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ObjectivesTo investigate associations between a high genetic disease risk and disease severity in patients with systemic lupus erythematosus (SLE).MethodsPatients with SLE (n=1001, discovery cohort and n=5524, replication cohort) and healthy controls (n=2802 and n=9859) were genotyped using a 200K Immunochip single nucleotide polymorphism array. A genetic risk score (GRS) was assigned to each individual based on 57 SLE risk loci.ResultsSLE was more prevalent in the high, compared with the low, GRS-quartile (OR 12.32 (9.53 to 15.71), p=7.9×10–86 and OR 7.48 (6.73 to 8.32), p=2.2×10–304 for the discovery and the replication cohorts, respectively). In the discovery cohort, patients in the high GRS-quartile had a 6-year earlier mean disease onset (HR 1.47 (1.22 to 1.75), p=4.3×10–5), displayed higher prevalence of damage accrual (OR 1.47 (1.06 to 2.04), p=2.0×10–2), renal disorder (OR 2.22 (1.50 to 3.27), p=5.9×10–5), anti-dsDNA (OR 1.83 (1.19 to 2.81), p=6.1×10–3), end-stage renal disease (ESRD) (OR 5.58 (1.50 to 20.79), p=1.0×10–2), proliferative nephritis (OR 2.42 (1.30 to 4.49), p=5.1×10–3), anti-cardiolipin-IgG (OR 1.89 (1.13 to 3.18), p=1.6×10–2), anti-β2-glycoprotein-I-IgG (OR 2.29 (1.29 to 4.06), p=4.8×10–3) and positive lupus anticoagulant test (OR 2.12 (1.16 to 3.89), p=1.5×10–2) compared with patients in the low GRS-quartile. Survival analysis showed earlier onset of the first organ damage (HR 1.51 (1.04 to 2.25), p=3.7×10–2), first cardiovascular event (HR 1.65 (1.03 to 2.64), p=2.6×10–2), nephritis (HR 2.53 (1.72 to 3.71), p=9.6×10–7), ESRD (HR 6.78 (1.78 to 26.86), p=6.5×10–3) and decreased overall survival (HR 1.83 (1.02 to 3.30), p=4.3×10–2) in high to low quartile comparison.ConclusionsA high GRS is associated with increased risk of organ damage, renal dysfunction and all-cause mortality. Our results indicate that genetic profiling may be useful for predicting outcomes in patients with SLE.

ObjectiveAntinuclear antibody (ANA) analysis by immunofluorescence (IF) microscopy remains a diagnostic hallmark of systemic lupus erythematosus (SLE). The clinical relevance of ANA fine-specificities in SLE has been addressed repeatedly, whereas studies on IF-ANA staining patterns in relation to disease manifestations are very scarce. This study was performed to elucidate whether different staining patterns associate with distinct SLE phenotypes.DesignObservational cohort study.SettingOne university hospital rheumatology unit in Sweden.ParticipantsThe study population consisted of 222 cases (89% women; 93% Caucasians), where of 178 met ≥4/11 of the 1982 American College of Rheumatology (ACR-82) criteria. The remaining 20% had an SLE diagnosis based on positive IF-ANA (HEp-2 cells) and ≥2 typical organ manifestations at the time of diagnosis (Fries’ criteria).Outcome measuresThe IF-ANA staining patterns homogenous (H-ANA), speckled (S-ANA), combined homogenous and speckled (HS-ANA), centromeric (C-ANA), nucleolar (N-ANA)±other patterns and other nuclear patterns (oANA) were related to disease manifestations and laboratory measures. Antigen-specificities were also considered regarding double-stranded DNA (Crithidia luciliae) and the following extractable nuclear antigens: Ro/SSA, La/SSB, Smith antigen (Sm), small nuclear RNP (snRNP), Scl-70 and Jo-1 (immunodiffusion and/or line-blot technique).Results54% of the patients with SLE displayed H-ANA, 22% S-ANA, 11% HS-ANA, 9% N-ANA, 1% C-ANA, 2% oANA and 1% were never IF-ANA positive. Staining patterns among patients meeting Fries’ criteria alone did not differ from those fulfilling ACR-82. H-ANA was significantly associated with the 10th criterion according to ACR-82 (‘immunological disorder’). S-ANA was inversely associated with arthritis, ‘immunological disorder’ and signs of organ damage.ConclusionsH-ANA is the dominant IF-ANA pattern among Swedish patients with SLE, and was found to associate with ‘immunological disorder’ according to ACR-82. The second most common pattern, S-ANA, associated negatively with arthritis and organ damage.

Summary Serum immunoglobulin (Ig)G anti‐nuclear antibodies (ANA) detected by indirect immunofluorescence (IF) microscopy remains a hallmark of systemic lupus erythematosus (SLE). Whether or not IF‐ANA status varies over time is controversial. We therefore designed a prospective study with longitudinal follow‐up of patients with recent‐onset SLE. The study population consisted of 54 recently diagnosed SLE cases, all meeting the 1982 American College of Rheumatology (ACR) and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria. Clinical follow‐up data, including disease activity, organ damage and sera, were collected from clinical onset of SLE and onwards, in most cases yearly (0‒96 months). IF‐ANA was analysed on human epithelial cells‐2 (HEp‐2) cells and categorized regarding staining patterns. Using an addressable laser bead assay (FIDIS™ Connective profile), we measured IgG‐ANA fine specificities against Ro52/SSA, Ro60/SSA, Sjögren’s syndrome type B antigen (La/SSB), Smith antigen (Sm), Smith antigen/ribonucleoprotein (Sm/RNP), U1 RNP (U1RNP), dsDNA, ribosomal‐P protein and histone. At baseline, all patients were judged ANA‐positive at an abnormal titre corresponding to the 95th percentile of healthy blood donors, but seven of 54 patients (13%) lost ANA‐positivity over time. Homogeneous (AC‐1; 46%) and speckled (AC‐4 or 5; 31%) were the most frequently observed patterns at inclusion, whereas 7% switched pattern at least once during follow‐up. Established associations between ANA fine specificities and clinical data were confirmed. Levels of anti‐Sm/RNP, but not of anti‐dsDNA, correlated with clinical disease activity [modified SLE disease activity 2000 (mSLEDAI‐2K)]. Our data indicate that a considerable proportion of Swedish patients with SLE lose ANA‐positivity over time, whereas consistent staining patterns were frequent. The clinical and mechanistic relevance of ANA seroconversion remains uncertain. Further prospective evaluations in larger SLE populations with more diverse ethnicities are warranted.

We observed a negative impact of smoking on the efficacy of belimumab in mucocutaneous SLE. In contrast, no impact of smoking on belimumab efficacy was seen in patients with articular manifestations.

ObjectivesPatients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) have increased risk of cardiovascular disease (CVD). We investigated whether single nucleotide polymorphisms (SNPs) at autoimmunity risk loci were associated with CVD in SLE and RA.MethodsPatients with SLE (n=1045) were genotyped using the 200K Immunochip SNP array (Illumina). The allele frequency was compared between patients with and without different manifestations of CVD. Results were replicated in a second SLE cohort (n=1043) and in an RA cohort (n=824). We analysed publicly available genetic data from general population, performed electrophoretic mobility shift assays and measured cytokine levels and occurrence of antiphospholipid antibodies (aPLs).ResultsWe identified two new putative risk loci associated with increased risk for CVD in two SLE populations, which remained after adjustment for traditional CVD risk factors. An IL19 risk allele, rs17581834(T) was associated with stroke/myocardial infarction (MI) in SLE (OR 2.3 (1.5 to 3.4), P=8.5×10−5) and RA (OR 2.8 (1.4 to 5.6), P=3.8×10−3), meta-analysis (OR 2.5 (2.0 to 2.9), P=3.5×10−7), but not in population controls. The IL19 risk allele affected protein binding, and SLE patients with the risk allele had increased levels of plasma-IL10 (P=0.004) and aPL (P=0.01). An SRP54-AS1 risk allele, rs799454(G) was associated with stroke/transient ischaemic attack in SLE (OR 1.7 (1.3 to 2.2), P=2.5×10−5) but not in RA. The SRP54-AS1 risk allele is an expression quantitative trait locus for four genes.ConclusionsThe IL19 risk allele was associated with stroke/MI in SLE and RA, but not in the general population, indicating that shared immune pathways may be involved in the CVD pathogenesis in inflammatory rheumatic diseases.

​ObjectivesA single nucleotide polymorphism in the NCF1 gene (NCF1-339, rs201802880), encoding NADPH oxidase type II subunit NCF1/p47phox, reducing production of reactive oxygen species (ROS) is strongly associated with the development of systemic lupus erythematosus (SLE). This study aimed at characterising NCF1-339 effects on neutrophil extracellular trap (NET) formation, type I interferon activity and antibody profile in patients with SLE.​MethodsNeutrophil NET-release pathways (n=31), serum interferon (n=141) and finally antibody profiles (n=305) were investigated in SLE subjects from Lund, genotyped for NCF1-339. Then, 1087 SLE subjects from the rheumatology departments of four Swedish SLE centres, genotyped for NCF1-339, were clinically characterised to validate these findings.​ResultsCompared with patients with normal-ROS NCF1-339 genotypes, neutrophils from patients with SLE with low-ROS NCF1-339 genotypes displayed impaired NET formation (p<0.01) and increased dependence on mitochondrial ROS (p<0.05). Low-ROS patients also had increased frequency of high serum interferon activity (80% vs 21.4%, p<0.05) and positivity for anti-β2 glycoprotein I (p<0.01) and anticardiolipin antibodies (p<0.05) but were not associated with other antibodies. We confirmed an over-representation of having any antiphospholipid antibody, OR 1.40 (95% CI 1.01 to 1.95), anti-β2 glycoprotein I, OR 1.82 (95% CI 1.02 to 3.24) and the antiphospholipid syndrome (APS), OR 1.74 (95% CI 1.19 to 2.55) in all four cohorts (n=1087).​ConclusionsThe NCF1-339 SNP mediated decreased NADPH oxidase function, is associated with high interferon activity and impaired formation of NETs in SLE, allowing dependence on mitochondrial ROS. Unexpectedly, we revealed a striking connection between the ROS deficient NCF1-339 genotypes and the presence of phospholipid antibodies and APS.

IntroductionImmune complexes are of importance in systemic lupus erythematosus pathogenesis, and autoantibodies are believed to participate in immune complex formation. Quantification of autoantibody levels in circulating IC might be of prognostic value.MethodsA C1q-binding-eluting technique was applied to purify immune complexes from 55 belimumab-treated systemic lupus erythematosus patients during a 24-month follow-up. Autoantibodies in serum and in solubilized immune complexes were quantified using addressable laser bead immunoassay. We investigated whether levels of autoantibodies in immune complexes associate with disease activity and response to belimumab treatment.ResultsHigh baseline anti-double-stranded DNA and anti-histone levels in immune complexes associated with attainment of zero scores in clinical systemic lupus erythematosus disease activity index 2000 during the 24-month follow-up (p = 0.003 and p = 0.048, respectively). Low complement levels associated with high serum anti-double-stranded DNA and anti-ribosomal P levels (p = 0.003 and p = 0.008, respectively) and high anti-double-stranded DNA (p = 0.002) but not anti-ribosomal P levels in immune complexes. Anti-SSA/SSB serum levels were lower in patients attaining lupus low disease activity state at month 6; these associations were stronger for corresponding immune complex levels. Serum levels of most autoantibodies had declined at month 3, whereas autoantibody levels in immune complexes, except for anti-double-stranded DNA, showed a more gradual decline over 1–2 years. Serum anti-double-stranded DNA levels decreased in all patients irrespective of systemic lupus erythematosus disease activity index 2000=0 attainment, whereas immune complex levels decreased only in achievers.ConclusionImmune complex levels of autoantibodies against double-stranded DNA and the SSA/SSB complex show more specific associations with treatment outcome compared with serum levels in belimumab-treated systemic lupus erythematosus patients. Characterization of autoantibody content in circulating immune complexes could prove useful in treatment evaluation in systemic lupus erythematosus and other immune complex-associated diseases.