Factors Associated with Survival and Discontinuation of Anti-Malarial Agents in Systemic Lupus Erythematosus: Results from a Tertiary Swedish Referral Centre.

Background: Antimalarial agents (AMAs) are cornerstone drugs in the treatment of systemic lupus erythematosus (SLE), and their use has established benefits, such as improved prognosis and decelerated accrual of organ damage. The aim of this study was to investigate the frequency of discontinuation of AMAs and associated factors in a Swedish SLE population. Methods: We retrieved data from a regional SLE register where all patients fulfilled the 1982 ACR and/or the 2012 SLICC classification criteria. A total of 328 subjects were included in the analysis. Results: Altogether, 92.4% (303/328) had been prescribed AMAs at some point during their disease. At the last available visit, 67.7% (222/328) were currently prescribed AMAs. Among individuals who had discontinued use, 24.7% (20/81) had developed a contraindication. Side effects were also common reasons for discontinuation (n = 38); gastrointestinal symptoms (52.6%, 20/38) were most common. Patients who discontinued had accrued more organ damage at the last visit (mean SDI: 2.9; SD: 2.8) compared with those still on AMAs (mean SDI: 1.4; SD: 1.8; p = 0.001). Conclusions: Most patients had been exposed to AMAs, but 25% discontinued therapy. Among side effects leading to discontinuation, >50% were gastrointestinal, calling for adequate gastroprotection towards drug retention and prevention of organ damage progression.

The prevalence of neutropenia and association with infections in patients with systemic lupus erythematosus: a Swedish single-center study conducted over 14 years.

Hematologic abnormalities are common manifestations of SLE, although neutropenia is observed less frequently and is not included in the classification criteria. Nonetheless, neutropenia is a risk factor for infections, especially those caused by bacteria or fungi. We aimed to evaluate the impact of neutropenia in SLE through a systematic investigation of all infections in a large cohort of well-characterized patients, focusing on neutropenia, lymphopenia, and hypocomplementemia. Longitudinal clinical and laboratory parameters obtained at visits to the Rheumatology Unit, Linköping University Hospital, and linked data on all forms of healthcare utilization for all the subjects included in our regional SLE register during 2008-2022 were assessed. Data regarding confirmed infections were retrieved from the medical records. Overall, 333 patients were included and monitored during 3,088 visits to a rheumatologist during the study period. In total, 918 infections were identified, and 94 occasions of neutropenia (ANC < 1.5 × 109/L) were detected in 40 subjects (12%). Thirty neutropenic episodes in 15 patients occurred in association with infections, of which 13 (43%) required in-hospital care, 4 (13%) needed intensive care, and 1 (3%) resulted in death. Bayesian analysis showed that patients with ≥ 1 occasion of neutropenia were more likely to experience one or more infections (OR = 2.05; probability of association [POA] = 96%). Both invasiveness (OR = 7.08; POA = 98%) and severity (OR = 2.85; POA = 96%) of the infections were significantly associated with the present neutropenia. Infections are common among Swedish SLE patients, 12% of whom show neutropenia over time. Importantly, neutropenia is linked to both the invasiveness and severity of infections. Awareness of the risks of severe infections in neutropenic patients is crucial to tailor therapies to prevent severe illness and death.

Obesity and tobacco smoking are independently associated with poor patient-reported outcomes in SLE: a cross-sectional study.

We investigated associations of obesity and tobacco smoking with health-related quality of life (HRQoL), pain, fatigue, and functional impairment in systemic lupus erythematosus (SLE). Furthermore, we explored whether there was an effect modification between these two factors. We included adult SLE patients from the Linköping University Hospital (n = 325) in the present cross-sectional analysis. We further included population-based controls and performed cardinality matching to balance age and sex distributions with cases (n = 224). HRQoL was assessed with the EQ-5D index score; pain, fatigue, and overall SLE-related health state with visual analogue scales (VAS; 0 [best] to 100 [worst]); and functional impairment with the HAQ-DI. Unacceptable outcomes were defined as VAS scores corresponding to the 90th percentile derived from the matched controls. SLE patients reported worse scores than controls in all measures, and approximately 30% experienced unacceptable outcomes. When compared with normal-weight, obese SLE patients reported lower HRQoL, and greater functional impairment and risk of unacceptable pain (OR: 3.2; 95% CI 1.6-6.7) and fatigue (OR: 2.1; 95% CI 1.0-4.3). Similarly, the current smokers reported higher levels of functional impairment and a greater risk of unacceptable pain (OR: 3.8; 95% CI 1.8-8.2) and fatigue (OR: 2.8; 95% CI 1.3-5.9) than never smokers. The associations were independent of age, sex, disease duration, disease activity, and organ damage. There was no evidence of a synergistic effect between increased BMI and smoking on any outcome. In summary, obesity and smoking are risk factors for unacceptable patient-reported outcomes in SLE, regardless of clinical activity.

Low CD4 + T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy.

BACKGROUND: Lymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy. METHODS: Repeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4 + and CD8 + T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren's syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and ß2 glycoprotein I [ß2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records. RESULTS: Women with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-ß2GPI), IFNα protein levels and disease activity. CD4 + T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4 + T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4 + T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4 + T cell count was unrelated to treatment. CONCLUSION: Lymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.

Lupus Low Disease Activity State and organ damage in relation to quality of life in systemic lupus erythematosus: a cohort study with up to 11 years of follow-up.

OBJECTIVES: Beyond prevention of organ damage, treatment goals in systemic lupus erythematosus (SLE) include optimisation of health-related quality of life (HRQoL). The Lupus Low Disease Activity State (LLDAS) has received increasing attention as a goal whenever remission cannot be achieved. How SLE disease activity, organ damage, and LLDAS attainment relate to patient-reported outcomes (PROs) is not fully explored, which formed the scope of this investigation. METHODS: We included 327 patients with SLE from a tertiary referral centre. Longitudinal registrations of disease activity using SLEDAI-2K and physician global assessment (PhGA), organ damage using the SLICC/ACR damage index (SDI), pharmacotherapies, EQ-5D-3L data, as well as visual analogue scale (VAS) scores for fatigue, pain, and overall SLE-related health state over a median follow-up time of 8.5 years were analysed. RESULTS: In the overall population, as well as subgroups of patients with recent-onset SLE and those with clinically active, autoantibody-positive disease, LLDAS attainment, lower PhGA, and lower clinical SLEDAI-2K scores were associated with favourable HRQoL by EQ-5D-3L and VAS assessments, while increasing SDI scores were associated with poor PROs yet not fatigue in the overall population. PROs were further enhanced by being in LLDAS sustainedly. In fully adjusted models of the entire study population, LLDAS attainment and lower disease activity were associated with favourable PROs, irrespective of SDI. CONCLUSION: In one of the longest to date observational studies, we demonstrated that low disease activity and being sustainedly in LLDAS were coupled with favourable HRQoL, pain, fatigue, and overall health experience, irrespective of organ damage.

A survey of ficolin-3 activity in Systemic Lupus Erythematosus reveals a link to hematological disease manifestations and autoantibody profile.

The complement system plays a central role in the pathogenesis of Systemic Lupus Erythematosus (SLE), but most studies have focused on the classical pathway. Ficolin-3 is the main initiator of the lectin pathway of complement in humans, but its role in systemic autoimmune disease has not been conclusively determined. Here, we combined biochemical and genetic approaches to assess the contribution of ficolin-3 to SLE risk and disease manifestations. Ficolin-3 activity was measured by a functional assay in serum or plasma samples from Swedish SLE patients (n = 786) and controls matched for age and sex (n = 566). Genetic variants in an extended 300 kb genomic region spanning the FCN3 locus were analyzed for their association with ficolin-3 activity and SLE manifestations in a Swedish multicenter cohort (n = 985). Patients with ficolin-3 activity in the highest tertile showed a strong enrichment in an SLE cluster defined by anti-Sm/DNA/nucleosome antibodies (OR 3.0, p < 0.001) and had increased rates of hematological disease (OR 1.4, p = 0.078) and lymphopenia (OR = 1.6, p = 0.039). Genetic variants associated with low ficolin-3 activity mapped to an extended haplotype in high linkage disequilibrium upstream of the FCN3 gene. Patients carrying the lead genetic variant associated with low ficolin-3 activity had a lower frequency of hematological disease (OR 0.67, p = 0.018) and lymphopenia (OR 0.63, p = 0.031) and fewer autoantibodies (p = 0.0019). Loss-of-function variants in the FCN3 gene were not associated with SLE, but four (0.5 %) SLE patients developed acquired ficolin-3 deficiency where ficolin-3 activity in serum was depleted following diagnosis of SLE. Taken together, our results provide genetic and biochemical evidence that implicate the lectin pathway in hematological SLE manifestations. We also identify lectin pathway activation through ficolin-3 as a factor that contributes to the autoantibody response in SLE.

Belimumab and antimalarials combined against renal flares in patients treated for extra-renal systemic lupus erythematosus: results from 4 phase III clinical trials.

OBJECTIVES: To determine the effect of antimalarial agents (AMA) and different doses and pharmaceutical forms of belimumab on preventing renal flares in patients with SLE treated for extra-renal disease. METHODS: We pooled data from the BLISS-52, BLISS-76, BLISS-SC and BLISS-Northeast Asia trials of belimumab (n = 3225), that included patients with active SLE yet no severe ongoing nephritis. Participants were allocated to receive intravenous belimumab 1 mg/kg, intravenous belimumab 10 mg/kg, subcutaneous belimumab 200 mg, or placebo in addition to standard therapy. We estimated hazards of renal flare development throughout the study follow-up (52-76 weeks) using Cox regression analysis. RESULTS: In total, 192 patients developed a renal flare after a median of 197 days. Compared with placebo, the risk of renal flares was lower among patients receiving intravenous belimumab 10 mg/kg (HR: 0.62; 95% CI: 0.41, 0.92; P = 0.018) and intravenous belimumab 1 mg/kg (HR: 0.42; 95% CI: 0.22, 0.79; P = 0.007), while no significant association was found for subcutaneous belimumab 200 mg. AMA use yielded a lower hazard of renal flares (HR: 0.66; 95% CI: 0.55, 0.78; P < 0.001). The protection conferred was enhanced when belimumab and AMA were co-administered; the lowest flare rate was observed for the combination intravenous belimumab 1 mg/kg and AMA (18.5 cases per 1000 person-years). CONCLUSIONS: The protection conferred from belimumab against renal flare development in patients treated for extra-renal SLE appears enhanced when belimumab was administered along with AMA. The prominent effect of low-dose belimumab warrants investigation of the efficacy of intermediate belimumab doses. CLINICAL TRIAL IDENTIFICATION: BLISS-52: NCT00424476; BLISS-76: NCT00410384; BLISS-SC: NCT01484496; BLISS-NEA: NCT01345253.

B cell polygenic risk scores associate with anti-dsDNA antibodies and nephritis in systemic lupus erythematosus.

OBJECTIVE: B cell function and autoantibodies are important in SLE pathogenesis. In this work, we aimed to investigate the impact of cumulative SLE B cell genetics on SLE subphenotype and autoantibody profile. METHODS: Female patients with SLE (n=1248) and healthy controls (n=400) were genotyped using Illumina's Global Screening Array. Two polygenic risk scores (PRSs), one representing B cell genes and the other B cell activation genes, were calculated for each individual using risk loci for SLE in genes assigned to B cell-related pathways according to the Kyoto Encyclopedia of Genes and Genomes, Gene Ontology and Reactome Databases. RESULTS: Double-stranded DNA (dsDNA) antibodies were more prevalent among patients with a high compared with a low SLE B cell PRS (OR 1.47 (1.07 to 2.01), p=0.018), and effect sizes were augmented in patients with human leucocyte antigen (HLA) risk haplotypes HLA-DRB1*03:01 and HLA-DRB1*15:01 (DRB1*03/15 -/- (OR 0.99 (0.56 to 1.77), p=0.98; DRB1*03/15 +/- or -/+ (OR 1.64 (1.06 to 2.54), p=0.028; and DRB1*03/15 +/+ (OR 4.47 (1.21 to 16.47), p=0.024). Further, a high compared with a low B cell PRS was associated with low complement levels in DRB1*03/15 +/+ patients (OR 3.92 (1.22 to 12.64), p=0.022). The prevalence of lupus nephritis (LN) was higher in patients with a B cell activation PRS above the third quartile compared with patients below (OR 1.32 (1.00 to 1.74), p=0.048). CONCLUSIONS: High genetic burden related to B cell function is associated with dsDNA antibody development and LN. Assessing B cell PRSs may be important in order to determine immunological pathways influencing SLE and to predict clinical phenotype.

Effect of Belimumab on Preventing de novo Renal Lupus Flares.

Introduction: Belimumab was recently approved for treating lupus nephritis (LN), yet de novo LN cases during belimumab treatment given for nonrenal causes have been reported. Identification of reliable signals of impending flare is imperative. Methods: We evaluated belimumab efficacy in preventing de novo renal flares and factors associated with renal flare occurrence in nephritis-naïve patients with systemic lupus erythematosus (SLE) who are receiving add-on belimumab or placebo in 5 phase 3 clinical trials using Cox regression analysis. Results: Of 1844 eligible patients, 136 (7.4%) developed a de novo renal flare during a 52-week long follow-up. Asian origin (Adjusted Hazard Ratio [HRadj]: 1.97; 95% confidence interval [CI]: 1.32-2.94; P = 0.001), positive baseline anti-double stranded DNA (anti-dsDNA) levels (HRadj: 1.32; 95% CI: 1.07-1.63; P = 0.008), and increasing mean prednisone dose during follow-up (HRadj: 1.03; 95% CI: 1.02-1.04; P < 0.001) were associated with de novo renal flares. Low-dose intravenous (IV) belimumab (1 mg/kg monthly) yielded a nearly 3-fold lower hazard of de novo renal flare (HRadj: 0.38; 95% CI: 0.20-0.73; P = 0.004). Subcutaneous (SC) belimumab (200 mg weekly) also yielded a lower hazard (HRadj.: 0.69; 95% CI: 0.54-0.88; P = 0.003). The labeled IV dose (10 mg/kg monthly) conferred no clear protection (HRadj.: 0.74; 95% CI: 0.50-1.09; P = 0.127). Conclusion: We corroborated the substantial vulnerability of the Asian SLE population to renal affliction. Add-on low-dose IV belimumab (1 mg/kg) and SC belimumab appeared protective against renal flares in nephritis-naïve patients with SLE. The approved IV dose (10 mg/kg) yielded no clear protection.

Pentameric C-reactive protein is a better prognostic biomarker and remains elevated for longer than monomeric CRP in hospitalized patients with COVID-19.

The differing roles of the pentameric (p) and monomeric (m) C-reactive protein (CRP) isoforms in viral diseases are not fully understood, which was apparent during the COVID-19 pandemic regarding the clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Herein, we investigated the predictive value of the pCRP and mCRP isoforms for COVID-19 severity in hospitalized patients and evaluated how the levels of the protein isoforms changed over time during and after acute illness. This study utilized samples from a well-characterized cohort of Swedish patients with SARS-CoV-2 infection, the majority of whom had known risk factors for severe COVID-19 and required hospitalization. The levels of pCRP were significantly raised in patients with severe COVID-19 and in contrast to mCRP the levels were significantly associated with disease severity. Additionally, the pCRP levels remained elevated for at least six weeks post inclusion, which was longer compared to the two weeks for mCRP. Our data indicates a low level of inflammation lasting for at least six weeks following COVID-19, which might indicate that the disease has an adverse effect on the immune system even after the viral infection is resolved. It is also clear that the current standard method of testing pCRP levels upon hospitalization is a useful marker for predicting disease severity and mCRP testing would not add any clinical relevance for patients with COVID-19.

Antigen-presenting autoreactive B cells activate regulatory T cells and suppress autoimmune arthritis in mice.

B cells undergo several rounds of selection to eliminate potentially pathogenic autoreactive clones, but in contrast to T cells, evidence of positive selection of autoreactive B cells remains moot. Using unique tetramers, we traced natural autoreactive B cells (C1-B) specific for a defined triple-helical epitope on collagen type-II (COL2), constituting a sizeable fraction of the physiological B cell repertoire in mice, rats, and humans. Adoptive transfer of C1-B suppressed arthritis independently of IL10, separating them from IL10-secreting regulatory B cells. Single-cell sequencing revealed an antigen processing and presentation signature, including induced expression of CD72 and CCR7 as surface markers. C1-B presented COL2 to T cells and induced the expansion of regulatory T cells in a contact-dependent manner. CD72 blockade impeded this effect suggesting a new downstream suppressor mechanism that regulates antigen-specific T cell tolerization. Thus, our results indicate that autoreactive antigen-specific naïve B cells tolerize infiltrating T cells against self-antigens to impede the development of tissue-specific autoimmune inflammation.

Epidemiology and Damage Accrual of Systemic Lupus Erythematosus in Central Sweden: A Single-Center Population-Based Cohort Study Over 14 Years From Östergötland County.

OBJECTIVE: Variations in prevalence and incidence of systemic lupus erythematosus (SLE) within a geographically defined area of central Sweden over a time period of 14 years were examined. Longitudinal differences in disease activity, laboratory test results, and damage accrual were investigated. METHODS: Adults (aged ≥18 years) residing in Östergötland County between 2008 and 2021 (mean adult population: 357,000 citizens) with confirmed SLE were identified and followed prospectively until death, December 31, 2021, or emigration. We estimated annual incidence per 100,000 inhabitants stratified by sex and age. Linear regression with year of diagnosis as the outcome assessed whether each clinical measurement at diagnosis varied over time. RESULTS: Prevalence on December 31, 2021, was 71.5 of 100,000 (87% female). One hundred twenty-six new cases were identified during the study period, yielding a mean annual incidence of 3.0 of 100,000 inhabitants; this was higher in females (4.8/100,000) than in males (1.2/100,000). Mean age at diagnosis was 43.7 years (SD 17.3). Age at diagnosis and disease activity measures increased over the calendar year of diagnosis (P < 0.05) whereas disease manifestations, including lupus nephritis, did not vary significantly. Accrual of organ damage was demonstrated over time since diagnosis and stratified by sex, lupus nephritis, and corticosteroid-related damage. Approximately 40% developed damage within 5 years. CONCLUSION: SLE prevalence and incidence estimates remained constant over 14 years, and disease phenotypes at SLE onset were similar. SLE was diagnosed also among older individuals with a smaller female-to-male ratio. Estimates of prevalence and incidence were comparable to previous Scandinavian reports but lower than observed in registry data from the US and the UK.

Clinical experience and safety of Janus kinase inhibitors in giant cell arteritis: a retrospective case series from Sweden.

The Janus kinase (JAK)-STAT signaling pathway is relevant in both Takayasu and giant cell arteritis (GCA), and the use of JAK inhibitors (JAKi) in arthritis, psoriasis, and inflammatory bowel disease is nowadays common. Some evidence of the clinical efficacy of JAKi in GCA exists and a phase III randomized controlled trial (RCT) of upadacitinib is currently recruiting. In 2017, we started using barcitinib in a GCA patient with inadequate response to corticosteroids, and later on, we treated other 14 GCA patients with baricitinib/tofacitinib during intense follow-up. The retrospective data of these 15 individuals are here summarized. GCA was diagnosed based on the ACR criteria and/or imaging techniques combined with increased C-reactive protein (CRP) and/or erythrocyte sedimentation rate (ESR) followed by a good initial response to corticosteroids. JAKi was initiated based on inflammatory activity, with increased CRP, presumably dependent on GCA with clinical symptoms, despite unsatisfying high doses of prednisolone. The mean age at JAKi initiation was 70.1 years and the mean exposure to JAKi was 19 months. From initiation, significant reductions in CRP were seen already at 3 (p = 0.02) and 6 (p = 0.02) months. A slower decrease was observed regarding ESR at 3 (p = 0.12) and 6 (p = 0.02) months. Furthermore, the daily prednisolone doses were reduced at 3 (p = 0.02) and 6 (p = 0.004) months. No GCA relapses were observed. Two patients were affected by serious infections, but JAKi therapy was retained or reintroduced after recovery. We present encouraging observational data on JAKi in GCA in one of the hitherto largest case series with long-term follow-up. Our clinical experiences will complement the results from the awaited RCT.

Plasma Osteopontin Reflects Tissue Damage in Acute Pancreatitis.

Several scoring systems for clinical prediction of the severity of acute pancreatitis (AP) have been proposed. Yet, there is still a need for an easy-to-measure biomarker. Osteopontin (OPN) may be released to the circulation early during tissue injury, but the significance of OPN in AP has not yet been established. We aimed to evaluate plasma levels of OPN in relation to the severity of AP. In 39 individuals with confirmed AP, plasma was collected on the day of admission and consecutively for three days thereafter. Sex- and age-matched healthy blood donors (n = 39) served as controls. Plasma OPN was measured by a commercial enzyme-linked immunosorbent assay. At admission, patients with AP displayed higher OPN, 156.4 ng/mL (IQR 111.8-196.2) compared to controls, 37.4 ng/mL (IQR 11.7-65.7) (p < 0.0001). However, OPN levels on admission could not discriminate between mild and moderate-to-severe disease (132.6 ng/mL vs. 163.4 ng/mL). Nevertheless, the changes in OPN within 24 h of admission and Day 2/3 were higher among patients with moderate/severe AP (33.7%) compared to mild AP (-8.1%) (p = 0.01). This indicates that OPN is a relevant biomarker reflecting tissue injury in AP. The increase in OPN over time suggests that serial OPN measurements could contribute to the early detection of at-risk patients. Prospective studies assessing OPN in relation to outcome in AP are warranted.

Doubtful Clinical Value of Subtyping Anti-U1-RNP Antibodies Regarding the RNP-70 kDa Antigen in Sera of Patients with Systemic Lupus Erythematosus.

The detection of antinuclear antibodies is central to the diagnosis and prognosis of systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS) and mixed connective tissue disease (MCTD). Anti-U1-RNP and anti-RNP70 antibodies were assayed in the sera of patients with SLE (n = 114), pSS (n = 54) and MCTD (n = 12). In the SLE group, 34/114 (30%) were anti-U1-RNP positive, and 21/114 (18%) were both anti-RNP70 positive and anti-U1-RNP positive. In the MCTD group, 10/12 (83%) were anti-U1-RNP positive, and 9/12 (75%) were anti-RNP70 positive. Only one individual with pSS was antibody positive (for both anti-U1-RNP and anti-RNP70). All anti-RNP70-positive samples were also anti-U1-RNP positive. Anti-U1-RNP-positive subjects with SLE were younger (p < 0.0001); showed lower concentrations of complement protein 3 (p = 0.03); had lower eosinophil (p = 0.0005), lymphocyte (p = 0.006) and monocyte (p = 0.03) counts; and had accrued less organ damage (p = 0.006) than the anti-U1-RNP-negative SLE patients. However, we observed no significant clinical or laboratory parameter differences between the anti-U1-RNP-positive individuals with/without anti-RNP70 in the SLE group. In conclusion, anti-RNP70 antibodies are not exclusive to MCTD but are rarely detected in pSS and healthy individuals. In SLE, anti-U1-RNP antibodies are associated with a clinical phenotype that resembles MCTD, with hematologic involvement and less damage accrual. Based on our results, the clinical value of subtyping anti-RNP70 in anti-U1-RNP-positive sera appears to be of limited value.

Extracellular vesicles opsonized by monomeric C-reactive protein (CRP) are accessible as autoantigens in patients with systemic lupus erythematosus and associate with autoantibodies against CRP.

The pentraxin C-reactive protein (CRP) is a pentameric protein now known to be able to undergo dissociation into a monomeric, modified isoform, referred to as mCRP. In carefully assessing the bioactivities of each isoform, mCRP has strong pro-inflammatory activities while pCRP has mild anti-inflammatory activities. Systemic lupus erythematosus (SLE) is a disease characterized by a vast number of autoantibodies, including anti-CRP autoantibodies which have been associated with SLE disease activity and lupus nephritis. The origin of these autoantibodies is currently unknown. Extracellular vesicles (EVs) have been implicated in SLE pathogenesis as they can expose nuclear antigens on their outside surface, thereby being a potential adjuvant for the generation of autoantibodies. Herein, we studied exposure of both pCRP and mCRP on EVs in SLE plasma and the implications of each in disease activity, organ damage and clinical manifestations. We used flow cytometry to detect CRP isoforms on EV surfaces in 67 well-characterized SLE patients and 60 sex- and age-matched healthy controls. Autoantibodies against mCRP were measured using ELISA. We found an abundance of both pCRP and mCRP on SLE EVs compared to controls. Furthermore, mCRP+ but not pCRP+ EVs were elevated in patients with active disease and in anti-CRP positive patients. The proportions of mCRP+ EVs were lower in patients with acquired organ damage, especially in patients with lupus nephritis (LN), and displayed an inverse relationship with disease duration in LN and patients with active disease. Speculatively, these data suggest EV-bound mCRP as a relevant factor in SLE pathogenesis, which could contribute to development of anti-CRP autoantibodies by stimulating an immune response.

Low-density granulocytes are related to shorter pregnancy duration but not to interferon alpha protein blood levels in systemic lupus erythematosus.

BACKGROUND: An increased risk of pregnancy complications is seen in women with systemic lupus erythematosus (SLE), but the specific immunopathological drivers are still unclear. Hallmarks of SLE are granulocyte activation, type I interferon (IFN) overproduction, and autoantibodies. Here we examined whether low-density granulocytes (LDG) and granulocyte activation increase during pregnancy, and related the results to IFNα protein levels, autoantibody profile, and gestational age at birth. METHODS: Repeated blood samples were collected during pregnancy in trimesters one, two, and three from 69 women with SLE and 27 healthy pregnant women (HC). Nineteen of the SLE women were also sampled late postpartum. LDG proportions and granulocyte activation (CD62L shedding) were measured by flow cytometry. Plasma IFNα protein concentrations were quantified by single molecule array (Simoa) immune assay. Clinical data were obtained from medical records. RESULTS: Women with SLE had higher LDG proportions and increased IFNα protein levels compared to HC throughout pregnancy, but neither LDG fractions nor IFNα levels differed during pregnancy compared to postpartum in SLE. Granulocyte activation status was higher in SLE relative to HC pregnancies, and it was increased during pregnancy compared to after pregnancy in SLE. Higher LDG proportions in SLE were associated with antiphospholipid positivity but not to IFNα protein levels. Finally, higher LDG proportions in trimester three correlated independently with lower gestational age at birth in SLE. CONCLUSION: Our results suggest that SLE pregnancy results in increased peripheral granulocyte priming, and that higher LDG proportions late in pregnancy are related to shorter pregnancy duration but not to IFNα blood levels in SLE.

Limited Association between Antibodies to Oxidized Low-Density Lipoprotein and Vascular Affection in Patients with Established Systemic Lupus Erythematosus.

Patients with systemic lupus erythematosus (SLE) are at an increased risk of cardiovascular disease. We aimed to evaluate whether antibodies to oxidized low-density lipoprotein (anti-oxLDL) were associated with subclinical atherosclerosis in patients with different SLE phenotypes (lupus nephritis, antiphospholipid syndrome, and skin and joint involvement). Anti-oxLDL was measured by enzyme-linked immunosorbent assay in 60 patients with SLE, 60 healthy controls (HCs) and 30 subjects with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Intima-media thickness (IMT) assessment of vessel walls and plaque occurrence were recorded using high-frequency ultrasound. In the SLE cohort, anti-oxLDL was again assessed in 57 of the 60 individuals approximately 3 years later. The levels of anti-oxLDL in the SLE group (median 5829 U/mL) were not significantly different from those in the HCs group (median 4568 U/mL), while patients with AAV showed significantly higher levels (median 7817 U/mL). The levels did not differ between the SLE subgroups. A significant correlation was found with IMT in the common femoral artery in the SLE cohort, but no association with plaque occurrence was observed. The levels of anti-oxLDL antibodies in the SLE group were significantly higher at inclusion compared to 3 years later (median 5707 versus 1503 U/mL, p < 0.0001). Overall, we found no convincing support for strong associations between vascular affection and anti-oxLDL antibodies in SLE.

Serum levels of soluble urokinase plasminogen activator receptor in juvenile idiopathic arthritis: a single-center Swedish case-control study.

OBJECTIVES: Reliable biomarkers in the early stages of idiopathic arthritis (JIA) are scarce and the disease heterogeneity makes it clinically challenging to predict the risk of joint damage. Biomarkers with prognostic potential are warranted in order to individualize treatment and follow-up in JIA. The soluble urokinase plasminogen activator receptor (suPAR) has been reported as an easily measurable biomarker for prognosis and severity in several rheumatic diseases but it has never been studied in JIA. METHODS: Sera from 51 well-characterized patients with JIA and 50 age- and sex-matched control subjects were collected and stored for later analysis of suPAR. Patients were carefully followed clinically over 3 years and analysis of erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) were analyzed as part of clinical routine. Signs of joint erosions were evaluated by radiography. RESULTS: Overall, the levels of suPAR did not differ significantly between JIA patients and controls but those with polyarticular involvement showed higher suPAR (p = 0.013). In addition, elevated suPAR were associated with joint erosions (p = 0.026). Two RF/anti-CCP negative individuals with erosions showed high levels of suPAR. CONCLUSIONS: We present new data on the biomarker suPAR in JIA. Our results indicate that, apart from RF and anti-CCP, analysis of suPAR could be of additional value in assessing the risk of erosions. Analysis of suPAR early could potentially guide treatment decision-making in JIA, but our observations should be confirmed in prospective studies.