A clinicopathologic correlation of the idiopathic hypereosinophilic syndrome. I. Hematologic manifestations.

A retrospective blind study of 32 patients with the hypereosinophilic syndrome was undertaken utilizing a hematologic scoring system that was based on peripheral blood and bone marrow findings, cytogenetics B12 levels, and leukocyte alkaline phosphatase determinations. In addition to the grading system, which allowed formulation of a hematologic score, the date could also be normalized for individuals who did not have all tests performed by use of the hematologic quotient. This study clearly defined two groups of patients within the idiopathic hypereosinophilic syndrome. One group were those individuals with low hematologic scores and quotients who did not require therapy or who responded to prednisone therapy, while the second group of patients required cytotoxic therapy. These patients had significantly higher hematologic scores and quotients and a significant number of abnormalities similar to those seen in myeloproliferative syndromes, such as myelofibrosis and cytogenetic abnormalities. This type of hematologic scoring seems useful in predicting therapy and/or evaluating individuals or groups of patients with the hypereosinophilic syndrome.