Clarifying the relationship between ABO/Rhesus blood group antigens and upper gastrointestinal bleeding

The relationship between blood group antigens and peptic ulcer disease has been widely evaluated in the past. Data concerning the same association with upper gastrointestinal bleeding are very limited. We aimed to evaluate this association and we thought it was worthwhile to try to determine whether these components take some part in this complication.

The study population consisted of 1,098 adults (364 patients and 734 volunteer blood donors as controls). Demographic features, comorbid illnesses, and use of aspirin/nonsteroidal anti-inflammatory drugs (NSAIDs) were recorded. Blood groups were examined by gel centrifugation method. We included only patients with bleeding from peptic ulcer disease and erosive gastropathy. Ulcers were classified by using Forrest's classification system in terms of rebleeding risk. Helicobacter pylori was examined by histology.

The gender distribution was similar in both groups. The ABO blood group phenotype distribution in patients and controls (respectively) was as follows: 46.2% versus 34.9% for group O, 32.4% versus 39.5% for group A, 15.7% versus 18.4% for group B, and 5.8% versus 7.2% for group AB. Blood group O was found to have higher frequency in the patient group than in the control group (P=0.004). Rh positivity was also higher in patients than in controls (P=0.007). H. pylori positivity was similar between blood groups among patients. The rebleeding and mortality rates between blood groups were also similar.

ABO blood group O had an important role in patients with upper gastrointestinal bleeding. The impact of blood group on rebleeding and mortality may be a focus for further studies.