Abstract
Background: Expression of T cell specific zeta-associated protein 70 (ZAP-70) by B-cell chronic lymphocytic leukemia (B-CLL) cells, as investigated by flow cytometry, has both prognostic relevance and predictive power as surrogate for immunoglobulin heavy chain variable region (IgVH) mutations, although a standardization of the cytometric protocol is still lacking. Methods: Flow cytometric analyses for ZAP-70 were performed in peripheral blood samples from 145 B-CLL (124 with IgVH mutations) by a standard three-color protocol. Identification of ZAP-70+ cell population was based on an external negative control, i.e., the isotypic control (ISO method) or an internal positive control, i.e., the population of residual normal T/NK cells (TNK method). A comparison between these two approaches was performed. Results: While 86/145 cases were concordant as for ZAP-70 expression according to the two methods (ISO+TNK+ or ISO -TNK-), 59/145 cases had discordant ZAP-70 expression, mainly (56/59) showing a ISO+TNK- profile. These latter cases express higher levels of ZAP-70 in their normal T cell component. Moreover, discordant ISO+TNK- cases had a IgVH gene mutation profile similar to that of concordantly positive cases and different from ZAP-70 concordantly negative B-CLL. Conclusion: Analysis of ZAP-70 expression by B-CLL cells by using the ISO method allows to overcome the variability in the expression of ZAP-70 by residual T cells and yields a better correlation with IgVH gene mutations. A receiver operating characteristic analysis suggests to employ a higher cut-off than the commonly used 20%. A parallel evaluation of the prognostic value of ZAP-70 expression, as determined according to the ISO and TNK methods, is still needed.
| Original language | English |
|---|---|
| Pages (from-to) | 284-292 |
| Number of pages | 9 |
| Journal | Cytometry Part B - Clinical Cytometry |
| Volume | 70 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Jul 15 2006 |
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Keywords
- B-CLL
- Propuostic factors
- ZAP-70
ASJC Scopus subject areas
- Hematology
- Cell Biology
- Pathology and Forensic Medicine
- Biophysics
- Endocrinology
Cite this
ZAP-70 expression in B-cell chronic lymphocytic leukemia : Evaluation by external (isotypic) or internal (T/NK cells) controls and correlation with IgVH mutations. / Zucchetto, Antonella; Bomben, Riccardo; Dal Bo, Michele; Nanni, Paola; Bulian, Pietro; Rossi, Francesca Maria; Del Principe, Maria Ilaria; Santini, Simone; Del Poeta, Giovanni; Degan, Massimo; Gattei, Valter.
In: Cytometry Part B - Clinical Cytometry, Vol. 70, No. 4, 15.07.2006, p. 284-292.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - ZAP-70 expression in B-cell chronic lymphocytic leukemia
T2 - Evaluation by external (isotypic) or internal (T/NK cells) controls and correlation with IgVH mutations
AU - Zucchetto, Antonella
AU - Bomben, Riccardo
AU - Dal Bo, Michele
AU - Nanni, Paola
AU - Bulian, Pietro
AU - Rossi, Francesca Maria
AU - Del Principe, Maria Ilaria
AU - Santini, Simone
AU - Del Poeta, Giovanni
AU - Degan, Massimo
AU - Gattei, Valter
PY - 2006/7/15
Y1 - 2006/7/15
N2 - Background: Expression of T cell specific zeta-associated protein 70 (ZAP-70) by B-cell chronic lymphocytic leukemia (B-CLL) cells, as investigated by flow cytometry, has both prognostic relevance and predictive power as surrogate for immunoglobulin heavy chain variable region (IgVH) mutations, although a standardization of the cytometric protocol is still lacking. Methods: Flow cytometric analyses for ZAP-70 were performed in peripheral blood samples from 145 B-CLL (124 with IgVH mutations) by a standard three-color protocol. Identification of ZAP-70+ cell population was based on an external negative control, i.e., the isotypic control (ISO method) or an internal positive control, i.e., the population of residual normal T/NK cells (TNK method). A comparison between these two approaches was performed. Results: While 86/145 cases were concordant as for ZAP-70 expression according to the two methods (ISO+TNK+ or ISO -TNK-), 59/145 cases had discordant ZAP-70 expression, mainly (56/59) showing a ISO+TNK- profile. These latter cases express higher levels of ZAP-70 in their normal T cell component. Moreover, discordant ISO+TNK- cases had a IgVH gene mutation profile similar to that of concordantly positive cases and different from ZAP-70 concordantly negative B-CLL. Conclusion: Analysis of ZAP-70 expression by B-CLL cells by using the ISO method allows to overcome the variability in the expression of ZAP-70 by residual T cells and yields a better correlation with IgVH gene mutations. A receiver operating characteristic analysis suggests to employ a higher cut-off than the commonly used 20%. A parallel evaluation of the prognostic value of ZAP-70 expression, as determined according to the ISO and TNK methods, is still needed.
AB - Background: Expression of T cell specific zeta-associated protein 70 (ZAP-70) by B-cell chronic lymphocytic leukemia (B-CLL) cells, as investigated by flow cytometry, has both prognostic relevance and predictive power as surrogate for immunoglobulin heavy chain variable region (IgVH) mutations, although a standardization of the cytometric protocol is still lacking. Methods: Flow cytometric analyses for ZAP-70 were performed in peripheral blood samples from 145 B-CLL (124 with IgVH mutations) by a standard three-color protocol. Identification of ZAP-70+ cell population was based on an external negative control, i.e., the isotypic control (ISO method) or an internal positive control, i.e., the population of residual normal T/NK cells (TNK method). A comparison between these two approaches was performed. Results: While 86/145 cases were concordant as for ZAP-70 expression according to the two methods (ISO+TNK+ or ISO -TNK-), 59/145 cases had discordant ZAP-70 expression, mainly (56/59) showing a ISO+TNK- profile. These latter cases express higher levels of ZAP-70 in their normal T cell component. Moreover, discordant ISO+TNK- cases had a IgVH gene mutation profile similar to that of concordantly positive cases and different from ZAP-70 concordantly negative B-CLL. Conclusion: Analysis of ZAP-70 expression by B-CLL cells by using the ISO method allows to overcome the variability in the expression of ZAP-70 by residual T cells and yields a better correlation with IgVH gene mutations. A receiver operating characteristic analysis suggests to employ a higher cut-off than the commonly used 20%. A parallel evaluation of the prognostic value of ZAP-70 expression, as determined according to the ISO and TNK methods, is still needed.
KW - B-CLL
KW - Propuostic factors
KW - ZAP-70
UR - http://www.scopus.com/inward/record.url?scp=33748503730&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33748503730&partnerID=8YFLogxK
U2 - 10.1002/cyto.b.20127
DO - 10.1002/cyto.b.20127
M3 - Article
C2 - 16906587
AN - SCOPUS:33748503730
VL - 70
SP - 284
EP - 292
JO - Cytometry Part B - Clinical Cytometry
JF - Cytometry Part B - Clinical Cytometry
SN - 1552-4949
IS - 4
ER -