Faculty Bibliography

OBJECTIVE:To examine change in health-related quality of life in association with clinical outcomes of neuropsychiatric events in systemic lupus erythematosus (SLE). METHODS:An international study evaluated newly diagnosed SLE patients for neuropsychiatric events attributed to SLE and non-SLE causes. The outcome of events was determined by a physician-completed seven-point scale and compared with patient-completed Short Form 36 (SF-36) health survey questionnaires. Statistical analysis used linear mixed-effects regression models with patient-specific random effects. RESULTS:274 patients (92% female; 68% Caucasian), from a cohort of 1400, had one or more neuropsychiatric event in which the interval between assessments was 12.3 ± 2 months. The overall difference in change between visits in mental component summary (MCS) scores of the SF-36 was significant (p<0.0001) following adjustments for gender, ethnicity, centre and previous score. A consistent improvement in neuropsychiatric status (N=295) was associated with an increase in the mean (SD) adjusted MCS score of 3.66 (0.89) in SF-36 scores. Between paired visits when the neuropsychiatric status consistently deteriorated (N=30), the adjusted MCS score decreased by 4.00 (1.96). For the physical component summary scores the corresponding changes were +1.73 (0.71) and -0.62 (1.58) (p<0.05), respectively. Changes in SF-36 subscales were in the same direction (p<0.05; with the exception of role physical). Sensitivity analyses confirmed these findings. Adjustment for age, education, medications, SLE disease activity, organ damage, disease duration, attribution and characteristics of neuropsychiatric events did not substantially alter the results. CONCLUSION/CONCLUSIONS:Changes in SF-36 summary and subscale scores, in particular those related to mental health, are strongly associated with the clinical outcome of neuropsychiatric events in SLE patients.

OBJECTIVE:Neuropsychiatric events occur unpredictably in systemic lupus erythematosus (SLE) and most biomarker associations remain to be prospectively validated. This study examined a disease inception cohort of 1047 SLE patients to determine which autoantibodies at enrolment predicted subsequent neuropsychiatric events. METHODS:Patients with a recent SLE diagnosis were assessed prospectively for up to 10 years for neuropsychiatric events using the American College of Rheumatology case definitions. Decision rules of graded stringency determined whether neuropsychiatric events were attributable to SLE. Associations between the first neuropsychiatric event and baseline autoantibodies (lupus anticoagulant (LA), anticardiolipin, anti-β(2) glycoprotein-I, anti-ribosomal P and anti-NR2 glutamate receptor) were tested by Cox proportional hazards regression. RESULTS:Disease duration at enrolment was 5.4 ± 4.2 months, follow-up was 3.6 ± 2.6 years. Patients were 89.1% female with mean (±SD) age 35.2 ± 13.7 years. 495/1047 (47.3%) developed one or more neuropsychiatric event (total 917 events). Neuropsychiatric events attributed to SLE were 15.4% (model A) and 28.2% (model B). At enrolment 21.9% of patients had LA, 13.4% anticardiolipin, 15.1% anti-β(2) glycoprotein-I, 9.2% anti-ribosomal P and 13.7% anti-NR2 antibodies. LA at baseline was associated with subsequent intracranial thrombosis (total n=22) attributed to SLE (model B) (HR 2.54, 95% CI 1.08 to 5.94). Anti-ribosomal P antibody was associated with subsequent psychosis (total n=14) attributed to SLE (model B) (HR 3.92, 95% CI 1.23 to 12.5, p=0.02). Other autoantibodies did not predict neuropsychiatric events. CONCLUSION/CONCLUSIONS:In a prospective study of 1047 recently diagnosed SLE patients, LA and anti-ribosomal P antibodies are associated with an increased future risk of intracranial thrombosis and lupus psychosis, respectively.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disorder with a complex pathogenesis in which genetic, hormonal and environmental factors have a role. Rare mutations in the TREX1 gene, the major mammalian 3'-5' exonuclease, have been reported in sporadic SLE cases. Some of these mutations have also been identified in a rare pediatric neurological condition featuring an inflammatory encephalopathy known as Aicardi-Goutieres syndrome (AGS). We sought to investigate the frequency of these mutations in a large multi-ancestral cohort of SLE cases and controls. A total of 40 single-nucleotide polymorphisms (SNPs), including both common and rare variants, across the TREX1 gene, were evaluated in approximately 8370 patients with SLE and approximately 7490 control subjects. Stringent quality control procedures were applied, and principal components and admixture proportions were calculated to identify outliers for removal from analysis. Population-based case-control association analyses were performed. P-values, false-discovery rate q values, and odds ratios (OR) with 95% confidence intervals (CI) were calculated. The estimated frequency of TREX1 mutations in our lupus cohort was 0.5%. Five heterozygous mutations were detected at the Y305C polymorphism in European lupus cases but none were observed in European controls. Five African cases incurred heterozygous mutations at the E266G polymorphism and, again, none were observed in the African controls. A rare homozygous R114H mutation was identified in one Asian SLE patient, whereas all genotypes at this mutation in previous reports for SLE were heterozygous. Analysis of common TREX1 SNPs (minor allele frequency (MAF)>10%) revealed a relatively common risk haplotype in European SLE patients with neurological manifestations, especially seizures, with a frequency of 58% in lupus cases compared with 45% in normal controls (P=0.0008, OR=1.73, 95% CI=1.25-2.39). Finally, the presence or absence of specific autoantibodies in certain populations produced significant genetic associations. For example, a strong association with anti-nRNP was observed in the European cohort at a coding synonymous variant rs56203834 (P=2.99E-13, OR=5.2, 95% CI=3.18-8.56). Our data confirm and expand previous reports and provide additional support for the involvement of TREX1 in lupus pathogenesis.

The EXPLORER study was designed to assess the response to rituximab versus placebo in patients with moderate to severe extrarenal systemic lupus erythematosus (SLE) receiving background immunosuppression. The definition of response required reduced clinical activity without subsequent flares over 52 weeks, and the study did not meet its efficacy endpoint. The current exploratory analysis assessed flare rates in patients who achieved initial low disease activity response (British Isles Lupus Assessment Group [BILAG] C or better in all organs) during the study. Exploratory reanalysis of data from the EXPLORER trial was conducted, considering alternative definitions for flare. No difference was found between rituximab and placebo in preventing or delaying moderate to severe flares. However, when severe (BILAG A) flares alone were examined, rituximab reduced the risk of a subsequent first A flare (hazard ratio = 0.61; p = 0.052) and lowered mean +/- SD annualized A flare rates (0.86 +/- 1.47 vs. 1.41 +/- 2.14; p = 0.038). Eighty-four (49.7%) rituximab-treated patients achieved low disease activity without subsequent A flares versus 31 (35.2%) placebo-treated patients (p = 0.027). Prednisone rescue for A flares was similar in rituximab- (24%) and placebo-treated (14%) patients (p = 0.204). This post hoc analysis evaluates the hypothesis that assessment of BILAG A flares may distinguish potential treatment effects with greater sensitivity than assessment of BILAG B flares.