Antithyroid Drug-Induced Agranulocytosis: Is Routine White Blood Cell Count Effective for the Detection?-Reply

In Reply.— We appreciate and agree with comment by Asawa et al that the leukocyte differentiated count, not only routine white blood cell count is critically important for correct diagnosis of antithyroid drug-induced agranulocytosis in some cases. From January 1975 to May 1989, total white blood cell (WBC) count was measured using automatic blood-cell analyzer (Sysmex CC700, Toa Medical Electronics Co Ltd, Kobe, Japan). Whenever total WBC count was 4.0 × 10 9 /L or less, a blood smear analysis was carried out. This fact was not mentioned in our article, 1 therefore, we would like to clarify it here. From 1975 to 1990, 72 patients presented with antithyroid drug-induced agranulocytosis. In 12 patients, total WBC count was greater than 3.0 × 10 9 /L (3.1 to 5.9 × 10 9 /L. Nine of 12 patients showed a downward trend in their leukocyte counts.