Sensitivity Of Immunostaining Research Articles

Value of the detection of BRAF(V600E) gene mutation and protein expression in auxiliary cytological diagnosis of papillary thyroid carcinoma

Objective: To evaluate the utility of the BRAF(V600E) mutation detection in different cytoloy categories and to determine if the VE1 antibody can serve as a screening tool for the detection of BRAF(V)600E mutation in thyroid fine needle aspiration (FNA) specimens. Methods: A total of 273 FNA residual specimens were collected. BRAF(V600E) testing was performed on these liquid-based specimens. And also 78 specimens with enough residual cells were stained with VE1 antibody. Comparisons of molecular and immunocytochemistry results with clinicopathological outcomes were performed. SPSS 17.0 software was used to analyze the data. Results: There were 70 indeterminated diagnoses in 273 cases with FNAs. Fifty-eight cases were proven to be papillary thyroid carcinoma (PTC) by histology, including 9 cases of atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS), 3 cases of follicular neoplasm/suspicious for follicular neoplasm (FN/SFN), and 46 cases of suspicious for malignancy (SM). BRAF(V600E) analysis detected PTC in 3 of 9 cases with AUS/FLUS, and in 31 (67.4%) of 46 cases with SM. The sensitivity of immunostaining with VE1 antibody was 62.8%(27/43) and the specificity was 91.4% (32/35). VE1 expression showed moderately concordance with the molecular mutation (κ=0.524, P<0.001). Conclusions: Additional BRAF(V600E) detecting can improve the diagnostic efficacy for PTC in AUS/FLUS and SM. VE1 expression may be an alternative method for BRAF(V600E) detecting when molecular detecting is unavailable.

The expression and clinical effects of alpha-methylacyl-CoA racemase (AMACR/ P504S) as an immunohistochemical marker in malign pleural mesothelioma.

Alpha-methylacyl-CoA racemase (AMACR), an intracellular enzyme involved in lipid metabolism, has emerged as an immunohistochemical marker for many types of cancer. Recent studies about the role of lipid metabolism in pathogenesis of mesothelioma have brought up some positive results. This study was conducted to investigate AMACR expression in the diagnosis of malignant pleural mesothelioma (MPM) and the correlation of this marker with clinical characteristics and survival. The clinicopathologic characteristics and resection materials of 71 patients were reviewed retrospectively. AMACR expression was evaluated immunohistochemically. The correlations among AMACR expression, clinicopathologic factors, and survival were investigated. AMACR expression was detected in 42.3% of the study group. The specificity and sensitivity of AMACR immunostaining in detecting mesothelioma were 41.1% and 42.3%, respectively. AMACR-positive and negative groups were similar for age, sex, smoking history, tumor diameter, lymph node involvement, differentiation, T-N factor, and stage. Overall survival was not significantly different between the groups, either. The sensitivity of immunostaining was not high enough to use AMACR as a diagnostic tool in MPM. AMACR expression did not have a prognostic value in MPM, either.

The identification of oncogene products in neoplastic astrocytes using colloidal gold/silver immunostaining

The detection of expression of oncogene products in human neoplasms requires fresh tissue for karyotyping, DNA and RNA extraction and immunoblotting. Immunostaining of formalin-fixed paraffin embedded sections provides a reliable and more feasible alternative, which permits study of archival material. Twenty high grade astrocytomas and twenty-nine low grade astrocytomas were examined by immunostaining for expression of EGF-R, c-myc, c-myb, N-ras/c-Ha-ras and c-fos oncoproteins. A comparison of the relative efficacy of peroxidase - antiperoxidase (PAP) and colloidal gold immunostaining (IG) revealed greater sensitivity of IG at antibody dilutions of 1:500 and 1:600. The detection of antigens at lower levels of expression is possible with IG because of one-to-one binding of colloidal gold markers to antigens. Additional advantages of IG over PAP immunohistochemistry include potential semiquantitative applications to electron microscopy and subcellular localization of antigens. A modified immunogold-silver technique was developed for application to the nervous system.