Frequency of ABO and Rhesus blood groups in Saudi healthy blood donors versus non-Saudi in a retrospective study in Makkah City

Purpose: to assess the frequency of ABO and Rh blood groups among Saudi and non-Saudi healthy blood donors and to compare

Frequency of ABO and Rhesus blood groups in Saudi healthy blood donors versus non-Saudi in a retrospective study in Makkah City The terms Rh positive and Rh negative refer to the presence or absence of D antigen [7,8]. The frequency of these blood groups varies from one geographic location to another. This reflects human people underlying genetic and ethnic diversity and suggests that a particular blood group showed protection or selective advantage to certain diseases [9][10][11][12]. In different parts of the world, the ABO and Rh rate showed variations in blood groups frequency. Some areas with a higher frequency of O, other of A, and others of B, and the Rh-positive is predominant [9,[13][14][15][16][17][18][19][20][21][22]. In Saudi Arabia, many studies have been carried out on ABO and Rh frequency, with few in Makkah city which have many residents of different nationalities. Most of these studies were done on the Saudi population and reported that the blood group O is the predominant one, followed by A ,B, and AB, and the Rh-positive is dominant except for the Hail province, which showed a group frequency of O>B>A>AB [23][24][25][26][27][28]. The Aim of the study is to assess ABO and Rh blood groups frequency in Saudi and non-Saudi healthy blood donors in Makkah city and compare the frequency between different populations.

Methods
A retrospective cross-sectional study was conducted from April 2020 to January 2021 at the Hematology and Immunology Department of the Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia. The data were collected from the blood bank of King Abdul Aziz hospital. The collected data were from January 2014 to August 2019. The biomedical ethics of the faculty of medicine of the Umm Al-Qura University approved the protocol of this study, and the approval number was HAPO-02-K-012-2020-05-385. The followings data were collected: 1-Sociodemographic character data, which include age, sex, and nationality. 2-The ABO and Rh blood groups. The automated and manual methods were used for determination of ABO and Rh. The automated methods were the microplate or gel card [29][30]. In the microplate, the red cell suspension and monoclonal antibodies were pipetted onto a microwell plate and examined for agglutination. In reverse typing, the cells and patient's plasma were mixed and examined for agglutination. In the gel card (forward), the RBC suspension was added to the column, which contains antisera of ABO/Rh. After centrifugation, the cell pellet was either at the top (positive) or bottom (negative). The manual methods were used to resolve discrepancies or confirm negativity of Rh [31].
All participants who were fulfilling the national blood transfusion guidelines in Saudi Arabia were included. All persons who were rejected from the blood bank to donate blood were excluded.

Statistical analysis
This statistical analysis was done using the SPSS program version 20. Quantitative data was described in the form of mean ± SD. The numbers and percentage of participants and the blood groups were calculated. The comparison between groups was performed by using the Student t-test.

Results:
The results were summarized in (Tables 1-4) and ( Figure 1). This study included 15,365 persons. They were 15,181 males and 184 females with a ratio of 82.5:1. The mean age was 31.8±8.9 years, the median was 30 years, and their age ranged from 18 to 62 years. The nationality of the participants, their numbers, their age, and sex were showed in (Table1). There was a significant increase in the age between Saudi and Malian, Myanmar, and Pakistani and a significant decrease between the Egyptian people. The frequency of blood groups in all the populations studied was showed in (Table 2) Table 3). The distributions of both the ABO and Rh in all populations studied were showed in (Table4). Frequency of ABO and Rhesus blood groups in Saudi healthy blood donors versus non-Saudi in a retrospective study in Makkah City     Frequency of ABO and Rhesus blood groups in Saudi healthy blood donors versus non-Saudi in a retrospective study in Makkah City

Discussion
This retrospective study was done in Makkah city on healthy blood donors (Saudi and non-Saudi). 98.8 % were male, and 1.2% were female. This is because there is no good awareness in females about blood donation or they are not accepted as blood donors because of anemia [32]. The blood donors' age ranged from 18 to 62 years, which is accepted for blood donation [33]. The significant difference in the age between Saudi and non-Saudi is of no importance as all matching the accepted age for donations. The Saudi population showed a frequency of O>A>B>AB. This agrees with previous studies [23][24][25][26][27]. The Mauritanian, Yemeni, Thai, Malian, Sudanese, Jordanian, Indian, and Moroccan had the same incidence of ABO as the Saudi population. This is in accordance with previous studies with few discrepancies [14, 18-19, 22, 34-40]. In India, certain regions had a higher frequency of O and others of B or A [18,22,41]. In Thailand, the frequency was O>B>A>AB and not O>A>B>AB [38,39]. In Mali, some authors reported O>A>B>AB, and others O>B>A>AB [36,42]. The Malaysian (n=7) and Somali (n=18) had the frequency of O>A>AB with an absence of B blood group. In Malaysia, the frequency was either O>B>A>AB or O>A>B>AB [43,44]. In Somalia, the frequency was O>A>B>AB [45]. The absence of blood group B may be due to their small number. The Indonesian (n=44), Myanmar (n=439), and Nigerian (n=439) had the frequency of O>B>A>AB, which agrees [46][47][48], and disagrees [49,50], with their countries results. In Indonesia, the frequency was B>O>AB>A [49], and in Nigeria, it was O>A>B>AB [50]. This may be explained by that these countries have different ethnic's origins. In Pakistan, the frequency was either B>O>A>AB or A>O>B>AB [51,52], and both are in contrast to our results, which was O>B>A>AB (n=853). This because some people have higher blood group incidence than others. The Bangladeshi (n=224) showed O=B>A>AB. This is similar to the results done in Bangladesh [17], which reported a higher frequency of either O or B. The Algerian (n=6) and Djibouti (n=5) had the frequency of O>A=B=AB. It agrees with previous studies in Algeria, but no studies were found for Djibouti. In Algeria, the frequency was either O>A>B>AB, or A>O>B>AB [53,54]. The equal frequency of other blood groups in our work may be due to the small number of participants. The Burkinabe (n=21) had O>B>A with the absence of AB. This agrees with a study done in Burkina Faso [55], in the higher incidence of O. The AB blood group is the least proportion of the ABO blood group. The Eritrean (n=10) had O=B>A with the AB's absence. There were no previous references about the ABO in Eritrea. However, it agrees with most African people, which have a higher incidence of O blood group [48,50,55]. The Ghanaian (n=9) had O>B with the absence of the A and AB. They were like their country in the higher frequency of O [20,21]. The lack of other blood groups is due to their small number. The Bahraini (n=2), Canadian (n=1), Boasian (n=1), Sri -Lanka (n=5), Iraqi (n=1), and Gambian (n=6), all had frequency of O blood group only. This because they do not represent the whole population of their nationalities. They had a similar frequency as in their countries with some exception [56][57][58][59][60][61][62]. In Bosna, some districts had a higher frequency of O, and others had of A [59]. In the American (n=3) and Nepalese (n=4), the frequency was B>O with the absence of other blood groups. These results contrasted with previous results and which showed a higher frequency of O [9,50,53,54,63]. The discrepancy is because they do not represent the whole population. In the Nigerien (n=12), the frequency was B>O>A=AB, but no previous results were found. In Chinese, participants (n=2) had an AB blood group with the absence of other blood groups. This is in contrast to a previous work, which was either A>O>B>AB or O>A>B>AB [64].The discrepancy is due to our participants' small number. In Filipino (n=8), they had AB>B=O>A, which contrasts with previous work that reported O>A>B>AB. The discrepancy is because they do not represent the whole population [65]. The Turkish (n=35), Palestinian (n=68), Syrian (n=430), Lebanese (n=12), Egyptian (n=1130), and Afghan (n=74) showed frequency of A > O > B > AB. In Turkish, Syrian, and Egyptian, our results agree with previous studies [13,[66][67][68][69]. In Palestinian and Lebanese previous works, the frequency was O>A>B>AB in some regions and A>O>B>AB in other regions [70][71][72]. Our results disagree with previous results in the Afghan, which was of O or B or O=B but not of A [73]. This may because they do not represent the whole population. In Ethiopian participants, both A and O had equal frequency. This agrees with previous results, which found some areas with a higher frequency of A and other of O [15,74]. The Chadian(n=9), French (n=1), Tunisian (n=6), Cameroonian (n=3), and British (n=2) all had a higher frequency of blood group A which was followed by O or AB or equal to B or absent of other blood groups. This agrees with France and contrasts with Cameron, Tunisia, and England, which reported O>A>B>AB [16,[75][76][77]. The discrepancy because they do not represent the whole population. In the Chadian, no previous works were found. Of all populations studied, 46.8 % were O, 28.8 % A, 19.5 % B, and 4.9% AB. This is in agreement with previous results, which stated that the O allele is (63%), A (21%), and B (16%) [78]. The blood group A, B, AB, and O of the Saudi population had a significant or no significant Frequency of ABO and Rhesus blood groups in Saudi healthy blood donors versus non-Saudi in a retrospective study in Makkah City difference when compared to other people, (Figures1). The presence or absence of significance is due to the variations in the blood group's higher frequency. The variations are due to genetic and environmental factors. Also, the ABO blood group frequency may play a role in human disease [79]. The Rh-positive was predominant, and the Rh-negative ranged from 3.2% to 66.7%. The absence of Rh-negative in Indonesian, Malaysian, Thai, and Filipino agree with studies, which reported <1% of Rh-negative [38,44,49,[80][81][82]. The higher negativity in Tunisian, Chinese, and Cameroonian is due to their small number. All over the world, 5-11% are Rh-negative except Britain and the USA, 15 and 17%, respectively [83].

Limitation of the study
Some of the nationalities in our work had few numbers of participants, which need further studies to confirm our results.

Conclusion:
In Makkah city, the higher frequency of ABO blood group in Saudi and non -Saudi people is O followed by A, then B, and AB. The Rh-positive is predominant, and 8.4% of the participants are negative. The encouragement of blood donation is essential for providing suitable blood storage for individuals in need. We recommendations further studies are needed to be performed on the ABO and Rh genes frequencies and their alleles in Makkah city.