Israel Medical Association Journal

Background: Pericardial biopsies are rarely performed during the diagnosis and management of pericardial diseases. The circumstances and clinical profile of patients undergoing pericardial biopsies are largely uncharacterized.



Objectives: To examine the circumstances in which pericardial biopsies are obtained and to evaluate their diagnostic yield.



Methods: We studied a total of 100 cases (71% males, mean age 60.8 years, range 8.1–84.5 years) of surgically resected pericardium specimens obtained from 2000 to 2015 at Sheba Medical Center, the largest medical center in Israel. Patients were classified into groups according to four major histological etiologies: idiopathic pericarditis, constrictive pericarditis, malignant pericarditis, and post-cardiac injury syndrome (PCIS). The clinical history and course, laboratory, echocardiography, and histological results were reviewed retrospectively.



Results: Causes of pericarditis according to histological definitions included idiopathic pericarditis (29%), constrictive pericarditis (29%), PCIS (9%), and malignant pericarditis (26%). Overall sensitivity of the pericardial biopsy in patients with malignancy was 57.7%. During the study period, we found a trend toward an increased number of biopsies due to constrictive pericarditis and PCIS, along with a decrease in the number of biopsies performed in patients with malignant or idiopathic pericarditis. The diagnosis following biopsy did not change for any of the patients.



Conclusions: Our findings suggest a low diagnostic yield from pericardial biopsies, especially in malignant pericarditis. This conclusion, along with novel therapies, resulted in the infrequent use of pericardial biopsy in recent years.

Background: HER2 is an important prognostic and predictive marker in invasive breast cancer. It is currently assessed by immunohistochemistry for protein over-expression and by fluorescence in situ hybridization for gene amplification. The immunohistochemistry-equivocal cases (2+) are currently retested by FISH[1] to determine eligibility for trastuzumab treatment. Retesting by FISH significantly raises the cost of patient management and sometimes delays treatment. The 4B5 is a new, FDA-approved, rabbit monoclonal antibody for HER2 testing.

Objectives: To examine the reliability of 4B5 IHC[2] HER2 testing in cases found to be HER2 status equivocal by CB11 IHC.

Methods: Twenty-eight invasive breast cancer cases, with an equivocal HER2 status by CB11 IHC, were retested by the 4B5 antibody as well as by FISH analysis. The scoring was performed using the same guidelines as HercepTest and was correlated with the FISH ratio. Results: Of the original 28 CB11 clone designated equivocal cases, 14 (50%) showed negative HER2 staining using the 4B5 clone (HercepTest score 0 and 1+). Five cases (18%) proved to be positive (HercepTest score 3+) and 9 cases (32%) remained equivocal (HercepTest score 2+). The corresponding FISH ratio results showed that all 4B5 negative cases were negative by FISH testing, with a negative predictive value of 100% 4 of 5 of the 4B5-positive cases were positive by FISH testing, with a positive predictive value of 80%. One 4B5-positive case was borderline-high (2.2 ratio) by FISH. The correlation between 4B5 IHC and FISH was statistically significant (P = 0.0013) by chi-square test.

Conclusions: Sequential testing by 4B5 IHC could greatly reduce the need for FISH testing in cases considered HER2 equivocal by CB11 IHC.
 

 
[1] FISH = fluorescence in situ hybridization

[2] IHC = immunohistochemistry

Background: Vitamin A and its derivative retinoic acid regulate various aspects of cell behavior as growth, differentiation, and proliferation. Retinoic acid derivatives have been suggested to play a role in processes such as hepatic regeneration and fibrosis.

Objectives: To evaluate the influence of vitamin A on rat liver epithelial cell proliferation.

Methods: We performed common bile duct ligation in rats that had been subjected to differing vitamin A diets and compared their livers to control rats. Proliferation, apoptosis, and retinoic acid receptors were evaluated by histology and immunohistochemistry in bile duct cells and hepatocytes.

Results: Vitamin A deficiency was found to be associated with enhanced proliferation of bile duct epithelial cells following CBD[1] ligation. The proliferation was manifested by increased numbers of ducts, by aberrant extended ductal morphology, and by elevated numbers of nuclei expressing the proliferation marker Ki67. The amount of vitamin A in the rat diet did not affect detectably ductal cell apoptosis. We observed up-regulated expression of the retinoid X receptor-alpha in the biliary epithelium of vitamin A-deficient rats that had undergone CBD ligation, but not in vitamin A-sufficient rats.

Conclusions: We speculate that the mechanism underlying the ductal proliferation response involves differential expression of RXR[2]-alpha. Our observations suggest that deficiency of vitamin A may exacerbate cholestasis, due to excessive intrahepatic bile duct proliferation.