Clonal haematopoiesis of indeterminate potential and cardiovascular events in systemic lupus erythematosus (HEMATOPLUS study).

OBJECTIVE: The detection of somatic mutations among the genes of myeloid cells in asymptomatic patients-defining clonal haematopoiesis of indeterminate potential (CHIP)-is associated with a predisposition to cardiovascular events (CVEs) in the general population. We aimed to determine whether CHIP was associated with CVEs in SLE patients. METHODS: The study is an ancillary study of the randomized, double-blind, placebo-controlled, multicentre PLUS trial conducted from June 2007 through August 2010 at 37 centres in France, involving 573 SLE patients. The search for somatic mutations by high-throughput sequencing of 53 genes involved in clonal haematopoiesis was performed on genomic DNA collected at PLUS inclusion. CHIP prevalence was assessed in SLE and in a retrospective cohort of 479 patients free of haematological malignancy. The primary outcome was an incident CVE in SLE. RESULTS: Screening for CHIP was performed in 438 SLE patients [38 (29-47) years, 91.8% female]. Overall, 63 somatic mutations were identified in 47 patients, defining a CHIP prevalence of 10.7% in SLE. Most SLE patients (78.7%) carried a single mutation. Most variants (62.5%) were located in the DNMT3A gene. CHIP frequency was related to age and to age at SLE diagnosis, and was associated with a lower frequency of aPLs. CHIP occurred >20 years earlier (P < 0.00001) in SLE than in controls. The detection of CHIP at inclusion was not found to be associated with occurrence of CVEs during follow-up [HR = 0.42 (0.06-3.21), P = 0.406]. CONCLUSION: The prevalence of CHIP is relatively high in SLE for a given age, but was not found to be associated with incident CVEs. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT05146414.

Highly sensitive serum cardiac troponin T and cardiovascular events in patients with systemic lupus erythematosus (TROPOPLUS study).

OBJECTIVE: Identification of biological markers able to better stratify cardiovascular risks in SLE patients is needed. We aimed to determine whether serum cardiac troponin T (cTnT) levels measured with a highly sensitive assay [high sensitivity cTnT (HS-cTnT)] may predict cardiovascular events (CVEs) in SLE. METHOD: All SLE patients included between 2007 and 2010 in the randomized, double-blind, placebo-controlled, multicentre PLUS trial were screened. Patients with no past history of CVE at inclusion and a follow-up period of >20 months were analysed. HS-cTnT concentration was measured using the electrochemiluminescence method on serum collected at PLUS inclusion. The primary outcome was the incident CVE. Factors associated with the primary outcome were identified and multivariate analysis was performed. RESULTS: Overall, 442 SLE patients (of the 573 included in the PLUS study) were analysed for the primary outcome with a median follow up of 110 (interquartile range: 99-120) months. Among them, 29 (6.6%) experienced at least one CVE that occurred at a median of 67 (interquartile range: 31-91) months after inclusion. Six out of 29 patients had more than one CVE. In the multivariate analysis, dyslipidaemia, age and HS-cTnT were associated with the occurrence of CVE. Kaplan-Meier analysis showed that a concentration of HS-cTnT > 4.27 ng/l at inclusion increased by 2.7 [hazard ratio 2.7 (95% CI: 1.3, 5.6), P =0.0083] the risk of CVE in SLE. CONCLUSION: HS-cTnT measured in serum is the first identified biomarker independently associated with incident CVE in SLE patients.

Risk factors for hydroxychloroquine retinopathy in systemic lupus erythematosus: a case-control study with hydroxychloroquine blood-level analysis.

OBJECTIVE: HCQ is an essential medication in SLE, proven to lengthen survival and reduce flares. Its use, however, is limited by its rare but severe ophthalmological complications. Here, we aimed to analyse factors associated with HCQ retinopathy including HCQ blood levels. METHODS: This case-control study compared SLE patients with and without HCQ retinopathy, defined by abnormal results for at least two of the following ophthalmological tests: automated visual fields, spectral-domain optical coherence tomography (SD-OCT), multifocal electroretinogram (mfERG) and fundus autofluorescence. We compared clinical and laboratory findings to assess risk factors for HCQ retinopathy. RESULTS: The study included 23 patients with confirmed retinopathy (cases) and 547 controls. In the univariate analysis, age (P < 0.001), height (P = 0.045), creatinine clearance (P < 0.001), haemoglobin concentration (P = 0.01), duration of HCQ intake, (P < 0.001), higher cumulative HCQ dose (P < 0.001) and geographical origin (West Indies and sub-Saharan Africa) (P = 0.007) were associated with the risk of retinopathy, while HCQ blood levels were not. In the multivariate analysis, only cumulative dose (P = 0.016), duration of intake (P = 0.039), creatinine clearance (P = 0.002) and geographical origin (P < 0.0001, odds ratio 8.7) remained significantly associated with retinopathy. CONCLUSION: SLE patients on HCQ should be closely monitored for retinopathy, especially those from the West Indies or sub-Saharan Africa, or with renal insufficiency, longer HCQ intake or a high cumulative dose. Although reducing the daily dose of HCQ in patients with persistently high HCQ blood levels seems logical, these concentrations were not associated with retinopathy in this study with controls adherent to treatment.

Effects of BAFF Neutralization on Atherosclerosis Associated With Systemic Lupus Erythematosus.

OBJECTIVE: Cardiovascular disease (CVD) is the leading cause of death in systemic lupus erythematosus (SLE). B cells play a key role in the pathogenesis of lupus, and anti-BAFF therapy has been approved for use in SLE. Since mature B cells also promote atherosclerosis, we undertook this study to evaluate, in a mouse model and in SLE patients, whether BAFF neutralization has an atheroprotective effect in SLE. METHODS: The effect of BAFF on atherosclerosis associated with lupus was investigated in the atherosclerosis/lupus-prone apolipoprotein E-knockout D227K mouse model and in a cohort of SLE patients. Mice were treated with a blocking anti-BAFF monoclonal antibody (mAb), while fed a standard chow diet. Carotid plaque and carotid intima-media thickness were assessed by ultrasound at baseline and during follow-up in SLE patients who were asymptomatic for CVD. RESULTS: Anti-BAFF mAb in ApoE-/- D227K mice induced B cell depletion, efficiently treated lupus, and improved atherosclerosis lesions (21% decrease; P = 0.007) in mice with low plasma cholesterol levels but worsened the lesions (17% increase; P = 0.06) in mice with high cholesterol levels. The atheroprotective effect of the BAFF-BAFF receptor signaling inhibition on B cells was counterbalanced by the proatherogenic effect of the BAFF-TACI signaling inhibition on macrophages. In SLE patients, blood BAFF levels were associated with subclinical atherosclerosis (r = 0.26, P = 0.03). Anti-BAFF mAb treatment had a differential effect on the intima-media thickness progression in SLE patients depending on body mass index. CONCLUSION: Depending on the balance between lipid-induced and B cell-induced proatherogenic conditions, anti-BAFF could be detrimental or beneficial, respectively, to atherosclerosis development in SLE.