Ticlopidine-induced aplastic anemia: two new case reports, review, and meta-analysis of 55 additional cases.

Ticlopidine-induced aplastic anemia (TIAA) is considered very uncommon. We present two new cases, and we review 55 additional cases from the literature. The first case concerns a 70-year-old man who developed severe aplastic anemia 7 weeks after treatment with 500 mg of ticlopidine daily. The patient sustained a severe septic episode, was treated with antibiotics and GM-CSF, and recovered the 14(th) day after ticlopidine withdrawal. The second was an 82-year-old man receiving ticlopidine for 2 years when, during a febrile episode, he was found neutropenic with marrow aplasia. Ticlopidine withdrawal and treatment with antibiotics, transfusions, and G-CSF helped him to recover. When the data of the 57 patients are evaluated, a reversible direct cytotoxic effect of ticlopidine on the pluripotent/bipotent hematopoietic progenitor stem cell is proposed. It is estimated that the real incidence if TIAA is higher, and many cases, initially presented as agranulocytosis +/- thrombocytopenia, might be true aplastic anemias, not proven by marrow aspiration or trephine biopsy. There is no effective monitoring to prevent this side effect. Recombinant growth factors appear not to help in shortening the neutropenic period.