TNF and systemic lupus erythematosus: To determine whether SLE patients have unique patterns of cytokine secretion in response to apoptotic material, we studied a large number of patients (47 patients) and quantified the production of TGF-β and TNF-α using a highly standardized and reproducible assay in which control or SLE monocytes are co-incubated in the absence or presence of dying cells in which apoptosis was induced by ultraviolet B (UVB)-irradiation.