Results of Determination of Some Non-Abo Red Blood Cell Antigens of Patient No. 2

The patient's body can cause the patient to produce antibodies against Jk b . We also mobilized a blood donor who is compatible with 16/17 antigens outside the ABO system but not compatible with Fy b antigen to donate blood to the patient. This blood unit was transfused to the patient on June 2, 2017.

Table 3.34. Results of selection and transfusion of red blood cell antigen-compatible blood units of patient number 3 (from August 2015 to April 2020)

Comments: All 45 KHC units gave negative compatibility reactions with the patient's serum. The patient did not have any transfusion reactions. The patient also did not develop KTBT despite receiving 01 KHC unit that was not compatible with the Jk b antigen with a follow-up period of 39 months and 01 KHC unit that was not compatible with the Fy b antigen with a follow-up period of 34 months.

Chapter 4. DISCUSSION

4.1. Discuss the general characteristics of the research object

4.1.1. Gender characteristics of research subjects

Of the total 240 thalassemia patients with some red blood cell abnormalities identified, male patients accounted for 49.6% (119 patients), female patients accounted for 50.4% (121 patients), the proportion of male patients was lower than that of female patients, however, the difference between the two sexes was not statistically significant with p > 0.05 (chart 3.1). This may explain that thalassemia is a genetic disease related to autosomal chromosomes, not related to gender, so the proportion of men and women with the disease is similar. The results of our study are also consistent with the studies of other authors [44], [85], [86], [87].

4.1.2. Age and disease characteristics of the study subjects

The results of Table 3.1 show that patients with β thalassemia/HbE have the highest rate of 55.4%, followed by patients with β thalassemia (29.2%) and patients with α thalassemia (15.4%). The results of our study are similar to the studies of authors Pham Quang Vinh (2010) [88] and Nguyen Thi Thu Ha (2015) [89], in the studies of these authors, patients with β thalassemia/HbE also accounted for the majority. This is completely consistent with the world literature: Hemoglobin E is the most common abnormal hemoglobin in Southeast Asia and the rate of patients with β thalassemia/HbE in Southeast Asia is up to more than 50% [1].

The median age of patients with α thalassemia and β thalassemia/HbE was 11 years old, the median age of β thalassemia was 7.5 years old (Table 3.1). The results of this study are different from those of some domestic authors [88], [89] , [44]. According to previous studies, the median age of patients

thalassemia are all higher than this study, specifically: the study by author Pham Quang Vinh in 2010 at the National Institute of Hematology and Blood Transfusion showed that the average age of α thalassemia patients was 33.58 years old, the average age of β thalassemia patients was 29.8 years old, and the average age of β thalassemia/ HbE patients was 24.84 years old [88]. This can be explained by the fact that in previous studies, the research subjects were all thalassemia patients including newly diagnosed patients who had not received any treatment and patients who had been treated at lower levels and were transferred to the National Institute of Hematology and Blood Transfusion for further treatment. Meanwhile, in this study, our research subjects only included new thalassemia patients with no history of blood transfusion, so the average age of thalassemia patients in this study was lower than in previous studies.

4.2. Discussion on the red blood cell antigen ratios of some blood group systems ABO, Rh, Lewis, Kell, Kidd, MNS, Lutheran, Duffy, P1PK in thalassemia patients at the Central Institute of Hematology and Blood Transfusion

4.2.1. The rate of ABO blood group in thalassemia patients

In our study, the rate of thalassemia patients with blood group O was the highest at 53.8%, followed by patients with blood group B (30.7%), patients with blood group A accounted for 11.3% and the lowest was patients with blood group AB (4.2%) (chart 3.2). The results of our study are similar to the studies of author Vandana (2019) in India [90] and author Zulfiqar Ali Laghari (2018) in Pakistan on thalassemia patients [91].

Compared with the studies of other domestic authors on the proportion of ABO blood groups in healthy subjects, our research results are also similar: group O has the highest proportion, followed by blood group B, followed by blood group A and the lowest is blood group AB [23], [83], [92], [93], [94].

4.2.2. Antigen and phenotype ratios of the Rh system found in thalassemia patients

The results of tables 3.2 and 3.3 show that: The proportion of antigens D, C, c, E, e in thalassemia patients are 100%, 95.8%, 36.7%, 29.6% and 97.1%, respectively. The R 1 R 1 phenotype has the highest proportion (59.6%), followed by the R 1 R 2 phenotype (21.7%) and R 1 r (10.4%), the other phenotypes have lower proportions, the two phenotypes with low proportions are R 0 R 0 (0.4%) and R 2 R z (0.4%). Tables 4.1 and 4.2 below compare the results of the antigen proportions of the Rh system in our study with some authors on thalassemia patients and blood donors.

Table 4.1. Comparison of the proportions of some antigens of the Rh system in thalassemia patients

Author

The results of our study are different from the study of author Salwa Hindawi (2020) on thalassemia patients in Saudi Arabia.

[64] and Karina Yazdanbakhsh (2012) on African American thalassemia patients

[34] but similar to the study of author Sylvia T. Singer (2000) [33] on Asian thalassemia patients (table 4.1) [95], [96], [97]. This shows that blood group antigens are specific to each race, in different countries, different races, the ratio of red blood cell antigens is also different.

Table 4.2. Comparison of the proportions of some antigens of the Rh system in thalassemia patients and blood donors

Author

The ratio of antigens D, C, c, E, e in thalassemia patients in our study was similar to the study of domestic authors on blood donors (Table 4.2) [23], [95], [96], [97 ] .

Table 4.3. Comparison of the proportion of some Rh system phenotypes in thalassemia patients with blood donors

Phenotype

When comparing the phenotype ratio of the Rh system in thalassemia patients with that of blood donors, we found that the phenotype ratio of the Rh system in thalassemia patients was similar to that of blood donors (Table 4.3) [23], [96].

Thus, with the similarity in antigen ratio and phenotype of the Rh blood group system between thalassemia patients and Vietnamese blood donors, the selection of Rh compatible blood units for thalassemia patients is completely feasible, even for patients with rare phenotypes such as R 0 R 0 (0.4%) and R 2 R z (0.4%).

4.2.3. Antigen and phenotype ratios of the Lewis system found in thalassemia patients

The results of Table 3.4 and Chart 3.3 show that the proportion of antigens Le a and Le b are 40% and 49.2% respectively, the common phenotype of the Lewis blood group system in thalassemia patients is Le(a-b+) (34.6%), followed by phenotypes Le(ab-) and Le(a+b-) (25.4%) and the least common is phenotype Le(a+b+) (14.6%).

Table 4.4. Comparison of the proportion of some antigens and phenotypes of the Lewis system in thalassemia patients with blood donors

Antigen/ Phenotype

The ratio of KN and KH of the Lewis system in thalassemia patients in our study is similar to that of other Asian thalassemia patients [33] but is different from that of NHM at the National Institute of Hematology and Immunology [23], [96]. In NHM, the ratio of Le a antigen only fluctuates from 26 - 26.2%, while the Le b antigen accounts for a high ratio with a range of 84.4 - 85.1%. The Le(ab-) phenotype in NHM occurs at a ratio of 12.9 - 13.5%, while the Le(a+b-) phenotype occurs at a low ratio of 2.1% (Table 4.4). This makes it difficult to select the units