Haematologica 2003 - Supplements

MGUS but most likely not crucial for the transition of MGUS to
MM.
Recently, we have demonstrated that trisomies of chromosome
arms 1q, 9q, and 11q (+1q, +9q, +11q) are among the most
common chromosomal aberrations in MM. However, the
incidence of these frequent trisomies in MGUS and their
significance in the pathogenesis of MM remain to be explored.
Aims: To determine the incidences of chromosomal gains and
losses involving chromosome bands 1q21, 9q34, 11q25, and
13q14 in individuals with MGUS and to distinguish primary
aberrations (present in MGUS) from secondary genetic changes
(not or infrequently detectable in MGUS, but common in MM)
by comparing these incidences with that previously identified in a
large series of myeloma tumors.
Material and Methods: Bone marrow aspirates from all
individuals diagnosed with MGUS were obtained during routine
diagnostic procedures. In 13 out of 21 cases, a positive selection
of plasma cells using immunomagnetic beads (CD 138) was
performed. The following DNA probes were used for tri-color
FISH: RP11-71L20 (mapping to chromosome band 1q21), RP11-
40A07 (9q34), RP11-17M17 (11q25 – all from the RPCI human
BAC library 11, National Center for Biotechnology Information,
NCBI; http://www.ncbi.nlm.nih.gov/), and PAC clone 272/3
(13q14, locus D13S272).
Results: The most frequent chromosomal imbalances in this
preliminary study were (in order of decreasing prevalence): +9q
(5/14 – 36%), 13q- (5/21 – 24%), +11q (2/14 – 14%), 11q- (2/14
– 14%), +1q (2/20 – 10%), and tetrasomy 1q (2/20 – 10%).
Conclusions: Our data obtained from a small series of cases show
that +1q, +9q, and +11q are detectable in MGUS. While the
incidence of +9q appears to be in the range of that found in MM,
+1q and +11q, as well as 13q- seem to occur less frequently in
MGUS. The precise incidences of all chromosomal imbalances
have to be determined in a larger series of individuals with
MGUS. This work is under way in our laboratory.
Supported by grants from the Deutsche Krebshilfe (70-2899-Li I)
and the Wilhelm Sander-Stiftung (No. 2002.098.1) to P.L.
043
Cytogenetics, fluorescence in situ hybridization (FISH)
and comparative genomic hybridization (CGH) studies
of 11q in multiple myeloma.
M. Belén González, Norma C. Gutiérrez, Eva Lumbreras,
Juan L. García, Jesús M. Hernández, M. Ángeles
Hernández, Mariana Castellanos, Isabel Isidro, Jesús F.
San Miguel.
Servico de Hematología. Hospital Universitario de Salamanca &
Centro de Investigación del Cáncer.
Background: A large number of chromosomal and genetic
abnormalities have been detected in multiple myeloma (MM), the
most frequently are translocations affecting immunoglobulin
heavy chain (IGH) and chromosome 13q deletions. Both of them
have been associated with an adverse outcome. By contrast,
abnormalities on 11q, other than t(11;14), have been less study.
Purpose: To analyse 11q by conventional cytogenetics (CC),
fluorescence “in situ” hybridization (FISH) and Comparative
Genomic Hybridization (CGH).
Patients & Methods: A total of 53 patients were included. Three
different groups were defined according to the chromosomal data:
1. Patients with both normal CC and CGH (n=20). 2. Cases with
cytogenetics and/or CGH aberrations with no 11q involvement
(n=19). 3. Patients with abnormalities in 11q assessed by
cytogenetics and/or CGH (n=14). FISH analyses were performed
with three different specific probes for the regions containing the
genes BCL1 (11q13), ATM (11q22) and MLL (11q23).
Conventional cytogenetics and CGH were carried out according
to standard methodologies.
Results: Overall 23 out of the 53 patients analysed by FISH
(43%) showed abnormalities on 11q: gains on 11q were present
in 20 cases (38%) while rearrangements on 11q were present in 4
cases (7%) (one case had both t(11;14) and gain on 11q). All but
one gains involved the three different regions (BCL1, ATM and
MLL genes) analysed. Only rearrangements of BCL1 were
observed. In the group of patients with normal cytogenetics and
CGH, 7 out 20 cases analysed (35%) showed abnormalities on
11q: 2 patients had ins(11;14), one patient a t(11;14) and the
remaining 4 cases gains of 11q. Seven out the 19 (37%) patients
displaying other cytogenetics abnormalities had also 11q gains.
No translocations involving 11q were present in this group. In the
third group FISH studies confirmed in all but one case the
presence of gains on 11q detected by conventional cytogenetics
or CGH. The negative case had a gain on 11q11-12 ascertained
only by CGH.
Conclusions: Chromosomal abnormalities on 11q are frequent in
MM. In these cases FISH refined cytogenetics and CGH studies
and showed more sensitivity. Therefore FISH studies for
abnormalities on 11q it should be use in the routine evaluation of
MM.
(Partially supported by Grants of the Spanish FIS 01/1161 &
G03/136)
044
GENETIC CHANGES BY COMPARATIVE GENOMIC
HYBRIDIZATION IN SMOLDERING MULTIPLE
MYELOMA (SMM). DIFFERENT PATTERN ACCORDING
TO THE SMM TYPE (EVOLVING vs NON-EVOLVING).
L. Rosiñol, R. Queralt, A. Carrió, M. Aymerich, M. Rozman,
J. Bladé, E. Campo, E. Montserrat
Hematology Department. Hospital Clínic. IDIBAPS. Barcelona.
Spain.
Introduction: Patients with SMM met the diagnostic criteria of
multiple myeloma (MM) but have no anemia, hypercalcemia,
renal faillure or extramedullary plasmacytomas. After a period of
stability (median 3.5 yrs) most of these patients develop
symptomatic MM. We identified two subsets of SMM: 1)
evolving SMM, characterized by a progressive increase in the M-
protein, a previous MGUS in most patients and a shorter time to
progression into overt MM (median 1.6 yrs), and 2) nonevolving
SMM, characterized by a stable M-protein that abruptly
increases when symptomatic MM develops and a longer time to
progression (median 4.3 yrs). Previous studies with comparative
genomic hybridization (CGH) in patients with symptomatic MM
have shown multiple abnormalities, including gains in 9q, 11q
and15q and losses in 13q, 16q and 22q. However, there are no
reports on CGH studies in patients with SMM.
Objective: To study the cytogenetics abnormalities by CGH in
patients with both types of SMM.
Patients and methods: Seventeen patients with SMM (7 evolving,
8 non-evolving) were studied by CGH. Previous enrichment of
plasma cell was performed in all bone marrow samples with
monoclonal antibody BB4 conjugated with immunomagnetic
beads. CGH was performed as described in the supplier’s
protocol (Vysis ®).
Results: Thirteen of the 15 patients (87%) showed chromosomal
imbalances by CGH analysis. Twelve of the 13 patients (92%)
had chromosomal gains whereas in only 6 patients (46%),
S107