Endocrine Abstracts

A 26yr old man presented to haematology with a short history of easy bruising. There was no spontaneous bleeding. Past medical history was unremarkable. Family history of clotting disorders was negative. On examination there was significant lower limb bruising.

Initial investigations revealed platelets of 238 (150–450), prothrombin time (PT) of 12.0 (12.0–17.0 s) and elevated activated partial thromboplastin time (APTT) of 41.0 (24.0–38.0 s). The elevation in APTT alluded to an intrinsic pathway abnormality which was investigated through further clotting factor analysis. This revealed reduced levels of chromogenic factor VIII 0.46 (0.6–1.3 U/dl), factor VIII clotting assay 0.4 (0.6–1.3 IU/ml), von Willebrand Factor antigen 0.31 (0.7–2.0 IU/ml) and von Willebrand Factor activity 0.39 (0.7–2.0 IU/ml). Factor IX assay was normal at 0.63 (0.6–1.3 U/ml). This confirmed the diagnosis of von Willebrand disease.

On further questioning he complained of cold intolerance, dry skin and lethargy and there was a positive family history of hypothyroidism in an aunt. Clinical examination was unremarkable. Thyroid function was significantly deranged with unmeasurable free T4 <5.5 (9.0–19.0 pml/l) and grossly elevated TSH of 711.1 (0.4–4.5 mU/l). Anti-thyroid peroxidase antibodies were elevated at 3000 (0–135 U/ml) confirming the diagnosis of Hashimoto’s thyroiditis. He was commenced on levothyroxine and the coagulopathy reversed (APTT 36.3 s, Factor VIII clotting assay 0.71 IU/ml, von Willebrand Factor Activity 0.78 IU/ml) as his thyroid function normalised.

This is a case of acquired von Willebrand disease due to Hashimoto’s thyroiditis. It is the most common coagulopathy in hypothyroidism and is characterised clinically by easy bruising, epistaxis and mucosal bleeding and biochemically through elevated APTT, reduced Factor VIII and von Willebrand Factor. Normalisation of the thyroid axis usually reverses the coagulopathy negating the need for further treatment. Although a relatively uncommon complication of hypothyroidism it should be considered at diagnosis and coagulation status measured if clinically indicated.