The utility of BRAF V600E mutation-specific antibody VE1 for the diagnosis of hairy cell leukemia.
OBJECTIVES: BRAF V600E mutation is characteristic of hairy cell leukemia (HCL). A V600E mutation-specific antibody, VE1, has been recently developed. We studied the diagnostic utility of this antibody in HCL and compared it with other B-cell neoplasms.
METHODS: VE1 activity was assessed using immunohistochemistry in 90 mature B-cell neoplasms, including HCL (n = 17), HCL variant (n = 6), chronic lymphocytic leukemia (CLL) (n = 20), and 47 other B-cell lymphomas. Most (87/90) specimens were formalin-fixed, paraffin-embedded bone marrow (BM) biopsy specimens decalcified in either hydrochloric acid or formic acid.
RESULTS: VE1 was positive in 15 (88%) cases of HCL and two (10%) cases of CLL and was negative in all other tumors assessed. The VE1-positive HCL cases showed uniform staining in all tumor cells, but intensity was variable. The two VE1-negative HCL cases had BRAF V600 mutations proven by molecular analysis. The two CLL cases positive with VE1 showed an atypical staining pattern with expression in a minority of lymphoma cells. Immunohistochemistry using the VE1 antibody had a sensitivity of 88% and a specificity of 97% for HCL.
CONCLUSIONS: VE1 immunohistochemistry is a useful and convenient surrogate for detecting BRAF V600E mutation in BM biopsy specimens decalcified with hydrochloric or formic acid-based solutions.
Published In/Presented At
Uppal, G., Ly, V., Wang, Z. X., Bajaj, R., Solomides, C. C., Banks, P. M., Medeiros, L. J., Peiper, S. C., & Gong, J. Z. (2015). The utility of BRAF V600E mutation-specific antibody VE1 for the diagnosis of hairy cell leukemia. American journal of clinical pathology, 143(1), 120–125. https://doi.org/10.1309/AJCPQLQ89VXTVWKN
Medicine and Health Sciences
Department of Pathology and Laboratory Medicine