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

Transfusion medicine and vascular biology
0832
AN AUDIT OF RED CELL CONCENTRATE, FRESH FROZEN PLASMA AND CRYOPRECIPITATE
USE WITHIN THE WEST OF SCOTLAND: A 5-YEAR REPEAT ANALYSIS
J. Laird, R. Soutar
West of Scotland Blood Transfusion Centr, GLASGOW, United Kingdom
Background. The Regional Haematology Audit Group covers a population
of 3 million (the area of the regional transfusion centre). An audit
was undertaken in 2000 analysing use of plasma products and was published:
discrepancies in use were identified between hospitals and the
following represents a repeat analysis over the interim 5-year period.
Aims. The main aim was to show a change in FFP and cryoprecipitate use
between the 2 study periods in order to assess the effectiveness of modifications
introduced following the last audit. Additional areas evaluated
were the assessment of Rhesus status on prescription of FFP and the
laboratory systems in place to recognise those requiring methylene bluetreated
FFP (MBTFFP). Methods. A questionnaire was distributed to all 15
regional hospitals with an 87% response rate. This compared April 2004-
March 2005 with the same period 1999-2000. Results. The results showed
a decline in blood product use during this period despite a 2.9% increase
in bed numbers within the region. Since 2000, there was a 9.1% reduction
in red cell transfusions, but an even greater reduction in FFP (17%)
and cryoprecipitate (20%) used. Using bed numbers as a surrogate reflection
of activity, a mean of 13.65 red cell units were issued per bed (range
7.68-21.32, SD 4.51) in 2000, compared to11.99 in 2005 (range 5.15-
17.91, SD 3.34) p=0.046. Repeat analysis identified a substantial change
in practice in previously outlying hospitals in terms of blood product use;
two hospitals, shown to have excessive use of both FFP and cryoprecipitate
in the initial study (presumed due to automatic issue in 'crashpacks')
now compare favourably to the rest of the region This practice
has now been discontinued at both institutions and as a result they are
mainly responsible for the observed reduction in use within the area.
Resultant savings of around £250,000 per annum have been estimated
due to this alteration in practice. A marked difference in blood product
use between the two cardiac surgery centres was observed, which was
thought to be attributable to regular use of thromboelastography in one.
Interestingly, 15% of centres still continue to take Rhesus D status into
consideration on FFP issue whilst 23% consider it in females of childbearing
age, contrary to recent guidance from the BCSH. It was also observed
that no standard laboratory procedures were in place for the issue of
MBTFFP and only 50% of the hospitals with potential use of this product
had it in stock. Conclusions. At a time when national FFP use is rising,
we have shown a reduction in red cell, FFP and cryoprecipitate use. The
report demonstrates that effective audit can improve and change clinical
practice - something that is often questioned.
0833
TRANSFUSION-RELATED ACUTE LUNG INJURY (TRALI) FOLLOWING INTRAVENOUS
IMMUNOGLOBULIN (IVIG) INFUSION
G.A. Zakout, 1 J.E. Tighe, 1 D. Culligan, 1 M.A. Greiss2 1 2 Aberdeen Royal Infirmary, ABERDEEN; Aberdeen Blood Transfusion Center,
ABERDEEN, United Kingdom
Background. Transfusion related acute lung injury is an uncommon life
threatening complication of blood product transfusion. It is defined in the
recent Canadian consensus conference on TRALI as a new episode of
acute lung injury (ALI) that occurs during or within 6 hours of completed
transfusion, and which is not temporally related to a competing aetiology
of ALI. The Serious Hazards of Transfusion (SHOT) data from
the United Kingdom showed an incidence of 70 confirmed cases per 16
to 17 million-blood components transfused. However, the true incidence
of TRALI remains unknown mainly due to the previous lack of standardisation
of its definition and under recognition. Virtually all plasma-containing
blood products have been implicated, particularly when they are
sourced from female donors. Despite the ample amount of leucocyte
antibodies in IVIG, this blood product has rarely been reported to cause
TRALI. Aim. To report an adverse event to IVIG that has rarely been
reported on literature review. We also highlight that TRALI is a clinical
rather than a laboratory diagnosis. Methods. A 55-year-old patient with
angioimmunoblastic T-cell lymphoma (AITL) was admitted 3 weeks
after his first cycle of oral fludarabine and cyclophosphamide with severe
pneumonia. Three days following his clinical and radiological recovery
12 th Congress of the European Hematology Association
from pneumonia, he was given prophylactic IVIG as he had secondary
hypogammaglobulinemia, which is an unusual finding in AITL (polyclonal
increase in immunoglobulins is commonly found). He developed
non-cardiogenic pulmonary oedema 40 minutes into the IVIG infusion.
This manifested itself by a drop in O2 saturation to 77% and bilateral
pulmonary infiltrates on a chest X-ray. His O2 saturation improved to
91% on 15 L/min oxygen and he made a complete recovery within 12
hours of onset. Results. Testing in our regional Blood Transfusion Centre
revealed a positive direct granulocyte immunofluorescence (GIF),
which persisted for 11 weeks following the TRALI event, and a negative
indirect GIF assay. This suggests the presence of granulocyte-bound
rather than free antibodies. A crossmatch between the patient’s granulocytes
and IVIG was positive. No anti-HLA Class I or II antibodies were
detected on standard complement-dependent cytotoxicity (CDC) and
ELISA assays respectively, in either the patient or the residual IVIG
infused. Summaryand Conclusions. TRALI still remains a challenging diagnosis
despite the proposed guidelines for defining it. The same consensus
panel that proposed the definition agrees that TRALI is a clinical and
radiographic diagnosis rather than a laboratory one. Based on this, our
patient fulfilled the clinical diagnostic criteria. AITL is commonly associated
with autoimmune phenomena secondary to marked immune activation
evidenced by increased expression of an array of cytokines. A significant
proportion of patients have circulating autoantibodies. There is
at least 1 case report in which antigranulocyte antibodies were noted in
association with AITL. Such phenomena can ‘prime’ neutrophils, which
upon exposure to the IVIG infused are activated resulting in endothelial
damage and capillary leak. IVIG has rarely been reported to cause TRALI.
We postulate that the immune dysregulation associated with AITL predisposed
to the development of TRALI following IVIG in this case.
0834
CONTRIBUTION OF STORAGE-INDUCED PLATELET MICROPARTICLES TO THROMBIN
GENERATION
G. Ivanov, 1 N. Bowen, 1 C. Saunders, 2 P.W. Collins1 1 2 University Hospital of Wales, CARDIFF; The Welsh Blood Service, PONTY-
CLUN, United Kingdom
Background. Procoagulant activity of platelet microparticles (MPs) has
been extensively described. The number of platelet-derived MPs increases
significantly with time during platelet storage. The understanding of
storage-induced MPs’ contribution to thrombin generation (TG) could be
important in situations when additional procoagulant effect of platelet
transfusions is undesirable (e.g. disseminated intravascular coagulation).
Aims. To assess the contribution of storage-induced platelet MPs to
thrombin generation at the beginning and the end of platelet concentrate
shelf life. Methods. Platelet concentrates used were leucodepleted pooled
preparations, sampled initially at Day 2 and at the end of shelf life (6 to
8 days, mean 7.25 days, n=13). Platelet concentrates were stored under
standard blood bank conditions, at 22ºC on a lateral shaking device.
After sampling, platelet concentrates were diluted with autologous
platelet-free plasma (PFP) and mixed 1:2 with freshly prepared donors’
PFP containing corn trypsin inhibitor (CTI). This step was introduced in
order to prevent contact activation as well as to replenish plasma clotting
factors that may have been lost during platelet storage. Thrombin
generation was triggered with 0.5 pM TF and recorded using automated
calibrated thrombography. Parameters such as lag, peak thrombin, initial
and maximal velocity of TG were studied in platelet-rich (PRP) and
PFP, as well as in PFP filtered through 0.1 µm filter. Initial velocity of TG
(Vini) was defined as the slope of the TG curve between 1 and 10
nM/min. Vmax was calculated as the maximal velocity of TG. Results.
Using low-dose TF trigger in presence of CTI, we observed minimal or
no TG in freshly prepared PFP obtained from normal donors. However,
in PFP obtained by centrifugation of platelet concentrates, we demonstrated
significant procoagulant activity both at early and late stages of
storage. All of the TG parameters tested in MP-containing PFP of stored
platelets were not significantly different from those produced by PRP
with a platelet concentration of 50×10 9 /L. Further increase in platelet
concentration to 100×10 9 /L did not lead to a significant rise in procoagulant
activity. Removal of MPs by filtration of PFP, derived from Day 2
platelet concentrates, led to a significant prolongation of lag time and
reduction in thrombin peak, Vini and Vmax as compared with unfiltered
PFP. TG was completely abolished when PFP from 7 day-old platelets
was subjected to filtration. We observed a significant loss of both
platelet-dependent and MP-dependent procoagulant activity in platelet
concentrates stored for 7 days as compared with ones stored for 2 days.
Although all of the tested parameters pointed to a significant loss of
thrombin generation potential with platelet storage, most noticeable dif-
haematologica/the hematology journal | 2007; 92(s1) | 311