A Novel Immunohiostochemical Staining Pattern for Keratin 8/18 Plus Ubiquitin in Nonalcoholic Fatty Liver Disease Is Associated with Increased Disease Severity and Advanced Fibrosis.
Cynthia D Guy, Ayako Suzuki, James L Burchette, Elizabeth M Brunt, Manal F Abelmalek, Diana Cardona, Shannon J McCall, Aynur Unlap, Patricia Belt, Laura Wilson, Linda D Ferrell, Anna Mae Diehl. Duke University Medical Center, Durham, NC; Washington University School of Medicne, St. Loius, MO; Johns Hopkins Bloomberg School of Public Health, Baltimore, MD; Univeristy of California at San Francisco
Background: Nonalcoholic fatty liver disease (NAFLD) is a global health dilemma. The gold standard for diagnosis is liver biopsy. Ballooned hepatocytes (BH) are histologic manifestations of hepatocellular injury and are characteristic features of steatohepatitis (SH), the more severe and potentially more progressive form of NAFLD. Definitive histologic identification of BH on routine stains, however, can be difficult. Immunohistochemical (IHC) staining for loss of the normal hepatocytic keratin 8/18 (K8/18) can serve as an objective marker of BH. We sought to explore the utility of a K8/18 plus ubiquitin (Ub) double IHC stain for the histologic evaluation of adult NAFLD.
Design: Double IHC staining for K8/18 and Ub was analyzed using 40 core liver biopsies from clinically and histologically well-characterized adult patients with NAFLD enrolled in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN) Database study. Our cohort was preselected for a representative range of disease severity. Immunohistochemical staining analysis was performed in a blinded fashion.
Results: Ballooned hepatocytes lack K8/18 staining (KBH), as previously shown by others, but normal size hepatocytes with keratin loss (KH) are approximately five times more numerous than KBH. Linear regression analysis demonstrates that KBH, KH, and Ub deposits show a zonal distribution and are positively associated with each other (P < 0.0001). KBH, KH, and Ub deposits are frequently found adjacent to or intermixed with fibrous matrix and linear regression analyses show that these patterns of injury are associated with advanced fibrosis stages (P = 0.0002, 0.0032, and < 0.0001, respectively). Furthermore, these patterns of injury correlate with insulin resistance.
Conclusions: This double IHC may be a useful research tool and/or clinical diagnostic confirmatory aid for the identification of hepatocellular injury in nonalcoholic steatohepatitis (NASH).
Category: Liver & Pancreas
Tuesday, March 1, 2011 1:15 PM
Platform Session: Section C, Tuesday Afternoon