Anti-neutrophil cytoplasmic autoantibodies in leprosy.

The objective was to evaluate the frequency of cytoplasmic and peripheral antineutrophil cytoplasmic antibodies (ANCA) in patients with leprosy, and to correlate the presence of ANCA with type and disease activity. Consecutive patients with leprosy were assessed clinically, and IgG ANCA were measured by indirect immunofluorescence. The presence of three of the following was used to assess disease activity: reactional state, fever, new cutaneous lesions, erythrocyte sedimentation rate and C-reactive protein. Sixty-four patients were studied and divided according to the Ridley-Jopling classification: of 38 patients with lepromatous leprosy, eight (21%) had perinuclear (p) ANCA and two (6%) had cytoplasmic ANCA. ANCA titres ranged from 1:20 to 1:320. Of six borderline leprosy patients, one (16%) had p-ANCA. All 20 tuberculoid leprosy patients and 65 healthy control subjects had negative ANCA. There was no correlation between ANCA titres and disease activity in positive patients. ANCA, mainly those with a perinuclear pattern, may be present in leprosy, especially in the lepromatous pole. This disease should be added to the spectrum of diseases with ANCA positivity.