Ab1615-HPR Hlab5801 Testing for Patients at High Risk for Allopurinol Hypersensitivity Syndrome: A Quality Improvement Initiative

Background: Allopurinol Hypersensitivity Syndrome (AHS) is a severe systemic drug reaction to the urate-lowering therapy, allopurinol, resulting in fever, prominent cutaneous eruption, eosinophilia, hepatic abnormalities, and acute renal failure. Mortality rate has been reported to be as high as 26%. HLA-B58:01 increases risk for AHS; the allele is found at higher frequency in those of Asian or African ancestry. Allopurinol is the leading cause of SJS/TEN. The 2020 American College of Rheumatology Guideline for the Management of Gout recommends testing for HLA-B58:01 in high-risk patients of Asian and African American descent prior to starting allopurinol therapy, but the European Alliance of Associations for Rheumatology (EULAR) 2016 recommendations leaves testing at the discretion of the clinician with recommendations of further research on the cost-utility of testing for HLA-B*58:01 Objectives: In a quality improvement initiative, to develop a local testing program for HLA-B58:01 for patients at high risk for AHS and evaluate test utilization before and after provider education. Methods: Baseline evaluation of allopurinol prescriptions in self-identified African American and Asian patients was performed from October, 1, 2022 through May 17, 2023 at the Lebanon VA Medical Center. Data were gathered via chart review and record review was performed for the following 3 months after initiation of allopurinol since the highest risk for AHS occurs is in the first three months of therapy. A new initiation in therapy was defined as a first-time prescription of allopurinol and initial exposure to allopurinol occurring between July 1, 2023 and May 17, 2023. In September 2023, the HLA-B58:01 test was added to the EMR for use by all providers, and an informational message was added to all electronic prescriptions of allopurinol identifying the need for testing in black or Asian patients with no previous allopurinol exposure. Educational conferences on diagnosis of gout, indications for use of urate lowering therapy, and appropriate use of HLA-B58:01 testing were given to primary care physicians in virtual and in-person format. HLA-B58:01 testing and appropriate utilization was acquired via chart review for 3 months after EMR test development for HLA-B58:01 and education presentations to primary care. Results: 33 patients identifying as African American or Asian in their demographic information were prescribed allopurinol between October 1, 2022 and May 17, 2023 at the Lebanon VA Medical Center. Of these 33 patients, 11 were determined to be a new initiation of treatment. No patients were screened for presence of HLA-B:58:01 haplotype prior to starting treatment. Testing data gathered after the intervention of test availability and provider education demonstrated 2 uses of the testing for the HLA-B58:01 allele, both in black patients with gout. Of the 2 patients on which it was ordered, one patient was allopurinol naïve with 50% appropriate utilization of the test. Both test results were negative. During the 3 months after EMR alert and testing availability, 22 patients met eligibility for appropriate testing but were not tested, with a 4% rate of appropriate testing. Conclusion: EMR implementation of a provider alert combined with education conference resulted in successful testing and screening of HLA-B58:01 testing in patients of high risk for AHS. Despite intervention by way of education and an alert message in the EMR when ordering allopurinol, testing frequency was low with only 2 HLA-B58:01 tests ordered out of 23 appropriate patients. 50% of the tests ordered had appropriate indication for testing for HLA-B58:01. Further education to providers is needed about both appropriate use of the testing in high risk individuals without previous allopurinol exposure and also indications for testing. Follow up on further plan-do-study-act cycles is needed to improve testing utilization and screening. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.