methimazole and Granulomatosis-with-Polyangiitis

Clinical and serological profiles of idiopathic and drug-induced autoimmune diseases can be very similar. We compared data from idiopathic and antithyroid drug (ATD)-induced antineutrophil cytoplasmic antibody (ANCA)-positive patients. From 1993 to 2003, 2474 patients were tested for ANCA in the Laboratory for Allergy and Clinical Immunology in Belgrade. Out of 2474 patients, 72 (2.9%) were anti-proteinase 3 (PR3)- or anti-myeloperoxidase (MPO)-positive and their clinical and serological data were analyzed. The first group consisted of ANCA-associated idiopathic systemic vasculitis (ISV) diagnosed in 56/72 patients: 29 Wegener's granulomatosis (WG), 23 microscopic polyangiitis (MPA) and four Churg-Strauss syndrome. The second group consisted of 16/72 patients who became ANCA-positive during ATD therapy (12 receiving propylthiouracil and four receiving methimazole). We determined ANCA and antinuclear (ANA) antibodies by indirect immunofluorescence; PR3-ANCA, MPO-ANCA, anticardiolipin (aCL) and antihistone antibodies (AHA) by ELISA; and cryoglobulins by precipitation. Complement components C3 and C4, alpha-1 antitrypsin (alpha1 AT) and C reactive protein (CR-P) were measured by nephelometry. Renal lesions were present in 3/16 (18.8%) ATD-treated patients and in 42/56 (75%) ISV patients (p <0.001). Skin lesions occurred in 10/16 (62.5%) ATD-treated patients and 14/56 (25%) ISV patients (p <0.01). ATD-treated patients more frequently had MPO-ANCA, ANA, AHA, aCL, cryoglobulins and low C4 (p <0.01). ISV patients more frequently had low alpha1 AT (p = 0.059) and high CR-P (p <0.001). Of 16 ATD-treated patients, four had drug-induced ANCA vasculitis (three MPA and one WG), while 12 had lupus-like disease (LLD). Of 56 ISV patients, 13 died and eight developed terminal renal failure (TRF). There was no lethality in the ATD-treated group, but 1/16 with methimazole-induced MPA developed pulmonary-renal syndrome with progression to TRF. ANCA-positive ISV had a more severe course in comparison with ATD-induced ANCA-positive diseases. Clinically and serologically ANCA-positive ATD-treated patients can be divided into two groups: the first consisting of patients with drug-induced WG or MPA which resemble ISV and the second consisting of patients with LLD. Different serological profiles could help in the differential diagnosis and adequate therapeutic approach to ANCA-positive ATD-treated patients with symptoms of systemic disease.

Topics: Adolescent; Adult; Aged; Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Antithyroid Agents; Autoantigens; Autoimmune Diseases; Churg-Strauss Syndrome; Cyclophosphamide; Female; Fluorescent Antibody Technique, Indirect; Follow-Up Studies; Granulomatosis with Polyangiitis; Graves Disease; Hashimoto Disease; Humans; Hyperthyroidism; Immunoprecipitation; Kidney; Lung; Male; Methimazole; Middle Aged; Myeloblastin; Nephelometry and Turbidimetry; Peroxidase; Polyarteritis Nodosa; Prednisone; Pregnancy; Pregnancy Complications; Propylthiouracil; Retrospective Studies; Serine Endopeptidases; Skin; Vasculitis; Vasculitis, Leukocytoclastic, Cutaneous

Clinical recognition of drug-induced vasculitic and lupus-like syndromes is very important because continued use of the offending drug can lead to irreversible and life-threatening vasculitic organ damage (e.g. end-stage renal disease or pulmonary haemorrhage). Withdrawal of the drug often leads to spontaneous recovery, meaning that immunosuppressive therapy can be avoided. The presence of myeloperoxidase-antineutrophil cytoplasmic antibodies, IgM anticardiolipin antibody, and antihistone antibodies in combination was found to be characteristic of drug-induced vasculitic syndromes caused by the antithyroid drugs propylthiouracil and methimazol. Clinically, skin vasculitis and arthralgias predominated and renal vasculitis was rare.

Topics: Acute Kidney Injury; Antibodies, Anticardiolipin; Antibodies, Antineutrophil Cytoplasmic; Antithyroid Agents; Autoantibodies; Autoimmune Diseases; Churg-Strauss Syndrome; Diagnosis, Differential; Granulomatosis with Polyangiitis; Humans; Immunoglobulin M; Kidney; Lupus Erythematosus, Systemic; Methimazole; Propylthiouracil; Skin; Thrombophilia; Vasculitis, Leukocytoclastic, Cutaneous