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

findings confirmed the significant increase of vWF:Ag and F VIII in
patients with multiple myeloma, which contribute to the thromboembolic
risk. The analysis of these results, taking also the other risk thromboembolic
factors into consideration, may be helpful to decide the correct
prophylaxis of thrombembolism. To confirm these results the larger
randomized patient groups and following-up the changes of selected
haemocoagulation parameters depending on activity of the disease are
required.
1277
INDOLEAMINE 2,3-DIOXYGENASE (IDO) MAY NOT BE A MAJOR FACTOR FOR TUMOUR
IMMUNE EVASION IN MULTIPLE MYELOMA
M. Schreder, 1 N. Zojer, 1 S. Graffi, 1 D. Fuchs, 2 S.S. Sahota, 3 H. Ludwig1 1 Wilhelminenspital Wien, VIENNA, Austria; 2 Medical University Innsbruck,
INNSBRUCK, Austria; 3 University of Southampton, SOUTHAMPTON,
United Kingdom
Background. Indoleamine 2,3-dioxygenase (IDO) is a tryptophan
catabolising enzyme expressed by several cancers that induces immune
tolerance. High IDO expression has been linked with short survival in
some cancers, but data on the possible role of IDO are not available as
yet in multiple myeloma (MM). Aims. In this study we aimed to evaluate
IDO expression in a series of previously untreated patients with multiple
myeloma. Methods. We used conventional and quantitative (q) PCR
to determine expression levels of IDO in CD138 sorted bone marrow
(BM) cells from MM patients (n=17), MM cell lines (n=6) and MM BM
stromal cells (SCs) (n=5). Results. Low level expression of IDO was found
in the CD138 + BM fraction of 17 myeloma patients using qPCR (median
0.52 fold compared to normal PBMNC; range, 0.08-15.03). Even in the
patient with highest IDO expression, IDO mRNA levels were >100x
lower than in DCs or HeLa cells stimulated with IFN-gamma. Similarly,
6 myeloma cell lines had low IDO expression by qPCR (median 0.04;
range 0.001-0.68). Stimulation with IFN-gamma led to an upregulation
of IDO in 2 of these cell lines, as shown by qPCR and Western blot, but
again with expression levels being >100x lower than in activated DCs.
Analysis of the tryptophan/kynurenin ratio in cell line culture supernatants
furthermore revealed little sign of enzyme activity, even after
stimulation. IDO expression could not be induced in the IDO- cell lines.
Interestingly, when comparing CD138 + and CD138 – cell fractions from
BM of 3 myeloma patients, a detectable, although weak, PCR band was
demonstrated in the CD138 – fraction only. By conventional PCR using
purified cell subsets from the CD138- fraction, a weak band was amplified
from monocytes and T-cells. In cultured BM SCs from myeloma
patients, IDO expression was low at baseline, but could be upregulated
by interferon-gamma. IDO also proved functional in this setting with
reversal of the tryptophan/kynurenin ratio after 48 hours of interferongamma.
BM-derived SCs from myeloma patients thus seem to have similar
characteristics with regard to IDO expression as SCs from normal
donors and do not appear to be a major source of IDO in myeloma when
examined in isolation. Conclusions. IDO is weakly expressed in myeloma
plasma and stromal cells and may not contribute to immune paralysis
in this disease.
1278
REGULATORY EFFECTS OF PHYTOESTROGEN DAIDZEIN ON MURINE MYELOPOIESIS
F.H. Lo, K.N. Leung
The Chinese University of Hong Kong, HONG KONG, Hongkong, China
Background. previous work in this laboratory has shown that daidzein
(4’,7-dihydroxyisoflavone), a well-known phytoestrogen, can exert antitumour
effects on neuronal cancers such as neuroblastoma. In addition,
this naturally-occurring compound has also been reported to have various
health benefits, such as chemopreventive and cardiovascular-protective
activities. Despite its abundance in Asian foods, other biological
effects of daidzein, especially its roles in cell development, are relatively
undetermined. Aims. in this study, attempts had been made to investigate
the potential regulatory role of daidzein on the process of myelopoiesis
in the mouse. Methods and results. we began our studies on the matured
macrophages. Daidzein was shown to have stimulatory effects on the
thioglycollate-elicited murine peritoneal macrophages as it enhanced the
phagocytic activity, nitric oxide production, and TNF-α expression in the
treated cells. Moreover, daidzein exhibited no mRNA concomitant cytotoxic
effect on the cells. We then continued our studies on the
myelomonocytic cells. Daidzein was shown to inhibit the proliferation,
induced G0/G1 phase cell cycle arrest and triggered apoptosis in the murine
myelomonocytic WEHI-3B (JCS) cells. Interestingly, daidzein also induced
the monocytic differentiation of the JCS cells, as judged by the increases
in cytoplasm-to-nucleus ratio, superoxide anions production, and expression
of the macrophage differentiation antigens (Mac-1 and F4/80). Furthermore,
we also studied the possible effects of daidzein on the long
term bone marrow derived murine myeloid progenitor cells, 32D.
Daidzein treatment of 32D cells was shown to suppress the proliferation
and increased the proportion of cells at the G2/M phase. In addition,
daidzein also induced morphological changes (cell size and granularity)
and increased the expression of macrophage differentiation antigen Mac-
1 in the cells. Summary/Conclusions. taken together, our results hinted that
daidzein possessed similar differentiation-inducing properties to colony
stimulating factors (CSFs); but unlike CSFs, whose action was limited to
cells at specific maturation status, the effects of daidzein was independent
of that status. This interesting differentiation-inducing property of
daidzein on myeloid cells should be further pursued to let us understand
more about the mechanism(s) of myeloid cell development and possibly,
the design of differentiation therapy for certain forms of myeloid
leukemias.
1279
ONCE-DAILY INTRAVENOUS BUSULFAN PRIOR TO ALLOGENIC HAEMATOPOIETIC STEM
CELL TRANSPLANTATION: EFFICACY AND TOXICICY IN OUR CENTER
R. Mónica, M. Colorado, A. Bermúdez, M. López-Duarte,
R. Pérez-Montes, A. Iriondo
Hospital Marqués de Valdecilla, SANTANDER, Spain
Oral busulfan is a common component of pretransplant conditioning
regimens but has an erratic and unpredictable bioavailability. Intravenous
busulfan (IV Bu) has substituted oral busulfan for conditioning regimen
before haematopoietic stem cell transplantation (HSCT). The aim of this
study was to evaluate the early toxicity and efficacy of once-daily administration
of IV Bu in our hospital. Patiens. We retrospectively evaluated
19 patients underwent allogenic HSCT between May 2005 to January
2007. All patients received intravenous busulfan in conditioning regimens.
10 patients with haematological malignancies suitable for conventional
allogenic transplantation were treated with IV Bu (3.2 mg/kg/per
day/four days) and cyclophosphamide. 9 patients received reduced
intensity conditioning with IV Bu (3.2 mg/kg/per day/two days) and fludarabine.
All patients received phenytoin prophylaxis. No pharmacokinetics
study of IV Bu was made. No significant differences were observed
between two groups respect age or other risk factors to develop pulmonary
or hepatic toxicity. 11/19 patients had previous history of cigarette
smoking and/or alcohol intake. Pre-transplant evaluation detected
abnormalities in hepatic and pulmonary function test (reduced of CO diffusion),
7 and 4 patients respectively. All of these patients were asymptomatic.
The stem cell source was bone marrow in 14 patients (8 allo-
HSCT) and peripheral blood in 5 patients (2 allo-HSCT and 3 RIC). The
median number of CD34 + cell infused was 3.18×106 (1.23-8.65) and
3.61×106 (0.75-8.25) for allo-HSCT and RIC respectively. All patients
received graft versus host disease prophylaxis with cyclosporine and
methotrexate. Methods. We analysed clinical symptoms, laboratory test
and radiological images to evaluated gastrointestinal, hepatic, neurological
and pulmonary toxicity. (We used WHO score for classification toxicity
grades). We also analysed haematological engraftment. We studied
100 days mortality rate in our group.
Table 1.
12 th Congress of the European Hematology Association
Results. 15 patients developed mild transitory liver function tests
abnormalities. Only one patient developed hyperbilirrubinemia and
veno-occlusive disease. All patients developed gastrointestinal toxicity
and were severe in five of them. Not patient developed neurology complications
or interstitial pneumonitis. All patients achieved engraftment
and haematopoietic recovery. No patients died due to toxicity related
haematologica/the hematology journal | 2007; 92(s1) | 463