difference was observed in the number of lymphocytes B between C (91.4+/-44.1) and P treated (58.2+/-53.7) groups (p=0.097). BIOLOGICAL MARKERS: TNFalpha and IL-1beta were dramatically lower in the Permixon treated group. Other parameters did not show significant changes. CLINICAL: IPSS in the Permixon treated group was significantly reduced (p<0.006) from 20.0+5.9 to 14.9+3.8 after three months of treatment.
The BPH inflammatory hypothesis was tested in humans. Our pilot study shows a significant reduction of some inflammatory parameters in prostatic tissues of patients treated with Permixon. These biological findings justify a pharmacological effect of this drug on the inflammatory status of the adenoma. A correlation with clinical improvement was observed.
European Urology 11/2003; 44(5):549-55. DOI:10.1016/S0302-2838(03)00368-3 · 13.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recent studies have shown that exogenous administration of vascular endothelial growth factor (VEGF) is protective against cyclosporine A (CsA) renal toxicity. No data are available, however, on the possible role of endogenous VEGF. Our objective was to examine whether endogenous VEGF has a significant role in the renal response against CsA toxicity.
In vivo, we used high-dose (50-150 mg/kg/day) CsA +/- specific goat anti-mouse VEGF blocking monoclonal antibody (alpha-VEGF) in mice. In vitro, we exposed mouse tubular cells (MCT) to CsA +/- alpha-VEGF.
alpha-VEGF markedly enhanced CsA renal toxicity, inducing severe tubular damage and increased blood urea nitrogen. In animals treated with CsA + alpha-VEGF, damage progressed to generalized tubular injury (histology) and apoptosis (terminal deoxynucleotide transferase-mediated dUTP nick-end labeling) with associated anemia and reticulocytosis (18 days of treatment). CsA + alpha-VEGF treatments strikingly increased tubular VEGF and Bcl-xL proteins. In vitro, autocrine production of VEGF by MCT was identified by Western blot. Of specific interest, CsA toxicity in MCT increased significantly in the presence of alpha-VEGF.
Endogenous VEGF has a relevant role in the renal tubular defense against CsA toxicity. Blockade of the VEGF effect by alpha-VEGF results in clear-cut intensification of the tubular injury and appearance of regenerative anemia in the CsA + alpha-VEGF-treated animals. The occurrence of both in vivo and in vitro effects of VEGF blockade provides evidence of a direct protective effect of VEGF on the tubular cell.
[Show abstract][Hide abstract] ABSTRACT: The presence of mononuclear cells infiltrating the prostate adenoma is a morphological observation well established in the literature. However, its biological meaning is a subject of controversy. It has been postulated that it may represent a local immunological reaction contributing to the pathogenesis of prostatic adenoma. Several studies have been performed to test this hypothesis, both in humans and animals. The purpose of this review is to update available information, including our own ongoing studies. Morphological research has shown that cells infiltrating the adenoma are lymphocyte T, lymphocyte B and macrophages with a high proportion of lymphocyte T. Many of the inflammatory markers, such as lymphoquines (IL1, IL2, IL4, IL6, IL13), are elevated in the adenoma tissue as are some growth factors (EGF, TGF alpha, IFN gamma, TGF beta). The general impression is that an inflammatory process is activated in the adenoma during growth and maturing. It has also been proved that this inflammatory process could be modified with treatment and, in our case, with the lipido-sterolic extract of Serenoa Repens.
[Show abstract][Hide abstract] ABSTRACT: The presence of mononuclear cells infiltrating the prostate adenoma is a morphological observation well established in the literature. However, its biological meaning is a subject of controversy. It has been postulated that it may represent a local immunological reaction contributing to the pathogenesis of prostatic adenoma. Several studies have been performed to test this hypothesis, both in humans and animals. The purpose of this review is to update available information, including our own ongoing studies. Morphological research has shown that cells infiltrating the adenoma are lymphocyte T, lymphocyte B and macrophages with a high proportion of lymphocyte T. Many of the inflammatory markers, such as lymphoquines (IL1, IL2, IL4, IL6, IL13), are elevated in the adenoma tissue as are some growth factors (EGF, TGFα, IFNγ, TGFβ). The general impression is that an inflammatory process is activated in the adenoma during growth and maturing. It has also been proved that this inflammatory process could be modified with treatment and, in our case, with the lipido-sterolic extract of Serenoa Repens.
[Show abstract][Hide abstract] ABSTRACT: Hepatitis C virus (HCV) infection has been associated with several renal pathologies, including membranoproliferative and membranous glomerulonephritis. Although the presence of HCV proteins has been reported, there are no data concerning detection of the viral RNA in renal cells from HCV-infected patients with kidney disease. In this report we analysed, by in situ hybridization, the presence of HCV RNA in renal biopsies from 10 patients who were positive for antibodies to HCV (anti-HCV) and serum HCV RNA positive, and from four patients without HCV infection, with different renal disease. HCV RNA was detected in the renal biopsies from all of the 10 HCV-infected patients. Hybridization signals were detected in the tubular and capillary endothelial cells. No hybridization signals were found in the renal biopsies of the four anti-HCV-negative patients. In conclusion, our results demonstrate that HCV RNA is common in kidney cells of patients with renal diseases who are infected with HCV. The presence of HCV RNA is not necessarily associated with a pathogenetic consequence.