N31 HLA-DQA1*05 detection in saliva, an effective alternative in the monitoring and control of patients with Inflammatory Bowel Disease

Abstract

Abstract Background The development of Inflammatory Bowel Disease (IBD) appears to be related to genetic susceptibility and an excessive immune response of the intestinal mucosa. Tumour necrosis factor (anti-TNF) therapies are the most widely used biologic drugs to treat immune-mediated diseases, but repeated administration may induce the formation of anti-drug antibodies. The ability to identify patients at increased risk of developing anti-TNFα antibodies would facilitate the selection of therapy and the use of preventive strategies. It has been shown that approximately 40% of the European population carries the HLA-DQA1*05 allele, and that its presence could have an important impact on treatment as it has been associated with: - Increased risk of immunogenicity of anti-TNFα therapy, regardless of concomitant treatment or anti-TNFα drug selected. - Decreased efficacy due to the formation of neutralising antibodies, leading to possible primary or secondary failures. - Occurrence of adverse events such as infusion reactions or hypersensitivity reactions. - Alterations in pharmacokinetics, so that drug clearance is accelerated regardless of whether the antibodies are neutralising. In our hospital we have the possibility to request the determination of the HLA-DQA1*05 allele through a detection kit in saliva. The main aim is to present a useful and effective tool for the detection of the HLA-DQA1*05 allele. Methods The methodology requires the inclusion of 30 newly diagnosed patients, patients naïve to biological treatment or patients on treatment with a first biological drug for no more than 24 months, by both the doctor and the nurse.The nurse will explain the previous preparation to the patient and will collect the sample using the saliva detection kit. Once the results have been received, the physician is notified. Results The detection of the HLA-DQA1*05 allele in our patients is 36.84%, a percentage similar to that detected in the European population through the detection of the HLA-DQA1*05 allele in blood. Conclusion - Having the ability to identify individuals at high risk of anti-TNF antibody formation and apply targeted combination therapy to these individuals is very valuable in clinical practice. - Saliva determination of the HLA-DQA1*05 allele is an efficient and cheaper alternative in hospitals where HLA-DQA1*05 detection in blood is not available in the laboratory. - The extraction and performance of the technique is simple, fast, obtaining the results within 5 days of submission, and convenient for both the patient and the healthcare professional.