Pharmacogenetics to optimize immunosuppressant therapy in systemic lupus erythematosus: a scoping review

Systemic lupus erythematosus (SLE) is a complex autoimmune disease requiring immunosuppressive medications to control symptoms and prevent organ damage. This review explores the influence of genetic polymorphisms on the pharmacokinetics and therapeutic responses of immunosuppressants in SLE. A total of 37 studies were reviewed, focusing on mycophenolic acid, tacrolimus, azathioprine, glucocorticoids, and cyclophosphamide. Genetic variants in UGT1A9, UGT2B7, CYP3A5, ABCB1,ABCC2 and TPMT significantly affect drug metabolism, efficacy, and toxicity. For instance, ABCB1 polymorphisms influence drug transport and bioavailability, impacting tacrolimus and glucocorticoid response, while ABCC2 variants alter MPA clearance, potentially affecting therapeutic outcomes, UGT1A9 and UGT2B7 variants influence mycophenolic acid metabolism, CYP3A5 impacts tacrolimus dosing, TPMT determines azathioprine metabolism, and CYP2C19 and CYP2B6 affect cyclophosphamide processing. These genetic differences can alter treatment effectiveness and risk of adverse effects. However, most pharmacogenetic studies focus on organ transplantation, leaving a critical gap in SLE-specific research, particularly among diverse populations. Addressing this gap is essential to optimizing personalized treatment for SLE. Integrating pharmacogenetics into clinical practice holds great potential to enhance the safety, efficacy, and outcomes of immunosuppressive therapy in SLE. This review highlights the urgent need for further studies to advance precision medicine for SLE patients.