ANA-negative systemic lupus erythematosus.

After implantation oftwo metal plates a 24 year old woman developed fever of unknown origin and successively more symptoms of an ANA-negative systemic lupus erythematosus (SLE). These symptoms resolved after removal of the plates and recurrred during patch testing of the metal components, which showed a reaction to molybdenum. A lymphocyte transformation test indicated a delayedtype hypersensitivity to molybdenum. Subsequent progressive flare ups of SLE appeared without molybdenum reexposure. This is the first report suggesting the existence ofa hypersensitivity to molybdenum, which may act as another environmental trigger for SLE. (Ann Rheum Dis 1994; 53: 403-405) Medizinische Abteilung, Spital Schweizerische Pflegerinnenschule, Zurich, Switzerland M Federmann B Morell G Graetz Department of Dermatology, University Hospital Zurich, Switzerland M Wyss P Elsner R von Thiessen B Wuthrich Schulthess Hospital, Orthopedic Surgery, Zurich, Switzerland D Grob Correspondence to: Dr Martin Federmann, Department of Internal Medicine, University Hospital, CH-8091 Zurich, Switzerland. Accepted for publication 23 February 1994 In the pathogenesis of systemic lupus erythematosus (SLE) both genetic predisposition and environmental triggers are likely to play an important role with differing factors for different individuals.' These factors can induce a loss of self-tolerance, a polyclonal B-cell activation and/or an antigen-driven immune response, which subsequently give rise to the production of characteristic autoantibodies and lead to the highly variable clinical manifestations of the disease.' 2 Potential environmental triggers are heterogenous and seem to act by distinct mechanisms. According to Krieg' ultra-violet light, certain drugs like procainamide, and hair dyes, possibly some chemicals (such as hydrazine), certain foods, stress, and infections, and other agents (such as tobacco smoke) are thought to be implicated in the induction or activation of