Objectives Hydroxychloroquine (HCQ) is a key therapy in systemic lupus erythematosus (SLE). Medication non-adherence is reported in up to 80% of lupus patients and results in increased morbidity, mortality, and health care utilization. HCQ levels are a sensitive and reliable method to assess medication adherence. Our study evaluated the role of HCQ level measurement in routine clinical care and its association with disease activity in a predominantly Hispanic population. Methods SLE patients from the Columbia University Lupus cohort treated with HCQ for ≥ 6 months and reporting medication adherence were included. HCQ levels were measured by whole blood high performance liquid chromatography. Non-adherence was defined as an HCQ level <500 ng/ml. The association between HCQ levels and disease activity measured by Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) was evaluated. Results One hundred and eight patients were enrolled; the median age was 38 years, 91% were female, and 63% were Hispanic. The median SLEDAI-2K was 4.3 (0–20). Forty-one percent of patients had an HCQ level <500 ng/ml consistent with non-adherence, of which 19% had undetectable levels. A higher SLEDAI-2K score was associated with low HCQ levels ( p = 0.003). This association remained significant after adjusting for depression ( p = 0.0007). Conclusion HCQ levels < 500 ng/ml were associated with higher disease activity and accounted for 32% of the SLEDAI-2K variability. HCQ blood measurement is a simple and reliable method to evaluate medication adherence in SLE. Reasons for non-adherence (levels < 500 ng/ml) should be further explored and addressed.

ObjectivesCardiovascular diseaseand heart failure (CHF) are leading causes of death in systemic lupus erythematosus (SLE). The underlying mechanisms for increased CHF in SLE are unclear but myocardial inflammation and lupus myocarditis (LM) may play a role. We propose that 18F-fluorodeoxyglucose–positron emission tomography (18F-FDG–PET)/CT can help diagnose LM.MethodsThis report describes eight patients with presumed LM; five patients were evaluated due to active cardiorespiratory symptoms and three patients were participating in a pilot study to determine the prevalence of subclinical myocarditis in SLE. Clinical characteristics, laboratory and cardiac testing including electrocardiography (ECG), transthoracic echocardiogram (TTE), coronary artery evaluation as well as 18F-FDG–PET/CT imaging are discussed.ResultsFour patients were African American and the others were Hispanic. Half presented with chest pain; 37% had dyspnoea and 25% were asymptomatic. The median SLE Disease Activity Index (SLEDAI-2K) was 5 (2–18) and SLICC Damage Index (SDI) 0.5 (0–5). The median troponin level was 0.08 ng/mL (0–0.9). The most common ECG findings were non-specific ST-T wave abnormalities (n=5). Fifty per cent of the patients had a decreased ejection fraction on TTE and all patients had diffuse myocardial FDG uptake on 18F-FDG–PET/CT consistent with myocardial inflammation.ConclusionThis case series is the first to describe the use of 18F-FDG–PET/CT in the diagnosis of LM and discuss the clinical characteristics and cardiac findings of eight patients with LM supporting the role for cardiac 18F-FDG–PET/CT in its diagnosis.