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

12 th Congress of the European Hematology Association
(n=5); refractory anemia with excess blasts type II, RAEB II (n=4); RAEB
type I ( n=1), refractory cytopenia with multilineage dysplasia and ringed
sideroblasts RCMD-RS (n=2); refractory anaemia with ringed sideroblasts
RARS (n=2) and refractory anaemia RA (n=1). Six patients with
bicytopenia and dysplastic uni - bilineage features were diagnosed with
non MDS pathology. Proper cytogenetic studies from 14 patients were
obtained and only five of them (35.7%) had cytogenetic MDS characteristic
abnormalities. Karyotype was normal in the rest of patients.
Results. According to Cherian et al. indications, standard deviation (SD)
and median (M) were calculated for the following parameters in healthy
donors (Table 1).
Table 1.
Score: 1 point was assigned when patient neutrophils had 1-2 SD of
the healthy donor values, and 2 points if >2 SD for the SSC diminishing
or CD66 and CD11a over-expression. 2 points were scored when
patient granulocytes shown CD10 loss expression or showed abnormal
expression (over-under) with more than 2 SD of CD116 MFI. A sensibility
of 83% and specificity of 66% was found when scores >3 points
were assigned to patients. Conclusions. According to our results, FCs
determined in PB samples is a useful non invasive tool to diagnose different
MDS types. However it is necessary to take into consideration
that the reproducibility of these results could vary depending on several
factors. We would like to highlight that analytical and preanalytical
factors may influence surface markers expression on granulocytes. A
technique standarization to solve these problems must be reached.
0978
SEROPREVALENCE OF HEPATITIS B, C AND HUMAN -IMMUNODEFICIENCY VIRUS
AMONG BLOOD DONORS IN OSOGBO, SOUTHWESTERN NIGERIA
E.O. Akanni, 1 V.O Mabayoje, 2 P. Oparinde, 3 A. Muhibi, 4 S. Taiwo, 5
T. Adebayo3 1 Ladoke Akintola University of Technology, OSOGBO; 2 Haematology & Blood
trans. Dept. LAUTECH, OSOGBO; 3 Chemical Path Dept.Lautech OSOG-
BO,NIG., OSGBO; 4 Haem/Blood trans. Dept; LTH, OSOGBO, NIG, OSG-
BO; 5 Med.Micro/Para CHS, Lautech, OSOGBO, NIG, OSGBO, Nigeria
Background. Screening for hepatitis B surface antigen (HBsAg) and antibodies
to hepatitis C (HCV) and Human immunodeficiency virus (HIV)
was carried out in 2,496 volunteer and replacement blood donors (1988
males and 508 females) at the Ladoke Akintola University of Technology
Teaching Hospital, Osogbo between July 2005 and December 2006
after obtaining informed consent from each participant. Aim. This is to
estimate the seroprevalence of and to identify risk factors of chronic
hepatitis B and C and HIV infections among prospective blood donors
in our institution. Methods. Sandwich immunoassay test strip (Using
monoclonal and polyclonal antibodies) was used for the detection of
HBsAg while a recombinant double antigen sandwich immunoassay
was employed in testing for hepatitis C virus. Antibodies to HIV-1, HIV-
2, and HIV-1 O subtypes were detected with the aid of HIV1/2/O Triline
Human immunodeficiency virus Rapid Test Device (Qualitative
immunochromatographic assay). Results. Of the number screened, 496
(19.9%) were positive for HBsAg. 160(6.4%) for anti HCV and 80(3.2%)
for anti HIV antibodies. HBsAg and HCV antibodies were found in 40
(1.6%) donors, HBsAg and HIV antibody in 12(0.5%) and anti HCV and
anti HIV antibody in 12 (0.5%). There was no case positive for HBsAg,
anti HCV and anti HIV antibodies. There was no sex differences in the
distribution of single HBV infection (X2=3.287, OR=0.7986, p=0.0698),
HCV infection (X2 = 0.6804, OR=1.219, p=0.4095) or HIV (X2 =0.00634,
OR=1.023, p=0.9365) among the donors. There was also no significant
differences in the age group distribution of HBV infection (X2= 3.043,
df =3, p=0.3850), HCV infection (X2=6.474, df = 3, p=0.0907) and HIV
(X2=7.544, df= 3, p=0.0564) among the donors. Summary / Conclusions.
When compared with figures obtained from other parts of the world,
the prevalence of isolated chronic hepatitis B, hepatitis C and HIV infections
among donors and dual infections of HBV and HCV or HBV and
364 | haematologica/the hematology journal | 2007; 92(s1)
HIV or HCV and HIV are high. There is need to increase public awareness
on health care and socio-cultural practices that can predispose to
transmission of these viruses in our environment.
0979
MULTISTEP REGULATION OF TELOMERASE DURING DIFFERENTIATION OF HL60 CELLS
O. Yamada, 1 K. Ozaki, 1 M. Akiyama, 2 K. Kawauchi, 1 R. Matsuoka1 1 2 Tokyo Women's Medical University, TOKYO, Japan; Jikei University School
of Medicine, TOKYO, Japan
Background. Telomerase plays a key role in maintaining telomere
length and in replicative senescence. Telomerase is active in immature
somatic cells and is suppressed in differentiated cells, but the mechanism
by which telomerase activity is regulated during cell differentiation
remains unclear. Several regulatory mechanisms for telomerase have
been reported, including transcriptional, translational, and post-translational
mechanisms, suggesting that the regulation of telomerase activity
is a complex process. Aims. To determine the mechanisms modulating
telomerase activity during differentiation of the granulocytic and
monocytic lineages of hematopoietic cells. Methods. A human acute
myeloblastic leukemia cell line (HL60) was induced to undergo differentiation
into monocytes by exposure to VD3, and into neutrophils by
exposure to ATRA or Am80 (an RAR-α/β-selective retinoid that does not
bind and activate RAR-Á and RXRs). Changes of several signaling proteins
during differentiation were examined by western blotting. To
assess the effect of PI3K inhibitors on granulocytic and monocytic differentiation,
HL60 cells were preincubated with LY294002 and then differentiation
inducers were added before further incubation. Cell cycle
progression, esterase staining, flow cytometric analysis, telomerase
activity, expression of human telomerase reverse transcriptase (hTERT)
protein and mRNA, and epigenetic factors within the telomerase promoter
region were examined. Results. Telomerase activity and expression
of hTERT decreased gradually throughout differentiation of HL60 cells
into both lineages. Exposure to any of VD3, ATRA, or Am80 caused a
significant increase of various signaling proteins, including AKT, mTOR,
and p70 S6K, at 3 days after differentiation. In addition, a dose-dependent
increase of telomerase activity was observed after exposure to
recombinant AKT and transcription of telomerase was inhibited by
LY294002. Pretreatment of HL60 cells with a PI3K inhibitor, LY294002,
before induction of differentiation suppressed the phosphorylation of
AKT and mTOR. It also decreased the number of α-naphthyl-butyratepositive
cells, without affecting CD14 – or CD33 – positive cells. To further
assess the transcriptional regulation of telomerase, a chromatin
immunoprecipitation (ChIP) assay was performed. Acetyl-Histone H4
(which binds to the hTERT promoter) underwent deacetylation during
differentiation, while trimethyl-Histone H3 remained stable during differentiation.
Conclusions. There was a decrease of telomerase activity
and hTERT (protein and mRNA) expression during granulocytic and
monocytic differentiation stimulated by ATRA, Am80 or VD3, respectively.
Active forms of AKT, mTOR, and p70 S6K were increased 3 days
after the induction of differentiation. It has been reported that AKT promotes
transcription of hTERT and post-translationally activates telomerase.
The discrepancy between telomerase protein expression and
telomerase activity observed during Am80-based differentiation, suggests
post-translational regulation of telomerase activity. Changes of
acetyl-Histone H4 that regulate transcription of telomerase gene were
observed before the activation of AKT, which might mean that epigenetic
control of telomerase transcription takes place before AKT activation
occurs during differentiation. These results indicate that telomerase
activity is regulated by at least two mechanisms during granulocytic
and monocytic differentiation, with one being transcriptional and the
other being post-translational.
0980
AN ATYPICAL CASE OF A TRANSLOCATION T(8 ;16) (Q12;P13) WITH AN INV(8)(P11Q11)
ASSOCIATED WITH A SECONDARY ACUTE MONOCYTIC LEUKEMIA INVOLVES THE MOZ
AND CBP GENES
S. Hayette, 1 I. Tigaud, 2 S. Gazzo, 2 C. Charlot, 2 M. Michallet, 3
J.P. Magaud, 4 S. Hayette4 1 Centre Hospitalier Lyon Sud, PIERRE BENITE; 2 1Hematology Laboratory and
UMR 5239 CNRS, PIERRE BENITE; 3 Hematology Department E Herriot Hospital,
LYON; 4 Hematology/UMR 5239 CNRS/CHLS, PIERRE BENITE,
France
Background. The infrequent recurrent translocation t(8;16)(p11;p13) is