Abstract
A 22-year-old female was hospitalized with pyrexia and multiple arthralgia as main complaints and was then diagnosed systemic erythematosus. This case was lupus nephritis ISN/PRS classification ⅢA/C type with a high level of SLEDAI; 29 points. We considered that the disease activity was high and thus conducted steroid half-pulse therapy, 3 days of mPSL 500 mg/day intravenous infusion. Although the symptoms were alleviated temporarily, because it recurred during post-therapy with PSL 40 mg, multi-target therapy combined with tacrolimus and mizoribine was initiated. Because the effective blood concentration of tacrolimus didn’t increase, the drug was changed to cyclosporine, resulting in rapid increase in the effective blood concentration and notably alleviated symptoms. The gene polymorphisms of drug-metabolic enzymes were thus measured and it was then found that it was CYP3A5*1/*1 whose blood concentration didn’t increase easily. Thus, On Day 64 of the hospitalization, the patient was discharged to home and has had favorable course since then. This is a case that the measurement of gene polymorphisms of drug metabolic enzymes in selection of immunosuppressant was effective. As gene polymorphisms may be measured conveniently and rapidly in recent years, it may be a useful method to predeict the efficacy of a drug and may lead to an efficacious decision of immunosuppressant agent.
