Radiation-related eosinophilia. Correlation with delayed hypersensitivity, lymphocyte count, and survival in patients treated by curative radiotherapy.

Abdominal irradiation may produce eosinophilia. The relationship between radiation-related eosinophilia (RRE), reactivity to 2-4 dinitrochlorobenzene (DNCB), lymphocyte count, and prognosis was evaluated in 98 patients irradiated for tumors below the diaphragm. Forty-two per cent manifested RRE and 62% reacted to DNCB. Fifteen of 19 (79%) reactors who had RRE were disease-free at 6 months. Fourteen of 22 (64%) nonreactors who had RRE and 26 of 42 (62%) DNCB reactors without RRE were controlled. Fourteen of 15 (93%) nonreactors without RRE had disease at 6 months. Those who had RRE had double the median survival of those who did not.