Predictors of quality of life, functional status, depression and fatigue in early arthritis: comparison between clinically suspect arthralgia, unclassified arthritis and rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is often preceded by symptomatic phases during which classification criteria are not fulfilled. The health burden of these "at-risk" stages is not well described. This study assessed health-related quality of life (HRQoL), function, fatigue and depression in newly presenting patients with clinically suspect arthralgia (CSA), unclassified arthritis (UA) or RA. METHODS: Cross-sectional analysis of baseline Patient-Reported Outcome Measures (PROMs) was conducted in patients from the Birmingham Early Arthritis Cohort. HRQoL, function, depression and fatigue at presentation were assessed using EQ-5D, HAQ-DI, PHQ-9 and FACIT-F. PROMs were compared across CSA, UA and RA and with population averages from the HSE with descriptive statistics. Multivariate linear regression assessed associations between PROMs and clinical and sociodemographic variables. RESULTS: Of 838 patients included in the analysis, 484 had RA, 200 had CSA and 154 had UA. Patients with RA reported worse outcomes for all PROMs than those with CSA or UA. However, "mean EQ-5D utilities were 0.65 (95%CI: 0.61 to 0.69) in CSA, 0.61 (0.56 to 0.66) in UA and 0.47 (0.44 to 0.50) in RA, which was lower than in general and older (≥ 65 years) background populations." In patients with CSA or UA, HRQoL was comparable to chronic conditions such as heart failure, severe COPD or mild angina. Higher BMI and older age (≥ 60 years) predicted worse depression (PHQ-9: -2.47 (-3.85 to -1.09), P < 0.001) and fatigue (FACIT-F: 5.05 (2.37 to 7.73), P < 0.001). Women were more likely to report worse function (HAQ-DI: 0.13 (0.03 to 0.21), P = 0.01) and fatigue (FACIT-F: -3.64 (-5.59 to -1.70), P < 0.001), and residents of more deprived areas experienced decreased function (HAQ-DI: 0.23 (0.10 to 0.36), P = 0.001), greater depression (PHQ-9: 1.89 (0.59 to 3.18), P = 0.004) and fatigue (FACIT-F: -2.60 (-5.11 to 0.09), P = 0.04). After adjustments for confounding factors, diagnostic category was not associated with PROMs, but disease activity and polypharmacy were associated with poorer performance across all PROMs. CONCLUSIONS: Patient-reported outcomes were associated with disease activity and sociodemographic characteristics. Patients presenting with RA reported a higher health burden than those with CSA or UA, however HRQoL in the pre-RA groups was significantly lower than population averages.

The value of ultrasound-defined tenosynovitis and synovitis in the prediction of persistent arthritis.

OBJECTIVES: The value of US-defined tenosynovitis in predicting the persistence of inflammatory arthritis is not well described. In particular, the predictive utility of US-defined tenosynovitis of larger tendons is yet to be reported. We assessed the value of US-defined tenosynovitis alongside US-defined synovitis and clinical and serological variables in predicting persistent arthritis in an inception cohort of DMARD-naïve patients with early arthritis. METHODS: One hundred and fifty DMARD-naïve patients with clinically apparent synovitis of one or more joints and a symptom duration of ≤3 months underwent baseline clinical, laboratory and US (of 19 bilateral joints and 16 bilateral tendon compartments) assessments. Outcomes were classified as persistent or resolving arthritis after 18 months' follow-up. The predictive value of US-defined tenosynovitis for persistent arthritis was compared with those of US-defined synovitis, and clinical and serological variables. RESULTS: At 18 months, 99 patients (66%) had developed persistent arthritis and 51 patients (34%) had resolving disease. Multivariate logistic regression analysis showed that US-detected digit flexor tenosynovitis [odds ratio (OR): 6.6, 95% CI: 2.0 , 22.1, P = 0.002] provided independent predictive data for persistence over and above the presence of US-detected joint synovitis and RF antibodies. In the RF/ACPA-negative subcohort, US-defined digit flexor tenosynovitis remained a significant predictive variable (OR: 4.7, 95% CI: 1.4, 15.8, P = 0.012), even after adjusting for US-defined joint synovitis. CONCLUSION: US-defined tenosynovitis provided independent predictive data for the development of persistent arthritis. The predictive role of US-defined digit flexor tenosynovitis should be further assessed; investigators should consider including this tendon site as a candidate variable when designing imaging-based predictive algorithms for persistent inflammatory arthritis development.

Infrared Study of OCS Binding and Size-Selective Reactivity with Gold Clusters, Aun+ (n = 1-10).

OCS binding to and reactivity with isolated gold cluster cations, Aun+ (n = 1-10), has been studied by infrared multiple photon dissociation (IR-MPD) spectroscopy in conjunction with quantum chemical calculations. The distribution of complexes AunSx(OCS)m+ formed reflects the relative reactivity of different cluster sizes with OCS, under the multiple collision conditions of our ablation source. The IR-MPD spectra of Aun(OCS)+ (n = 3-10) clusters are interpreted in terms of either µ1 or µ2 S binding motifs. Analysis of the fragmentation products following infrared excitation of parent Aun(OCS)+ clusters reveals strongly size-selective (odd-even) branching ratios for OCS and CO loss, respectively. CO loss signifies infrared-driven OCS decomposition on the cluster surface and is observed to occur predominantly on even n clusters (i.e., those with odd electron counts). The experimental data, including fragmentation branching ratios, are consistent with calculated potential energy landscapes, in which the initial species trapped are molecularly bound entrance channel complexes, rather than global minimum inserted structures. Attempts to generate Rhn(OCS)+ and Ptn(OCS)+ equivalents failed; only sulfide reaction products were observed in the mass spectrum, even after cooling the cluster source to -100 °C.

Short-term efficacy and safety of rituximab therapy in refractory systemic lupus erythematosus: results from the British Isles Lupus Assessment Group Biologics Register.

Objectives: To describe the baseline characteristics of SLE patients requiring biologic therapy in the UK and to explore short term efficacy and infection rates associated with rituximab (RTX) use. Methods: Patients commencing biologic therapy for refractory SLE and who consented to join BILAG-BR were analysed. Baseline characteristics, disease activity (BILAG 2004/SLEDAI-2K) and rates of infection over follow-up were analysed. Response was defined as loss of all A and B BILAG scores to ⩽ 1 B score with no new A/B scores in other organ systems at 6 months. Results: Two hundred and seventy SLE patients commenced biologic therapy from September 2010 to September 2015, most commonly RTX (n = 261). Two hundred and fifty (93%) patients were taking glucocorticoids at baseline at a median [interquartile range (IQR)] oral dose of 10 mg (5-20 mg) daily. Response rates at 6 months were available for 68% of patients. The median (IQR) BILAG score was 15 (10-23) at baseline and 3 (2-12) at 6 months (P < 0.0001). The median (IQR) SLEDAI-2K reduced from 8 (5-12) to 4 (0-7) (P < 0.001). Response was achieved in 49% of patients. There was also a reduction in glucocorticoid use to a median (IQR) dose of 7.5 mg (5-12 mg) at 6 months (P < 0.001). Serious infections occurred in 26 (10%) patients, being more frequent in the first 3 months post-RTX therapy. A higher proportion of early infections were non-respiratory (odds ratio = 1.98, 95% CI: 0.99, 3.9; P = 0.049). Conclusion: RTX is safe and is associated with improvement in disease activity in refractory SLE patients with concomitant reductions in glucocorticoid use. Early vigilance for infection post-infusion is important to further improve treatment risks and benefits.

Reduced Fluorescence versus Forward Scatter Time-of-Flight and Increased Peak versus Integral Fluorescence Ratios Indicate Receptor Clustering in Flow Cytometry.

Clustering of surface receptors is often required to initiate signal transduction, receptor internalization, and cellular activation. To study the kinetics of clustering, we developed an economic high-throughput method using flow cytometry. The quantification of receptor clustering by flow cytometry is based on the following two observations: first, the fluorescence signal length (FL time-of-flight [ToF]) decreases relative to the forward scatter signal length (FSc-ToF), and second, the peak FL (FL-peak) increases relative to the integral FL (FL-integral) upon clustering of FL-labeled surface receptors. Receptor macroclustering can therefore be quantified using the ratios FL-ToF/FSc-ToF (method ToF) or FL-peak/FL-integral (method Peak). We have used these methods to analyze clustering of two immune receptors known to undergo different conformational and oligomeric states: the BCR and the complement receptor 3 (CR3), on murine splenocytes, purified B cells, and human neutrophils. Engagement of both the BCR and CR3, on immortalized as well as primary murine B cells and human neutrophil, respectively, resulted in decreased FL-ToF/FSc-ToF and increased FL-peak/FL-integral ratios. Manipulation of the actin-myosin cytoskeleton altered BCR clustering which could be measured using the established parameters. To confirm clustering of CR3 on neutrophils, we applied imaging flow cytometry. Because receptor engagement is as a biological process dependent on cell viability, energy metabolism, and temperature, receptor clustering can only be quantified by gating on viable cells under physiological conditions. In summary, with this novel method, receptor clustering on nonadherent cells can easily be monitored by high-throughput conventional flow cytometry.

Relationships between functional movement screen scores, maturation and physical performance in young soccer players.

The purpose of this study was to examine relationships between functional movement screen scores, maturation and physical performance in young soccer players. Thirty males (11-16 years) were assessed for maturation, functional movement screen scores and a range of physical performance tests (squat jump, reactive strength index protocol and reactive agility cut). Older players significantly outperformed younger participants in all tests (P < 0.05; effect sizes = 1.25-3.40). Deep overhead squat, in-line lunge, active straight leg raise and rotary stability test were significantly correlated to all performance tests. In-line lunge performance explained the greatest variance in reactive strength index (adjusted R(2) = 47%) and reactive agility cut (adjusted R(2) = 38%) performance, whilst maturation was the strongest predictor of squat jump performance (adjusted R(2) = 46%). This study demonstrated that variation of physical performance in youth soccer players could be explained by a combination of both functional movement screen scores and maturation.

Osteoclast Differentiation Is Impaired in a Subgroup of SLE Patients and Correlates Inversely with Mycophenolate Mofetil Treatment.

Osteoporosis can arise in systemic lupus erythematosus (SLE) patients secondary to medication and/or chronic inflammation. To analyze if patients with SLE have phenotypically-impaired osteoclastogenesis, we differentiated ex vivo monocytes from 72 SLE patients and 15 healthy individuals into osteoclasts followed by TRAP staining and counting. We identified a subgroup of SLE patients (45%) with a significantly impaired osteoclast differentiation, relative to the other SLE patients or healthy individuals (OR 11.2; 95% CI 1.4-89.9). A review of medication indicated that patients with osteoclast counts equal to healthy donors were significantly more likely to be treated with mycophenolate mofetil (MMF) compared to patients with impaired osteoclastogenesis. We analyzed expression of RANKL and the MMF target genes IMPDH1 and IMPDH2 in osteoclasts by qPCR, but detected no difference. Since MMF might influence interferon-α (IFNα) and -γ (IFNγ) we measured serum IFNα and IFNγ levels. Patients with very low osteoclast counts also had comparably higher IFNα serum levels than patients with normal osteoclast counts. We conclude that in vitro osteoclastogenesis is impaired in a subgroup of SLE patients. This correlates inversely with MMF treatment and high IFNα serum levels. Further observational study will be required to determine whether this translates into a clinically meaningful effect.

Differences in management approaches for lupus nephritis within the UK.

Objectives: Outcomes of therapy for LN are often suboptimal. Guidelines offer varied options for treatment of LN and treatment strategies may differ between clinicians and regions. We aimed to assess variations in the usual practice of UK physicians who treat LN. Methods: We conducted an online survey of simulated LN cases for UK rheumatologists and nephrologists to identify treatment preferences for class IV and class V LN. Results: Of 77 respondents, 48 (62.3%) were rheumatologists and 29 (37.7%) were nephrologists. A total of 37 (48.0%) reported having a joint clinic between nephrologists and rheumatologists, 54 (70.0%) reported having a multidisciplinary team meeting for LN and 26 (33.7%) reported having a specialized lupus nurse. Of the respondents, 58 (75%) reported arranging a renal biopsy before starting the treatment. A total of 20 (69%) of the nephrologists, but only 13 (27%) rheumatologists, reported having a formal departmental protocol for treating patients with LN (P < 0.001). The first-choice treatment of class IV LN in pre-menopausal patients was MMF [41 (53.2%)], followed by CYC [15 (19.6%)], rituximab [RTX; 12 (12.5%)] or a combination of immunosuppressive drugs [9 (11.7%)] with differences between nephrologists' and rheumatologists' choices (P = 0.026). For class V LN, MMF was the preferred initial treatment, irrespective of whether proteinuria was in the nephrotic range or not. RTX was the preferred second-line therapy for non-responders. Conclusion: There was variation in the use of protocols, specialist clinic service provision, biopsies and primary and secondary treatment choices for LN reported by nephrologists and rheumatologists in the UK.

The rs1143679 (R77H) lupus associated variant of ITGAM (CD11b) impairs complement receptor 3 mediated functions in human monocytes.

OBJECTIVES: The rs1143679 variant of ITGAM, encoding the R77H variant of CD11b (part of complement receptor 3; CR3), is among the strongest genetic susceptibility effects in human systemic lupus erythematosus (SLE). The authors aimed to demonstrate R77H function in ex-vivo human cells. METHODS: Monocytes/monocyte-derived macrophages from healthy volunteers homozygous for either wild type (WT) or 77H CD11b were studied. The genotype-specific expression of CD11b, and CD11b activation using conformation-specific antibodies were measured. Genotype-specific differences in iC3b-mediated phagocytosis, adhesion to a range of ligands and the secretion of cytokines following CR3 ligation were studied. The functionality of R77H was confirmed by replicating findings in COS7 cells expressing variant-specific CD11b. RESULTS: No genotype-specific difference in CD11b expression or in the expression of CD11b activation epitopes was observed. A 31% reduction was observed in the phagocytosis of iC3b opsonised sheep erythrocytes (sRBC(iC3b)) by 77H cells (p=0.003) and reduced adhesion to a range of ligands: notably a 24% reduction in adhesion to iC3b (p=0.014). In transfected COS7 cells, a 42% reduction was observed in phagocytosis by CD11b (77H)-expressing cells (p=0.004). A significant inhibition was seen in the release of Toll-like receptor 7/8-induced pro-inflammatory cytokines from WT monocytes when CR3 was pre-engaged using sRBC(iC3b), but no inhibition in 77H monocytes resulting in a significant difference between genotypes (interleukin (IL)-1ß p=0.030; IL-6 p=0.029; tumour necrosis factor alpha p=0.027). CONCLUSIONS: The R77H variant impairs a broad range of CR3 effector functions in human monocytes. This study discusses how perturbation of this pathway may predispose to SLE.

Transancestral mapping of the MHC region in systemic lupus erythematosus identifies new independent and interacting loci at MSH5, HLA-DPB1 and HLA-G.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic multisystem genetically complex autoimmune disease characterised by the production of autoantibodies to nuclear and cellular antigens, tissue inflammation and organ damage. Genome-wide association studies have shown that variants within the major histocompatibility complex (MHC) region on chromosome 6 confer the greatest genetic risk for SLE in European and Chinese populations. However, the causal variants remain elusive due to tight linkage disequilibrium across disease-associated MHC haplotypes, the highly polymorphic nature of many MHC genes and the heterogeneity of the SLE phenotype. METHODS: A high-density case-control single nucleotide polymorphism (SNP) study of the MHC region was undertaken in SLE cohorts of Spanish and Filipino ancestry using a custom Illumina chip in order to fine-map association signals in these haplotypically diverse populations. In addition, comparative analyses were performed between these two datasets and a northern European UK SLE cohort. A total of 1433 cases and 1458 matched controls were examined. RESULTS: Using this transancestral SNP mapping approach, novel independent loci were identified within the MHC region in UK, Spanish and Filipino patients with SLE with some evidence of interaction. These loci include HLA-DPB1, HLA-G and MSH5 which are independent of each other and HLA-DRB1 alleles. Furthermore, the established SLE-associated HLA-DRB1*15 signal was refined to an interval encompassing HLA-DRB1 and HLA-DQA1. Increased frequencies of MHC region risk alleles and haplotypes were found in the Filipino population compared with Europeans, suggesting that the greater disease burden in non-European SLE may be due in part to this phenomenon. CONCLUSION: These data highlight the usefulness of mapping disease susceptibility loci using a transancestral approach, particularly in a region as complex as the MHC, and offer a springboard for further fine-mapping, resequencing and transcriptomic analysis.

Evaluation of imputation-based association in and around the integrin-alpha-M (ITGAM) gene and replication of robust association between a non-synonymous functional variant within ITGAM and systemic lupus erythematosus (SLE).

We recently identified a novel non-synonymous variant, rs1143679, at exon 3 of the ITGAM gene associated with systemic lupus erythematosus (SLE) susceptibility in European-Americans (EAs) and African-Americans. Using genome-wide association approach, three other studies also independently reported an association between SLE susceptibility and ITGAM or ITGAM-ITGAX region. The primary objectives of this study are to assess whether single or multiple causal variants from the same gene or any nearby gene(s) are involved in SLE susceptibility and to confirm a robust ITGAM association across nine independent data sets (n = 8211). First, we confirmed our previously reported association of rs1143679 (risk allele 'A') with SLE in EAs (P = 1.0 x 10(-8)) and Hispanic-Americans (P = 2.9 x 10(-5)). Secondly, using a comprehensive imputation-based association test, we found that ITGAM is one of the major non-human leukocyte antigen susceptibility genes for SLE, and the strongest association for EA is the same coding variant rs1143679 (log(10)Bayes factor=20, P = 6.17 x 10(-24)). Thirdly, we determined the robustness of rs1143679 association with SLE across three additional case-control samples, including UK (P = 6.2 x 10(-8)), Colombian (P = 3.6 x 10(-7)), Mexican (P = 0.002), as well as two independent sets of trios from UK (P(TDT) = 1.4 x 10(-5)) and Mexico (P(TDT) = 0.015). A meta-analysis combing all independent data sets greatly reinforces the association (P(meta) = 7.1 x 10(-50), odds ratio = 1.83, 95% confidence interval = 1.69-1.98, n = 10 046). However, this ITGAM association was not observed in the Korean or Japanese samples, in which rs1143679 is monomorphic for the non-risk allele (G). Taken together along with our earlier findings, these results demonstrate that the coding variant, rs1143679, best explains the ITGAM-SLE association, especially in European- and African-derived populations, but not in Asian populations.

Tumefactive fibroinflammatory lesion of the maxilla: Successful resection and microvascular reconstruction after failed medical therapy.

Tumefactive fibroinflammatory lesions (TFILs) of the head and neck are rare and benign but locally aggressive lesions. The etiology and pathogenesis of these lesions are unknown. Medical management is regarded the first line of treatment. Surgical management has been rarely reported for head and neck lesions. A 51-year-old female presented with a 6-month history of left facial swelling and pain that subsequently developed into progressive inframalar hollowing and asymmetry. Biopsies confirmed tumefactive fibroinflammatory lesion of the maxilla. Initial treatment with high-dose steroids led to temporary partial involution; however, symptoms progressed. Cyclophosphamide and then rituximab were commenced, with minimal response. Imaging showed progression toward the infratemporal fossa. The patient subsequently underwent a resection and microvascular free flap reconstruction This patient had a successful surgical outcome and resolution of serum inflammatory markers with no evidence of recurrence after 18-month follow-up. A multidisciplinary approach is crucial to ensure a pragmatic patient-specific management plan is developed. Surgical resection and reconstruction can be successful in these lesions and should be considered if medical therapy has failed.

A genetic association study of serum acute-phase C-reactive protein levels in rheumatoid arthritis: implications for clinical interpretation.

BACKGROUND: The acute-phase increase in serum C-reactive protein (CRP) is used to diagnose and monitor infectious and inflammatory diseases. Little is known about the influence of genetics on acute-phase CRP, particularly in patients with chronic inflammation. METHODS AND FINDINGS: We studied two independent sets of patients with chronic inflammation due to rheumatoid arthritis (total 695 patients). A tagSNP approach captured common variation at the CRP locus and the relationship between genotype and serum CRP was explored by linear modelling. Erythrocyte sedimentation rate (ESR) was incorporated as an independent marker of inflammation to adjust for the varying levels of inflammatory disease activity between patients. Common genetic variants at the CRP locus were associated with acute-phase serum CRP (for the most associated haplotype: p = 0.002, p<0.0005, p<0.0005 in patient sets 1, 2, and the combined sets, respectively), translating into an approximately 3.5-fold change in expected serum CRP concentrations between carriers of two common CRP haplotypes. For example, when ESR = 50 mm/h the expected geometric mean CRP (95% confidence interval) concentration was 43.1 mg/l (32.1-50.0) for haplotype 1 and 14.2 mg/l (9.5-23.2) for haplotype 4. CONCLUSIONS: Our findings raise questions about the interpretation of acute-phase serum CRP. In particular, failure to take into account the potential for genetic effects may result in the inappropriate reassurance or suboptimal treatment of patients simply because they carry low-CRP-associated genetic variants. CRP is increasingly being incorporated into clinical algorithms to compare disease activity between patients and to predict future clinical events: our findings impact on the use of these algorithms. For example, where access to effective, but expensive, biological therapies in rheumatoid arthritis is rationed on the basis of a DAS28-CRP clinical activity score, then two patients with identical underlying disease severity could be given, or denied, treatment on the basis of CRP genotype alone. The accuracy and utility of these algorithms might be improved by using a genetically adjusted CRP measurement.

Fine-mapping the genetic basis of CRP regulation in African Americans: a Bayesian approach.

Basal levels of C-reactive protein (CRP) have been associated with disease, particularly future cardiovascular events. Twin studies estimate 50% CRP heritability, so the identification of genetic variants influencing CRP expression is important. Existing studies in populations of European ancestry have identified numerous cis-acting variants but leave significant ambiguity over the identity of the key functional polymorphisms. We addressed this issue by typing a dense map of CRP single-nucleotide polymorphisms (SNPs), and quantifying serum CRP in 594 unrelated African Americans. We used Bayesian model choice analysis to select the combination of SNPs best explaining basal CRP and found strong support for triallelic rs3091244 alone, with the T allele acting in an additive manner (Bayes factor > 100 vs. null model), with additional support for a model incorporating both rs3091244 and rs12728740. Admixture analysis suggested SNP rs12728740 segregated with haplotypes predicted to be of recent European origin. Using a cladistic approach we confirmed the importance of rs3091244(T) by demonstrating a significant partition of haplotype effect based on the rs3091244(C/T) mutation (F = 8.91, P = 0.006). We argue that weaker linkage disequilibrium across the African American CRP locus compared with Europeans has allowed us to establish an unambiguous functional role for rs3091244(T), while also recognising the potential for additional functional mutations present in the European genome.

Outcomes and compliance with standards of care in anti-neutrophil cytoplasmic antibody-associated vasculitis-insights from a large multiregion audit.

OBJECTIVES: We aimed to conduct a large audit of routine care for patients with ANCA-associated vasculitis. METHODS: We invited all 34 hospitals within one health region in England to undertake a retrospective case note audit of all patients newly diagnosed or treated with CYC or rituximab (RTX) for ANCA-associated vasculitis from April 2013 to December 2014. We compared clinical practice to the British Society for Rheumatology guidelines for the management of adults with ANCA-associated vasculitis and the use of RTX with the National Health Service (NHS) England commissioning policy and National Institute for Health and Care Excellence (NICE) technology appraisal. RESULTS: We received data from 213 patients. Among 130 newly diagnosed patients, delay from admission to diagnosis ranged from 0 to 53 days (median 6, interquartile range 3-10.5) for those diagnosed as inpatients. BVAS was recorded in 8% of patients at diagnosis. Remission at 6 months was achieved in 83% of patients. The 1-year survival was 91.5%. A total of 130 patients received CYC for new diagnosis or relapse. The correct dose of i.v. CYC (within 100 mg of the target dose calculated for age, weight and creatinine) was administered in 58% of patients. A total of 25% of patients had an infection requiring hospital admission during or within 6 months of completing their CYC therapy. Seventy-six patients received RTX for new diagnosis or relapse. A total of 97% of patients met the NHS England or NICE eligibility criteria. Pneumocystis jiroveci pneumonia prophylaxis (recommended in the summary of product characteristics) was given in only 65% of patients. CONCLUSION: We identified opportunities to improve care, including compliance with safety standards for delivery of CYC. Development of a national treatment protocol/checklist to reduce this heterogeneity in care should be considered as a priority.

Systemic lupus erythematosus: An update for ophthalmologists.

Systemic lupus erythematosus (SLE) is a life-threatening multisystem inflammatory condition that may affect almost any part of the eye. We provide an update for the practicing ophthalmologist comprising a systematic review of the recent literature presented in the context of current knowledge of the pathogenesis, diagnosis, and treatment of this condition. We review recent advances in the understanding of the influence of genetic and environmental factors on the development of SLE. Recent changes in the diagnostic criteria for SLE are considered. We assess the potential for novel molecular biomarkers to find a clinical application in disease diagnosis and stratification and in the development of therapeutic agents. We discuss limited forms of SLE and their differentiation from other collagen vascular disorders and review recent evidence underlying the use of established and novel therapeutics in this condition, including specific implications regarding monitoring for ocular toxicity associated with antimalarials.

Resequencing the susceptibility gene, ITGAM, identifies two functionally deleterious rare variants in systemic lupus erythematosus cases.

INTRODUCTION: The majority of the genetic variance of systemic lupus erythematosus (SLE) remains unexplained by the common disease-common variant hypothesis. Rare variants, which are not detectable by genome-wide association studies because of their low frequencies, are predicted to explain part of this "missing heritability." However, recent studies identifying rare variants within known disease-susceptibility loci have failed to show genetic associations because of their extremely low frequencies, leading to the questioning of the contribution of rare variants to disease susceptibility. A common (minor allele frequency = 17.4% in cases) nonsynonymous coding variant rs1143679 (R77H) in ITGAM (CD11b), which forms half of the heterodimeric integrin receptor, complement receptor 3 (CR3), is robustly associated with SLE and has been shown to impair CR3-mediated phagocytosis. METHODS: We resequenced ITGAM in 73 SLE cases and identified two previously unidentified, case-specific nonsynonymous variants, F941V and G1145S. Both variants were genotyped in 2,107 and 949 additional SLE cases, respectively, to estimate their frequencies in a disease population. An in vitro model was used to assess the impact of F941V and G1145S, together with two nonsynonymous ITGAM polymorphisms, A858V (rs1143683) and M441T (rs11861251), on CR3-mediated phagocytosis. A paired two-tailed t test was used to compare the phagocytic capabilities of each variant with that of wild-type CR3. RESULTS: Both rare variants, F941V and G1145S, significantly impair CR3-mediated phagocytosis in an in vitro model (61% reduction, P = 0.006; 26% reduction, P = 0.0232). However, neither of the common variants, M441T and A858V, had an effect on phagocytosis. Neither rare variant was observed again in the genotyping of additional SLE cases, suggesting that their frequencies are extremely low. CONCLUSIONS: Our results add further evidence to the functional importance of ITGAM in SLE pathogenesis through impaired phagocytosis. Additionally, this study provides a new example of the identification of rare variants in common-allele-associated loci, which, because of their extremely low frequencies, are not statistically associated. However, the demonstration of their functional effects adds support to their contribution to disease risk, and questions the current notion of dismissing the contribution of very rare variants on purely statistical analyses.