HIVAN phenotype: consequence of epithelial mesenchymal transdifferentiation.

Human immunodeficiency virus (HIV)-1-associated nephropathy (HIVAN) is characterized by proliferation of glomerular and tubular epithelial cells. We studied the role of epithelial mesenchymal transdifferentiation (EMT) in the development of HIVAN phenotype. Renal cortical sections from six FVB/N (control) and six Tg26 (HIVAN) mice were immunolabeled for PCNA, alpha-smooth muscle actin (alpha-SMA), fibroblast-specific protein-1 (FSP1), CD3, and F4/80. Since periglomerular cells (PGCs) and peritubular cells (PTCs) did not show any labeling for CD3 and F4/80 but showed labeling for alpha-SMA or FSP1, it appears that these were myofibroblasts that migrated from either glomerular or tubular sites, respectively. Occurrence of EMT was also supported by diminished expression of E-cadherin by renal epithelial cells in Tg26 mice. Interestingly, Tg26 mice also showed enhanced renal tissue expression of ZEB2; henceforth, it appears that transcription of molecules required for maintenance of de novo renal epithelial cell phenotype was suppressed. To evaluate the role of ANG II, Tg26 mice in groups of three were administered either normal saline or telmisartan (an AT1 receptor blocker) for 2 wk, followed by evaluation for renal cell EMT. Renal cortical section of Tg26 mice showed a sevenfold increase (P < 0.001) in parietal epithelial cell (PEC)-PGC and a threefold increase (P < 0.01) in tubular cell (TC)-PTC proliferation (PCNA-positive cells). Similarly, both PECs-PGCs and TCs-PTCs in Tg26 mice showed enhanced expression of alpha-SMA and FSP1. Both PECs and podocytes contributed to the glomerular proliferative phenotype, but the contribution of PECs was much greater. Telmisartan-receiving Tg26 mice (TRM) showed attenuated number of proliferating PECs-PGCs and TCs-PTCs compared with saline-receiving Tg26 mice (SRM). Similarly, TRM showed diminished expression of alpha-SMA and FSP1 by both PECs-PGCs and TCs-PTCs compared with SRM. We conclude that EMT contributes to the manifestation of the proliferative phenotype in HIVAN mice.

Diagnostic yield of renal biopsies: a retrospective single center review.

BACKGROUND: Previous studies have examined the spectrum of diseases identified with a kidney biopsy and the complications of the procedure. However, few studies have examined the utility of the test to clarify the diagnosis and guide treatment of pediatric patients. This retrospective, single-center chart review was performed to test the hypothesis that at least 80% of native kidney biopsies provide clinically valuable information that rationally guides diagnosis and patient management. METHODS: 200 biopsies performed between January 1, 2000 and June 30, 2008 were reviewed. A scheme composed of six categories was devised to classify the utility of each kidney biopsy. RESULTS: 196 complete case files were available for review. Twenty-four (12.2%) biopsies did not shed light on the diagnosis and were unhelpful in patient management - 21 biopsies (10.7%) were non-diagnostic and 3 (1.5%) failed to yield enough tissue for examination. The number of unhelpful biopsies did not cluster in any specific disease entity. CONCLUSION: Our findings provide guidance to nephrologists about the total risk of a kidney biopsy, including uninformative results, when seeking informed consent for the procedure. The results suggest an appropriate balance has been reached which maximizes the use of kidney biopsies while minimizing the risk of this invasive procedure (word count: 202).

IgA nephropathy: a twenty year retrospective single center experience.

IgA nephropathy (IgAN) is a common glomerular disease whose etiology is unknown. Previous studies have described the clinical and laboratory features but none have specifically compared patients during different time periods. This 20 year retrospective study was performed to assess trends in the severity of IgAN from 1989-2008. We reviewed 57 patient charts that contained a confirmed biopsy diagnosis of IgAN and recorded data at the time of diagnosis and the final follow-up appointment. Clinical data included physical examination, urine, and blood tests. Patients were separated into two cohorts, Cohort 1 1989-1998 and Cohort 2 1999-2008. An increase in severity was noted in Cohort 2 based on a significantly higher Up/c and lower serum albumin level. Other prognostic indicators including GFRe, hematocrit, and glomerular injury score also demonstrated a trend towards more severe disease over the past 20 years. The patients in both Cohorts received similar treatments and had comparable renal function at the last follow-up visit. Based on our findings, we suggest that although a kidney biopsy is required to diagnose IgAN, the procedure may not be necessary in patients clinically suspected of having the disease but who have normal kidney function and minimal urine abnormalities.

Nonalcoholic fatty liver disease in severely obese subjects.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has been consistently associated with obesity and insulin resistance. Nonalcoholic steatohepatitis (NASH) is a histological entity within NAFLD that can progress to cirrhosis. The exact prevalence of NASH in severe obesity is unknown. It is unclear whether differences in insulin sensitivity exist among subjects with NASH and simple fatty liver. OBJECTIVE: To evaluate the prevalence and correlates of NASH and liver fibrosis in a racially diverse cohort of severely obese subjects. DESIGN: Ninety-seven subjects were enrolled. Liver biopsies, indirect markers of insulin resistance, metabolic parameters, and liver function tests were obtained. RESULTS: Thirty-six percent of subjects had NASH and 25% had fibrosis. No cirrhosis was diagnosed on histology. Markers of hyperglycemia, insulin resistance, and the metabolic syndrome but not body mass index were associated with the presence of NASH and fibrosis. Elevated transaminase levels correlated strongly with NASH and fibrosis but 46% subjects with NASH had normal transaminases. Subjects with NASH had more severe insulin resistance when compared to those with simple fatty liver. A signal detection model incorporating AST and the presence of diabetes predicted the presence of NASH while another incorporating ALT and HbA1C predicted the presence of fibrosis. CONCLUSIONS: NAFLD is associated with the metabolic syndrome rather than excess adipose tissue in severe obesity. Insulin resistance is higher in subjects with NASH versus those with simple fatty liver. Statistical models incorporating markers of liver injury and hyperglycemia may be useful in predicting the presence of liver pathology in this population.

Mucocelelike lesions of the breast: mammographic findings with pathologic correlation.

OBJECTIVE: The purpose of this study was to review the imaging features of mucocelelike breast lesions, correlate the mammographic and pathologic findings, and determine recommendations for management. CONCLUSION: Mucocelelike lesions are more common than previously reported and are likely to exhibit indeterminate calcifications on mammography. Diagnosis is most often made with Mammotome biopsy. A large number of patients have associated atypia or carcinoma. For patients with purely benign histologic findings at Mammotome biopsy, optimal management should be excisional biopsy to exclude associated malignancy.