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Animal models of chronic kidney disease (CKD) approximate the human condition and are keys to understanding its pathogenesis and to developing rational treatment strategies. The ethical use of animals requires a detailed understanding of the strengths and limitations of each species and the disease model, and the way in which findings can be translated from animals to humans. While not perfect, the careful use of animal experiments offers the opportunity to examine individual mechanisms in an accelerated time frame.

Background Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder resulting from the deficiency of trihexosylceramide α-galactosidase (α-Gal A). The diagnosis is often missed or delayed, and specific diagnostic tests (serum α-Gal A activity, genotyping or biopsy) are expensive and not widely available. We evaluated the diagnostic potential of urine microscopy in AFD. Methods We studied 35 male and female AFD patients across a wide phenotypic spectrum and 21 controls with other renal diseases. Fresh urine sediment was examined under phase-contrast microscopy using polarized light for Maltese cross (MC) particles, anti-CD77 antibody to detect globotriaosylceramide (GL3, the substrate of α-Gal A), and anti-podocalyxin antibody to assess podocyte excretion. Results Characteristic MC 2 particles and anti-CD77 binding within vacuolated urinary epithelial cells were both detected in AFD with high sensitivity and specificity (MC 2 detection sensitivity 100%, 95% confidence interval (CI) 85.4-100%, specificity 100%, CI 80.8-100%; anti-CD77-binding sensitivity 97.1%, CI 83.3-99.9, specificity 100%, CI 80.8-100%). Albuminuria (urinary albumin-to-creatinine ratio, ACR) correlated with quantitative particle excretion--in low, intermediate and high MC excretors, and median ACR was 1.6, 6.9 and 20.0 mg/μmol, respectively (analysis of variance P = 0.017). Podocyte staining was positive in ~50% of all AFD patients and was similar in those with and without clinical Fabry nephropathy (FN), whether or not treated with enzyme replacement. Conclusions Targeted urinary microscopy is a non-invasive, inexpensive, accessible and rapid diagnostic technique, especially applicable where serum α-Gal A activity and genotyping are not affordable or available. As the number of urinary MC 2 particles increases with rising albuminuria, the technique may also be useful in assessing FN burden.

Background. Renal fibroblasts are important effector cells in tubulointerstitial fibrosis, with experimental antifibrotic strategies focusing on the functional downregulation of these cells. Several experimental models of fibrosis have provided evidence for the effectiveness of the polypeptide hormone relaxin as a potential antifibrotic agent. This study was conducted to further elucidate the antifibrotic mechanisms of relaxin on renal fibroblasts in vitro. Methods. Rat cortical fibroblasts were obtained from outgrowth culture of renal tissue isolated from kidneys 3 days post-unilateral ureteric obstruction and constituted 100% of cells studied. A relaxin radio-receptor assay was used to establish binding of relaxin to renal fibroblasts in vitro. Functional studies then examined the effects of H2 relaxin (0, 1, 10 and 100 ng/ml) on fibroblast kinetics, expression of alpha-smooth muscle actin (-SMA), total collagen synthesis, collagenase production and collagen-I lattice contraction. CTGF mRNA expression was also measured by northern analysis. Results. H2 relaxin bound with high affinity to rat renal fibroblasts, but receptor numbers were low. Consistent with its previously reported bimodal effect, transforming growth factor (TGF-1) reduced fibroblast proliferation, an effect abrogated by H2 relaxin. Fibroblasts exposed to H2 relaxin (100 ng/ml) for 24 h demonstrated decreased immunostaining for -SMA and reduced -SMA protein expression compared with controls. There was a trend for a relaxin-mediated reduction in total collagen synthesis and 1(I) mRNA expression with large dose-related increases in collagenase protein expression being observed. TGF-1-stimulated collagen-I lattice contraction was significantly inhibited following co-incubation with 100 ng/ml relaxin. Incremental doses of H2 relaxin had no significant effect on CTGF mRNA expression. Conclusions. The findings of this study suggest that the antifibrotic effects of relaxin involve down-regulation of fibroblast activity, increase in collagenase synthesis and restructuring of collagen-I lattices, which are consistent with its known physiological role of matrix remodelling. Although there appears to be an interaction between TGF-1 and H2 relaxin, this does not appear to involve a reduction in CTGF mRNA expression.

BACKGROUND: Expression of the beta1 family of integrins allows dermal fibroblasts in wounds to contribute to the healing process through migration, adhesion, synthesis, and rearrangement of extracellular matrix. To date the ability of human renal fibroblasts to reorganize collagens and the role of cell surface receptors in this process remain unknown. METHODS: Renal fibroblasts were grown from the cortical tissue of surgically removed human kidneys. The ability of human renal fibroblasts to reorganize interstitial collagen I was examined in vitro using solidified collagen I lattices. Integrin function was blocked by incubating fibroblasts with isotype-specific antibodies prior to addition to collagen I lattices. RESULTS: Human renal fibroblasts embedded in collagen I lattices progressively decreased lattice diameter to 60.6+/-11.4% of initial diameter at 48 h post-release (P

Background. No conventional immunosuppressive agent preferentially inhibits antibody production. Studies in experimental animals and in human cells in vitro suggested mycophenolate mofetil (MMF) might have such an effect. If this was the case in vivo it could have significant implications in terms of both MMF toxicity and the rational design of immunotherapeutic regimens. Methods. Subjects were renal transplant recipients (25 patients treated with prednisolone, cyclosporine and azathioprine, and 13 treated with prednisolone, cyclo­ sporine and MMF) and 20 normal controls. The three groups received influenza vaccination, and the anti­ body response to it was measured 4-6 weeks later using a standard haemagglutination assay. Results. MMF profoundly suppressed the humoral immune response to influenza vaccination when added to prednisolone and cyclosporine. This effect could be seen when comparing the rise in the mean titre of antibody after vaccination. It was also reflected in the number of patients mounting responses deemed to be clinically protective by either demonstrating a 4-fold rise in titre or an increase in titre to ~ 40. Conclusions. Suppression of the humoral immune response by MMF has implications for the design of immunization protocols to protect the immuno­ suppressed, and raises the possibility that MMF use may be accompanied by more or different infections than complicate more conventional immunosuppres­ sion. More importantly, consideration should be given to harnessing the relatively specific effect of MMF on antibody production to treat antibody-mediated diseases.

The aim of this study was to assess the prevalence of human papillomavirus (HPV) DNA in women who had received a renal transplant and to compare this with two control groups. Women who had a functioning renal transplant for greater than 6 months (n = 69) were compared with women on maintenance dialysis (n = 89) and women with impaired renal function (creatinine 0.15-0.39 mmol/l) (n = 22). Women were excluded if they had had a hysterectomy, were older than 65 years, or were not yet sexually active. A questionnaire and cervical scrape were obtained from each participant. The cervical scrape was analysed for HPV DNA using PCR and the L1 consensus primers. The participation rate of transplant patients, dialysis patients and those with impaired renal function ('normal' group) was 69, 68, and 78% respectively. The characteristics of the three groups of women at enrollment were similar. No cytological abnormalities were present in the 'normal' population but 11 of 89 patients on maintenance dialysis and nine of 69 transplant patients had cytological abnormalities of atypia or greater (P = 0.08 and P = 0.07, for 'normal' compared to dialysis and transplant groups respectively). One (4.5%) of the 'normal' women had evidence of HPV DNA, while 18 (20%) of patients on maintenance dialysis and 15 (22%) of transplant patients were positive (P = 0.07 and P = 0.05, for 'normal' compared to dialysis and transplant groups respectively). This study suggests that not only transplant recipients but also dialysis patients may have a higher prevalence of risk factors (cytological abnormalities and HPV DNA) for the development of cervical cancer.

Chronic atrophic pyelonephritis is associated with vesicoureteric reflux in infancy. Reflux disappears during childhood in 50% of cases. It is more commonly detected in infants (49%) and children (26%) with infection than in adults (4.4%). Severe reflux may persist in adults and is usually (94%) associated with scarring. Patients with end-stage renal failure due to pyelonephritis are much younger than patients with end-stage renal failure due to other causes. The incidence of reflux according to sex is equal in infancy, but after infancy both pyelonephritic scarring and reflux are far more common in females. Infection is the likely cause of progressive scarring in females. Hypertension is associated with chronic atrophic pyelonephritis. Proteinuria is the worst prognostic feature in patients with reflux nephropathy and pyelonephritic scarring. Intrarenal reflux determines the site of scarring. The role of surgical correction of vesicoureteric reflux remains uncertain, but meticulous control of infection appears to prevent progressive scarring.

A variety of fixatives and four immunohistochemical technics were compared for demonstration of binding of monoclonal antibodies to cell surface antigens in tissue sections. Three recently described monoclonal antibodies, directed against the human leukocyte-common antigen (PHM 1) and antigens present on mononuclear phagocytes (PHM 2, PHM 3), were used. Antigen stability to fixation and heat were first assessed by quantitating the resultant effect on binding of the monoclonal antibodies to a macrophage cell line in vitro, using a radiolabeled second antibody. All fixatives affected their binding, but least effect was seen with formaldehyde-based fixatives and ethanol. Sections of formaldehydeand ethanol-fixed lymph nodes were then labeled with monoclonal antibodies, and four developing methods were compared: indirect immunofluorescence, indirect immunoperoxidase, 3-layer heterologous peroxidase-antiperoxidase (PAP), and a 4-layer PAP technic. The 4-layer PAP proved to be the most sensitive technic since all three antibodies were localized successfully while both indirect technics only detected PHM 1, and the heterologous PAP method was not successful with any monoclonal antibody. The best combination of specific labeling and adequate morphology was seen with periodate-lysine-paraformaldehyde (PLP) fixation and the 4-layer PAP method. (

SUMMARY Twenty-two patients with crescentic anti-GBM nephritis or Goodpasture's syndrome with renal impairment were reviewed. All patients were treated with a combination of plasma exchange and immunosuppression. Sixteen patients (73 per cent) showed improvement in renal function (> 30 per cent reduction in serum creatinine level) apparently in response to treatment, and nine patients (41 per cent) made long-term recoveries in renal function. The most important features carrying a bad prognosis were total anuria, and/or a very high percentage of glomeruli showing crescents (> 85 per cent) in the initial renal biopsy. Some patients with other so-called ‘bad’ prognostic features, including severely impaired renal function at presentation, oliguria and the need to institute dialysis had unexpected marked improvement in renal function and/or recovered renal function in the long term provided treatment with plasma exchange was begun promptly and maintained for a sufficient period to allow resolution of the disease process. Renal biopsies at the beginning and later proved to be an extremely valuable guide to the progress and outcome of the disease.