Background: Discoid lesion is the commonest cutaneous finding in lupus erythematosus and chronic types have their own immunological features, with Th1 inflammation profile. Although many diseases have association with blood-group systems, this fact was not enlightened in discoid lupus erythematosus. Objective: To investigate the association between blood groups (ABO and Rh) and discoid lupus erythematosus. Methods: A prospective cross-sectional study assessing clinical information, blood group systems (ABO and Rh), FAN and C4 serum levels from discoid lupus patients without characteristics of systemic disease, was carried out at a clinic from a Brazilian university hospital. Results: Sixty-nine patients were enrolled in the study, 71.0% were females (p1:160 in 31.9%, and low levels of C4 in 8.7%. There was no significant difference between the frequency of blood groups from discoid lupus patients and local population, however, blood group A was associated to disseminate forms of the disease (OR 4.1 and p < 0.05). Conclusions: Discoid lupus erythematosus patients with ABO and Rh blood groups exhibit similar frequencies as in the general population; nevertheless, disseminate clinical forms were more prevalent among group A patients.
ABO blood-group system; Epidemiology; Lupus erythematosus, discoid; Rh-Hr blood-group system
