Endocrine Abstracts

Benign Ethnic Neutropenia (BEN) is a common form of neutropenia defined as an absolute blood neutrophil count (ANC) of < 1.5 x 10⁹/l, usually observed in Afro-Caribbeans. These patients are not at increased risk of infection despite their neutropenia, unless they are on medications which can cause neutropenia. Amongst these drugs antithyroid medications are known to cause agranulocytosis defined as ANC of <500/μl. We report a case of 24 years old male with sickle cell disease who presented to clinic with a new diagnosis of Graves’ disease 2 months ago. His neutrophil count was 0.89 x10⁹/l when he was started on carbimazole 20 mg once a day. Whilst on it, counts dropped to 0.53 x10⁹/l after 1 month, hence carbimazole was held. Workup for neutropenia (viral infection & haematinic) was negative, concluding a diagnosis of BEN. Neutropenia improved with a count of 1.0 x 10⁹/l with persistent thyrotoxic picture on bloods, carbimazole was resumed at 40 mg with advice to do weekly blood counts and stop carbimazole when counts drop to less than 0.8 x 10⁹/l, with administration of granulocyte-colony stimulating factor (Filgrastim 30 million units) after discussion with Haematology team. Signs of neutropenic sepsis and urgency to attend emergency department were explained. His neutrophil count remained above 1.0 x 10⁹/l with stable thyroid function, hence carbimazole was reduced to 20 mg OD. Alternative treatment options of radioiodine ablation versus thyroidectomy were discussed. Patient was a prison inmate hence radioiodine ablation was not a favourable option due to being in proximity with others. He preferred to continue carbimazole, with a plan of referring for surgical intervention in the future. This case emphasizes the challenges faced while treating such cases of Graves’ disease, where recognition of risk of agranulocytosis, patient education, considering alternative options of treatment and discussion with Multidisciplinary Team are imperative