Roger K. Moreira

Hepatic Stellate Cells and Liver Fibrosis

Substantial evidence now exists to recognize hepatic stellate cells (HSCs) as the main matrix-producing cells in the process of liver fibrosis. Liver injury of any etiology will ultimately lead to activation of HSCs, which undergo transdifferentiation to fibrogenic myofibroblast-like cells. Quantitative analysis of HSC activation by immunohistochemistry has been shown to be useful in predicting the rate of progression of liver fibrosis in some clinical situations. In the activation process, transforming growth factor beta is thought to be the main mediator of fibrogenesis and platelet-derived growth factor is the major inducer of HSC proliferation. Different platelet-derived growth factor and transforming growth factor beta inhibitors have been shown to effectively prevent liver fibrosis in animal models and represent promising therapeutic agents for humans.

Liver biopsy in modern clinical practice: a pediatric point-of-view.

Liver biopsy remains the foundation of evaluation and management of liver disease in children, although the role of the liver biopsy is changing with development of alternative methods of diagnosis and advancement of hepatic imaging techniques. The indications for liver biopsy are evolving as current knowledge of etiologies, noninvasive biomarker alternatives, and treatment options in pediatric liver disease are expanding. The procedure can often be complicated in children by technical difficulties, cost, and smaller specimen size. Communication and partnership of clinicians with pathologists experienced in pediatric liver diseases are essential. DNA sequencing, novel imaging modalities, noninvasive biomarkers of fibrosis and apoptosis, proteomics, and genome-wide association studies offer potential alternative methods for evaluation of liver disease in children. This review presents specific indications, considerations, methods, complications, contraindications, and alternatives for pediatric liver biopsy.

Cholestatic hepatitis C following liver transplantation: An outcome-based histological definition, clinical predictors, and prognosis

Cholestatic hepatitis C virus (HCV) is a rare form of recurrent HCV following liver transplantation (LT) without specific diagnostic criteria. An outcome‐based method to improve its diagnosis and a description of its prognosis are needed. All 1‐year post‐LT protocol liver biopsy samples and biopsy samples initially reported to show cholestatic HCV from patients transplanted with HCV between February 2002 and December 2009 were reviewed for the inflammation grade, the fibrosis stage, and 4 cholestatic HCV features: ductular proliferation, canalicular cholestasis with or without intracellular cholestasis, hepatocyte swelling with or without lobular disarray, and sinusoidal/pericellular fibrosis. We used patient and graft survival to define histological criteria for cholestatic HCV, and compared the clinical features of these patients to those of patients with minimal or significant post‐LT fibrosis. One hundred seventy‐nine patients were analyzed, the median age was 56 years, and 73% were male. Patients with 3 or more of the 4 cholestatic HCV criteria had significantly worse survival (log‐rank P < 0.001) regardless of the fibrosis stage, and this was used as our novel definition of cholestatic HCV. Using this definition, we found that 27 patients (15%) had cholestatic HCV, 53 (30%) had significant fibrosis (stage ≥ 2/4), and 99 (55%) had minimal fibrosis (stage < 2/4). The final model for clinical predictors of cholestatic HCV included donor age [odds ratio (OR) = 1.37 per decade, P = 0.04] and previous rejection (Banff grade ≥ 5; OR = 4.19, P = 0.002). Total bilirubin was the strongest laboratory predictor of cholestatic HCV (area under the curve = 0.93), whereas the HCV viral load was not a significant predictor. The final model of post‐LT survival included the pathology group {cholestatic HCV [hazard ratio (HR) = 6.07, P < 0.001] and significant fibrosis (HR = 2.53, P = 0.02)}, donor age (HR = 1.49 per decade, P < 0.001), and cold ischemia time (HR = 1.11 per hour, P = 0.02). In conclusion, we propose diagnostic criteria for cholestatic HCV that include specific criteria (the presence of at least 3 of the 4 histopathological features on biopsy) and other supportive and exclusionary criteria. Older donor age and rejection increase the risk of cholestatic HCV, and an elevation in the total bilirubin level may help to identify these patients. These criteria must be validated prospectively. Liver Transpl 19:78–88, 2013.

Utility of an immunohistochemical panel consisting of glypican-3, heat-shock protein-70, and glutamine synthetase in the distinction of low-grade hepatocellular carcinoma from hepatocellular adenoma.

Background:The pathologic distinction between hepatocellular carcinoma (HCC) and hepatocellular adenoma (HCA) is sometimes problematic due to histologic overlap between the 2 entities, a problem amplified on small biopsy specimens. Several recently characterized immunohistochemical markers such as glypican-3 (GPC-3), heat-shock protein-70 (HSP-70), and glutamine synthetase (GS) help distinguish dysplastic nodules from HCC. The utility of this panel in the distinction of low-grade hepatocellular carcinoma (LG-HCC) from HCA has not been fully described. Objective:To determine whether the above markers are useful in the distinction of HCCs from HCAs. Design:Tissue microarrays were constructed with 30 LG-HCCs and 18 HCAs. The arrays were stained with the above markers and analyzed with respect to amount and pattern of staining. GPC-3 and HSP-70 were considered positive when 10% of tumor cells showed immunoreactivity. GS was considered positive when 50% of tumor cells showed immunoreactivity. Results:GPC-3 was positive in 13 of 30 LG-HCCs and 0 of 18 adenomas. The sensitivity was 43% and the specificity was 100%. HSP-70 was positive in 14 of 30 LG-HCCs and 0 of 18 adenomas. The sensitivity was 46% and the specificity was 100%. GS was positive in 24 of 30 LG-HCCs and 9 of 18 adenomas. The sensitivity was 80% and the specificity was 50%. Conclusions:GPC-3 and HSP-70 are helpful in separating carcinomas from adenomas. GS is not useful in this clinical context.

Hepatic Granulomas: Pathogenesis and Differential Diagnosis

Granulomatous liver disease constitutes a category of hepatic disorders and is at present diagnosed in approximately 4% of liver biopsies. Hepatic granulomas develop through the interactions of T lymphocytes and macrophages, with the integral involvement of T-helper (T(H)) 1 or T(H)2 pathways or both, depending on the specific granulomatous disease. Hepatic granulomas may be manifested clinically by elevated levels of serum alkaline phosphatase and g-glutamyltransferase enzymes, damage to specific structures (eg, intrahepatic bile ducts in primary biliary cirrhosis), or infrequently, progressive liver disease with portal hypertension and cirrhosis (eg, sarcoidosis). Systemic immunologic disorders, infectious diseases, drug hepatotoxicity, and reaction to neoplastic disease are the major causative factors responsible for granulomas in the liver. These causes and recent epidemiologic trends are covered in this discussion.

Whipple disease a century after the initial description: Increased recognition of unusual presentations, autoimmune comorbidities, and therapy effects

Although Whipple disease was described over a century ago, it remains challenging to recognize. To better understand the presentation of Whipple disease, we undertook a clinicopathologic study of our experience since implementation of the Whipple immunohistochemical stain. Twenty-three biopsy specimens from 15 patients were identified, and an association with immunomodulatory conditions was noted. Whipple disease involved the small intestine (19), brain (2), breast (1), and retroperitoneum (1). Whipple disease was suspected by 3 clinicians and by the majority of pathologists (9). Alternative clinical impressions included lymphoma, celiac disease, Crohn vasculitis, sepsis, an inflammatory process, liposarcoma, rheumatoid arthritis, seizure disorder, cerebrovascular accident, xanthoma, and central nervous system neoplasm. The nonspecific nature of the disease presentation likely contributed to the extended period between onset of symptoms and a definitive diagnosis, which ranged from at least 1 year to over 10 years. One patient died of unknown causes, and both patients with detailed follow-up had clinically persistent disease. We also describe Whipple disease with therapy effects, including partial and complete histologic treatment effects. Awareness of the unusual clinicopathologic presentations of Whipple disease is essential for timely diagnosis of this potentially lethal disease.

Liver MRI and histological correlates in chronic liver disease on multiphase gadolinium‐enhanced 3D gradient echo imaging

To evaluate intrinsic hepatic enhancement patterns on multiphase, gadolinium‐enhanced, fat‐suppressed, 3D T1‐weighted, gradient echo magnetic resonance imaging (MRI) as a quantitative correlate for severity of pathological changes in chronic liver disease (CLD).

Histopathologic distinction between fibrosing cholestatic hepatitis C and biliary obstruction.

The histopathologic distinction between posttransplantation fibrosing cholestatic hepatitis C (FCH-C) and biliary obstruction (BO) is challenging. We sought to identify histopathologic features that could be useful in the differential diagnosis between these 2 entities. A total of 38 cases of hepatitis C virus (HCV)-negative, cholangiography-proven BO (including 16 posttransplant and 22 nontransplant patients) and 13 patients with posttransplantation FCH-C were included. FCH-C patients were characterized by cholestatic disease, high HCV viral load, no evidence of biliary tract obstruction on imaging, and typical histopathologic findings (≥3 of the following: 1, prominent ductular reaction; 2, hepatocyte swelling with lobular disarray; 3, periportal sinusoidal fibrosis, and 4, cholestasis). Biopsies were evaluated with hematoxylin and eosin, Masson trichrome, Victoria blue, and rhodanine stains. Cytokeratin 7 (CK7) immunohistochemistry was used to assess for the presence of CK7+ intermediate hepatobiliary cells. We found that portal edema (63.1% vs. 7.6%; P<0.0001), bile duct dilatation (26.3% vs. 0%; P=0.0003), acute cholangitis (15.7% vs. 0%; P=0.008), bile infarcts (10.5% vs. 0%; P=0.03), periductal fibrosis (23.6% vs. 0%; P=0.0007), and periportal copper deposition (60.5% vs. 15.3%; P=0.0006) are significantly more common in BO, whereas hepatocellular swelling with lobular disarray (84.6% vs. 5.2%; P<0.0001) and periportal sinusoidal fibrosis (34.2% vs. 100%; P<0.0001) are seen more frequently in FCH-C. Furthermore, marked ductular reaction with rare or absent CK7+ intermediate cells is highly suggestive of FCH-C in this context (73.6% vs. 7.6%; P<0.0001). In summary, this study offers a comprehensive characterization of the histologic features discriminating FCH-C from BO.

Bile salt export pump: a sensitive and specific immunohistochemical marker of hepatocellular carcinoma.

Bile salt export pump (BSEP) is a transporter expressed exclusively at hepatic canaliculi and drives bile‐salt efflux. Minimal data exist about BSEP expression in tumours. We hypothesized that BSEP immunohistochemistry would be specific for hepatocellular carcinoma (HCC).

Glutamine synthetase, heat shock protein-70, and glypican-3 in intrahepatic cholangiocarcinoma and tumors metastatic to liver.

Introduction:Glutamine synthetase (GS), heat shock protein-70 (HSP-70), and glypican-3 (GPC-3) are markers best characterized in hepatocellular lesions, where they are useful in distinguishing hepatocellular carcinoma from dysplastic nodules. Their staining patterns in intrahepatic cholangiocarcinoma (IH-ChCa) and metastatic tumors in liver are not well described. Methods:Tissue microarrays containing 41 IH-ChCa and 24 metastatic tumors in liver were stained with commercially available antibodies to GS, HSP-70, and GPC-3. Five percent staining of tumor cells was considered positive for HSP-70 and GPC-3. For GS, 50% was the cut-off. Results:GS reactivity was present in 31 of 41 IH-ChCa (76%), with the median amount of staining being 65% of tumor cells. HSP-70 reactivity was present in 36 of 41 IH-ChCa (88%) with the median amount of staining being 75% of tumor cells. GPC-3 reactivity was absent from all IH-ChCa. Twenty-seven of 41 IH-ChCa cases were positive for both GS and HSP-70 (66%). GS reactivity was present in 17 of 24 tumors metastatic to liver (71%), with the median amount of staining being 50% of tumor cells. HSP-70 reactivity was present in 21 of 24 tumors metastatic to liver (88%) with the median amount of staining being 80% of tumor cells. GPC-3 reactivity was present in 2 of 24 tumors metastatic to liver (8%) with one showing 5% staining and the other showing 50% staining of tumor cells. Fifteen of 24 cases were positive for both GS and HSP-70 (63%), and 2 cases were positive for all 3 markers (8%). Discussion:Of the panel of immunostains currently commonly used to distinguish hepatocellular carcinoma from dysplastic hepatocytic nodules, only GPC-3 did not react frequently with metastatic tumors and IH-ChCa, although there was staining in 2 metastatic tumors. GS and HSP-70 are typically positive in IH-ChCa and metastatic tumors. Nothing should be inferred about the histogenesis of a tumor based on positive staining with either of these 2 markers, which currently have no role in tumor of unknown origin panels.