Stimulation of monocyte-mediated, antibody-dependent cytotoxicity in mycosis fungoides.

Antibody-dependent cytotoxicity mediated by purified blood monocytes were determined in untreated patients with plaque-stage mycosis fungoides (MF), parapsoriasis en plaques, exfoliating erythroderma, and noncutaneous malignant lymphoma. Compared with healthy control subjects and control subjects with varicose ulcers, patients with MF had increased monocyte cytotoxicity. In the other dermatoses, normal monocyte cytotoxicity was found. Patients with noncutaneous malignant lymphoma showed normal or decreased monocyte cytotoxicity. There was no evidence that abnormal monocyte cytotoxicity in cutaneous and noncutaneous malignant lymphoma were caused by interaction with lymphocytes or serum. The presence of increased monocyte cytotoxicity in patients with plaque-stage MF may be a clinically useful finding when this diagnosis is suspected clinically but not proved histopathologically.