[Cyclic thrombocytopenia with chronic thyroiditis and ankylosing spondylitis].

A 58-year-old man with cyclic thrombocytopenia who was initially diagnosed as idiopathic thrombocytopenic purpura (ITP), concomitant with chronic thyroiditis and ankylosing spondylitis, was reported. Serum level of T 3 (0.48 ng/ml) and T 4 (2.1 micrograms/ml) were both subnormal and that of TSH (257.1 microU/ml) was markedly elevated. Thyroid test (6400X) and microsome test (6400X) was both positive, but anti-nuclear antibodies were negative. Radiographic findings of lumbar spine showed the typical "bamboo spine" and HLA B 27 was positive. Therapies for ITP, such as adrenocorticosteroids including steroid pulse therapy, high-dose intravenous gamma-globulin, danazol, slow infusion of vinca alkaloids and splenectomy, were only effective transiently. After these therapies platelet counts began to fluctuate from 0.4 X 10(10)/L to 34.4 X 10(10/L, therefore the diagnosis of cyclic thrombocytopenia was done. Interestingly low-dose methotrexate (MTX) was effective, and the cyclic fluctuation of platelet counts disappeared. These observations in this case were very suggestive of the pathogenesis of cyclic thrombocytopenia and mechanisms of cyclic change of platelet counts.