The relationship between bone marrow characteristics and the clinical prognosis of antithyroid drug-induced agranulocytosis.

This study is aimed to explore the relationship between bone marrow characteristics and clinical prognosis of antithyroid drug (ATD) induced agranulocytosis. A retrospective study was conducted in the first affiliated hospital of the University of South China. A total of 33 hospitalized patients diagnosed with ATD-induced agranulocytosis were analyzed. The bone marrow characteristics were classified into two types. Type I was characterized by reduction or absence of granulocytic precursors and type 11 was recognized as hypercellular bone marrow with dysmaturity of granulocytic cells. Bone marrow of 20 cases (61%) were characterized with type I whereas 13 cases (39%) with type II. The median duration of neutrophil recovery and high-grade fever were 4.7 +/- 1.0 days and 3.6 +/- 2.5 days respectively for type II, compared to 8.0 +/- 2.8 days and 8.6 +/- 3.1 days for type I (p < 0.01 in both compared groups). However, there was no significant difference between the two types in terms of age, median duration of drug administration before the diagnosis of agranulocytosis, the amount of neutrophil count on admission and the total administration dose of granulocyte-colony stimulating factor (G-CSF) before bone marrow examination. Two cases of type I died of complications from infection. This study showed that the bone marrow characteristics of ATD-induced agranulocytosis could be classifed into two types. Also, the clinical prognosis was closely related to the bone marrow features. Type I is the dominant type which is usually associated with worse clinical prognosis compared to type II.