A novel eosinophil chemotactic factor derived from a histiocytic lymphoma of the central nervous system.

An eosinophil chemotactic activity was identified in extracts of tumour tissue and cerebrospinal fluid from a patient with a histiocytic lymphoma of the brain and spinal cord that was infiltrated extensively with eosinophils and associated with peripheral blood eosinophilia. The histiocytic lymphoma-derived eosinophils chemotactic factor, termed ECF-HL, exhibited a mol. wt of 13,000-14,000 by filtration on Sephadex G-50, was highly acidic based on its elution from a high pressure anion exchange column at pH 2 x 3 - 2 x 1, and was susceptible to inactivation by proteolytic digestion. ECF-HL was absent from extracts of control human brain tissue, glioblastomas, other lymphomas and a variety of carcinomas that lacked an accumulation of eosinophils. Partially purified ECF-HL had no chemokinetic activity, but rendered eosinophils unresponsive to other chemotactic factors. Thus ECF-HL is structurally and functionally distinct from other recognized peptides that are preferentially chemotactic for eosinophils.