Release of TNF alpha and IL6 from human monocytes infected with Mycobacterium kansasii: a comparison to Mycobacterium avium.

Tumor necrosis factor alpha (TNF alpha) and interleukin 6 (IL6) are cytokines with a varied spectrum of inflammatory and immunological activities, for example modulation of acute phase proteins, fever and stimulation of B-lymphocytes. Mycobacterium avium has been shown to stimulate the release of TNF alpha and IL6 from cultured human monocytes and macrophages into the cell supernatant. Cultured human monocytes were infected with Mycobacterium kansasii and M. avium. The concentrations of TNF alpha and IL6 were measured in the supernatant. Monocytes infected with M. kansasii produced significantly lower amounts of TNF alpha (34.8 +/- 20.3 pg/ml) and IL6 (12.0 +/- 8.9 pg/ml) compared to monocytes infected with M. avium (198.3 +/- 171.7 pg/ml and 63.2 +/- 37.6 pg/ml respectively). The extent of cytokine production might be relevant for the clinical manifestation of mycobacterial disease.