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

erozygous mother has a more severe clinical phenotype than daughters
1 and 2, most probably due to the X inactivation process in females: the
chromosomes X selective inactivation favoured the wild type allele in the
mother’s erythropoietic cell line while in daughter 2 the process favoured
the mutant allele. This unbalanced X lionization is known to aggravate
with aging.
0789
BAND 3 AS A MARKER OF ERYTHROCYTE CHANGES IN CHRONIC RENAL FAILURE
E. Costa, 1 S. Rocha, 2 P. Rocha-Pereira, 3 E. Castro, 2 V. Miranda, 4 M.
Sameiro Faria, 4 A. Loureiro, 5 A. Quintanilha, 6 L. Belo, 7 A. Santos-Silva7 1 ESS-IPB. FF and IBMC of UP., BRAGANÇA; 2 FF and IBMC, UP., PORTO;
3 Universidade da Beira Interior, COVILHÃ; 4 FMC, Dinefro, PORTO; 5 Uninefro,
PORTO; 6 IBMC and ICBAS, UP, PORTO; 7 FF and IBMC, UP, PORTO,
Portugal
Band 3 protein is the major integral protein of the red blood cell (RBC)
membrane. It is known as the senescent neoantigen, as modifications in
band 3 protein, by proteolytic cleavage, clustering or exposure of unusual
epitopes, trigger the binding of specific anti-band 3 autoantibodies
and complement activation, marking RBC for death. An abnormal band
3 profile [% of band 3 monomer; high molecular weight aggregates
(HMWAg); proteolytic fragments (Pfrag)] has been associated with RBC
damage/aging in inflammatory conditions associated with oxidative
stress, namely in cardiovascular disease, pregnancy and acute physical
exercise. Chronic renal failure (CRF) has also been associated with both
inflammation and oxidative stress. A deficient renal erythropoietin secretion
underlies the development of an anaemia, which is usually corrected
by therapy with recombinant human erythropoietin (rhEPO). However,
about 25% of the patients do not respond to this therapy. Our aim
was to study the band 3 profile, as a cumulative marker of RBC damage,
in CRF patients under haemodialysis and rhEPO therapy. We studied
44 CRF patients, 22 responders and 22 non-responders to rhEPO
therapy, and 25 healthy individuals matched for age and gender. We
evaluated the band 3 profile, membrane bound haemoglobin (MBH),
RBC count, haematocrit (Ht), haemoglobin concentration (Hb), haematimetric
indices, red cell distribution width (RDW), reticulocyte count
and reticulocyte production indice (RPI). CRF patients (patients vs control)
showed a statistically significant decrease in RBC count, Hb and Ht;
a significant increase in reticulocyte count, RDW and RPI was also
observed; band 3 profile presented a significant reduction in HMWAg
and Pfrag and a significant increase in band 3 monomer. No difference
was found in MBH, though a trend to lower values was observed. A positive
correlation was found between Pfrag and Hb (r=0.352, p=0.019)
and Ht (r=0.384, p=0.010). When comparing responders to non responders,
we found a statistically significant reduction in Hb, Ht, mean cell
haemoglobin and mean cell haemoglobin concentration. A statistically
significant increase in RDW was found in non-responders patients. Concerning
band 3 profile, we found differences statistically significant in
Pfrag (lower in non-responders). CRF patients presented an anaemia,
which was enhanced in non-responders; this anaemia is regenerative, as
patients presented twice the reticulocyte control value, being higher in
non-responders. The higher RDW observed in patients, may reflect this
rise in reticulocyte count; however, the higher RDW value for nonresponders
may also reflect a higher RBC damage. Actually, the changes
observed in band 3 profile presented by CRF patients, a decrease in
HMWAg and a rise in Pfrag, seems to reflect a younger erythrocyte population,
However, the higher HMWAg presented by non-responders,
when compared to responders, suggest a higher RBC damage in that
patients. Our data suggest that in CRF patients there is an underlying oxidatixe
stress, which is linked to RBC damage, triggering the enhancement
of the reticulocyte production. Band 3 changes suggest an increase
in damaged RBC, but also an increase in younger RBCs. Band 3 profile
could be used as a marker of RBC changes in these patients and in understanding
the mechanism of resistance to rhEPO therapy.
12 th Congress of the European Hematology Association
0790
IRON DEFICIENCY IN CHILDREN WITH MALABSORPTION
M.F. Ferrara, C.L. Capozzi, S.G. Save, E.L. Esposito
Second University of Naples, NAPLES, Italy
Background. The malabsorption represent a frequent cause of iron deficiency
(ID) in children and adolescents unresponsive to iron therapy.
Aims. In these patients an early diagnosis is necessary for an appropriate
therapy. Methods. A retrospective study on 240 subjects with ID, age
range 7.5 months- 16 years was performed. In patients unresponsive to
iron therapy the causes of malabsorption were studied. ID was estabilished
by Hb, MCV, serum iron, serum transferring saturation and serum
ferritin (EIA) determination. Parasitologic stool analysis, fecal blood test,
measurement of antigliadin IgA and IgG, antiendomysial IgA and antitransglutaminase
IgA and IgG were performed in unresponsive patients
and in patients with gastrointestinal (GI) symptoms. The biopsy of the
small intestine via upper GI endoscopy confirmed diagnosis of celiac
disease (CD). Results. Our retrospective analysis shows that 41.5% of
patients of both sexes aged between 3 and 16 years had ID due to malabsorption.
The cause of malabsorption were: CD: 37 cases - 91% children
(3-10 years), 8% adolescents (11-15 years). Helycobacter Pylori
infections (HPI): 39 cases- 51% children(3-10 years), 49% adolescents
(11-16 years). Enteromonas infection: 15 children (3-10 years). HPI+CD:
8 children (3-10 years). Conclusions. An abnormal iron absorption leading
to ID, often in the absence of G.I. symptoms and without other manifestations
of malabsorption syndrome is increasingly being recognized.
We found that in childhood and adolescence the most important cause
of ID unresponsive to specific therapy is a reduced absorption due to
C.D. and/or H.P.I. H.P.I. can produce gastro-duodenal lesions with acute
or chronic blood loss, but it mainly influences iron absorption, lowering
the concentration of gastric juice ascorbic acid. Another cause of unresponsive
iron deficiency in our patients was enteromonas infection probably
through low intestinal absorption. The gluten free diet, improving
bowel function, corrected the secondary iron deficiency and mild anemia,
while, in the cases of more severe anemia (Hb< 7g/dL), specific
parenteral iron therapy was necessary. The eradication of HPI or
enteromonas parasitic infection improved the ID with mild anemia
while in the cases with more severe anemia specific iron therapy was
necessary. In patients unresponsive to oral iron therapy the diagnosis of
malabsorption should always be suspected.
0791
EXPRESSION LEVELS OF CD47, CD35, CD55, CD59 ON RED CELLS, AND SIRP-ALPHA,
BETA ON PERIPHERAL MONOCYTES FROM PATIENTS WITH WARM AUTOIMMUNE
HEMOLYTIC ANEMIA (WAIHA)
M. Oliveira Barros, 1 M. Yamamoto, 1 M.S. Figueiredo, 1 R. Cançado, 2
E. Kimura, 1 D. Langhi Jr, 2 J.O. Bordin1
1 2 Universidade Federal de São Paulo, SAO PAULO; FCM da Santa Casa de
Sao Paulo, SAO PAULO, Brazil
AIHA is defined as an increased destruction of red cells (RBCs) in the
presence of anti-RBC autoantibodies. CD47 is an integrin-associated
protein expressed on all cells including RBCs. Signal-regulatory proteins
(SIRPs) comprise a novel transmembrane glycoprotein that is especially
abundant in macrophages. Animal models show that the binding of RBC
CD47 to SIRP-α on macrophages contributes to the inhibition of phagocytosis,
and CD47-deficient mice develop severe AIHA, while CD35
(CR1- complement receptor 1), CD55 (decay accelerating factor) and
CD59 (membrane inhibitor of reactive lysis) are complement inhibitory
proteins. Using flow cytometric analyses, in this study we evaluated
the expression of CD47, CD35, CD55, CD59 on RBCs and SIRP-α,β on
peripheral monocytes of patients with wAIHA. The study population
consisted of 38 patients with AIHA, 23 with active AIHA [M:F = 7:16;
median age: 43 yrs (3-73)], 15 AIHA in remission without required medical
treatment [M:F=0:15; median age 48.5 yrs (18-82)] and 20 healthy
controls [M:F = 8:12, median age: 36.5 yrs (25-71)]. Thirty patients presented
idiopathic AIHA while 8 patients had secondary AIHA (2 systemic
lupus erythematosus, 3 non-Hodgkin lymphomas and 3 HCV
infection). The median Hb levels of patients with active AIHA was 9.5
mg/dL (range: 2.9 to 13.5 mg/dL) and median absolute reticulocyte
counts was 170×10 9 /L (range: 54 to 756×10 9 /L). At the time of the analyses,
22 patients had a positive direct antiglobulin test, 22 (95.6%) had IgG
on their RBCs, 9 (39.1%) had IgG plus C3. The RBC eluates
(dichloromethane technique) from cell samples were positive in 22
patients, but the retrieved autoantibodies were pan-reactive showing
no specific reactivity. The mean fluorescence intensity (MFI) of the
haematologica/the hematology journal | 2007; 92(s1) | 295