Association between ABO Blood Group and Clinical Outcomes in Patients with Gastrointestinal Bleeding

Introduction: Gastrointestinal (GI) bleeding is one of the most common causes of Emergency Room (ER) visits all around the world. Previous studies proved the relationship between ABO blood group and the bleeding diathesis. Distribution of ABO blood type antigens is various among the different races. This study aimed to assess the role of ABO blood group system in the development of GI bleeding in Iranian population. Method and Material: Patients with acute upper and/or lower non-traumatic GI bleeding who admitted in ER of Rasoul-e-Akram hospital and the healthy blood donor between 2014 and 2016, were enrolled in this prospective case-control study. Demographic criteria, clinical presentation, laboratory data, endoscopic findings and GI bleeding outcome during the first 72 hours of admission were recorded. All variables were analyzed by SPSS software version 22. Results: Overall, 513 case and 520 control groups completed the study. The risk of bleeding originated from esophageal, gastric and duodenal ulcers were significantly higher among patients with O blood group (P value=0.032, 0.021 and 0.009, respectively). Need for blood transfusion was significantly higher among patients with O blood group (P value=0.032). Older males had higher risk of developing GI bleeding (P value is 0.001and 0.003, respectively) in this study. Conclusion: O blood type is significantly more common in Iranian patients with GI bleeding in comparison to the healthy blood donors. It seems that it is a prognostic genetic and individual risk factor for bleeding tendency in these patients, especially in those with upper GI bleeding.