Comparative analysis of flow cytometric techniques in assessment of ZAP-70 expression in relation to IgVH mutational status in chronic lymphocytic leukemia.
We compared 1 subjective and 5 objective flow cytometric methods to evaluate zeta-associated protein (ZAP-70) expression in relation to immunoglobulin heavy-chain variable-region (IgVH) gene mutational status in 154 samples from 125 patients with chronic lymphocytic leukemia (CLL). ZAP-70 expression determined by all methods used correlated with IgVH gene mutational status, but none of them demonstrated high concordance rates. Of the objective methods, ZAP-70 staining determined as a ratio of molecules of equivalent soluble fluorochrome intensity in CLL cells to that in normal B cells (ZAP-70+ staining in IgVH germline cases, 59%; ZAP-70- in IgVH mutated cases, 75%) or T cells (ZAP-70+ in IgVH germline cases, 66%; ZAP-70- in IgVH mutated cases, 57%) provides the best combination for assigning ZAP-70+ status to IgVH germline and ZAP-70- status to IgVH mutated cases. The subjective method based on ZAP-70 expression in natural killer/T cells gave a similar result, but reproducibility between laboratories may be difficult. Further studies on ZAP-70 expression in relation to clinical parameters may address whether ZAP-70 is an independent prognostic marker for CLL.
Chen
Yi-Hua
YH
Department of Pathology, John H Stroger, Jr Hospital of Cook County, Chicago, IL, USA.
Peterson
LoAnn C
LC
Dittmann
David
D
Evens
Andrew
A
Rosen
Steven
S
Khoong
Adela
A
Shankey
T Vincent
TV
Forman
Meryl
M
Gupta
Rohit
R
Goolsby
Charles L
CL
D004252:DNA Mutational Analysis; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D015973:Gene Expression Regulation, Leukemic / Q000235:genetics; D050438:Genes, Immunoglobulin Heavy Chain / Q000235:genetics; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D051746:ZAP-70 Protein-Tyrosine Kinase / Q000096:biosynthesis*
D007143:Immunoglobulin Heavy Chains; D007135:Immunoglobulin Variable Region; D051746:ZAP-70 Protein-Tyrosine Kinase