Spontaneous production of eosinophil chemotactic factors by T lymphocytes from patients with subcutaneous angioblastic lymphoid hyperplasia with eosinophilia.

Subcutaneous angioblastic lymphoid hyperplasia with eosinophilia (SALH) was reviewed with respect to eosinophil chemotaxis. Lymphoid cells separated from the granuloma spontaneously released at least two different eosinophil chemotactic factors (ECF): low-molecular-weight and high-molecular-weight ECF according to the profile on gel filtration (LMW-ECF, about 500; HMW-ECF, 45,000 to 70,000). The cells, however, failed to produce chemotactic activity for macrophages and neutrophils. By analysis with monoclonal antibodies against lymphocyte subpopulations, the granuloma T cells, probably OKT4-positive cells, were shown to be responsible for spontaneous production of these two ECF. Furthermore, the blood mononuclear leukocytes were separated from the patients with SALH. An ECF closely resembling HMW-ECF was also spontaneously produced by the blood OKT4-positive T lymphocytes, whereas no LMW-ECF was released. Mononuclear leukocytes from healthy donors, however, could produce an ECF resembling HMW-ECF and chemotactic activities for macrophages and neutrophils by stimulation with concanavalin A (Con A). Protein synthesis appeared to be essential for spontaneous ECF and for Con A-induced ECF production. These results suggest that the granuloma OKT4-positive T lymphocytes of the patients with SALH are in activated condition to release LMW- and HMW-ECF, whereas the blood OKT4-positive T lymphocytes are in activated condition to release only HMW-ECF. Such spontaneous and prolonged production of HMW-ECF by the cells can be one of the diagnostic means of SALH.