Nghiên cứu hiệu quả truyền máu hòa hợp một số kháng nguyên nhóm máu hồng cầu ở bệnh nhân thalassemia tại viện huyết học – truyền máu trung ương TT TIENG ANH

MINISTRY OF
EDUCATION AND TRAINING

MINISTRY OF
HEALTH

HANOI MEDICAL UNIVERSITY

HOANG THI THANH NGA
STUDY ON
EFFECTIVENESS OF RED CELL ANTIGEN
MATCHING TRANSFUSION FOR THALASSEMIA
PATIENTS AT NATIONAL INSTITUTE OF
HEMATOLOGY AND BLOOD TRANSFUSION

Specialism: Hematology and blood transfusion
Code:

62720151

ABSTRACT OF THESIS

HANOI – 2021


The thesis has been completed at
HA NOI MEDICAL UNIVERSITY

Supervisors:
Supervisor 1:

Prof. PhD. Bui Thi Mai An

Supervisor 2:

PhD.MD. Bach Quoc Khanh

Reviewer 1:
Reviewer 2:
Reviewer 3:

The thesis will be presented in front of board of university examiner
and reviewer level at Hanoi Medical University
The thesis can be found at:
-

National Library

-

National Medical Informatics Library

-

Library of Hanoi Medical University


1
INTRODUCTION
Thalassemia is a common hereditary disease in the world as well as
in Vietnam. Today, frequent blood transfusion and iron chelation is the

main and effective treatment method that can improve the life quality of
thalassemia patients. However, multiple transfusion is one of the major
causes for unexpected antibodies production, leading to transfusion
reaction and lower transfusion effectiveness for patients. To overcome
the consequences of unexpected antibodies, red cell antigen matching
transfusion is the best solution. Red cell antigen matching transfusion
for thalassemia patients has been applied in many countries all over the
world and showed obvious effectiveness.
The establishment of walking blood bank in 2007 at National
Institute of Hematology and Blood Transfusion (NIHBT) has provided
the database for selection of blood donors with proper phenotypes,
therefore it is possible to produce screening and identification red cell
panel and provide nationally to guarantee immunological transfusion
safety. Thanks to the walking blood bank, the selection and red cell
antigen matching transfusion for thalassemia patients can be performed
since 2011 and gradually expanded. Red cell antigen matching
transfusion has brought initially better treatment results for patients.
The study was carried out with two objectives:
1. To identify the rate of red cell antigens of some blood group
systems: ABO, Rh, Lewis, Kell, Kidd, MNS, Lutheran, Duffy, P1PK
in thalassemia patients at NIHBT.
2. To analyze the results of blood units selection and effectiveness of
red cell antigen matching transfusion for thalassemia patients.


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Practical significance and new findings of the thesis:
1. The thesis has made new contributions to the specialty in
improving the treatment results for thalassemia patients, helping
thalassemia patients to receive blood transfusions more safely and

effectively as well as reducing the rate of unexpected antibody
reduced significantly.
2. The thesis has identified the proportion of some blood group
antigens which is clinically significant in thalassemia patients at
NIHBT.
3. The thesis has also contributed to the way to select red cell
antigen matching units, except for ABO and Rh(D), in the context
of almost blood centers can not perform these tests for blood
donors.
4. With enough sample size (142 patients) and long follow-up
period (nearly 10 years), the thesis has also revealed the
effectiveness of red cell antigen matching transfusion compared to
traditional ABO and Rh(D) compatible transfusion.
Structure of the thesis: the thesis consists of 122 pages, including:
Introduction (2 pages), Chapter 1 overview (34 pages), Chapter 2
subjects and method (20 pages), Chapter 3 results (27 pages),
Chapter 4 discussion (36 pages), Conclusion (2 pages) and
Recommendation (1 page). The results are presented in 34 tables,
12 charts and graphs. There are 131 references including 72 English
and 59 Vietnamese articles.


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Chapter 1 OVERVIEW

1.1. Some red cell blood group system and clinical significance
Since 1900, many blood group systems have been discovered.
Until June of 2021, the International Society of Blood Transfusion has
approved that there are 43 blood group systems with 376 different
antigens. A blood group system is clinical significance when its

antibodies can shorten the lifetime of donor red cells in patients’
circulation and there is evidence of hemolysis or hemolytic anemia of
the fetus and newborn. Some red cell blood group systems are
considered clinically significant in transfusion practice including:
ABO, Rh, Lewis, Kell, Kidd, MNS, Lutheran, Duffy, P1PK. Most of
these have the high capacity of immunity stimulation. Their
corresponding antibodies can trigger acute hemolytic reaction (anti-A,
anti-B of ABO system, anti-D of Rh system..) or delayed hemolytic
reaction (anti-Jkb of Kidd system, anti-Fyb of Duffy system…) and
hemolytic disease of the newborn due to blood group incompatibility
between mothers and their babies.
1.2. Unexpected antibodies
Unexpected antibodies are antibodies that do not exist in serum
of normal people, they only appear when the patients are sensitized
with allogeneic red cells through blood transfusion with incompatible
blood group antigens or incompatible blood group antigens between
mothers and their babies.
1.2.1. Mechanism of unexpected antibody appearance
There are two main mechanism of irregular antibody
appearance, one is transfusion (the patients are transfused with
incompatible antigen from donors) and the other is pregnancy and
laboring process (the fetus carries antigen incompatible with the


4
mother).
1.2.2. Factors associated with unexpected antibodies appearance
- Red cell blood group antigen incompatibility between donors and
recipients or mothers and fetus is the first and mandatory condition.
- Immunogenicity of blood group antigens: Very different. D antigen is

considered to be the strongest immunogenicity, then the next is K
antigen.
- Blood transfusion times: The more times patients receive blood
transfusion, the more unexpected antibodies produces.
- Host factor: The ability of individual to produce antibodies in
response to antigen expose varies.
- The starting age of blood transfusion: Patients under 2 years old have
lower immunostimulation level compared to adults.
- Duration of transfusion treatment: Most of the antibodies appear six
months after transfusion.
1.2.3. Transfusion reaction related to unexpected antibodies
1.2.3.1. Acute hemolytic reaction
Acute hemolytic reaction happens very soon after incompatible
transfusion. It usually happens within 24 hours after transfusion. Some
cases occur only a few minutes after transfusion. The patients have
clinical symptoms including: dyspnea, chill, vomiting, nausea, fever,
back pain, pain along the transfused vein, shock, acute renal failure
and disseminated intravascular coagulation. The patient may die if not
diagnosed and treated early. Beside ABO system antigen, some
antigens of other blood group systems can bind and activate
complement cascade that induce acute hemolysis such as antibodies of
Rh, anti-K of Kell, anti-Jka of Kidd, anti-Fya of Duffy system.


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1.2.3.2. Delayed hemolytic reaction
Delayed hemolytic reaction usually happens after 24 hours of
transfusion. The characteristic is extravascular so clinical symptoms
are often milder than acute reaction. The patients often have symptoms
like fever, intermediate jaundice, hemoglobinurina. Red blood cell

destruction due to many different unexpected antibodies, the most
common are antibodies of Rh, Kidd, Duffy, Kell, MNS system.
1.3. Thalassemia
1.3.1. Definition
Thalassemia is a congenital hemolytic anemia, caused by
deficiency in synthesis of one or many polypeptides in the globin chain
of hemoglobin (Hb). Depending on the deficiency in alpha (α), beta
(β), or delta (δ) and β chain, it is called α-thalassemia, β-thalassemia or
δβ- thalassemia.
1.3.2. Classification
1.3.2.1. Classification based on disease type and severity
The disease can be classified into 2 main groups: α-thalassemia
(caused by reduction or loss of α globin chain synthesis), β-thalassemia
(caused by reduction or loss of β globin chain synthesis). Otherwise,
there may be a combination between α-thalassemia and β-thalassemia.
1.3.2.2. Classification based on principle of blood transfusion
Transfusion dependent thalassemia: the patients need frequent
transfusion to maintain their life. This includes major β thalassemia,
major β thalassemia/HbE, major HbH.
Transfusion independent thalassemia: the patients do not need
frequent transfusion to maintain their life, they may need transfusion in
some circumstances. This includes intermediate and minor β


6
thalassemia, intermediate and minor β thalassemia/HbE, intermediate
and minor HbH.
1.3.3. Pathological mechanism
When the gene coding globin synthesis is damaged, the
production of globin chain will be reduced or unable to synthesize,

leading to redundancy of the corresponding other chain. The redundant
globin chain will combine to form hemoglobin inclusions. These
inclusions can attach to the red cell membrane and change its
permeability and flexibility, so the red cell is fragile. Red cells lose
flexibility and become easier to be catched and destroyed at the spleen
and other reticuloendothelial organs, which causes anemia. In this
condition, the liver will reduce the synthesis of hepcidin, so ferroportin
will be released to increase liver absorption from the intestinal system
and inhibit iron release from macrophage which causes iron overload.
Thalassemia patients need multiple transfusions which also leads to
iron overload in the body and damages tissues and organs such as liver,
spleen…
1.3.4. Treatment
Nowadays, there are many treatment methods for thalassemia
patients. However, transfusion and iron chelation are the most effective
treatment methods, which can improve the quality of patients' life.
1.4. Red cell antigen matching transfusion for thalassemia patients
1.4.1. Red cell antigen proportion of some blood group systems in
thalassemia patients
Identification of red cell antigen proportion in thalassemia
patients helps estimate the supply ability of compatible blood units for
patients as well as predict the probability of unexpected antibodies
appearance. Study of Slwa Hindawi (2020) in Arabia Saudi in 104
thalassemia patients showed that the rate of C, c, E, e and K antigen


7
was 87.5%, 93.27%, 37.5%, 99.04% and 5.77% respectively which
similar to that of 1015 blood donors. Study of Karina Yazdanbakhsh
et al (2012) showed that the rates of A, B, O, AB in American

thalassemia patients with African origin were 27%, 20%, 49% and 4%
respectively. The rate of non-ABO red cell antigen: Rh system: D:
92%, C: 27%, c: 96%, E: 20%, e: 98%; Kell system: K: 2%; Kidd
system: Jka: 92%, Jkb: 49%; MNS system: S: 31%, s: 93%; Duffy
system: Fya: 10%, Fyb: 23%.
1.4.2. Unexpected antibody percentage and situation of red cell
antigen matching transfusion for thalassemia patients
Studies of many authors have shown that the rate of unexpected
antibodies in thalassemia patients is relatively high and the unexpected
antibodies model of thalassemia patients is specific for each region,
each country. Studies in Europe showed that the rates of unexpected
antibodies varies about 2.87 to 30%, in which the majority of
unexpected antibodies was Rh system and anti K of Kell system. In
Asian countries and Vietnam, the rates of unexpected antibodies in
thalassemia patients are similar to European regions, but the model of
unexpected antibodies is significantly different, common unexpected
antibodies in thalassemia patients are antibodies of Rh system and antiMia of MNS system.
From studies about the rate and model of unexpected antibodies in
thalassemia patients, the authors suggested the strategies of red cell
antigen matching transfusion. All authors agreed to propose priority of
phenotype matching transfusion for Rh system (D, C, c, E, e) and Kell
system (K)/ MNS system (Mia). If possible, it is recommended to
perform extended red cell antigen matching for transfusion such as
Duffy (Fya, Fyb), Kidd (Jka, Jkb) MNS (M, N, S, s), Lewis (Lea, Leb),
P1PK (P1).


8
With obvious effectiveness of reducing unexpected antibodies
production, red cell antigen matching transfusion has been widely

applied in many countries in the world. In the USA, there are 50% of
blood centers that perform phenotype matching transfusion for Rh
system and K antigen of Kell system for patients. In Canada, all
thalassemia patients are tested for ABO and non-ABO blood group
antigen in first time examination and receive red cell antigen matching
units with Rh system (D, C, c, E, e) and Kell system (K).
In NIHBT with the establishment of a walking blood bank, red cell
antigen matching transfusion for thalassemia patients started in 2011
and has brought about initial transfusion effectiveness for patients.
1.4.3. The issue of supplying red cell antigen matching units to the
patient
Supply of red cell antigen matching units for patients is always a
challenge for blood banks. To solve this issue, in developed countries,
red cell antigens typing for donors has been done routinely. In
developing countries like Vietnam, in the context of blood banks can
not perform tests for typing of some non-ABO antigens for donors, the
establishment of a walking blood bank is an effective solution.
Chapter 2
STUDY SUBJECTS AND METHOD
2.1. Study subjects
2.1.1. Study subjects
- Group I: To serve the first objective that identify the rate of red cell
antigens of some blood group systems: including 240 thalassemia
patients treated at Thalassemia center, National Institute of
Hematology and Blood Transfusion from 01/2021 to 04/2020, were
tested for blood group antigens of ABO, Rh (D, C, c, E, e), Lewis (Lea,


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Leb), Kell (K, k), Kidd (Jka, Jkb), MNS (M, N, S, s, Mia), Lutheran

(Lua, Lub), Duffy (Fya, Fyb), P1PK(P1).
+ Eligible criteria: thalassemia patients had no history of blood
transfusion and agreed to join the study.
+ Exclusion criteria: thalassemia patients had positive direct
Coombs test.
- Group II: To serve the second objective that analyze the results of
blood unit selection and effectiveness of red cell antigen matching
transfusion: including 142 thalassemia patients of group I who were
transfused red cell antigen matching units.
+ Eligible criteria: Patients are selected and transfused red cell
antigen matching units throughout all the courses of treatment.
+ Exclusion criteria:
 Patients who went to NIHBT for examination, diagnose and
red cell antigen matching transfusion for the first time then
did not return to treatment (32 patients of group I).
 Patients who do not comply with transfusion protocol
(transfused in both other hospitals and NIHBT) (66 patients
of group I).
2.1.2. Criteria for red cell antigen matching units selection
- Complete compatible blood units: the blood units are matched with
17 non-ABO blood group antigens , including Rh (D, C, c, E, e), Lewis
(Lea, Leb), Kidd (Jka, Jkb), MNS (M, N, S, s, Mia), Duffy (Fya, Fyb),
P1PK (P1).
- Incomplete compatible blood units: the blood units are not matched
with all 17 non-ABO antigens of 6 above systems.
- In cases that complete compatible blood units selection is impossible,
the selection priority should be: D > E > Mia > c > Fya > C > Jka > P1 >
M > e > Lea> Leb > S > s > N > Fyb > Jkb.

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2.1.3. Criteria for blood unit storage
Based on the Thalassemia Federation’s guidelines, all red cell
antigen matching units for transfusion to thalassemia patients need to
be stored at 2-8oC, no longer than 7 days.
2.1.4. Criteria for anemia classification
Anemia classification was based on the document "Anemia:
classification and treatment" (Internal pathology, Medical Publisher) of
author Pham Quang Vinh (2012):
- Mild anemia: Hb from 90 g/l to 120 g/l.
- Moderate anemia: Hb from 60 g/l to under 90 g/l.
- Severe anemia: Hb from 30 g/l to under 60 g/l.
- Very severe anemia: Hb lower than 30 g/l.
2.1.5. Criteria for ending a course of treatment
- The patient’s hemoglobin after transfusion is from 90 to 105
g/l;
- Acute complications of the disease are treated stably (infection,
acute liver damage ...)
2.2. Study method
2.2.1. First objective: To identify the rate of red cell antigens of
some blood group systems in thalassemia patients at NIHBT
2.2.1.1. Study design: Cross-sectional descriptive, retrospective and
prospective study.
2.2.1.2. Sample size and sampling method
-

Sampling method: Convenient sampling.
Sample size: Using sample size formulation to estimate for a
proportion:

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Details: n: sample size, p: the proportion from a previous study
with the same population; Δ: the expected deviation between results
from the sample and from the population; choose Δ = 0.05; α: level of
statistical significance, Z1-α/2: confidence score; Z value derives from
Z table, corresponding to chosen α value. Choose α = 0.05,
corresponding Z1-α/2 is 1.96.
Based on author Do Trung Phan's study (2000) about some red
cell antigens proportion in Vietnamese people from 1995-2000, the
rate of S antigen accounted for the lowest (9.6%), we calculated the
minimum required sample size for the first objective as 133 patients.
The actual sample size for the first objective in our study was 240
patients.
2.2.1.3. Study process
- Step 1: Collect general information of study subjects into study
records.
- Step 2: Perform tests to identify blood group types of ABO system
and some antigen of 8 systems by gel column agglutination technique.
- Step 3: Collect results into study records.
- Step 4: Enter data from study records into SPSS 16.0 software.
- Step 5: Calculate the rate of ABO blood groups, the rates of some
antigens and phenotypes of Rh, Lewis, Kell, Kidd, MNS, Lutheran,
Duffy, P1PK system.
2.2.2. Second objective: To analyze the results of blood unit
selection and effectiveness of red cell antigen matching
transfusion for thalassemia patients
2.2.2.1. Study design: nonrandomized, uncontrolled clinical trial.
2.2.2.2. Sample size and sampling method
All patients from group I satisfied for eligible criteria were

selected to study for second objective.


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2.2.2.3. Study process
- Step 1: Calculate the required transfused blood for patients and blood
transfusion is indicated.
- Step 2: Select red cell antigen matching units to transfuse for
patients:
+ Based on the database of donors’ antigens in walking blood bank
managed at NIHBT, selecting donors who have 17/17 compatible
antigens with patients. In cases that selection of 17/17 compatible
antigens donor is impossible, selecting compatible donors according
to priority antigen as follow: D > E > Mia > c > Fya > C > Jka > P1 >
M > e > Lea> Leb > S > s > N > Fyb > Jkb.
+ Contact blood donors by telephone or email to invite them for
blood donation
+ Blood donors are clinical examined, pre-donation tests are done
and blood is collected by plastic bag with procedures approved by
NIHBT.
+ Total blood units from donors are tested and produced to packed
red blood cell and other blood components, stored according to
Ministry of Health regulation and procedures approved by NIHBT.
- Step 3: Perform compatible tests before blood transfusion.
- Step 4: Transfuse blood and evaluate the results through:
+ Clinical symptoms of patients before, during and after
transfusion.
+ Tests including total peripheral blood analysis, indirect bilirubin,
LDH at times of blood transfusion and after each course of
treatment.

+ Calculate the medium transfused blood volume in one course of
treatment.
+ Calculate the medium transfused blood volume per kg weight in


13
one course of treatment.
+ Monitor the formation of unexpected antibodies through time
after transfusion.
+ Some typical cases about effectiveness of red cell antigen
matching transfusion.
- Step 5: Collect the results into study records.
- Step 6: Enter data into SPSS 16.0 software.
- Step 7: Data process.
2.3. Data processing
- Collected data was processed by a medically statistical method with
SPSS 16.0 software. For quantitative variables: T-Student validation
was used. For qualitative variables: χ2 validation was used. The
difference was significant when p < 0.05.
2.4. Ethical issue of the study
The study was approved by the Leaderboard of NIHBT and the
Ethical Committee in Biomedical research of Hanoi Medical
University (certificate number 81/HĐĐĐĐHYHN-30/5/2017).

Chapter 3
RESULTS
3.1. General features of study subjects
Among 240 thalassemia patients who were identified antigens of
some red cell blood groups, male accounted for 49.6% while female
was 50.4%. β thalassemia/HbE patients proportion was the highest

(55.4%), then β thalassemia patients percentage was 29.2%, the lowest
group was α thalassemia patients (15.4%). The median age of α
thalassemia and β/HbE was 11 years old, that of β thalassemia patients
was 7.5 years old.


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3.2. Identification of the rate of red cell antigens of some blood
group systems: ABO, Rh, Lewis, Kell, Kidd, MNS, Lutheran,
Duffy, P1PK in thalassemia patients at NIHBT
3.2.1. ABO system: the rate of A, B, O and AB group in thalassemia
patients was 11.3%, 30.7%, 53.8% and 4.2% respectively.
3.2.2. Rh system: the rate of Rh antigens in thalassemia patients was
D: 100%, C: 95.8%, c: 36.7%, E: 29.6% and e: 97.1%.
3.2.3. Lewis system: in total 240 thalassemia patients, the rate of
patients with Lea antigen was 40% while that of Leb antigen was
49.2%.
3.2.4. Kell system: all 240 thalassemia patients had k antigen on red
cell surface (100%), no patients had K antigen.
3.2.5. Kidd system: the rate of patients with Jka antigen and Jkb antigen
was 68.3% and 90.4% respectively.
3.2.6. MNS system: the rate of M, N, s antigen in thalassemia patients
was quite high, 91.3%, 75.8% and 100% respectively. S and Mia
antigen had lower frequencies, 10.8% and 37.5% respectively.
3.2.7. Lutheran system: all 240 thalassemia patients had Lub antigen on
red cell surface (100%), no patient had Lua antigen.
3.2.8. Duffy system: All patients had Fya antigen while only 14.2%
patients had Fyb antigen.
3.2.9. P1PK system: the rate of patients with P1 antigen was 40.4%.
3.3. Analysis of the results of blood units selection and

effectiveness of red cell antigen matching transfusion for
thalassemia patients
3.3.1. Results of selection of red cell antigen matching units for
thalassemia patients
Table 3.1. Non-ABO red cell antigens selected for transfusion for
thalassemia patients


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Rh
D

C

c

Lewis
E

e

Le

a

Le

Kidd
b

a

Jk

MNS
b

Jk

M

N

S s

Duffy
a

Mi

a

Fy

P1PK
b

Fy

P1

17 non-ABO antigens of 6 blood group systems were selected for
compatible transfusion for thalassemia patients.
We chose and provided 4,055 red cell antigen matching units for
142 thalassemia patients, the response rate was 95.5% compared to
clinical request. To get 4,055 red cell antigen matching units, we had
to mobilize 6,713 donation times, the successful rate of donor
mobilization was 60.4%.
Among 4,055 blood units selected, there were 3,901 units with
17/17 compatible antigens, 97 units with 16/17 compatible antigens,
and 57 units with 15/17 compatible antigens. There were 91 patients
transfused with 2,304 completely compatible blood units (17/17
antigens), 51 patients transfused with incompletely compatible blood
unit (1597 units with 17/17 compatible antigens, 97 units with 16/17
compatible antigens and 57 units with 15/17 compatible antigens). The
incompatible antigens were Lea, Leb of Lewis system, M, N, S of MNS
system, P1 of P1PK system and Jka, Jkb of Kidd system. The medium
blood units number selected for a patient was 14.5 units. All 4,055
selected blood units had negative results when tested with patients'
serum in 3 phases: 22oC, 37oC and AHG.
3.3.2. Effectiveness of red cell antigen matching transfusion for
thalassemia patients
3.3.2.1. Effectiveness of red cell antigen matching transfusion for
thalassemia patients
All 142 thalassemia patients had moderate to severe anemia, no
patients had mild anemia. After transfusion, the medium Hb of patients
increased significantly compared that before transfusion. Hb of


16

patients with moderate anemia increased from 74 g/l to 102.3 g/l while
Hb of patients with severe anemia increased from 52.1 g/l to 101.5 g/l.
Medium Hb of both patient groups increased from 70/1 g/l to 102.2 g/l.
Indirect bilirubin and LDH levels of patients before transfusion
were all high, specifically: medium indirect bilirubin was 34.7 ± 21.0
µmol/l and LDH was 877.9 ± 488.7 UI/l. After transfusion, both
indexes were still high but had no significant change compared to that
before transfusion, medium post-transfusion indirect bilirubin was 35.7
± 18.4 µmol/l and LDH was 880.0 ± 460.6 UI/l.
Medium total blood volume and blood volume/kg weight of
thalassemia patients in one treatment course was 506.5 ml and 12.1
ml/kg respectively.
The mean duration between 2 transfusion times in α thalassemia
patients was 7.2 weeks, β thalassemia patients was 5.8 weeks, β
thalassemia/HbE patients was 6.9 weeks.
In all 142 patients with 4,055 times of blood transfusion, none had
acute or chronic transfusion reaction. No patient produced unexpected
antibodies after 21.3 months of follow-up, including patients who
received blood units with 15/17 compatible antigens or 16/17 antigens.
3.3.2.2. Some cases about red cell antigen matching transfusion for
thalassemia patients
3.2.2.2.1. Case 1
Patient N.Q.D, male, born in 2011, was first treated in NIHBT in
6/2014. The patient was diagnosed with β thalassemia/HbE. The tests
for non-ABO antigen showed that the patient had 9/17 negative
antigen, including: c-, E-, Lea-, Jka-, M-, S-, Mia-, Fyb-, P1-. When
searching in the walking blood bank of NIHBT there were only 19
blood donors with compatible phenotype for the patient. We mobilized
these donors to donate blood for the patient during the treatment

17
course. From 06/2014 to 04/2020, the patients had been admitted to
hospital 47 times, and were transfused with 56 blood group antigen
compatible blood units. The patient's Hb was increased significantly
and no transfusion reaction was seen in all 56 transfusion times. The
patients had no unexpected antibodies after nearby 6 years of followup.
3.2.2.2.2. Case 2
Patient C.T.K, male, born in 2013, was first admitted to NIHBT
in 8/2015. The patient was diagnosed with β thalassemia. The tests for
non-ABO antigen showed that the patient had 9/17 negative antigen,
including: C-, e-, Lea-, Jkb-, M-, S-, Mia-, Fyb- and P1-. When searching
in the reserved blood bank of NIHBT there were only 6 blood donors
with compatible phenotype for the patient. We mobilized these 6
donors to donate blood for the patient during the next hospitalization.
From 08/2015 to 04/2020, the patient had been admitted to hospital 42
times, and was transfused with 45 red cell antigen matching units.
Among 45 blood units, there were only 2 blood units that were
compatible with 16/17 antigens because we could not mobilize those 6
donors to donate blood for the patients. For those 2 blood units, there
was one unit incompatible with Jkb antigen and one unit incompatible
with Fyb antigen. The patient had no reaction and unexpected
antibodies after more than 5 years of followi-up.
Chapter 4
DISCUSSION
4.1. Discussion about general features of study subjects
Among 240 thalassemia patients, males accounted for 49.6% (119
patients), similar to females with 50.4% (121 patients). β
thalassemia/HbE patients proportion was the highest (55.4%), then β

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thalassemia was 29.2% and the lowest group was α thalassemia
patients with 15.4%. The median age of α thalassemia and β/HbE was
11 years old, that of β thalassemia patients was 7.5 years old. Our
results were similar to studies of other domestic authors.
4.2. Discussion about identification of the rate of red cell antigens
of some blood group systems: ABO, Rh, Lewis, Kell, Kidd,
MNS, Lutheran, Duffy, P1PK in thalassemia patients at
NIHBT
Basically, the rates of some red cell antigens of ABO, Rh, Lewis,
Kell, Kidd, MNS, Lutheran, Duffy, P1PK system in thalassemia
patients at NIHBT were similar to those in Asia according to Sylvia T.
Singer (2000), but there was a difference compared to studies on other
races such as African American or Arabian according to studies of
Karina Yazdanbakhsh (2012) and Salwa Hindawi (2020). That showed
red cell antigens are specific for each country and race.
When comparing the rates of red cell antigen in thalassemia
patients at NIHBT with that in blood donors to predict the supply
ability of red cell antigen matching units for thalassemia patients, it
revealed that: the majority of red cell antigen in patients was similar to
donors, including D, C, c, E, e of Rh system, K and k of Kell system,
Jka of Kidd system, M, N, s of MNS system, Lua and Lub of Lutheran
system, Fya and Fyb of Duffy system. Some antigens in thalassemia
patients had higher rate than in donors, including Lea of Lewis system,
Jkb of Kidd system, S and Mia of MNS system, P1 of P1PK system.
These results made a great cntribution to select red cell antigen
matching units for thalassemia patients. Particularly, the Leb antigen
rate was much lower than in donors (49.2% in patients and 84.4 85.1% in donors). This brought difficulty in selecting red cell antigen
matching units with Lewis system for patients. Actually, if there was

19
unable to select or mobilize donors with 17/17 compatible antigens, we
had to accept Lewis incompatible donors who were compatible with
other priority antigen because Lewis system antigens are weak
immunostimulants and their corresponding antibodies rarely cause
transfusion reaction or only mild symptoms.
4.3. Discussion about analysis of the results of blood units selection
and effectiveness of red cell antigen matching transfusion for
thalassemia patients
4.3.1. Discussion about results of selection of red cell antigen
matching units for thalassemia patients
Non-ABO antigens that we chose to perform compatible
transfusion for thalassemia patients included 17 antigens of 6 blood
group systems, that were: 5 antigens D, C, c, E, e of Rh system, 2
antigens Lea, Leb of Lewis system, 2 antigens Jka, Jkb of Kidd system,
5 antigens M, N, S, s, Mia of MNS system, 2 antigen Fya, Fyb of Duffy
system and P1 antigen of P1PK system. We chose these antigens
because: 1. These are antigens with high immunogenicity and their
corresponding antibodies are all clinically significant; 2. Based on
study about unexpected antibodies in hematological patients as well as
thalassemia patients in NIHBT in previous studies, these are common
unexpected antibodies. 3. Based on studies of some authors which
revealed that transfusion with matching these antigens can
significantly reduce the rate of unexpected antibodies in patients. We
did not mention Kell and Lutheran systems because there was
complete compatibility of these antigens between patients and donors.
We chose 4,055 red cell antigen matching units for 142
thalassemia patients, which responded 95.5% to the clinical request.

The medium number of selected blood unit for a patient was 14.5
units. To get these 4,055 blood units, we had to mobilize 6,713 donor


20
times from the walking blood bank of NIHBT with the successful rate
was 60.4%. Supplying compatible blood units that are compliant to
transfusion protocol is always a challenge for study groups and all
blood centers. Based on immunogenicity of blood group antigen,
clinical significance of antibodies, in some cases that red cell antigen
matching units selection was impossible, we selected antigens based
on priority order: D > E > Mia > c > Fya > C > Jka > P1 > M > e > Lea>
Leb > S > s > N > Fyb > Jkb. Among 4,055 blood units selected, there
were 3,901 units with 17/17 compatible antigens, 97 units with 16/17
compatible antigens, and 57 units with 15/17 compatible antigens.
There were 91 patients transfused with 2,304 completely compatible
blood units (17/17 antigens), 51 patients transfused with incompletely
compatible blood unit (1597 units with 17/17 compatible antigens, 97
units with 16/17 compatible antigens and 57 units with 15/17
compatible antigens). The incompatible antigens were Lea, Leb of
Lewis system, M, N, S of MNS system, P1 of P1PK system and Jka,
Jkb of Kidd system. The medium blood units number selected for a
patient was 14.5 units. All 4,055 selected blood units had negative
results when tested with patients' serum in 3 phases: 22oC, 37oC and
AHG. This result showed that the donor's red blood cells and the
patient's serum are compatible.
4.3.2. Discussion about effectiveness of red cell antigen matching
transfusion for thalassemia patients
4.3.2.1. Discussion about effectiveness of red cell antigen matching
transfusion for thalassemia patients

After transfusion, Hb of patients increased significantly higher
than before transfusion, specifically: patients with moderate anemia,
Hb increased from 74 g/l to 102.3 g/l, patients with severe anemia, Hb
increased from 52.1 g/l to 101.5 g/l. Medium Hb of both patient groups


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increased from 70/1 g/l to 102.2 g/l. Our study results were similar to
studies of other domestic authors and treatment goals were achieved
according to guidelines of Thalassemia International Federation.
The indirect bilirubin and LDH level of patients after transfusion
were not significantly different compared to that before transfusion.
This proved that donor red cells were not hemolysis after transfused
because there was no immune incompatibility.
Medium total blood volume and blood volume/kg weight of a
patient in a treatment course were 506.5 ml and 12.1 ml/kg
respectively, significantly lower than previous studies.
The interval between transfusions was prolonged in α thalassemia,
β thalassemia and β thalassemia/HbE patients. This may help patients
reduce the number of hospitalizations and bring about economic
effectiveness.
All 142 patients with 4,055 transfusion times had no transfusion
reaction and no patient produced unexpected antibodies after 21.3
months of follow-up. These results showed that red cell antigen
matching transfusion is immunologically safe for patients.
4.3.2.2. Some cases about red cell antigen matching transfusion for
thalassemia patients
Case 1 was a β thalassemia/HbE who was admitted to hospital
early and had no history of transfusion. The tests for non-ABO antigen
showed that the patient had 9/17 negative antigen, including: c-, E-,

Lea-, Jka-, M-, S-, Mia-, Fyb-, P1-. According to AABB, the probability
for choosing a completely compatible blood unit is 0.01, it means that
only 01 compatible unit can be selected in 100 blood units. This is very
hard to do because the testing cost is high. Donor mobilization from
walking blood banks was the best way to solve that problem. With 19
blood donors with compatible phenotype for the patient in the walking


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blood bank, we successfully mobilized 56 times of donation. From first
hospitalization to 04/2020, the patients had been transfused with 56
compatible blood units. The patient's Hb was improved significantly
and no transfusion reaction was seen in all 56 transfusion times. The
patients had no unexpected antibodies after nearby 6 years of followup.
Case 2 was a β thalassemia patient without history of transfusion.
The tests for non-ABO antigen showed that the patient had 9/17
negative antigen, including: C-, e-, Lea-, Jkb-, M-, S-, Mia-, Fyb- and
P1-. This was a rare phenotype in thalassemia patients as well as blood
donors, so the probability of selecting a red cell antigen matching unit
for the patient was very low, only 0.005, it means that there was only 1
compatible one in out of 200 random blood units. When searching in
the walking blood bank, there were only 6 blood donors with
compatible phenotype for the patient. This was difficult for us to select
a compatible blood unit for patients in the next hospitalization.
From 08/2015 to 04/2020, the patients had been admitted to
hospital 42 times, and were transfused 45 compatible blood units.
Among 45 blood units, there were only 2 blood units that were
compatible with 16/17 antigens because we could not mobilize those 6
donors to donate blood for the patients (01 unit with incompatible Jkb
antigen, 01 unit with incompatible Fyb antigen).

All 45 blood units were negative with patients’ serum. The patient
had no reaction and unexpected antibodies after more than 5 years of
follow-up. Therefore, in cases without completely compatible donors,
to avoid delay in transfusion which may threaten the patient's life, we
can choose compatible blood units according to antigen priority.
Beside, the number of blood donors in walking blood banks should be
expanded to supplied enough for thalassemia patients.


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CONCLUSION
1. The rate of red cell antigens of some blood group systems: ABO,
Rh, Lewis, Kell, Kidd, MNS, Lutheran, Duffy, P1PK in
thalassemia patients at NIHBT
- ABO system: group A: 11.3%, group B: 30.7%, group O:
53.8%, group AB: 4.2%;
- Rh system: the rate of 5 antigens D, C, c, E, e were 100%,
95.8%, 36.7%, 29.6% and 97.1%;
- Lewis system: the rate of Lea antigen 40%, Leb: 49.2%;
- Kell system: the rate of K antigen: 0%, k: 100%;
- Kidd system: the rate of Jka antigen 68.3%, Jkb: 90.4%;
- MNS system: the rate of M, N, S, s, Mia antigens were
respectively 91.3%, 75.8%, 10.8%, 100% and 37.5%;
- Lutheran system: the rate of Lua antigen: 0%, Lub: 100%;
- Duffy system: the rate of Fya antigen: 100%, Fyb: 14.2%;
- P1PK system: the rate of P1 antigen: 40.4%.
2. Transfusion with 17 compatible non-ABO blood group
antigens system has brought initially about treatment
effectiveness and transfusion safety for thalassemia patients
- 4,055 red cell antigen matching units were chosen for 142

thalassemia patients, the response rate was 95.5% compared to
clinical request (3,901 units with 17/17 compatible antigens, 97
units with 16/17 compatible antigens and 57 units with 15/17
compatible antigens).
- The compatible tests between patient serum with 4055 blood
unit at 22oC, 37oC and AHG phase were all negative;
- Patients' Hb levels were improved significantly after
transfusion: Hb before transfusion: 70.1 g/l, Hb after
transfusion: 102.2 g/l.