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 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: 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 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: 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 The thesis has identified the proportion of some blood group antigens which is clinically significant in thalassemia patients at NIHBT 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 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 overview (34 pages), Chapter subjects and method (20 pages), Chapter results (27 pages), Chapter 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 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 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 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 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 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 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 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) 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 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, 11 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 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 12 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 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 14 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 15 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 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 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 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 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 years of followup 3.2.2.2.2 Case 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 blood donors with compatible phenotype for the patient We mobilized these 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 blood units that were compatible with 16/17 antigens because we could not mobilize those donors to donate blood for the patients For those 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 years of followi-up Chapter 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 18 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 blood group systems, that were: antigens D, C, c, E, e of Rh system, antigens Lea, Leb of Lewis system, antigens Jka, Jkb of Kidd system, antigens M, N, S, s, Mia of MNS system, antigen Fya, Fyb of Duffy system and P1 antigen of P1PK system We chose these antigens because: These are antigens with high immunogenicity and their corresponding antibodies are all clinically significant; Based on study about unexpected antibodies in hematological patients as well as thalassemia patients in NIHBT in previous studies, these are common unexpected antibodies 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 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 21 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 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 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 22 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 years of followup Case 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 compatible one in out of 200 random blood units When searching in the walking blood bank, there were only 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 blood units that were compatible with 16/17 antigens because we could not mobilize those 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 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 23 CONCLUSION 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 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% 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 24 - All 142 patients with 4,055 transfusion times had no reaction No patients developed unexpected antibodies after 21.3 months following up RECOMMENDATION Red cell antigen matching transfusion should be expanded to patients whose main treatment method is transfusion to guarantee transfusion safety in immunological aspects improve treatment effectiveness for patients In cases without completely compatible blood donors, to avoid delay in transfusion which may threaten patients’ lives, we can choose compatible blood units according to antigen priority 25 THE LIST OF WORKS HAS PUBLISHED AND RELATED TO THE THESIS Hoang Thi Thanh Nga, Bui Thi Mai An, Nguyen Thi Thu Ha, Bach Quoc Khanh (2018) Study on compatible blood transfusion for thalassemia patients with rare blood groups: some cases Vietnam Medicine, 467, 525-533 Hoang Thi Thanh Nga, Bui Thi Mai An, Bach Quoc Khanh, Nguyen Thi Thu Ha (2020) Study on rate of antigens and phenotypes of some blood groups except for ABO in thalassemia patients at National Institute of Hematology and Blood Transfusion Vietnam Medicine, 496, 199-207 Hoang Thi Thanh Nga, Bui Thi Mai An, Bach Quoc Khanh, Nguyen Quang Tung (2020) Results of red cell antigen matching transfusion for thalassemia patients at National Institute of Hematology and Blood Transfusion Vietnam Medicine, 496, 100-107 ... 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 main groups: α -thalassemia. .. 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: ... 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