ESPE Abstracts

Background: Autoimmune thyroid disease can be sometimes associated with autoimmune thrombocytopenia and decreased renal function.

Case report: A 17-year-old female patient was referred to our endocrine department for evaluation of hypothyroidism (TSH=150 mcIU/ml, FT3=0 pg/ml, FT4<0.1 ng/dl) presenting severe fatigability and myalgia. From her medical history we mention that she was diagnosed with thrombocytopenia 1 year ago (85.000/mm³) and significant menometroragy in Nov 2015 (Hb=4.5 g/dl) for which she was treated with oral contraceptives. After the vaginal bleeding her creatinine doubled and the patient was referred to the nephrologist. All the causes for thrombocytopenia and elevated creatinine were excluded (domestic and drug toxicity, viral infection, autoimmune) and the platelet autoantibodies were negative. The endocrine evaluation revealed mixedema, H=156.6 cm (−1.3 SD), W=45.5 kg, hoarseness, slurring of speech, pale, dehydrated skin. The blood test showed moderate thrombocytopenia (70000/mm³) elevated VEM, moderate dyslipidemia, elevated creatinine (1.4 mg/dl), normal blood urea (52 mg/dl), elevated CK (1309 UI/ml). The hormonal profile showed severe autoimmune hypothyroidism (TSH>75 mcIU/ml, TT3<40 ng/dl, FT4<0.3 ng/dl, antithyroglobulin antibodies>3000 UI/ml, antiperoxidase antibodies=392 IU/ml). The thyroid ultrasound revealed a small thyroid gland with a heterogeneous echotexture, decreased flow at color Doppler, abdominal ultrasound showed completely normal kidneys, but the echocardiography showed poor left ventricular performance and decrease in the rate of ventricular diastolic relaxation. A diagnosis of severe autoimmune hypothyroidism with myopathy was made and the elevated creatinine was thought to be secondary to excessive production rather than impaired renal function as the blood urea was normal. The associated thrombocytopenia has probably an autoimmune etiology, though the platelet antibodies were negative. Substitutive treatment with levothyroxine was started.

Conclusion: Elevation in serum creatinine levels can occur even in the absence of a decline in the glomerular filtration rate, and one should look hard for unusual causes, especially in a patient with normal blood urea.