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 PATIE

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

- National Medical Informatics Library

- Library of Hanoi Medical University

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

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

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

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

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

1.3.2 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

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

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 anti-

Mia 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)

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,

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

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:

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

- 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