Jundishapur J Microbiol. 2019 June; 12(6):e94687. Published online 2019 July 16. doi: 10.5812/jjm.94687. Research Article Differences in Antibodies Against Blood Group, HBV, and Salmonella Regarding Protein Content, Activity, and Affinity in Black and Yellow Healthy Individuals Abdelhakam G. Tamomh 1, 2 and Hui Liu 1, * 1 College of Medical Laboratory, Dalian Medical University, Dalian, China 2 Faculty of Medical Laboratory Sciences, University of El Imam El Mahdi, Kosti, Sudan * Corresponding author: College of Medical Laboratory, Dalian Medical University, 116044, Dalian, China. Email: immunology@dlmedu.edu.cn Received 2019 May 30; Revised 2019 June 28; Accepted 2019 July 02. Abstract Background: Black and Yellow individuals of various ethnic populations may differ in the immunity to infectious diseases. Objectives: Our study aimed to explore and compare the detailed production characteristics (protein, activity, and affinity) of anti- bodies against blood group (natural antibodies), hepatitis B virus (HBV), and Salmonella typhi to find the differences in anti-infectious immunity between Black and Yellow populations. Methods: Serum samples of Black and Yellow healthy individuals were collected, diluted in serial dilutions, and several immuno- logical methods were used. Entire antibody features of all antibodies were calculated, according to the results obtained for each dilution. Results: The affinity of natural antibodies, anti-HBs, and S. typhi O antibody was significantly higher among Black individuals than Yellow individuals (P < 0.05). The activity of all antibodies among Blacks was higher than Yellow individuals (P < 0.05). The protein content of all antibodies was significantly higher among Blacks (P < 0.05). Conclusions: Clearly, differences between Black and Yellow individuals for protein, activity, and affinity among different antibodies may lead to exploring the differences in anti-infectious immunity or understanding the incidence of infectious diseases among different races. Keywords: Infectious Diseases, Race, Adaptive Immunity, Antibody Affinity, Ethnic Groups 1. Background Black people (African) and Yellow people (Asian) ethnic groups are more different in terms of their environmen- tal structures, habitats and, their adaptation to local sur- vival. Also, there are more variations in their ethnicity and susceptibility to infectious diseases. Therefore, studying their adaptive immune responses to various infectious dis- eases might add new findings to our knowledge. The im- mune responses of Black African race populations might be strong against various diseases, so their resistance and defense to various infections can be attributed to their abil- ity to adapt and survive in local conditions. In this case, we compare the characteristics of antibodies against different infectious diseases in Black and Yellow individuals. Antibody and antigen interactions play an important role in most of our numerous life processes and there is a property of how strong an antigen binds its related an- tibody, which is known as the affinity (1). In the process of an immune response, B-cells produce antibodies that have a stronger and higher affinity to the target pathogen, which attacks the human (2-4). This process, which is called affinity maturation, strengthens the attachment to the pathogen and leads to a higher immune defense effi- cacy (1, 5). Another property of the antibody is the activity. The activity of an antibody depends on its affinity and pro- tein content; therefore, the identification of different an- tibodies in clinical laboratory specimens must encompass the quantification of these detailed characteristics of anti- body. The protein content, activity, and affinity are impor- tant parameters that determine the role of antibody in the interactions between antigens and antibodies. However, these parameters are rarely studied between Black and Yel- low individuals. Antibody affinity, protein, and activity are valuable pa- rameters that should be analyzed and measured to un- derstand the differences in immune responses to infec- tious diseases between Black and Yellow different ethnic Copyright © 2019, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.