title: Agranulocytosis caused by ticlopidine and its mechanism.
abstract: A 75-year-old female patient with agranulocytosis caused by ticlopidine is reported. She took the drug at 200 mg/day for 30 days to prevent recurrence of cerebral infarction. The leukocyte count at the nadir was 500/microliters on the 34th day since she started to take the drug. Complete recovery of her peripheral leukocytes came 12 days after its withdrawal. In this patient, mechanisms of ticlopidine-caused agranulocytosis were studied. The lymphocyte stimulation test using ticlopidine was negative. In the culture of marrow cells depleted of lymphocytes, ticlopidine directly inhibited the CFU-C in a dose-dependent manner. Neither the serum on the day of admission nor the T-lymphocytes pre-cultured with ticlopidine had any effect on the CFU-C. The lymphocyte stimulation test is useless in an attempt to find the causal drug in agranulocytosis if it is caused in a directly toxic manner. Agranulocytosis caused by ticlopidine is rare, but careful follow-up is necessary in the case of patients on the drug because there are some whose marrow cells are very sensitive to it.
authors.affiliation: Department of Internal Medicine, Saga Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: K
authors.initials: K
authors.lastname: Kurohara
authors.forename: M
authors.initials: M
authors.lastname: Yoshihara
authors.forename: Y
authors.initials: Y
authors.lastname: Shimamoto
authors.forename: M
authors.initials: M
authors.lastname: Yamaguchi
mesh_terms: D000368:Aged; D000380:Agranulocytosis / Q000139:chemically induced*; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D003114:Colony-Forming Units Assay; D005260:Female; D006801:Humans; D008213:Lymphocyte Activation; D013601:T-Lymphocytes / Q000166:cytology; D013988:Ticlopidine / Q000009:adverse effects*
chemical_list: D013988:Ticlopidine