Test Catalog

Test ID: TNFA    
Tumor Necrosis Factor (TNF), Plasma

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluation of patients with suspected systemic infection, in particular infection caused by gram-negative bacteria


Evaluation of patients with suspected chronic inflammatory disorders, such as rheumatoid arthritis, inflammatory bowel disease, or ankylosing spondylitis

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Tumor necrosis factor (TNF)-alpha is expressed primarily by activated monocytes as part of the innate immune response to various microbes, gram-negative bacteria in particular.(1) TNF-alpha is synthesized as a type II membrane protein, which can be cleaved by a membrane-associated metalloproteinase. The subunit that is released will polymerize to form a homotrimer, which is the circulating form of TNF-alpha. The primary function of TNF-alpha is to recruit other leukocytes to the site of infection and to stimulate their activation. TNF-alpha also has some systemic effects, including induction of fever through action on the hypothalamus. In cases of severe gram-negative bacterial infection, septic shock can occur. Septic shock is induced by large-scale production of inflammatory cytokines, including TNF-alpha. This disorder is characterized by hypotension, disseminated intravascular coagulation, tachycardia, and increased respiration, and can be fatal.


Dysregulation of TNF-alpha expression is thought to be a critical pathogenic mechanism in numerous autoimmune diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), and ankylosing spondylitis (AS).(2)


There are currently 5 monoclonal antibodies approved by the FDA for blockage of TNF-alpha as a clinical treatment.(3,4) The different drugs are approved for various diseases, with some available for treatment of pediatric IBD and juvenile RA.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

< or =2.8 pg/mL

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Clark IA: How TNF was recognized as a key mechanism of disease. Cytokine Growth Factor Rev 2007;18:335-343

2. Bradley JR: TNF-mediated inflammatory disease. J Pathol 2008;214:149-160

3. Horiuchi T, Mitoma H, Harashima S, et al: Transmembrane TNF-alpha: structure, function and interaction with anti-TNF agents. Rheumatology 2010;49:1215-1228

4. Willrich MAV, Murray DL, Snyder MR: Tumor necrosis factor inhibitors: clinical utility in autoimmune diseases. Trans Res 2015;165:270-282