Characterization of a new monoclonal antibody against PAX5/BASP in 1525 paraffin-embedded human and animal tissue samples.
BACKGROUND
We describe the newly generated DAK-PAX5 monoclonal antibody raised against a fixation-resistant epitope of the human PAX5/BSAP molecule.


METHODS
Following Western-blot, absorption, and chess-board titration tests, and optimization of antigen-retrieval and detection methods, DAK-Pax5 was used in parallel with a reference antibody (clone 24) on tissue micro-arrays (TMAs) constructed from normal human and animal tissues and from hematologic and nonhematologic human malignancies. Such TMAs were also tested with an anti-PAX2 antibody.


RESULTS
DAK-Pax5 reacted with normal human and animal B-cells and with 460/473 B-cell non-Hodgkin lymphomas (B-NHLs). All plasmacytomas/plasmablastic tumors (n=13) and T/NK-cell neoplasms (n=264) turned out consistently negative as did acute myelogenous leukaemias (n=19) except 2 carrying t(8;21). Positivity was found in 6/6 and 155/169 lymphocyte predominant and classical HLs, respectively, although the staining intensity varied through cases. Among 521 nonhematologic malignancies, DAK-Pax5 reacted with 22/399 carcinomas (4/11 neuroendocrine, 2/4 Merkel-cell, 4/21 prostatic, 1/11 urothelial, 1/26 renal, 2/12 cervical squamous-cell, 3/13 ovarian, and 5/75 colonic). When compared with clone 24, DAK-Pax5 produced a stronger positivity in most if not all B-NHLs and HLs. No cross-reactivity with the anti-PAX2 antibody was recorded.


CONCLUSIONS
DAK-Pax5 represents a new reliable tool for diagnostics and research.
Agostinelli
Claudio
C
Departments of Haematology and Clinical Oncology L. and A. Seràgnoli, Pathology and Haematopathology Unit, St. Orsola-Malpighi Hospital, University of Bologna, Via Massarenti 9, Bologna, Italy. claudioagostinelli@gmail.com
Sabattini
Elena
E
Gjørret
Jakob Oemar
JO
Righi
Simona
S
Rossi
Maura
M
Mancini
Manuela
M
Piccaluga
Pier Paolo
PP
Bacci
Francesco
F
Marafioti
Teresa
T
Bettini
Giuliano
G
Falini
Brunangelo
B
Pileri
Stefano A
SA
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D001402:B-Lymphocytes / Q000737:chemistry* / Q000473:pathology; D014408:Biomarkers, Tumor / Q000737:chemistry* / Q000276:immunology*; D015153:Blotting, Western; D000939:Epitopes / Q000737:chemistry* / Q000276:immunology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008228:Lymphoma, Non-Hodgkin / Q000276:immunology / Q000473:pathology; D008297:Male; D051379:Mice; D009369:Neoplasms / Q000737:chemistry* / Q000175:diagnosis / Q000473:pathology* / Q000648:ultrastructure; D051757:PAX5 Transcription Factor / Q000737:chemistry / Q000276:immunology; D016612:Paraffin Embedding / Q000379:methods; D040081:Protein Array Analysis
D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D000939:Epitopes; D051757:PAX5 Transcription Factor; C497281:PAX5 protein, human