RT Journal Article SR Electronic T1 DPP-4 inhibitor (sitagliptin)-induced seronegative rheumatoid arthritis JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e228981 DO 10.1136/bcr-2018-228981 VO 12 IS 8 A1 Simonette Padron A1 Everett Rogers A1 Michelle Demory Beckler A1 Marc Kesselman YR 2019 UL http://casereports.bmj.com/content/12/8/e228981.abstract AB Sitagliptin is a dipeptidyl peptidase-4 inhibitor commonly used in the treatment of type 2 diabetes mellitus for glycaemic control. Concerns have arisen regarding adverse events caused by this drug, particularly concerning arthralgias. Here, we report on a 56-year-old man being treated with sitagliptin who developed inflammatory arthritis after taking the drug for 6 months. The patient presented with pain, swelling and erythema in multiple joints and was eventually diagnosed with seronegative rheumatoid arthritis (RA) under the 2010 American College of Rheumatology/European League Against Rheumatism classification criteria. His symptoms continued for several months after stopping sitagliptin and eventually went into remission after a tapered course of steroids, hydroxychloroquine and methotrexate. Furthermore, the patient is HLA-DRB3 positive, a genetic marker that is still being investigated for its role in the pathogenesis of RA and that may have been a predisposing factor in the development of this patient’s inflammatory arthropathy.