12th Congress of the European Hematology ... - Haematologica

12 th Congress of the European Hematology Association
Chronic lymphocytic leukemia and related
disorders - Biology
0908
EXPRESSION LEVELS OF CLLU1 AND LPL : NEW DISEASE-ASSESSMENT TOOLS IN CLL
PATIENTS IN BINET STAGE A ?
S. Hayette, 1 S. Hayette, 2 C. Bastard, 3 M.J. Mozziconacci, 4
C. Messana, 2 C. Charlot, 2 C. Locher, 2 M. Gadoux, 2 L. Baseggio, 2
M. Ticchioni, 5 B. Lenormand, 3 G. Salles, 2 C. Arnoulet, 4 J.P. Magaud, 2
E. Callet-Bauchu, 2 S. Raynaud 5
1 Centre Hospitalier Lyon Sud, PIERRE BENITE; 2 Hematology/UMR 5239
CNRS/CHLS, PIERRE BENITE; 3 Hematology, CR de lutte contre le cancer,
ROUEN; 4 Biopathology laboratory, IPC, MARSEILLE; 5 Oncohematology
/Hopital Pasteur, NICE, France
Background. IGVH mutational status is a strong predictor for outcome
in Chronic Lymphocytic Leukemia (CLL) but its determination remains
unadapted to routine practice. Several reports have shown that the
expression levels of other genes (such as LPL) could be used as surrogate
markers. Recently Buhl et al. identified a novel gene (CLLU1),
exclusively upregulated in CLL cells, and whose high expression mRNA
levels could predict poor clinical outcome in patients younger than 70
years. Methods. Non-purified peripheral blood mononuclear cells from
a cohort of 177 untreated Binet stage A-CLL patients from 4 centers
were examined for CLLU1 transcripts (cDNA1) and LPL expression levels
by real time quantitative PCR and compared to the same pool of
purified B cells from healthy individual donors (n=3). We correlated
the results with the previously determined IGVH mutational status
(MT: mutated; UNM: unmutated), expression of ZAP70, chromosomal
aberrations and clinical characteristics. Results. The selected cohort
included 61% of male and median age at diagnosis was 67 (38-90) years.
With a cut-off value arbitrary defined as 1 for the CLLU1/β2M and for
the LPL/β2M ratios from the control pool, the median level of up-regulation
of CLLU1 and LPL expressions were 12,2 and 54 fold above the
level found in normal B cells, respectively. This level was not surprisingly
lower than previously described for CLLU1 (27 fold) since our
cohort included only stage A patients. Expression levels of CLLU1 and
LPL were significantly associated with the IGVH mutational status
[median values: 9.4 and 21 in MT (n=129) versus (vs) 173 and 886 in UM
(n=43) (p=0.0000 for the two genes) , with ZAP70 expression [median:
86 and 631 in ZAP + cases (n=47) vs 6,5 and 22,6 in ZAP – cases (n=96)
(p=0.0012 and p=0.0000), respectively] and with poor prognosis cytogenetic
markers such as del17p (p=0.012 and p=0.0018) and del11q
(p=0.00019 andp=0.00003). CLLU1 and LPL expression level was in an
unexpected way (and more significantly for LPL) associated with the
presence of trisomy 12 (p=0.016 and p=0.00096). A slight correlation
was found between the young patient age at diagnosis and CLLU1
(p=0.02), between LPL expression and male gender (p=0.001) and
between LPL and CLLU1 (p=0.0041). Conclusions. Our study demonstrates
in a large cohort of recently diagnosed stage A CLL patients that
CLLU1 and LPL mRNA quantifications 1/ are good surrogate markers
of usual prognosis leukaemia-cell parameters, 2/ represent a reliable
alternative to IGVH genes sequencing. Moreover, these quantifications
do not require purification of B lymphocytes, a significant advantage for
routine practice. CLLU1 and LPL mRNAs levels could then be considered
as new disease-assessment tools in CLL. Follow up of our patients
will determine if these new parameters add independent prognostic
information to the definitions of smoldering and nonsmoldering CLL
in Binet stage A.
0909
QUANTITATIVE GENE EXPRESSION ANALYSIS OF SURROGATE MARKERS FOR GENETIC
RISK GROUPS AND SURVIVAL IN CLL
D.K. Kienle, 1 A. Benner, 2 C.S. Schneider, 1 D.W. Winkler, 1
A.H. Habermann, 1 M.H. Hensel, 3 P. Lichter, 4 R.D. Dalla-Favera, 5
H. Döhner, 1 S. Stilgenbauer1 1 University of Ulm, ULM, Germany; 2 Central Unit Biostatistics, DKFZ, HEI-
DELBERG, Germany; 3 University of Heidelberg, HEIDELBERG, Germany;
4 Department of Molecular Genetics, DKFZ, HEIDELBERG, Germany;
5 Columbia University, NEW YORK, USA
Background. The genetic factors VH mutation status, V3-21 gene usage,
and genomic deletions at 11q22-q23 and 17p13 have been shown to be
important prognostic markers in CLL. Given the high complexity of these
340 | haematologica/the hematology journal | 2007; 92(s1)
analyses in the recent years several molecular surrogate markers were
developed aiming at the facilitation of routine prognosis assessment.
Aims: To assess the value of potential surrogate markers for the prediction
of genetic risk groups and survival. Methods: Real-time RT-PCR (RQ-
PCR) of candidate genes was performed in a CD19-purified and a nonpurified
CLL cohort each comprising the relevant genetic subgroups (VH
mutated, VH unmutated, V3-21 usage, 11q-, 17p-). 17 markers
(ADAM29, ATM, CLLU1, DMD, GLO1, HS1, KIAA0977, LPL,
MGC9913, PCDH9, PEG10, SEPT10, TCF7, TP53, Vimentin, ZAP-70,
ZNF2) identified in previous studies were investigated in the non-purified
cohort of 102 CLL patients. Of these, 10 markers, either with an
overexpression in non-CLL cells or an impact on survival or risk group
prediction, were analyzed in the purified cohort of 112 cases. VH
sequencing and FISH screening for genomic aberrations were carried out
for all cases. Survival information was available for 80 (purified) and 88
cases (non-purified). Logistic regression was performed to test the predictive
value of gene expression for genetic risk groups, Cox proportional
hazards statistics for survival analysis. Results. The genetic risk groups in
both cohorts showed the expected correlation with survival with significantly
shorter survival of VH unmutated, 17p-, and 11q- cases indicating
a representative composition of the cohorts under study. In non-purified
cases, the best predictive marker for VH status was LPL (p=0.001).
While no reliable predictive markers were identified for V3-21 usage or
17p-, lower ATM expression was predictive for 11q-. In survival analysis
including all candidate genes TCF7 (p=0.001) and KIA0977 (p=0.016)
were of prognostic value. In multivariate survival analysis including candidate
gene expression and the genetic risk factors as variables, only 17premained
as a significant parameter. In the purified cohort, significant
markers (p