Background: Minocycline (MN), one of the commonly prescribed therapies for acne, is known to be associated with autoimmune disorders including drug-induced lupus. However, data are sparse regarding the prevalence of autoimmune disease in acne or in patients with acne treated with MN.
Objectives: To establish the prevalence of antinuclear antibodies (ANA), antineutrophil cytoplasmic antibodies (ANCA) and new autoimmune syndromes in an MN-exposed and unexposed population with acne.
Methods: In a cross-sectional study, 252 patients with acne vulgaris were assessed. Sixty-nine per cent had been exposed to MN at some point or were taking the drug at the time of the interview. Data recorded included duration of disease (acne) and drug history as well as possible side-effects of drugs, in particular joint symptoms (pain and swelling). In addition, blood was taken for ANA, ANCA, liver function tests and HLA analysis.
Results: There was no statistical difference in the prevalence of ANA positivity between patients exposed (13%) or not exposed (11%) to MN. However, higher titres of ANA (1/160 or higher) were found in the MN-exposed group (45% compared with 12% in the unexposed group). ANCA positivity was found in 7% of the MN-exposed group but no positivity was found in the unexposed cohort (P = 0.022). In 58% of cases, the ANCA detected were of the perinuclear pattern (p-ANCA) with myeloperoxidase specificity, and this finding was associated with clinical symptoms in the majority of cases. Two p-ANCA-positive patients were thought in retrospect to have developed a drug-induced lupus syndrome.
Conclusions: ANA positivity is seen in patients with acne irrespective of exposure to MN; however, p-ANCA appear to be a serological marker for developing autoimmune disease in patients receiving MN.