For staining of ALK protein, the novel D5F3 antibody demonstrates superior overall performance in terms of intensity and extent of staining in comparison to the currently used ALK1 antibody.
Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm. Approximately 50 % of IMTs show an anaplastic lymphoma kinase (ALK) gene fusion resulting in ALK overexpression on immunohistochemistry (IHC). A novel anti-ALK monoclonal antibody (D5F3) has been suggested to be of superior sensitivity to the ALK1 antibody which is currently used. We compared the performance of D5F3 in detecting ALK protein expression in IMTs from various anatomic sites compared to the currently utilized ALK1. We selected 25 IMTs from our surgical pathology files (2005-2015). The novel rabbit monoclonal anti-human CD246 (clone D5F3) and the currently used mouse monoclonal anti-human CD246 (clone ALK1) were used for immunohistochemical staining (IHC) in an automated slide stainer. The percentage of immunoreactive tumor cells (0, <5 %, 5-50 %, >50 %) and cytoplasmic staining intensity (graded 0-3) were assessed and compared between the two antibodies. Fluorescence in situ hybridization (FISH) studies for ALK gene rearrangement were performed on 11 tumors. D5F3 antibody stained 76 % and ALK1 antibody stained 72 % of IMTs (p = 0.747). Compared to staining with ALK1, D5F3 stained a higher proportion of cases extensively (>50 % cells) (76 vs. 28 %, p < 0.001) and with high intensity (grade 3 76 % vs 0; p < 0.001). FISH and IHC findings (for both antibodies) were concordant in 9/10 (90 %) IMTs, in which results were informative. The novel anti-ALK rabbit monoclonal antibody (D5F3 clone) demonstrates superior overall performance in term of intensity and extent of staining of ALK protein in IMT. We found IHC staining with both antibody clones to correlate equally well with FISH results for detection of ALK rearrangement.
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.|Department of Pathology, Isfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
Diana
D
Taheri
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
David J
DJ
Zahavi
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Maria
M
Del Carmen Rodriguez
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Abdelrazak
A
Meliti
Department of Surgery, Johns Hopkins Medical Institution, Baltimore, MD, USA.
Neda
N
Rezaee
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Raluca
R
Yonescu
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Bernardo F P
BF
Ricardo
Department of Pathology, Isfahan Kidney Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
Shahaboddin
S
Dolatkhah
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Yi
Y
Ning
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
Justin A
JA
Bishop
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA. gnetto1@jhmi.edu.
George J
GJ
Netto
Department of Pathology, The Johns Hopkins Hospital, 600 North Wolfe Street, Baltimore, MD, 21287, USA. rsharma@jhmi.edu.
Rajni
R
Sharma
D000328:Adult; D000077548:Anaplastic Lymphoma Kinase; D000906:Antibodies / Q000276:immunology; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D050939:Gene Fusion / Q000235:genetics; D015321:Gene Rearrangement / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020794:Receptor Protein-Tyrosine Kinases / Q000276:immunology* / Q000378:metabolism
D000906:Antibodies; C000626173:ALK protein, human; C000626174:Alk protein, mouse; D000077548:Anaplastic Lymphoma Kinase; D020794:Receptor Protein-Tyrosine Kinases
Anaplastic lymphoma kinase (ALK); Fluorescence in situ hybridization (FISH); Immunohistochemistry (IHC); Inflammatory myofibroblastic tumor (IMT)