The United Kingdom's National Institute for Health and Care Excellence (NICE) recently published recommendations on new diagnostic tests to guide treatment in patients with Crohn’s disease, suggesting that more research is needed before such tests can be used routinely in the U.K.'s National Health Service. Crohn's disease is a chronic, relapsing-remitting inflammatory bowel disease (IBD) that causes inflammation in the digestive system. So far, there is no cure. Symptoms include diarrhea, abdominal pain and cramping, exhaustion, and weight loss. The LISA-TRACKER ELISAs (Theradiag), IDKmonitor ELISAs (Immundiagnostik AG), and Promonitor ELISAs (Proteomika S.L.U) are currently used in the diagnostics of Crohn’s disease, particularly by measuring the levels of TNF-alpha inhibitors and antibodies against them. TNF-alpha inhibitors can stop the inflammatory response in the intestines, a characteristic of Crohn’s disease. Some patients with Crohn’s do not respond to treatment with TNF-alpha inhibitors, and many patients who initially respond to treatment eventually become non-responsive over time. This is explained by changes in disease progression and characteristics, inflammation dissociated to TNF concentrations, the presence of antibodies against TNF-alpha inhibitors, or even fluctuating drug levels. The regimen and dose of TNF-alpha inhibitor treatment is difficult to define, and treatment decisions are based on clinical judgment along with trial and error. In other words, patients who are responsive to treatment with TNF-alpha inhibitors usually receive the same dose even if it could be lowered or withdrawn completely without any detrimental impact. Prolonged treatment can cause unnecessary side effects. Patients who become non-responsive to TNF-alpha inhibitors are often given increased doses. This strategy can be successful for some patients, but others may experience unnecessary side effects without the clinical benefits. NICE suggested that doctors and diagnostic laboratories who are already using ELISA kits for disease diagnosis and monitoring should learn more about their application in Crohn’s disease patients who are not responsive to TNF-alpha inhibitors therapy. “Tests that can accurately measure levels of TNF-alpha inhibitors and antibodies to them could enable people with Crohn’s disease to receive treatment that’s better tailored to their needs to allow treatment optimization with fewer side effects," Prof. Carole Longson, MBE, director of the NICE Health Technology Evaluation Centre, said in a NICE press release. "The tests reviewed in this guidance show real promise. But the committee was concerned that, because of the complexities in interpreting test results, there is a risk they could be incorrectly used by clinicians without specialist knowledge of immunoassay analysis," she said. "The committee therefore concluded that in people with Crohn’s disease whose disease loses response to TNF alpha inhibitors, for the time being, these tests should be used only in those laboratories that have specialist expertise in immunoassay analysis," Longson said. "These laboratories should work closely with clinicians who refer samples for testing to ensure appropriate use of the tests and interpretation of the results. "The recommendations highlight that these clinicians and laboratories should work together to collect data on the use of the tests through a prospective study, for local audit, or for submission to an existing registry in order to gather more evidence to allow an update of this guidance in the future. The IBD Registry is being adapted to receive data on TNF alpha inhibitor levels and antibodies against TNF alpha inhibitors,” Longson said.