study of the kinetics of haemolysis in … of the kinetics of haemolysis in sickle cell trait: its...
TRANSCRIPT
STUDY OF THE KINETICS OF HAEMOLYSIS IN SICKLE CELL
TRAIT: ITS IMPLICATION IN TRANSFUSION
YM Sekongo *; S Kouamenan; A Abisse; S Konate; I Sanogo; S Konan; KD Yao;Centre National de Transfusion Sanguine, Abidjan, Côte d'Ivoire
INTRODUCTION
Sickle cell haemoglobinopathy: anomaly of the β chain of haemoglobin.
Glutamic acid at position 6 replaced by valine.
crystallization of haemoglobin,
Sickle cells formed
accentuation of physiological haemolysis
PO2 is lowered
Several haemoglobin phenotypes
Anaemic forms (SSFA2 et SFA2)
Non-anaemic forms (SAFA2 et SC).
Sickle cell trait AS is generally asymptomatic and detected by chance.
No treatment needed for Sickle Cell Trait, diagnosed during blood donations.
Legbedji (2009): 28% of sickle cell trait AS among blood donors
Cabannes et al: 12% of Ivory Coast population HbS carriers
INTRODUCTION
Sekongo Y.M. (2012) abnormal Hb : 15,06%; HbS 9,51%
Little is known of blood donation by heterozygous sickle cell trait AS persons.
Except in pathological conditions, haemolysis in subjects with sickle cell trait AS is not important
Normal red blood cells have a lifespan of 120 days
Kinetics of hemolysis undefined in heterozygous sickle cell trait AS
Ould A. (Trans Med 2006): 8% of sickle cell trait AS donors in Martinique; AS donors deferred
Bryant (Trans 2008) : variable in the US, depending on centres. If detected, red cell concentrate from AS donor contraindicated in neonates and in sickle cell disease recipients
Noizay-Pyrene (EFS site Mondor) 3.5% of donors with sickle cell trait
INTRODUCTION
Question : Is the level of haemolysis in a deoxygenated environment in bags that contain sickle cell trait AS phenotype blood significant, to the extent that residual haemoglobin becomes insufficient for transfusion?
Aim : determine the duration of storage of a bag that contains sickle cell trait AS blood
INTRODUCTION
GENERAL OBJECTIVECompare the kinetics of haemolysis in blood from AA and AS persons
SPECIFIC OBJECTIVES
1- determine potassium and haemoglobin level in each donor (AA and AS) at D0; D10; D20; D30
2- Estimate the haemoglobin weight in blood bags from AS and AA donors at D0; D10; D20; D30
3- Specify the optimal shelf-life of bags containing AS phenotype blood, to ensure an effective transfusion
METHODComparative Cohort Study: horizontal prospective
NBTS of Abidjan-Treichville
Duration : 2 (two) months: October 2010 – November 2010
11 AS donors and 11 AA control donors in a population of regular blood donors.
Donor eligibility criteria for blood donation: age, weight, pre-donation haemoglobin, medical consultation.
Random systematic sampling
All blood tested for transfusion transmissible infections HIV, HCV, HBV and Syphillis (negative) by serology on Architec
Total of 450 ml blood drawn +/-50 ml in triple bags with SAGM anti-coagulant
Sedimentation with extraction of plasma, to obtain one standard bag of red cell concentrate preserved in SAG-mannitol between 4°and 6°C.
After stripping the tube, several aliquots made and kept for 30 days between 4°and 6°C.
Bag of red cell concentrate introduced for distribution.
METHOD
EDTA and plain tube samples taken to perform serological and immuno-haematology tests on donated blood
Full blood count and serum potassium levels performed at D0; D10; D20 and D30.
Full blood count performed on automated haematology analyser of SYSMEX type.
Serial serum potassium levels performed on biochemistry autoanalyser by colorimetric and spectrophotometric methods.
Levels compared between normal donors (AA) and sickle cell trait (AS).
METHOD
RESULTS
0
5
10
15
20
25
Hb D0 Hb D10 Hb D20 Hb D30
AA1
AA2
AA3
AA4
AA5
AA6
AA7
AA8
AA9
AA10
AA11
Haemoglobin level among AA donors
Mean Hb AA g/dl)
D0 18,76 D10 17,76 D20 16,66 D30 16
RESULTSHaemoglobin level among AS donors
02468
101214161820
Hb D0 Hb D10 Hb D20 Hb DJ30
AS
AS
AS
AS
AS
AS
AS
AS
AS
AS
AS
Mean Hb AS g/dl)
16,43 15,26 11,76 10,76
D0 D10 D20 D30
HB weight (g) 78,871,9974,675,573,879,2178,6776,2273, 3173,6275,07
7466,472,9873,8671,7376,9976,4375,8971,4871,7273,11
73,260,9966,0167,1365,9270,1370,1969,7765,7165,9067,57
7255,9164,3765,2363,8467,9667,4667,5363,8163,8865,77
Mean 75.13 71.12 66.73 64.09
Percentage drop/ initial weight
X 5.33% 11.18% 14.69%
Haemoglobin weights in bags of AA donor blood and percentage drop relative to original weight
D0 D10 D20 D30
HB weight(g)
5668,869,859,762,460,3166,6358,3465,3561,3263,27
4866,8
66,6954,8
58,7859,0262,4756,7861,1359,5761,94
46,847,261,2352,3547,5950,9752,7251,0555,0150,7653,41
41,3841,258,8947,2143,2145,4347,4246,7450,7841,4746,09
Mean 64.86 60.49 51.74 47.15
percentage drop / initial weight
X 6.7% 20.22% 27.3%
Haemoglobin weights in bags of AS donor blood and percentage drop relative to original weight
AA0
20
40
60
80
D0 D10 D20 D30
AA
AS
Comparison of mean haemoglobin weights of blood bag s obtained from AS and AA donors
Comparison of drop in haemoglobin weight in blood b ags from AS and AA donors relative to initial weight
DO D10 D20 D30
percentage drop /initial
weightAS subjects
X 6.7% 20.22% 27.3%
Percentage drop / initial weight
AA subjects
X 5.33% 11.18% 14.69%
Evolution of serum potassium levels among AA donors
0
5
10
15
20
25
30
35
K+ D0 K+ D10 K+ D20 K+ D30
AA1
AA2
AA3
AA4
AA5
AA6
AA7
AA8
AA9
AA10
AA11
0
5
10
15
20
25
30
35
K+ D0 K+ D10 K+ D20 K+ D30
AA1
AA2
AA3
AA4
AA5
AA6
AA7
AA8
AA9
AA10
AA11
Evolution of potassium levels (Kaliémie) among AS donors
DISCUSSION
Mean haemoglobin levels in our donors prior to donation greater or equal to 12g/dl
Haemoglobin levels drop as from D10 among AS donors;
Brief drop at D10, then stable level among AA donors
Mean haemoglobin weight of blood bags from AS phenotype donors close to red cell concentrate production norms at D0 and D10
The weight drops as from D20.
Weight of blood bags from AS donors lower than those from AA donors.
Variation in weight among different AS donors; probably linked to endogenous or exogenous factors that need to be identified
DISCUSSION
Percentage of HbS in the blood bag?
Drop in haemoglobin weight as from D10: blood units from AS donations may be proposed for transfusion only in the 10-days following the date of donation.
Bryant USA: red cell concentrate contra-indicated in neonates and sickle cell disease patients
ACKLEY: After deglycerolisation of blood bags from AS donors, these retain their viability up to six (6) days
Difference in the drop of haemoglobin weight between AA subject and AS subject. Drop is more pronounced among AS subjects
DISCUSSION
Noizat-Pyrene (EFS ile de France site Mondor): Problems caused A/S red cell concentrate
Clogging of filters during leukodepletion
AS red cell concentrate: filter blocked within 7 min
AA red cell concentrate: filtration in 12 minMechanism
During blood donation: Anticoagulant
-hyperosmolarity, Acid with lowering of SaO2 levels
During storage:
-temperature, duration
« sickling » of AS red cells with increased adherenceExclusion of AS subjects from blood donations
DISCUSSION
Serum potassium levels increase with time: indirect marker of haemolysis
More marked increase in AA donor than in AS donor
Noizat-Pyrene: Increase in serum potassium level during storage of red cell concentrate
Higher serum potassium levels in AA subject than in AS subject: paradoxical
Distribute freshest possible blood to patients in critical condition.
DISCUSSION
CONCLUSIONHaemolysis is observed in both AA donors and AS donors, however it is increased in AS donors.
Mean haemoglobin weight in blood bags from AS donors is within quality norms for up to 10 days.
Given our conditions for distribution of blood products (few blood donors), AS donors cannot be excluded from giving blood.Transfusion of red cell concentrate from AS donors must be within 10 days post-donation
AS red cell concentrate contra-indicated in neonates and sickle cell disease patients
CONCLUSION
PERFORM HAEMOGLOBIN ELECTROPHORESIS IN BLOOD DONORS?
�YES
� NO
SICKLING TEST AN ALTERNATIVE?
ACKNOWLEDGEMENTPr Sanogo DG of CHU Treichville
Dr Kouamenan Sidonie Hémovigilence NBTS
Personnel from Consultation site NBTS Treichville
Dr Tchimou, Dr Konan S Distribution
Dr Yao D. RAQ NBTS
Quality Control Laboratory NBTS
QB laboratory of NBTS
Mr AKA Jules GIMED laboratory
Dr KONATE Seidou: Director NBTS