The iLite® Diluent C can be used in the anti-TNF-alpha NAb assay. It should be used for the dilution of test samples (not the first dilution step where Diluent B is used). It should also be used as negative control and for the preparation of the calibrator and positive control. Tumor necrosis factor alpha (TNF-alpha) promotes inflammatory responses, which, in turn, contribute to the clinical problems associated with many inflammatory disorders, including rheumatoid arthritis, ankylosing spondylitis, Crohn's disease, psoriasis and refractory asthma. These diseases are sometimes treated with TNF-alpha inhibitors, including infliximab, adalimumab, etanercept, certolizumab pegol or golimumab. Prolonged therapies with these TNF-alpha inhibitors may lead to development of neutralizing antibodies (NAbs), which may counteract the TNF-alpha antagonist activity of the drugs.