Prevalence of ABH(O) Blood Group Secretors Among Indigenous Population of Shillong: A Cross-Sectional Study

Background ABH antigens on the surface of red blood cells form Type A, B, AB, and O blood groups. These antigens are also found in body secretions like serum, gastric juices, ovarian cyst fluid, semen, amniotic fluid, sweat, urine, tears, bile, and saliva (except cerebrospinal fluid). People who have these antigens in their body fluids are called secretors. Purpose This study was conducted to find out the prevalence of salivary secretor status among the adult local indigenous population of Shillong, India. Method Unstimulated saliva was collected and processed from 250 apparently healthy adults, determined its secretor status using the absorption-inhibition method, and then analyzed using the Chi-square test to find its association with age, sex, tribe, and blood groups. Results The study found a prevalence of salivary secretor status of 57.2% (n=143), with a slight female predominance of 57.7% (n=64) over males (56.8%, n=79). The highest percentage was found in individuals aged 71-80 (68.8%, n=16), while the least in people aged 18-30 (48.2%, n=40). Khasi tribes had the highest incidence (64.2%, n=88), followed by Garo (55%, n=22), and least in Jaintia tribes (45.2%, n=33). O-blood group individuals had the highest percentage (71%, n=22), while AB-blood group individuals had the least (46%, n=23). We observed a statistically significant correlation of salivary secretor status with the blood group and tribe of the individuals but not with their sex and age. Conclusion Saliva can be found on various items in medicolegal cases like robberies, rapes, and hangings, but blood stains may not always be present. Saliva can be used to determine blood groups, potentially aiding in resolving claims of parentage, immigration, kidnapped children, disputed paternity, or identifying victims in mass disasters. ABO(H) determination from body fluids, especially saliva, has been used in forensic investigations before DNA technology. Currently, this can be an initial screening method because DNA methodology is not often available in laboratories in India.