Prognostic value of glomerular collagen IV immunofluorescence studies in male patients with X-linked Alport syndrome.

BACKGROUND AND OBJECTIVES: X-linked Alport syndrome (X-AS) is caused by mutations of the COL4A5 gene, which encodes for the collagen IV α5 chain (α5[COLIV]), resulting in structural and functional abnormalities of the glomerular basement membrane (GBM) and leading to CKD. The aim of the present study was to evaluate the prognostic value of residual collagen IV chain expression in the GBM of patients with X-AS. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The medical records of 22 patients with X-AS from 21 unrelated families collected between 1987 and 2009 were reviewed (median age at last follow-up, 19.9 years; range, 5.4-35.1 years); GBM expression of α1, α3, and α5(COLIV) chains was assessed by immunofluorescence microscopy. RESULTS: GBM distribution of the α5(COLIV) chain was diffuse in 1 and segmental or absent in 21 of the 22 patients; the expression of the α3(COLIV) chain was diffuse in 5 of 22 patients and segmental or absent in 17 of 22 patients. Patients with diffuse staining for the α3(COLIV) chain presented with proteinuria significantly later (median age, 16.9 versus 6.1 years; P=0.02) and reached an estimated GFR < 90 ml/min per 1.73 m(2) at an older age (median age, 27.0 versus 14.9 years; P=0.01) compared with patients with segmental or absent staining. Two thirds of patients with abnormal α3(COLIV) expression by immunofluorescence studies had null or truncating COL4A5 mutations, as opposed to none of the 4 tested patients with diffuse α3(COLIV) chain glomerular distribution. CONCLUSIONS: These results indicate that maintained expression of the α3(COLIV) chain is an early positive prognostic marker in patients with X-linked Alport symdrome.

Juvenile nephropathy in a Boxer dog resembling the human nephronophthisis-medullary cystic kidney disease complex.

A juvenile nephropathy in a 4-year-old male Boxer dog, closely resembling the Nephronophthisis (NPHP)-Medullary Cystic Kidney Disease Complex (MCKD) in humans is described. Gross examination of the kidneys revealed several multiple cysts at the corticomedullary junction and in the medulla. Histological examination was characterized by a widespread tubular atrophy and dilatation, with a marked thickening of the tubular basement membrane, interstitial lymphocytic infiltration and fibrosis. Ultrastructural studies revealed dilated tubules with irregular basement membrane thickening and splitting. Lectin histochemistry investigation revealed that the cysts originated in the distal convoluted tubule and collecting duct. Having excluded all other known cystic diseases of the kidney, and based on the lectin histochemistry results, the macroscopic and histological findings of our case are highly compatible with a diagnosis of the NPHP-MCKD complex. To our knowledge, this is the first report describing this particular lesion.

Histopathology of lupus nephritis.

The spectrum of morphologic changes in lupus nephritis, either microscopic, ultrastructural, or immunohistological, closely reflects the great variety of immune complexes that are produced in the course of the disease. Every tissue component of the kidney can be affected, but glomeruli are the target structure in most patients. Several attempts have been made to correlate the clinical severity and the outcome of the nephritis with the pathologic features; the current classification and the six classes that resulted from an international study group are entirely based on glomerular changes. Major criteria of classification include the focal or diffuse involvement of the glomerulus, the site of hypercellularity, the site of immune complex deposition and the presence of active and/or sclerotic lesions. Even if less thoroughly investigated than the glomerulus, the interstitial compartment has revealed many interesting features as are vascular lesions, a common and often underestimated feature. Typing of subpopulation of lymphoid infiltrates supports the emerging evidence indicating that B cells are promoting autoimmunity in mechanisms other than autoAb secretion. Many aspects are still debated and/or poorly understood, such as the interpretation of the so-called "full house nephropathy" that closely mimic lupus nephritis in seronegative patients.

Sensitivity, specificity, and diagnostic accuracy of three dermoscopic algorithmic methods in the diagnosis of doubtful melanocytic lesions: the importance of light brown structureless areas in differentiating atypical melanocytic nevi from thin melanomas.

BACKGROUND: Over the past decade numerous epiluminescence microscopy (ELM) criteria and algorithmic methods have been developed to improve the diagnosis of cutaneous melanocytic lesions. OBJECTIVE: Our purpose was to compare the sensitivity, specificity, and diagnostic accuracy of 3 algorithmic methods (pattern analysis, ABCD rule of dermoscopy, and the 7-point checklist) on a series of highly atypical melanocytic lesions. We also determined the diagnostic value of distinct ELM structures by evaluating their frequency in these lesions. METHODS: A total of 198 consecutive atypical macular melanocytic lesions were studied. ELM assessment was based on the presence or absence of 23 dermoscopic features. Two ELM-experienced dermatologists classified each lesion as benign or malignant using the pattern analysis, the ABCD rule of dermoscopy, and the 7-point checklist method. After surgical excision, 102 lesions were histologically diagnosed as Clark's nevi and 96 as thin melanomas (TMs) (mean tumor thickness, 0.3 mm). ELM and histologic diagnoses were then compared to assess the sensitivity, specificity, and diagnostic accuracy as well as positive and negative predictive values (PPV and NPV, respectively) for TMs of the 3 algorithmic methods. Univariate and multivariate analyses were performed to determine which ELM criteria were most strongly associated with TM. RESULTS: Of the melanocytic lesions studied, 82.3% were correctly diagnosed by using pattern analysis (85.4% sensitivity, 79.4% specificity, 79.6% PPV, and 70.8% diagnostic accuracy), compared with correct diagnosis of 79.3% (84.4% sensitivity, 74.5% specificity, 75.7% PPV, and 67.8% diagnostic accuracy) and 71.2% (78.1% sensitivity, 64.7% specificity, 67.6% PPV, and 57.7% diagnostic accuracy) with the ABCD and the 7-point checklist methods, respectively. The 7-point checklist yielded the highest number of false-negative results (21.8%) with respect to the ABCD rule (15.6%) and pattern analysis (14.6%). Univariate analysis showed that an atypical pigment network, a pigment network with sharp margins, irregular nonuniform brown globules, a nonuniform pigment distribution, homogeneous areas, and light brown structureless areas were the most sensitive and specific ELM features for TM. A backward stepwise logistic regression analysis revealed that the criterion with the strongest TM association was light brown structureless areas (odds ratio = 27.9; 95% confidence interval, 8.6-90.9). LIMITATIONS: The presence and value of light brown structureless areas should also be investigated in clinically nonatypical macular melanocytic lesions. CONCLUSION: The pattern analysis method showed the highest sensitivity, specificity, and diagnostic accuracy for TM. Light brown structureless areas were both a statistically significant discriminator and the most reliable predictor of TM (PPV = 93.8%, positive likelihood ratio = 16). Therefore the use of this previously underestimated ELM criterion may not only improve diagnostic performance of equivocal macular melanocytic lesions but also significantly decrease the rate of false-negative results obtained with the 7-point checklist method.

Cyclosporine therapy monitored with abbreviated area under curve in nephrotic syndrome.

Cyclosporin A (CsA) is an effective therapy for children with long-lasting nephrotic syndrome (NS). Long-term treatment can result in chronic CsA nephropathy (CsAN) and there is controversy concerning its incidence and severity. Trough levels are commonly used to monitor the drug concentration. We report a retrospective clinical and histological analysis of 18 children (12 males, 6 females) with steroid-dependent nephrotic syndrome (15 patients) and partially steroid-sensitive nephrotic syndrome (3 patients) treated with CsA for a long-term period (mean 4.9 years, range 2.2-6.9). Before CsA treatment all patients had normal creatinine clearance. CsA was started at a dose of 5 mg/kg per day administered orally in two divided doses and adjusted to maintain the mean CsA blood concentration between 250 and 350 ng/ml obtained from abbreviated area under the curve (AUC). A renal biopsy was performed after a mean period of 3.9 years (range 2.2-6.2) from the start of CsA treatment. Tubular, interstitial, and arteriolar lesions were evaluated in order to assess CsAN. The mean CsA dose and the mean CsA blood concentration were 4.4 mg/kg per day (range 3.6-5.8) and 276.6 ng/ml (range 162-346), respectively. No child had a worsening creatinine clearance during CsA treatment and follow-up after CsA discontinuation. If compared with the year before the start of CsA treatment, NS relapses and prednisone (PDN) dose significantly decreased during CsA treatment, 4/year versus 0.8/year (P <0.0001) and 0.9 mg/kg per day versus 0.2 mg/kg per day (P <0.0001), respectively. Histological analysis showed 15 patients with minimal change disease and 3 with focal segmental glomerulosclerosis. Clear-cut lesions diagnostic of CsAN were never found and only mild lesions were observed in 5 children (suggestive of CsAN in 2 patients and consistent with CsAN in 3 patients). Long-term CsA treatment is confirmed to be effective in preventing NS relapses and reducing PDN dose. Renal function is not a reliable indicator of CsAN. With the mean CsA blood concentrations used in our patients CsAN presented a low incidence (28%) and was generally mild. Renal biopsy should be performed 2-3 years from the start of long-term CsA treatment, especially if the mean CsA blood concentrations are not regularly monitored.

Frequent beta-catenin overexpression without exon 3 mutation in cutaneous lymphomas.

Beta-catenin is a ubiquitously cytoplasmic protein that has a critical role in embryonic development and mature tissue homeostasis through its effects on E-cadherin-mediated cell adhesion and Wnt-dependent signal transduction. Mutations that alter specific beta-catenin residues important for GSK-3beta phosphorylation, or increase the half-life of the protein, were identified in human cancer. However, the role of the Wnt pathway in B- and T-cell oncogenesis has not been extensively investigated. To assess the role of beta-catenin defects in primary cutaneous lymphomas, we examined the expression pattern and the genetic alteration of beta-catenin on 79 samples from 74 patients with primary cutaneous lymphomas from B- and T-cell origin. Immunohistochemical analysis revealed beta-catenin deregulation in five primary cutaneous B-cell lymphomas (21%) and in 21 primary cutaneous T-cell lymphomas (42%) without nuclear accumulation suggesting that activation and accumulation of beta-catenin may play an important role in the development of skin lymphomas. Mutation analysis of beta-catenin exon 3, which included the responsible element for Wnt signaling, was therefore done in 19 samples. However, genetic alterations of beta-catenin exon 3 were not detected in any of these cases suggesting that other regulatory mechanisms may be relevant in activating beta-catenin signaling in cutaneous lymphomas.

Interaction of estrogen receptor alpha with protein kinase C alpha and c-Src in osteoblasts during differentiation.

In cultured osteoblasts, protein kinase C (PKC) activity increases and estrogen receptor alpha (ERalpha) binding capacity decreases upon confluence. We investigated potential interactions between ERalpha and PKC isoforms and their confluence-induced modulations in clonal ROS.SMER#14 cells and primary osteoblasts. In sub-confluent ROS.SMER#14 cells, which express an exogenous plus small amounts of the endogenous ERalpha gene, the receptor appeared as two main bands of approximately 66 and approximately 46 kDa. In over-confluent, more differentiated cells, the cytosolic approximately 66 kDa ERalpha appeared decreased and the approximately 46 kDa variant increased. Enhanced expression and/or membrane translocation of PKCalpha and PKCepsilon, but not PKCzeta, was evidenced at over-confluence, along with transient increases in expression and kinase activity of c-Src, accompanied by membrane translocation of the kinase-activated enzyme. In contrast, negligible membrane translocation of PKCalpha and/or activated c-Src was observed in parental ROS 17/2.8 cells, which express low levels of full-length ERalpha. PKCalpha from over-confluent cells phosphorylated p60c-Src in vitro, suggesting functional interaction between the two kinases. ERalpha co-immunoprecipitated c-Src and PKCalpha, mostly in its cleaved form (PKMalpha). An analogous interaction was observed in primary osteoblasts. However, in these cells, much more PKCalpha/PKMalpha was ERalpha-co-immunoprecipitated at over-confluence, a condition in which the shorter, approximately 46 kDa ERalpha variant is increased. This interaction was enhanced by estradiol treatment or PKC down-regulation, but was unaffected by c-Src inhibition. These data highlight direct PKCalpha-c-Src-ERalpha interactions, which may be crucial in the modulation of estrogen responsiveness and the differentiation process in osteoblasts.

Epidermal basement membrane alpha 5(IV) expression in females with Alport syndrome and severity of renal disease.

BACKGROUND: X-linked Alport syndrome is a progressive nephritis caused by mutations of the COL4A5 gene. This gene encodes the collagen alpha 5(IV) chain, which is abnormally distributed in the glomerular basement membrane (GBM) and epidermal basement membrane (EBM). It has been reported a negative correlation between alpha 5(IV) chain distribution in EBM and the degree of proteinuria in heterozygous females with Alport syndrome. METHODS: In the present study, we evaluated the distribution of the alpha 5(IV) chain in the EBM and the degree of proteinuria in 22 females with X-linked Alport syndrome. The distribution of the cutaneous alpha 5(IV) chain was measured by a confocal laser microscope using an anti-alpha 5(IV) monoclonal antibody. The expression ratio of alpha 5(IV) distribution was quantified dividing the extension of the positive signal and the maximal extension of the specimen. Urinary protein excretion was expressed as urinary protein over urinary creatinine ratio. RESULTS: Proteinuria was present in five of the 22 patients. In two patients with proteinuria, alpha 5(IV)chain was normally distributed; in the remaining three, the expression ratio of alpha 5(IV)chain was 35%, 47%, and 48%. Of the 17 patients without proteinuria, two displayed a complete absence of the alpha 5(IV) chain in EBM, five displayed a normal staining, and the remaining 10 had an expression ratio between 18% and 65%. CONCLUSION: Our data suggest that there is no correlation between the severity of the glomerular involvement (expressed by proteinuria) and the staining of the alpha 5 chain in the EBM in females with X-linked Alport syndrome.

Renal mass dosing and graft function in children transplanted from pediatric donors.

It has been suggested that "renal mass dosing" may affect graft evolution. Between 1993 and 1999, 43 children, aged 4-17 years, received 43 pediatric cadaveric grafts. The ratio between graft volume (calculated by ultrasound within the first 24 h from transplantation, by ellipsoid formula) and the recipient's body surface area (BSA) ranged between 14.1 and 110 ml/m(2). Three groups were identified: group 1, 14-29 ml/m(2) (13 patients); group 2, 30-39 ml/m(2) (16 patients); group 3, 40-110 ml/m(2) (14 patients). As a consequence of the different renal volume increments in the three groups during the first year after transplant, no differences in the absolute renal volume were observed at the end of follow-up. The average follow-up was 38 months (range 12-80). In the 37 routine graft biopsies, performed on average 13 months after transplantation and with more than five glomeruli, maximum mean glomerular diameters were mostly above normal values. There were no significant differences among the three groups. At the end of follow-up, the three groups did not differ in microalbuminuria, proteinuria, glomerular function or in incidence of hypertension. From this retrospective study, we conclude that the very wide range of renal mass dosing did not cause differences in medium-term graft evolution. A longer follow-up will be necessary to ascertain the possible influence of disproportion between pediatric donors and recipients, on a long-term graft outcome.