Endocrine Abstracts

Introduction

Grave’s disease is an autoimmune disease characterized by hyperthyroidism. It is in some cases associated to more autoimmune organs dysfunction. The antithyroid drugs are the first line treatement, and sometimes they are responsible for severe adverse effects.

Observation

We report the case of a 34 year-old man, treated for his grave’s disease with thiamazol for two years. Two weeks after interrupting his treatment of his own volition, then reintroducing it, he consulted for asthenia, fever at 40°C and a poor state of health, the blood count revealed a severe pancytopenia with agranulocytosis (Hemoglobin 4.5 g/dl, WBC 760/µl, Neutrophils 320/µl, Platelets 23 000/µl). In front of this emergency, the antibiotherapy was started, and the thiamazol was immediately interrupted, but there was no noticeable amelioration in the blood count, so we suspected the presence of another factor such as the pernicious anemia, and a low level of vitamine B12 was indeed found (46 pg/ml). The anti intrinsic factor was positive at 80 RU/ml, and the gastric tissue biopsy showed a non active chronic gastritis with severe atrophia and moderate intestinal metaplasia confirming the diagnosis of the Biermer disease. The procedure to follow was to treat the patient with intra-muscular injection of vitamine B12 and his condition as well as his blood count improved within two weeks (Hemoglobin 9.6 g/dl, WBC 2330/µl, Neutrophils 1150/µl, Plateles 151 000/µl). As for his Grave’s disease, he received a radioactive iodine therapy. The severe pancytopenia was in this case due to two factors ; the allergic reaction to the antithyroid drug and the insidious presence of Biermer’s disease. This association of these two diseases is called autoimmune polyendocrine syndrome type 3B which is a group of rare diseases.

Conclusion

Pancytopenia with agranulocytosis is a rare adverse effect of the antithyroid drugs. Blood count must be evaluated before and after initiation. Moreover, the autoimmune thyroid disease may be associated to other autoimmune disorders, hence the importance of screening for other autoimmune diseases in front of new symptoms.