The Rh Factor in Humans : Beyond Blood Compatibility ; Examining Associations with Helicobacter pylori , Norovirus , Cholera , Malaria , Cardiovascular Disease

The Rh Factor in Humans: Beyond Blood Compatibility; Examining Associations with Helicobacter pylori, Norovirus, Cholera, Malaria, Cardiovascular Disease, and COVID-19 The term “Rhesus factor” was put forth by Karl Landsteiner and Alexander S. Wiener in 1937. The serum of rabbits and guinea pigs agglutinated 85% of the human samples following the immunization with RBCs of Macacus rhesus monkeys. If the Rhesus factor is present in blood cells, the blood is termed Rh-positive. In the absence of Rhesus factor, the blood is termed Rh-negative. Rh grouping is significant in assessing blood compatibility, performing a crucial role in Rh-negative women exposed to Rh-positive blood through transfusion or pregnancy. The Rh-negative blood type is distinctly human, originating from a mutation in the RHD gene. Depending on the source, about 85% of the United States’ population is Rh-positive, while 15% is Rh-negative. However, this ratio varies from country to country; globally, the ratio is estimated at 92% Rh-positive with the remaining Rh-negative. Technological advances have resulted in a better understanding of Rh antigens’ molecular basis; approximately 170 alleles of the Rh gene RHD have been identified. It is projected that the percentage of Rh-negative people should drop as the population growth rate in Europe is low, and Europeans contribute significantly to the Rh-negative population. The most familiar and established connection regarding Rh is in blood compatibility. Nevertheless, investigations are ongoing into similarities between ABO grouping and the Rh factor regarding susceptibility or predilection towards specific psychological disorders, physical conditions and diseases, and infections. One aim of future research is in developing a universal blood type, making donor blood more readily available and blood transfusions and immixing harmless.