TUMOR-NECROSIS-FACTOR-ALPHA BUT NOT LYMPHOTOXIN IS OVERPRODUCED BY BLOOD MONONUCLEAR-CELLS IN MULTIPLE-SCLEROSIS

The cytotoxic cytokines tumor necrosis factor alpha (TNF-alpha) and ly mphotoxin (LT) possess toxic activity against myelin and/or oligodendr ocytes in vitro. Multiple sclerosis (MS) plaques within the central ne rvous system (CNS) are infiltrated by peripheral blood mononuclear cel ls (PBMC). In this study the production of TNF-alpha and LT by PBMC in active MS were measured. PBMC were isolated from the blood of MS pati ents in relapse and also patients with other neurological diseases (ON D) and healthy controls (HC). Isolated cells were cultured unstimulate d or stimulated with phytohemagglutinin A (PHA), lipopolysaccharide (L PS) and myelin basic protein (MBP) - a hypothetical autoantigen for MS . Cytokine production was assessed using ELISA method. In the MS group , PBMC without stimulation as well as after stimulation with MBP displ ayed a significantly increased production of TNF-alpha. LT production was similar in MS and control groups. These results suggest that TNF-a lpha but not LT is overproduced by PBMC during MS relapse.