Minocycline-induced lupus: clinical features and response to rechallenge

Objective. To describe the spectrum of clinical features in patients with m inocycline-induced lupus (MIL) and determine their response to rechallenge. Methods. The clinical features and laboratory findings of 23 patients with MIL were recorded. Ten patients were rechallenged, and their. C-reactive pr otein (CRP) levels were monitored. Results. All subjects complained of polyarthralgia; three had metacarpophal angeal and proximal interphalangeal joint synovitis and one had bilateral k nee effusions. Elevated hepatic transaminases were noted in eight subjects. Cutaneous vasculitis was a feature ill two cases. None had renal or centra l nervous system disease, although five patients complained of impaired con centration and Door memory and a single patient had a peripheral sensory ne uropathy. The following serological abnormalities were detected: antinuclea r antibodies (19/23 patients); antibodies to double-stranded DNA (4/23); pe rinuclear antineutrophil cytoplasmic antibodies (10/15); IgG anti-cardiolip in antibodies (6/23); hypergammaglobulinaemia (12/19). Anti-histone antibod ies were negative in 9/9 cases. Rechallenge resulted in rapid recurrence of symptoms and elevation of CRP levels. Conclusion. MIL is associated with a wide spectrum of clinical and serologi cal features. The diagnosis can be confirmed by rechallenge, which results in rapid reappearance of symptoms and a rise in CRP.