ABO blood type and clinical characteristics of patients with ulcerative colitis: A hospital-based study in central Taiwan

Background The variations in ABO blood groups are reported to be associated with multiple disorders, including ulcerative colitis (UC). We aimed to investigate the distribution of ABO blood groups in UC patients and explore its impact on disease severity. Methods We retrospectively collected 129 UC patients diagnosed at our hospital between January 2000 and November 2019. Clinical characteristics, ABO blood groups, and operation rates were analyzed. Results The mean diagnostic age of patients was 38.97 years. Males accounted for the majority of all patients (62.8%). Of 129 patients, 43 (33.3%) were blood type O, 41 (31.8%) were blood type A, 38 (29.5%) were blood type B, and 7 (5.4%) were blood type AB. Although our patients had higher ratio of blood type A comparing our general population, there was no statistically significant association of ABO blood types distribution between these two groups (p = 0.1906). In the subgroup analysis, there were no significant difference of disease locations and operation rates between different ABO blood groups. Furthermore, blood type A patients had higher serum hemoglobin (Hb) levels compared to blood type O patients (13.31 g/dL vs. 12.30 g/dL, p = 0.0347). Blood type A patients had lower serum erythrocyte sedimentation rate (ESR) levels compared to blood type O patients (12.46 mm/hour vs. 21.5 mm/hour, p = 0.0288). Blood type O had higher serum ESR levels compared to non-O groups (p = 0.0228). In the ABO blood groups and mean diagnostic age (<= 40 years or > 40 years), there were no statistically significant difference between these two age groups, p = 0.5515. Conclusions Our results showed ABO blood groups are not associated with UC in spite of a higher ratio of blood type A in our patients. Blood type O patients had higher serum ESR levels; however, blood type A patients had higher Hb levels.