Is there an association of ABO blood groups and Rhesus factor with alopecia areata?

Summary Background/Objectives Alopecia areata (AA) is an autoimmune disease characterized by noncicatricial hair loss localized on hair, beard, mustache, eyebrow, eyelash, and sometimes on the body. Although etiopathogenesis is not fully understood, many studies show remarkable associations between various diseases and ABO blood groups. However, there is no study with AA and blood groups. Methods Healthy people and patients with AA were included in this study. A total of 155 patients with AA and 299 healthy controls were included in the study. Results ABO blood group distribution in patients with AA and distribution of healthy donors were similar. However, Rhesus factor positivity in the AA group was significantly higher than in healthy donors. The relationship between stress and AA was high as known. But, ABO blood group and Rhesus factor were not in a significant connection with stress. Conclusion We conclude that there was no association between ABO blood group and AA, but the observed distribution of Rhesus blood group differed slightly but significantly from that of the healthy population. The result of the study shows a small but statistically significant difference in the Rh blood group between patients with AA and the healthy population blood groups. This result is important because it suggests that genetic factors may influence the development of AA. The role of blood groups in the development of AA remains to be determined. We believe that the studies which will be carried out in other centers with wider series will be more valuable to support this hypothesis.