Endocrine Abstracts

In new classification of autoimmune polyendocrine syndromes (APS), APS-3 has defined as combination of autoimmune thyroid disease and other autoimmune disease except hypoparathyroidism and Addison’s disease. The present report describes a patient with APS-3 and pseudomalapsorbtion of levothyroxine (LT4). Twenty-three year old woman was referred to our center with hypothyroidism due to Hashimoto’s thyroiditis (HT) despite the usage of high dose LT4 treatment. HT was diagnosed firstly eight years ago and she had been treated with 125 μ/day LT4. In March 2007, thrombocytopenia with bleeding was developed and she was diagnosed as idiopathic thrombocytopenic purpura. Subsequently, in August 2007, she was admitted to hospital with palpitation and diagnosed as silent myocardial infarction. Serum IgG anticardiolipin antibodies were found positive but no further evaluation was made at that time. In October 2007, splenectomy was performed because her thrombocytopenia was refractory to the medical treatment. After splenectomy, she was maintained complete remission but euthyroidism could not be achieved despite escalating doses of oral LT4. After referral to our center, patient characteristics, nutritional habits, drug interference, gastrointestinal diseases and the other known reasons of LT4 malabsorption were evaluated but no pathology was detected. Oral LT4 load test was performed with 400μg of LT4 to investigate pseudomalabsorption. A peak increment of 3.8 μg/dl in serum total T4 levels was observed and pseudomalabsorption of LT4 was proven after the test. Serum IgG anticardiolipin antibody measurements were repeated and found positive. Primary antiphospholipid syndrome (PAPS) was diagnosed after evaluation of PAPS’s criteria.

To the best of our knowledge, this is the first report of combination PAPS and HT as newly called APS-3C. At the same time she had pseudomalabsorption. Oral LT4 load test should be considered in suspicion of pseudomalabsorption in such cases before proceeding to extensive evaluations for malabsorption syndromes.