Anti-Fc-Receptor Therapy of Refractory Immune Thrombocytopenic Purpura

To the Editor: The report in the May 8 issue 1 on monoclonal antibody therapy for refractory immune thrombocytopenic purpura adds to the observation that polyclonal intravenous gamma globulin decreases the cytotoxic activity, as well as the phenotypic presence, of natural killer (NK) cells in the circulation. 2 However, this study failed to consider the phenotypic as well as functional heterogeneity of the NK-cell population. The choice of the monoclonal antibody anti-Leu 7 (HNK-1) as an indicator of the quantitative NK-cell population, as well as a functional parallel of cytotoxic activity, is less than optimal. Anti-Leu 7 is a non-Fc-directed monoclonal antibody . . . No extract is available for articles shorter than 400 words.