METHOD: The APLC cohort is an ongoing, prospective longitudinal cohort. Adult patients who meet either the American College of Rheumatology (ACR) Modified Classification Criteria for systemic lupus erythematosus (SLE), or the Systemic Lupus International Collaborating Clinics (SLICC) Classification Criteria, and provide informed consent are recruited into the cohort. Patients are routinely followed up at 3- to 6-monthly intervals. Information on demographics, clinical manifestations, treatment, pathology results, outcomes, and patient-reported quality of life (Short-form 36 version 2) are collected using a standardized case report form. Each site is responsible for obtaining local ethics and governance approval, patient recruitment, data collection, and data transfer into a centralized APLC database.
RESULTS: The latest APLC cohort comprises 2160 patients with >12 000 visits from Australia, China, Hong Kong, Indonesia, Japan, Malaysia, Philippines, Singapore, Taiwan and Thailand. The APLC has proposed the Lupus Low Disease Activity State (LLDAS) as a treat-to-target (T2T) endpoint, and reported several retrospective and cross-sectional analyses consistent with the validity of LLDAS. Longitudinal validation of LLDAS as a T2T endpoint is currently underway.
CONCLUSION: The APLC cohort is one of the largest contemporary SLE patient cohorts in the world. It is the only cohort with substantial representation of Asian patients. This cohort represents a unique resource for future clinical research including evaluation of other endpoints and quality of care.
METHODS: The Asia Pacific Lupus Collaboration (APLC) prospectively collects data across numerous sites regarding demographic and disease characteristics, medication use, and lupus outcomes. Using propensity score methods and panel logistic regression models, we determined the association between lupus medications and outcomes.
RESULTS: Among 1707 patients followed over 12,689 visits for a median of 2.19 years, 1332 (78.03%) patients achieved the Lupus Low Disease Activity State (LLDAS), 976 (57.18%) experienced flares, and on most visits patients were taking an anti-malarial (69.86%) or immunosuppressive drug (76.37%). Prednisolone, hydroxychloroquine and azathioprine were utilised with similar frequency across all organ domains; methotrexate for musculoskeletal activity. There were differences in medication utilisation between countries, with hydroxychloroquine less frequently, and calcineurin inhibitors more frequently, used in Japan. More patients taking leflunomide, methotrexate, chloroquine/hydroxychloroquine, azathioprine, and mycophenolate mofetil/mycophenolic acid were taking ≤ 7.5 mg/day of prednisolone (compared to > 7.5 mg/day) suggesting a steroid-sparing effect. Patients taking tacrolimus were more likely (Odds Ratio [95% Confidence Interval] 13.58 [2.23-82.78], p = 0.005) to attain LLDAS. Patients taking azathioprine (OR 0.67 [0.53-0.86], p = 0.001) and methotrexate (OR 0.68 [0.47-0.98], p = 0.038) were less likely to attain LLDAS. Patients taking mycophenolate mofetil were less likely to experience a flare (OR 0.79 [0.64-0.97], p = 0.025). None of the drugs was associated with a reduction in damage accrual.
CONCLUSIONS: This study suggests a steroid-sparing benefit for most commonly used standard of care immunosuppressants used in SLE treatment, some of which were associated with an increased likelihood of attaining LLDAS, or reduced incidence of flares. It also highlights the unmet need for effective treatments in lupus.