Reduced Rate of Disease Flares in Japanese Patients with Systemic Lupus Erythematosus: An Altered Balance between the Use of Glucocorticoids and Immunosuppressants in Recent Decades

OBJECTIVE: This study examined whether or not the disease control in Japanese patients with systemic lupus erythematosus (SLE) had improved in recent years and its possible association with altered balance between the use of glucocorticoids and immunosuppressants. METHODS: We enrolled Japanese patients with SLE who visited our medical center during 2013-2017 (Group A, 75 patients) and compared them with patients encountered during 1999-2003 (Group B, 69 patients; not overlapping with Group A). Patient background characteristics, doses of glucocorticoids, and the use of immunosuppressants at the times of SLE onset and disease flares were reviewed from the medical records. Disease flare was defined as new British Isles Lupus Assessment Group 2004 A or B scores in at least one system. RESULTS: Lupus nephritis and neuropsychiatric manifestations were less frequently observed in Group A than in Group B (p=0.042 and p=0.045, respectively). Although the initial glucocorticoid dosage was similar between the groups, the inclusion rate of immunosuppressants in the initial SLE treatment was significantly higher in Group A than in Group B (56% vs. 6% in Group B, p<0.001). The median number of SLE flares per person-year was significantly lower in Group A than in Group B (0 vs. 0.3, respectively, p<0.001), and a propensity score-matched analysis indicated the association of SLE flare with the non-use of immunosuppressants in the initial treatment (p=0.012). The rates of infectious diseases and other complications were similar between the groups. CONCLUSION: The recent aggressive use of immunosuppressants in Japan resulted in a reduction in the rate of SLE flare.