Vancomycin-lnduced Cytopenias

Abstract

To the Editor. — In reference to the recent article by Zenon et al, 1 I would like to offer some comments concerning vancomycin-induced cytopenias. Christie et al 2 recently reported on a very elegant study demonstrating vancomycin-dependent anti-platelet antibodies in two patients. In 1990, I and Horowitz 3 also reported on a case of vancomycin-induced neutropenia clearly associated with anti-granulocyte antibodies. In addition, nonantibody-mediated red blood cell aggregation has been demonstrated with vancomycin. 4,5 To date, however, vancomycin-induced antierythrocyte antibodies have not been reported. The evidence is increasing that vancomycin has both immune and nonimmune effects on blood cells, but the mechanism(s) involved is (are) far from clear. For example, protein binding may or may not be an important factor for vancomycin's action at the cellular level. 4,5 What is clear, however, is the need to further study how vancomycin affects the immune system and/or interacts with blood cells,