C-reactive protein and systemic lupus erythematosus

Blood parameters in pediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

BACKGROUND AND OBJECTIVES

Patients with myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) clinically present e.g. with acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), transverse myelitis (TM) or aquaporin-4-IgG (AQP4-IgG) negative neuromyelitis optica spectrum disorders (NMOSD)-like phenotypes. We aimed to analyze and compare blood parameters in children with MOGAD, AQP4-IgG-positive NMOSD (hence NMOSD), multiple sclerosis (MS) and healthy controls (HC).

METHODS

We evaluated differences in complete blood counts (CBC), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and C-reactive protein (CRP) between these four groups and within the groups between clinical attack, acute treatment and remission.

RESULTS

Our cohort consisted of 174 children and adolescents with a total of 550 timepoints: 66 patients had MOGAD (202 timepoints), 11 NMOSD (76 timepoints), 58 MS (219 timepoints) and 39 were HC (53 timepoints). At clinical attack, leukocyte counts were elevated in MOGAD compared to remission (p < 0.001) and compared to all other groups (p < 0.001). NLR was high in MOGAD and NMOSD, and PLR was high in NMOSD, however, after correction for multiple testing these findings did not remain significant. While glucocorticoids caused an increase of leukocyte counts and NLR in NMOSD and MS, these values remained stable during acute treatment in MOGAD. In remission, NLR normalized in MOGAD, while it stayed high in NMOSD. PLR increased in NMOSD and was significantly higher compared to all other groups.

DISCUSSION

Some blood parameters, mainly leukocyte and differential counts, might help clinicians to evaluate disease activity, differentiate relapses from pseudo-relapses and even distinguish between different disease entities.

Assessment of hematologic indices for diagnosis in juvenile systemic lupus erythematosus

Introduction

The aim was to present effective approaches utilizing novel hematological parameters for early diagnosis of juvenile-onset systemic lupus erythematosus (jSLE).

Material and methods

Our study at Umraniye Training and Research Hospital involved a jSLE patient cohort from 2016 to 2022 and matched healthy controls aligning with sex and age. We use the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) for disease activity. Our approach was to analyze leukocyte, neutrophil, lymphocyte, monocyte, and platelet counts, along with ratios such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and monocyte-to-platelet ratio (MPR). We also explored novel indices: the systemic inflammatory index (SII), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI) to identify relationships between systemic indices and jSLE activity.

Results

Upon comparative analysis with the healthy control group, systemic lupus erythematosus (SLE) patients exhibited significantly elevated levels of the hematological parameters NLR, SII, and SIRI (p-values: 0.010, 0.048, 0.025, respectively). Among SLE patients, neutrophil, lymphocyte, and platelet distribution width (PDW) values were notably higher, while hemoglobin, red blood cell distribution width (RDW), and procalcitonin (PCT) values were significantly lower. In comparison, C-reactive protein (CRP) and sedimentation values were markedly elevated in the SLE group in contrast to the healthy control cohort. Patients with significantly elevated disease activity had notably higher values of NLR (p = 0.010) and SII (p = 0.048). Among patients with positive antinuclear antibodies (ANA), elevated levels of NLR, SII, and SIRI were noted (p-values: 0.018, 0.021, 0.035).

Conclusions

In this study, the novel hematological markers SII, SIRI, and AISI were found to effectively reflect inflammation in SLE patients, exhibit associations with high disease activity, and demonstrate heightened sensitivity in detecting cases with high disease activity.

Blood Composite Scores in Patients with Systemic Lupus Erythematosus

Complete blood count-derived ratios have been described as inflammatory biomarkers in several diseases. These hematological scores include the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammatory index ([SIRI]; neutrophils × monocytes/lymphocytes). Our aim was to study how these biomarkers are related to disease expression in a large and well-characterized series of patients with systemic lupus erythematosus (SLE). A total of 284 SLE patients and 181 age- and sex-matched healthy controls were recruited. The NLR, MLR, PLR, and SIRI were calculated, and activity (SLEDAI-2K), severity (Katz), and damage index (SLICC-DI) scores were assessed in patients with SLE. Multivariable linear regression analysis was performed to study whether these scores differ between patients and controls and how they are related to clinical and laboratory features of the disease. Crude cell counts of neutrophils, monocytes, lymphocytes, and platelets were lower in SLE patients compared to controls. Despite this, NLR, MLR, and PRL, but not SIRI, were higher in SLE patients than in controls after multivariable analysis. However, the relationship between the different scores and disease characteristics was limited. Only the Katz severity index revealed a significant positive relationship with SIRI, NLR, and MLR after adjustment for covariates. Similarly, alternative complement cascade activation and low C3 were significantly associated with higher NLR, MLR, and PLR. In conclusion, although cytopenias are a common feature of patients with SLE, hematologic composite scores are independently higher in this population compared to controls. However, the relationship of these scores with the characteristics of the disease is scarce, with the relationship with the complement system being the most consistent.

C-reactive protein: a target for therapy to reduce inflammation

C-reactive protein (CRP) is well-recognized as a sensitive biomarker of inflammation. Association of elevations in plasma/serum CRP level with disease state has received considerable attention, even though CRP is not a specific indicator of a single disease state. Circulating CRP levels have been monitored with a varying degree of success to gauge disease severity or to predict disease progression and outcome. Elevations in CRP level have been implicated as a useful marker to identify patients at risk for cardiovascular disease and certain cancers, and to guide therapy in a context-dependent manner. Since even strong associations do not establish causality, the pathogenic role of CRP has often been over-interpreted. CRP functions as an important modulator of host defense against bacterial infection, tissue injury and autoimmunity. CRP exists in conformationally distinct forms, which exhibit distinct functional properties and help explaining the diverse, often contradictory effects attributed to CRP. In particular, dissociation of native pentameric CRP into its subunits, monomeric CRP, unmasks "hidden" pro-inflammatory activities in pentameric CRP. Here, we review recent advances in CRP targeting strategies, therapeutic lowering of circulating CRP level and development of CRP antagonists, and a conformation change inhibitor in particular. We will also discuss their therapeutic potential in mitigating the deleterious actions attributed to CRP under various pathologies, including cardiovascular, pulmonary and autoimmune diseases and cancer.

Persistent inflammation-immunosuppression-catabolism syndrome in patients with systemic lupus erythematosus

OBJECTIVE

To evaluate the clinical characteristics and prognosis of systemic lupus erythematosus (SLE) with persistent inflammation-immunosuppression-catabolism syndrome (PICS).

METHODS

We retrospectively analyzed patients with SLE who were admitted to the renal intensive care unit (ICU) for over 14 days at Jinling Hospital from July 2010 to July 2018. According to the diagnostic criteria of PICS, we divided the SLE patients into a PICS group and a non-PICS group. We performed a multivariate Cox regression analysis on the risk factors for death in these two groups by comparing the clinical features and prognosis.

RESULTS

A total of 96 SLE patients met the inclusion and exclusion criteria of this study, including 61 patients in the PICS group and 35 patients in the non-PICS group. The PICS group patients required a longer length of stay in ICU with higher inflammatory indicators (such as C-reactive protein, procalcitonin and interleukin-6) and lower immune levels (such as total, CD3 + , CD4 + , CD8 + and CD20 + lymphocytes) compared to the non-PICS group patients (P < 0.01). Hemoglobin, platelets, serum creatinine, serum blood urea nitrogen and SLE Disease Activity Index (SLE-DAI) score in the PICS group were lower than those in the non-PICS group (P < 0.05), suggesting severe hematological injury in the PICS group and relatively severe renal damage in the non-PICS group. The rates of PICS combined with sepsis, acute respiratory distress syndrome, mechanical ventilation, gram-positive bacteria, gram-negative bacteria, fungi and double infections were higher than those in the non-PICS group (P < 0.05). The 3-year survival rate was 50.82% in the PICS group and 85.71% in the non-PICS group. The 3-year renal survival rate was 32.79% in the PICS group and 51.43% in the non-PICS group. Multivariate Cox regression found that the total lymphocyte count during ICU admission was an independent risk factor for death in SLE patients with PICS.

CONCLUSION

Patients with SLE complicated with PICS had longer ICU stays, a lower level of SLE activity, a higher risk of secondary infection and a significantly lower survival rate than non-PICS patients.

Associations of improvement in laboratory tests with clinical outcomes in patients with active systemic lupus erythematosus: a multinational longitudinal cohort study

BACKGROUND

The selection and categorisation of laboratory tests in disease activity measures used within systemic lupus erythematosus (SLE) trial endpoints lack strong evidence. We aimed to determine whether longitudinal improvements in routinely measured laboratory tests are associated with measures of clinical improvement in patients with baseline active SLE.

METHODS

We included patients from a multicentre longitudinal cohort (recruited between May 1, 2013, and Dec 31, 2019) with active SLE (SLEDAI-2K ≥6) coinciding with an abnormality in at least one of 13 routine laboratory tests, at a visit designated as baseline. At 12 months, we analysed associations between thresholds of improvement in individual laboratory test results, measured as continuous variables, and five clinical outcomes using logistic regression. Primary outcomes were damage accrual and lupus low disease activity state (LLDAS), and secondary outcomes were modified SLE responder index (mSRI), physician global assessment (PGA) improvement of at least 0·3, and flare.

FINDINGS

We included 1525 patients (1415 [93%] women and 110 [7%] men, 1328 [87%] Asian ethnicity) in separate subsets for each laboratory test. The strongest associations with LLDAS and damage protection were seen with improvements in proteinuria (complete response: adjusted odds ratio [OR] 62·48, 95% CI 18·79-208·31 for LLDAS, OR 0·22, 95% CI 0·10-0·49 for damage accrual), albumin (complete response: adjusted OR 6·46, 95% CI 2·20-18·98 for LLDAS, OR 0·42, 95% CI 0·20-1·22 for damage accrual), haemoglobin (complete response: adjusted OR 1·97, 95% CI 1·09-3·53 for LLDAS, OR 0·33, 95% CI 0·15-0·71 for damage accrual), erythrocyte sedimentation rate (complete response: adjusted OR 1·71, 95% CI 1·10-2·67 for LLDAS, OR 0·53, 95% CI 0·30-0·94 for damage accrual), and platelets (complete response: adjusted OR 4·82, 95% CI 1·54-15·07 for LLDAS, OR 0·49, 95% CI 0·20-1·19 for damage accrual). Improvement in serological tests were mainly associated with PGA and mSRI. White cell and lymphocyte count improvements were least predictive.

INTERPRETATION

Improvements in several routine laboratory tests correspond with clinical outcomes in SLE over 12 months. Tests with the strongest associations were discrepant with laboratory tests included in current trial endpoints, and associations were observed across a range of improvement thresholds including incomplete resolution. These findings suggest the need to revise the use of laboratory test results in SLE trial endpoints.

FUNDING

Abbvie.

Diet and Systemic Lupus Erythematosus (SLE): From Supplementation to Intervention

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease characterised by immune dysregulation affecting multiple organs. Current anti-inflammatory treatments used in SLE are associated with unwanted side-effects. Dietary supplementation has been suggested as a safe and effective addition to conventional treatment, but evidence of efficacy in SLE or preventing associated comorbidities is uncertain.

METHODS

We identified literature on clinical trials focused on nutritional interventions in SLE aiming to improve inflammation and comorbidities. A systematic-type search on Embase, Medline, and the Cochrane Library, was conducted to identify nutritional interventions among SLE patients in the past 15 years that met our inclusion criteria.

RESULTS

We identified 2754 articles, of which 14 were eligible for inclusion based on our set criteria and were subsequently quality assessed. Vitamin D or E supplementation was associated with respective improvement of inflammatory markers or antibody production, but not disease activity scores in most studies. Despite their expected synergistic actions, the addition of curcumin on vitamin D supplementation had no additional effects on disease activity or inflammatory markers. Trials of omega-3 fatty acid supplementation presented significant reductions in ESR, CRP, disease activity, inflammatory markers, and oxidative stress, and improved lipid levels and endothelial function, while a low glycaemic index (GI) diet showed evidence of reduced weight and improved fatigue in patients.

CONCLUSIONS

Different dietary guidelines can therefore be implicated to target specific SLE symptoms or therapeutic side-effects. This systematic review highlights the scarcity of larger and longer in duration trials with homogenous methodologies and verifiable outcomes to assess disease progression.

The utility of erythrocyte sedimentation rate, C-reactive protein, and procalcitonin in detecting infections in patients with systemic lupus erythematosus: A systematic review

OBJECTIVES

We conducted a systematic review with metanalysis to investigate the utility of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) in diagnosing infections in hospitalized patients with SLE.

METHODS

We searched Medline, Embase, Web of Science, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL) with a search strategy developed by a medical librarian. We included retrospective, cross-sectional, case-control, and prospective studies in our analysis. We used the Quality Assessment of Diagnostic Studies (QUADAS-2) to assess for bias and applicability. We obtained mean differences, sensitivities, and specificities in our analysis.

RESULTS

We included 26 studies in our analysis. Most studies had an unclear or high risk of bias and our results were widely heterogenous. For the diagnosis of infections, the CRP had a pooled sensitivity of 0.75 (95%CI 0.57-0.94) and specificity of 0.72 (0.59-0.85), PCT had a pooled sensitivity of 0.68 (95% CI 0.0.59-0.77) and specificity of 0.75 (0.59-0.90), and for ESR pooled estimates were not calculated but sensitivity ranged from 50 to 69.8 and specificity from 38.5 to 55.6. Modifying cut-offs improved sensitivities and specificities. The ESR, CRP, and PCT mean differences were all greater in infection groups versus non-infection (10.1, 95% CI 3.2-17.0; 46.8, 95% CI 36.5-57.0; 0.53, 95% CI 0.26-0.80; respectively).

DISCUSSION

Poor sensitivities and specificities were observed for the evaluated biomarkers with substantial heterogeneity in the cut-offs used to determine infection. Although mean biomarker values were increased in the infection group compared with the non-infection, our findings do not support the widespread use of ESR, CRP, or PCT in diagnosing infection in hospitalized patients with SLE due to increased heterogeneity and risk of bias. Further investigation is needed.

The Complex Role of C-Reactive Protein in Systemic Lupus Erythematosus

C-reactive protein (CRP) is well-known as a sensitive albeit unspecific biomarker of inflammation. In most rheumatic conditions, the level of this evolutionarily highly conserved pattern recognition molecule conveys reliable information regarding the degree of ongoing inflammation, driven mainly by interleukin-6. However, the underlying causes of increased CRP levels are numerous, including both infections and malignancies. In addition, low to moderate increases in CRP predict subsequent cardiovascular events, often occurring years later, in patients with angina and in healthy individuals. However, autoimmune diseases characterized by the Type I interferon gene signature (e.g., systemic lupus erythematosus, primary Sjögren’s syndrome and inflammatory myopathies) represent exceptions to the general rule that the concentrations of CRP correlate with the extent and severity of inflammation. In fact, adequate levels of CRP can be beneficial in autoimmune conditions, in that they contribute to efficient clearance of cell remnants and immune complexes through complement activation/modulation, opsonization and phagocytosis. Furthermore, emerging data indicate that CRP constitutes an autoantigen in systemic lupus erythematosus. At the same time, the increased risks of cardiovascular and cerebrovascular diseases in patients diagnosed with systemic lupus erythematosus and rheumatoid arthritis are well-established, with significant impacts on quality of life, accrual of organ damage, and premature mortality. This review describes CRP-mediated biological effects and the regulation of CRP release in relation to aspects of cardiovascular disease and mechanisms of autoimmunity, with particular focus on systemic lupus erythematosus.

Predictive factors for concomitant pulmonary arterial hypertension at diagnosis of systemic lupus erythematosus in a Chinese population

AIM

To investigate the predictive factors of pulmonary arterial hypertension (PAH) in systemic lupus erythematosus (SLE) patients.

METHOD

This chart review study included 408 SLE patients. We defined PAH as 2 consecutive systolic pulmonary arterial pressure (PAP) values ≥40 mm Hg by echocardiography. Demographic characteristics, clinical symptoms, autoantibodies, and laboratory tests were studied.

RESULTS

Thirty-four patients in the SLE/PAH+ group and 374 patients in the SLE/PAH- group were analyzed. The prevalence of PAH in SLE is 8.3% in this study. The occurrences of interstitial pneumonitis, polyserositis and myocardial damage were higher in the SLE/PAH+ group (P = .001, P = .033 and P < .001, respectively). The occurrence of anti-double-stranded DNA and anti-ribosomal RNA protein (anti-rRNP) antibodies were lower in the SLE/PAH+ group (P = .003, .010). Positive rates of anti-Sjögren's syndrome antigen A (anti-SSA)/Ro52 antibodies and anti-SSB antibodies were higher in the SLE/PAH+ group (P = .046, .021). C-reactive protein and immunoglobin G (IgG) were higher in the SLE/PAH+ group (P = .009, .005). Ejection fraction and SLE disease activity index between the 2 groups had no differences. Multivariable logistic regression indicated that interstitial pneumonitis, myocardial damage and high IgG are predictive factors for SLE-associated PAH patients.

CONCLUSION

From this study, we found that interstitial pneumonitis, myocardial damage, and high IgG were predictive factors of PAH in SLE patients.

Pattern of inflammatory immune response determines the clinical course and outcome of COVID-19: unbiased clustering analysis

The objective of the study was to identify distinct patterns in inflammatory immune responses of COVID-19 patients and to investigate their association with clinical course and outcome. Data from hospitalized COVID-19 patients were retrieved from electronic medical record. Supervised k-means clustering of serial C-reactive protein levels (CRP), absolute neutrophil counts (ANC), and absolute lymphocyte counts (ALC) was used to assign immune responses to one of three groups. Then, relationships between patterns of inflammatory responses and clinical course and outcome of COVID-19 were assessed in a discovery and validation cohort. Unbiased clustering analysis grouped 105 patients of a discovery cohort into three distinct clusters. Cluster 1 (hyper-inflammatory immune response) was characterized by high CRP levels, high ANC, and low ALC, whereas Cluster 3 (hypo-inflammatory immune response) was associated with low CRP levels and normal ANC and ALC. Cluster 2 showed an intermediate pattern. All patients in Cluster 1 required oxygen support whilst 61% patients in Cluster 2 and no patient in Cluster 3 required supplementary oxygen. Two (13.3%) patients in Cluster 1 died, whereas no patient in Clusters 2 and 3 died. The results were confirmed in an independent validation cohort of 116 patients. We identified three different patterns of inflammatory immune response to COVID-19. Hyper-inflammatory immune responses with elevated CRP, neutrophilia, and lymphopenia are associated with a severe disease and a worse outcome. Therefore, targeting the hyper-inflammatory response might improve the clinical outcome of COVID-19.

C-Reactive Protein Suppresses the Th17 Response Indirectly by Attenuating the Antigen Presentation Ability of Monocyte Derived Dendritic Cells in Experimental Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a classical murine model for Multiple Sclerosis (MS), a human autoimmune disease characterized by Th1 and Th17 responses. Numerous studies have reported that C-reactive protein (CRP) mitigates EAE severity, but studies on the relevant pathologic mechanisms are insufficient. Our previous study found that CRP suppresses Th1 response directly by receptor binding on naïve T cells; however, we did not observe the effect on Th17 response at that time; thus it remains unclear whether CRP could regulate Th17 response. In this study, we verified the downregulation of Th17 response by a single-dose CRP injection in MOG-immunized EAE mice in vivo while the direct and indirect effects of CRP on Th17 response were differentiated by comparing its actions on isolated CD4⁺ T cells and splenocytes in vitro, respectively. Moreover, the immune cell composition was examined in the blood and CNS (Central Nervous System), and a blood (monocytes) to CNS (dendritic cells) infiltration pathway is established in the course of EAE development. The infiltrated monocyte derived DCs (moDCs) were proved to be the only candidate antigen presenting cells to execute CRP’s function. Conversely, the decrease of Th17 responses caused by CRP disappeared in the above in vivo and in vitro studies with FcγR2B^−/− mice, indicating that FcγR2B expressed on moDCs mediates CRP function. Furthermore, peripheral blood monocytes were isolated and induced to establish moDCs, which were used to demonstrate that the antigen presenting ability of moDCs was attenuated by CRP through FcγR2B, and then NF-κB and ERK signaling pathways were manifested to be involved in this regulation. Ultimately, we perfected and enriched the mechanism studies of CRP in EAE remission, so we are more convinced that CRP plays a key role in protecting against EAE development, which may be a potential therapeutic target for the treatment of MS in human.

Exploratory classification of clinical phenotypes in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis using cluster analysis

A novel patient cluster in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may be identified in Japan. We performed multiple correspondence and cluster analysis regarding 427 clinically diagnosed AAV patients excluding eosinophilic granulomatosis with polyangiitis. Model 1 included the ANCA phenotype, items of the Birmingham Vasculitis Activity Score, and interstitial lung disease; model 2 included serum creatinine (s-Cr) and C-reactive protein (CRP) levels with model 1 components. In seven clusters determined in model 1, the ANCA-negative (n = 8) and proteinase 3-ANCA-positive (n = 41) groups emerged as two distinct clusters. The other five myeloperoxidase-ANCA-positive clusters were characterized by ear, nose, and throat (ENT) (n = 47); cutaneous (n = 36); renal (n = 256), non-renal (n = 33); and both ENT and cutaneous symptoms (n = 6). Four clusters in model 2 were characterized by myeloperoxidase-ANCA negativity (n = 42), without s-Cr elevation (< 1.3 mg/dL) (n = 157), s-Cr elevation (≥ 1.3 mg/dL) with high CRP (> 10 mg/dL) (n = 71), or s-Cr elevation (≥ 1.3 mg/dL) without high CRP (≤ 10 mg/dL) (n = 157). Overall, renal, and relapse-free survival rates were significantly different across the four clusters in model 2. ENT, cutaneous, and renal symptoms may be useful in characterization of Japanese AAV patients with myeloperoxidase-ANCA. The combination of s-Cr and CRP levels may be predictive of prognosis.

Acute lupus pneumonitis as the initial presentation of systemic lupus erythematosus

Systemic lupus erythematosus is a multisystem autoimmune disease with wide-ranging pleuropulmonary manifestations. Acute lupus pneumonitis is one of its uncommon complications. We report a 36-year-old woman with acute lupus pneumonitis as the initial presentation of systemic lupus erythematosus. Clinical, biological, radiological and functional improvements were noticed with the administration of steroids, hydroxychloroquine and immunoglobulin.

Serious Complication of Anticoagulation in Vessel Thrombosis-associated Behçet Disease

Anticoagulation in venous thrombosis associated with Behçet disease (BD) is controversial. We herein report a 47-year-old woman with vessel thrombosis and pulmonary artery aneurysm (PAA) associated with BD who died of massive hemoptysis under oral anticoagulant. Although she was initially diagnosed with oral contraceptive-induced venous thromboembolism, a subsequent investigation led to a diagnosis of BD. Follow-up computed tomography (CT) showed persistent thrombus, so anticoagulant was continued for persistent thrombus. She died of massive hemoptysis after the development of PAA was identified on follow-up CT during the period of anticoagulation. Great care to prevent bleeding events is required when administering anticoagulants for BD with vessel thrombosis.

Platelet distribution width as a marker for predicting lupus nephritis

BACKGROUND

Lupus nephritis (LN) is an important manifestation of systemic lupus erythematosus (SLE). The aim of this study was to investigate the predictive value of platelet distribution width (PDW) in LN.

METHODS

A retrospective study involving 212 SLE patients and 201 healthy controls were performed. All clinical characteristics and laboratory data were collected from their medical records.

RESULTS

The level of PDW was significantly decreased in SLE patients, which was negatively correlated with SLE disease activity index 2000 (SLEDAI-2K) score, disease duration, and 24-hour (24-h) urine protein, while positively correlated with serum IgG and IgM. There were more LN patients in low-PDW group than normal-PDW and high-PDW groups. In low-PDW group, SLEDAI-2K score, 24-h urine protein level, and anti-dsDNA antibody level was significantly higher, while serum IgG level was markedly lower. Moreover, PDW was negatively correlated with 24-h urine protein and disease duration, and it was positively correlated with serum IgG in LN patients. In addition, the area under the ROC curve of PDW was 0.87 and the optimal clinical cutoff level was 12.9, which provided a 87.41% sensitivity and a 74.63% specificity. Decreased PDW combined with high 24-h urine protein exhibited an excellent diagnostic value for LN. Importantly, 16.67% LN patients with negative 24-h urine protein can be detected in low PDW group.

CONCLUSION

PDW may be a potential marker for predicting LN. Low PDW accompanied with high 24-h urine protein may be a useful indicator for diagnosing LN.

Profile of common inflammatory markers in treatment-naïve patients with systemic rheumatic diseases

OBJECTIVES

To evaluate and compare the clinical implications of common inflammatory markers in systemic rheumatic diseases (SRDs).

METHOD

We investigated the profiles of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and white blood cell (WBC) count in treatment-naïve patients with SRDs, osteoarthritis and pneumonia diagnosed at Seoul National University Hospital during 2004-2016. SRDs included rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), systemic sclerosis (SSc), idiopathic inflammatory myopathy (IIM) and adult-onset Still's disease (AOSD). Associations between inflammatory markers were evaluated using Pearson's correlation and regression analysis. ROC curve analysis was performed to examine the predictive value of inflammatory markers for SRD diagnosis.

RESULTS

We identified a total of 1191 patients. Leukocytosis was present in < 20% SRD patients. There was marked variability in ESR and CRP levels among different SRDs. The highest mean CRP levels (mean ± SD, mg/dL) were observed in AOSD (11.3 ± 7.9), followed by RA (2.0 ± 3.3), IIM (1.8 ± 3.5), SLE (1.5 ± 3.1), SSc (0.6 ± 1.3) and AS (0.08 ± 0.1). Mean ESR (mm/h) was also highest in AOSD (71.2 ± 31.0), followed by SLE (47.3 ± 34.2), RA (45.5 ± 30.6), IIM (40.8 ± 24.8) and SSc (27.8 ± 26.0). All SRDs showed significant positive correlations between ESR and CRP: greatest in RA (r = 0.53, p < 0.001) and weakest in SLE (r = 0.20, p = 0.03). WBC correlated weakly with CRP but not with ESR in most SRDs. While the AUC for WBC count was less than that of ESR or CRP, the AUC for ESR and CRP were similar in SRD. The optimal cuff-off values for inflammatory markers predicting SRD were within or slightly above the normal limit.

CONCLUSIONS

ESR, CRP and WBC are not always elevated in treatment-naïve patients with SRD. Individual SRDs have a unique profile of inflammatory markers. However, routine inflammatory markers should still be interpreted with caution when diagnosing and assessing disease activity in those with SRD. Key Points •Leukocytosis and elevation of ESR and CRP are not always present in all systemic rheumatic diseases. •Inflammatory markers are often dissociated and they are not specific for disease diagnosis. •Better biomarkers, which measure disease-specific local and systemic inflammation, are needed.

Allelic Heterogeneity at the CRP Locus Identified by Whole-Genome Sequencing in Multi-ancestry Cohorts

Whole-genome sequencing (WGS) can improve assessment of low-frequency and rare variants, particularly in non-European populations that have been underrepresented in existing genomic studies. The genetic determinants of C-reactive protein (CRP), a biomarker of chronic inflammation, have been extensively studied, with existing genome-wide association studies (GWASs) conducted in >200,000 individuals of European ancestry. In order to discover novel loci associated with CRP levels, we examined a multi-ancestry population (n = 23,279) with WGS (∼38× coverage) from the Trans-Omics for Precision Medicine (TOPMed) program. We found evidence for eight distinct associations at the CRP locus, including two variants that have not been identified previously (rs11265259 and rs181704186), both of which are non-coding and more common in individuals of African ancestry (∼10% and ∼1% minor allele frequency, respectively, and rare or monomorphic in 1000 Genomes populations of East Asian, South Asian, and European ancestry). We show that the minor (G) allele of rs181704186 is associated with lower CRP levels and decreased transcriptional activity and protein binding in vitro, providing a plausible molecular mechanism for this African ancestry-specific signal. The individuals homozygous for rs181704186-G have a mean CRP level of 0.23 mg/L, in contrast to individuals heterozygous for rs181704186 with mean CRP of 2.97 mg/L and major allele homozygotes with mean CRP of 4.11 mg/L. This study demonstrates the utility of WGS in multi-ethnic populations to drive discovery of complex trait associations of large effect and to identify functional alleles in noncoding regulatory regions.

Targeted proteomics reveals serum amyloid A variants and alarmins S100A8-S100A9 as key plasma biomarkers of rheumatoid arthritis

Serum amyloid A (SAA) and S100 (S100A8, S100A9 and S100A12) proteins were previously identified as biomarkers of interest for rheumatoid arthritis (RA). Among SAA family, two closely related isoforms (SAA-1 and SAA-2) are linked to the acute-phase of inflammation. They respectively exist under the form of three (α, β, and γ) and two (α and β) allelic variants. We developed a single run quantitative method for these protein variants and investigated their clinical relevance in the context of RA. The method was developed and validated according to regulations before being applied on plasma coming from RA patients (n = 46), other related inflammatory pathologies (n = 116) and controls (n = 62). Depending on the activity score of RA, SAA1 isoforms (mainly of SAA1α and SAA1β subtypes) were found to be differentially present in plasma revealing their dual role during the development of RA. In addition, the weight of SAA1α in the total SAA response varied from 32 to 80% depending on the pathology studied. A negative correlation between SAA1α and SAA1β was also highlighted for RA early-onset (r = -0.41). SAA2 and S100A8/S100A9 proteins were significantly overexpressed compared to control samples regardless of RA stage. The pathophysiological relevance of these quantitative and qualitative characteristics of the SAA response remains unknown. However, the significant negative correlation observed between SAA1α and SAA1β levels in RA early-onset suggests the existence of still unknown regulatory mechanisms in these diseases.

Complement system biomarkers in first episode psychosis

Several lines of evidence implicate immunological/inflammatory factors in development of schizophrenia. Complement is a key driver of inflammation, and complement dysregulation causes pathology in many diseases. Here we explored whether complement dysregulation occurred in first episode psychosis (FEP) and whether this provides a source of biomarkers. Eleven complement analytes (C1q, C3, C4, C5, factor B [FB], terminal complement complex [TCC], factor H [FH], FH-related proteins [FHR125], Properdin, C1 inhibitor [C1inh], soluble complement receptor 1 [CR1]) plus C-reactive protein (CRP) were measured in serum from 136 first episode psychosis (FEP) cases and 42 mentally healthy controls using established in-house or commercial ELISA. The relationship between caseness and variables (analytes measured, sex, age, ethnicity, tobacco/cannabis smoking) was tested by multivariate logistic regression. When measured individually, only TCC was significantly different between FEP and controls (p=0.01). Stepwise selection demonstrated interdependence between some variables and revealed other variables that significantly and independently contributed to distinguishing cases and controls. The final model included demographics (sex, ethnicity, age, tobacco smoking) and a subset of analytes (C3, C4, C5, TCC, C1inh, FHR125, CR1). A receiver operating curve analysis combining these variables yielded an area under the curve of 0.79 for differentiating FEP from controls. This model was confirmed by multiple replications using randomly selected sample subsets. The data suggest that complement dysregulation occurs in FEP, supporting an underlying immune/inflammatory component to the disorder. Classification of FEP cases according to biological variables rather than symptoms would help stratify cases to identify those that might most benefit from therapeutic modification of the inflammatory response.

Association of Blood Concentrations of Complement Split Product iC3b and Serum C3 With Systemic Lupus Erythematosus Disease Activity

Objective

To examine correlations between blood levels of complement split product iC3b and serum component C3 with clinically meaningful changes in disease activity in patients with systemic lupus erythematosus (SLE).

Methods

A total of 159 consecutive patients with SLE, diagnosed according to the American College of Rheumatology or Systemic Lupus International Collaborating Clinics classification criteria, were enrolled in CASTLE (Complement Activation Signatures in Systemic Lupus Erythematosus), a prospective observational study. Patients with 1–7 study visits were included in this longitudinal analysis. In addition, 48 healthy volunteers were enrolled to establish a normal reference value for the ratio of blood iC3b to serum C3 concentrations. Serum C3 and C4 levels were measured by nephelometry, and blood iC3b levels were measured by a lateral flow assay. SLE disease activity was monitored with the Responder Index 50 instrument of the SLE Disease Activity Index 2000.

Results

Relative changes in the iC3b:C3 ratio, levels of anti–double‐stranded DNA (anti‐dsDNA) antibodies, and use of a supraphysiologic dose of prednisone (>7.5 mg/day) each independently correlated with SLE disease activity, as determined in multilevel multiple logistic regression analyses. Only the iC3b:C3 ratio was significantly associated with clinically meaningful improvements in disease activity among patients with SLE who were receiving a supraphysiologic dose of prednisone. The iC3b:C3 ratio outperformed C3 and C4 levels with regard to discriminating active SLE from inactive SLE, and major flares from no disease activity. The iC3:C3 ratio, anti‐dsDNA antibody levels, erythrocyte sedimentation rate, and use of a supraphysiologic prednisone dose were each independently associated with the presence of lupus nephritis, whereas none of these measures was associated with SLE rash. The association of the iC3b:C3 ratio with lupus nephritis was independent of other observed clinical manifestations.

Conclusion

The ratio of blood iC3b to serum C3 concentrations correlates with the extent of SLE disease activity and with clinically meaningful changes in disease activity in patients with SLE. Furthermore, the iC3b:C3 ratio may discriminate between active and inactive SLE, and between major flares and no active disease.

Utility of neutrophil CD64 and serum TREM-1 in distinguishing bacterial infection from disease flare in SLE and ANCA-associated vasculitis

Bacterial and opportunistic infections are a major cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis owing to treatment with immunosuppressants. Commonly used laboratory tests are unreliable in differentiating infection from active disease patients. Fc receptor (FcγR1 or CD64) expression on neutrophils and soluble TREM-1 (triggering receptor expressed on monocytes) are potential biomarkers of bacterial infections. Our aim was to measure the clinical usefulness of quantitative CD64 measurement on neutrophils and soluble TREM-1 measurements in differentiating bacterial infection from active disease in patients with SLE and ANCA vasculitis. Patients with bacterial infection (n = 25), active disease (n = 51), and healthy controls (n = 20) were included. Neutrophil CD64 expression using flow cytometry and sTREM-1 and procalcitonin levels by ELISA were studied. The percentage of neutrophils with CD64 expression and their mean fluorescence intensity in patients with infection (68.8 (56.9-86.5)%, 1037 (229-1828)) were significantly (p < 0.05) higher as compared to those without infection (7.7 (2.6-13.1)%, 456 (20-968)) and controls (7.05 (1.4-9.5)%, 99.5 (54.7-140.7)). The sensitivity and specificity of CD64 expression on neutrophils to diagnose bacterial infection (using a cutoff value of 30%) was 85% and 84%, respectively, whereas the sensitivity and specificity of procalcitonin was 75% and 85%, respectively. There was no significant difference in soluble TREM-1 levels between the two groups. Quantitative measurement of CD64 on neutrophils can distinguish between systemic infection and the flare of autoimmune diseases.

Macrophage Activation Syndrome (MAS) in a Recently Released Prisoner with Systemic Lupus Erythematosus (SLE)

Patient: Male, 38

Final Diagnosis: Systemic lupus erythematosus • macrophage activation syndrome

Symptoms: Altered mental status • diarrhea • fever • nausea • vomiting • weight loss

Medication: —

Clinical Procedure: —

Specialty: Rheumatology

Predictive value of the neutrophil-to-lymphocyte ratio and hemoglobin insystemic lupus erythematosus

The aim of the present study was to evaluate the association of the neutrophil-to-lymphocyte ratio (NLR) and hemoglobin levels with disease activity in patients with systemic lupus erythematosus (SLE) and to explore their clinical significance in predicting SLE. The present study included 212 patients with SLE and 201 healthy controls. All the clinical characteristics were collected from their medical records. The results revealed that the NLR was elevated and the hemoglobin level was markedly decreased in the patients with SLE compared with the healthy controls. NLR was positively correlated with the SLE Disease Activity Index 2000 (SLEDAI-2K), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), whereas it was not correlated with C3 or C4. The hemoglobin level was negatively correlated with SLEDAI-2K, ESR and CRP and positively correlated with C3 and C4. In addition, NLR [EXP(B)=1.986; 95% confidence interval (CI), 1.432-2.753; P=0.001] and hemoglobin [EXP(B)=0.947; 95% CI, 0.929-0.965; P=0.001] were independent predictive factors of SLE. The optimal NLR cut-off value for predicting SLE was 2.075, with 71.14% sensitivity and 69.57% specificity, whereas the optimal hemoglobin cut-off value was 131.5 mg/l, with 75.79% sensitivity and 77.98% specificity. In addition, high NLR together with low hemoglobin levels and high NLR or low hemoglobin levels had increased positive predictive values (86.05 and 66.95, respectively). High NLR with low hemoglobin levels and high NLR or low hemoglobin levels also had higher sensitivity (64.91 and 92.40, respectively) and specificity (64.91 and 18.95, respectively), compared with high NLR alone or low hemoglobin alone. In conclusion, NLR and hemoglobin may reflect SLE disease activity and may be used as markers for predicting the outcome of SLE.

Serial C-reactive protein measurements in patients treated for suspected abdominal tuberculosis

BACKGROUND

Response to treatment is often used as a criterion for the diagnosis of abdominal tuberculosis.

AIM

To determine utility of serum C reactive protein (CRP) in assessment of response to anti-tubercular therapy (ATT) in abdominal tuberculosis (ATB).

METHODS

We retrospectively analysed the database of patients with suspected ATB (intestinal and/or peritoneal). Response to ATT was assessed using subjective and objective (ulcer healing or ascites resolution) parameters. Serum CRP levels were estimated at baseline and then at 2 months and 6 months of ATT.

RESULTS

One hundred and twelve patients were included in the analysis. The mean age was 36.57 ± 15.04 years and 54.46% (61/112) were males. Sixty-six patients (58.92%) had intestinal, 28 (25%) had peritoneal and 18 (16.07%) had both. Eleven patients had a normal CRP at baseline while 101 had elevated levels. The CRP levels declined in 94 patients at 6 months. One patient with increased levels at 2 months had multi-drug resistant TB. Seven patients showed elevated or plateaued CRP levels on follow-up. These patients had underlying Crohn's disease (3 patients), peritoneal carcinomatosis (1), inter-current infection (1), lymphoma (1) and non-healing ulcers (1).

CONCLUSION

Lack of decline in CRP may suggest alternative diagnosis or drug-resistant tuberculosis.

The ratio of erythrocyte sedimentation rate to C-reactive protein is useful in distinguishing infection from flare in systemic lupus erythematosus patients presenting with fever

Background Both C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) can be elevated in systemic lupus erythematosus (SLE) flare and infection, and are therefore of limited utility for distinguishing between the two conditions in febrile SLE patients. Methods A medical records review of hospitalizations (1997-2006) of SLE patients in the Michigan Lupus Cohort was performed. Eligible hospitalizations were those in which patients presented with a temperature of >100.3°F or with subjective fevers as a presenting complaint at admission. Detailed demographic, clinical, and laboratory data were collected. Multivariable logistic regression was used to examine the associations between ESR and CRP and the outcome of flare vs infection, adjusted for confounders. Results Among 557 SLE patients screened, there were 53 eligible hospitalizations (28 flares and 25 infections). Each unit increase in the ratio of ESR:CRP was associated with a 17% increase in the odds of fever being attributable to SLE flare compared to infection (OR 1.17, 95% CI 1.04, 1.31; p = 0.009), when adjusted for white blood cell count, SLE duration, sex, race, and age. ESR and CRP were not individually associated with flare vs infection when modeled with their ratio. Conclusions The ratio of ESR:CRP may provide diagnostic value beyond individual ESR and CRP levels in distinguishing flare vs infection in SLE patients presenting with fever.

Cytokines in systemic lupus erythematosus: far beyond Th1/Th2 dualism lupus: cytokine profiles

The aims of this study were to delineate cytokine profiles of systemic lupus erythematosus (SLE), construct prediction models for diagnosis and disease activity using those profiles, and to examine the associations between TNFB Ncol polymorphism, body mass index (BMI) and vitamin D levels with cytokine levels. Two hundred SLE patients and 196 healthy controls participated in this case-control study. Plasma cytokines levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-1β, IL- 4, IL-6, IL-10, IL-12 and IL-17 were measured and cytokines profiles were computed. IL-6, IL-12, IL-17, IFN-γ and IL-10 levels were significantly higher in SLE, while IL-4 was lower in SLE. The Th1/Th2 and Th1+Th17/Th2 profiles were significantly higher in SLE than in healthy controls, whereas there were no significant differences in the proinflammatory cytokine profile (TNFα+IL-6+IL-1β). In total, 90.4% of all subjects were correctly classified using Th1+Th17 profile and IL-10 (positively associated) and IL-4 (negatively associated) as predictor variables (sensitivity=66.7% and specificity=96.9%). In all, 20.9% of the variance in the SLE Disease Activity Index was predicted by the Th1+Th17/Th2 ratio, IL-10 and BMI (all positively) and proinflammatory profile (inversely associated). B1/B1 genotype is accompanied by increased IL-17 and Th17/Th2 ratio, while B1/B2 genotype is accompanied by higher IL-4 and IFNγ values. 25-OH vitamin D was inversely associated with IFN-γ levels. SLE is accompanied by Th1, Th17 and Treg profile and lowered IL-4 production. Lowered vitamin D levels and B1/B1 genotype, but not BMI, contribute to changes in cytokines profiles. Future treatments should target Th1, Th2 and Th17 profiles rather than inflammatory cytokines.

Laboratory evaluation in rheumatic diseases

Autoantibodies can help clinicians to allow early detection of autoimmune diseases and their clinical manifestations, to determine effective monitoring of prognosis and the treatment response. From this point, they have a high impact in rheumatic disease management. When used carefully they allow rapid diagnosis and appropriate treatment. However, as they may be present in healthy population they may cause confusion for interpreting the situation. False positive test results may lead to wrong treatment and unnecessary anxiety for patients. Autoantibody positivity alone does not make a diagnosis. Similarly, the absence of autoantibodies alone does not exclude diagnosis. The success of the test is closely related to sensitivity, specificity and likelihood ratios. So, interpretation of these is very important for a proper laboratory evaluation. In conclusion, in spite of the remarkable advances in science and technology, a deeply investigated anamnesis and comprehensive physical examination still continue to be the best diagnostic method. The most correct approach is that clinicians apply laboratory tests to confirm or exclude preliminary diagnosis based on anamnesis and physical examination. This review will discuss these issues.

Negative Correlation Between miR-326 and Ets-1 in Regulatory T Cells from new-Onset SLE Patients

To analyze the relationship between miR-326 and Ets-1 mRNA levels in Treg cells and clinical manifestations in patients with SLE and explore the role of miR-326 and Ets-1 in the pathogenesis and activity of SLE. Twenty-five new-onset SLE patients without treatment, twenty-eight inactive SLE patients (SLEDA ≤ 4) and twenty-two healthy controls were included in the present study. Clinical data of SLE patients were recorded. Treg cells were purified by MACS from 20 ml peripheral blood, in which the quantity of miR-326 and Ets-1 mRNA were assessed by real-time PCR. Data were analyzed using SPSS Version 17.0. The nonparametric Mann-Whitney U test was used to compare the groups, The Spearman test was used for correlation analyses. Two-tailed p values <0.05 were considered statistically significant. 1.The level of miR-326 was significantly higher in Treg cells from SLE patients [1.98(0.592,6.148)] than that in healthy controls [0.921(0.345, 1.879)] (p = 0.032). The difference between new-onset SLE patients [6.192(0.673, 15.298)] and healthy controls was significant (p = 0.019). Significant difference of the miR-326 expression was found between new-onset SLE patients with serous cavity effusion and new-onset SLE patients without it(P<0.05). Significant positive correlation was found between the expression of miR-326 mRNA in Treg cells with CRP and anti-C1q antibody from new-onset SLE patients. 2. The level of Ets-1 mRNA was decreased in SLE patients [0.382(0.232, 0.572)] compared to healthy controls(p = 0.013). The difference was also found in new-onset SLE patients [0.222(0.125, 0.296)] while compared to healthy controls. Also, the level in new-onset SLE patients was lower than that in inactive SLE patients [0.482(0.398, 0.512)] (p = 0.001). 3. Negative correlation was found between miR-326 and Ets-1 mRNA expression in Treg cells from new-onset SLE patients (r = -0.583 p = 0.01). 4. There was no correlation of miR-326 or Ets-1 mRNA expression with SLEDAI. The increase of miR-326 expression in Treg cells from SLE patients may inhibit the expression of Ets-1 to participate in the pathological process of SLE.

Drug utilization and therapy provision patterns by prescriber types among patients with systemic lupus erythematosus in Korea

BACKGROUND

Systemic lupus erythematosus (SLE) poses a growing challenge for healthcare systems, affecting an increasing number of people in Korea. This study aimed to investigate the prescribing patterns of SLE therapies and to compare common drug regimens prescribed by provider types.

METHODS

Sampled national health insurance claims data in 2015 were used to select eligible SLE patients. Frequency analyses were carried out regarding patient characteristics related to relevant SLE prescriptions. Patient-days were calculated per substance and per drug class and then categorized by provider types. Differences in drug utilization trends among the main types of providers were examined with the chi-square test.

RESULTS

A total of 2,074 patients with SLE were selected for study inclusion. Systemic corticosteroid therapy was provided for up to 67.9% of patients, frequently in conjunction with other SLE therapies. About 33.2% and 18.7% of steroid users were treated for more than 150 days and 300 days during the study period, respectively. The provider group that most frequently prescribed systemic corticosteroids was dermatologists. Hydroxychloroquine, an antimalarial considered pivotal to SLE management, was prescribed for only 32.4% of patients, predominantly by rheumatologists. Antimalarial therapy was associated with the longest therapy duration (257.7±120.1 days), followed by immunosuppressant therapy (187.0±153.0 days). Prescription rates of antimalarials and immunosuppressants were substantially lower in primary care doctor group and particularly in dermatologist group, compared to rheumatologist group (P-value associated with prescription patterns by provider types was <0.001 for both drug classes).

CONCLUSION

The drug utilization patterns among the main provider groups commonly providing care for SLE patients differed significantly depending on their practice areas. The prescription rates of corticosteroids were disproportionately higher among dermatologists. Rheumatologists appeared more cognizant of the importance of providing antimalarial therapy for SLE patients compared to other types of providers.

Serum biomarkers of inflammation and muscle strength among women with systemic lupus erythematosus

OBJECTIVES

Muscle strength is an important determinant of physical function in women with systemic lupus erythematosus (SLE). Serum biomarkers of inflammation, including interleukin-6 (IL-6) and C-Reactive Protein (CRP), are associated with differences in muscle strength among individuals without rheumatologic disease. We examined whether serum levels of IL-6 and CRP are associated with upper and lower extremity muscle strength among adult women with SLE.

METHODS

One hundred thirty-six women with SLE participated in this cross-sectional study. High-sensitivity CRP was analyzed by nephelometry. IL-6 serum levels were analyzed by high sensitivity enzyme-linked immunosorbent assay. Upper and lower extremity muscle strength were assessed by grip strength and peak torque of knee extension and flexion, respectively. Regression analyses modeled associations of CRP and IL-6 with upper and lower extremity muscle strength controlling for age, SLE duration, physical activity, prednisone use, BMI, plaquenil use, and pain.

RESULTS

Higher serum levels of IL-6 and CRP were associated with significantly weaker upper and lower extremity muscle strength even when controlling for covariates.

CONCLUSIONS

Increased serum IL-6 and CRP are associated with clinically significant differences in upper and lower extremity muscle strength and may be useful in identifying those at risk for weakness and decreased physical function.

Is there still a place for erythrocyte sedimentation rate and C-reactive protein in systemic lupus erythematosus?

The inflammatory response during systemic lupus erythematosus (SLE) flares is known to be atypical, characterized by a disproportionately lower C-reactive protein (CRP) elevation when compared with erythrocyte sedimentation rate (ESR). Thus, in these patients, the analysis of inflammatory markers might be challenging in daily clinical practice. Clinicians need frequently to distinguish lupus reactivations and infectious conditions, and the significance of ESR and CRP seems to be different. Even though a non-specific marker of inflammation, ESR utility in SLE should not be neglected and it appears to be a useful biomarker for SLE activity assessment. Describing a specific cut-off for ESR in SLE is important for patients' follow-up, and levels up to 25-30 mm/h have been proposed as an upper limit of the normal range. Regarding CRP, even though higher baseline levels are described in SLE when compared with controls, including in remission periods, its response during flares seems to be incomplete and not always correlated with disease activity; while CRP values greater than 10 mg/l could be indicative for severe flares, when there is no serositis or arthritis, higher CRP levels above 50-60 mg/l may be associated with infection.

Breakdown of Immune Tolerance in Systemic Lupus Erythematosus by Dendritic Cells

Dendritic cells (DC) play an important role in the pathogenesis of systemic lupus erythematosus (SLE), an autoimmune disease with multiple tissue manifestations. In this review, we summarize recent studies on the roles of conventional DC and plasmacytoid DC in the development of both murine lupus and human SLE. In the past decade, studies using selective DC depletions have demonstrated critical roles of DC in lupus progression. Comprehensive in vitro and in vivo studies suggest activation of DC by self-antigens in lupus pathogenesis, followed by breakdown of immune tolerance to self. Potential treatment strategies targeting DC have been developed. However, many questions remain regarding the mechanisms by which DC modulate lupus pathogenesis that require further investigations.

Autoantibodies to C-reactive protein in incomplete lupus and systemic lupus erythematosus

OBJECTIVE

Anti-C-reactive protein (CRP) antibodies have been described in patients with systemic lupus erythematosus (SLE). We investigated the potential of the anti-CRP antibody as a marker for disease activity in SLE patients and as a predictor of progression to SLE in patients with incomplete lupus.

METHODS

Immunoglobulin G anti-CRP antibody levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Patients with incomplete lupus exhibited clinical and immunologic characteristics different from those in SLE patients: no serositis and alopecia, more common oral ulcers and arthritis, lower disease activity index, lower positivity for antinuclear and anti-double-strand DNA antibodies, and higher complement levels. Anti-CRP antibody levels were higher in SLE patients (35.6 [35.1] AU) than in patients with incomplete lupus (23.1 [25.8] AU, P = 0.016) and normal controls (21.0 [14.3] AU, P < 0.001). Anti-CRP antibody was significantly higher in SLE patients with arthritis and correlated with disease activity markers, including antichromatin antibody. However, no difference in anti-CRP antibody levels was observed between patients with incomplete lupus that progressed to SLE and those whose did not.

CONCLUSION

These data suggest that anti-CRP antibodies can neither be used as biomarkers in SLE nor predict SLE progression in patients with incomplete lupus.

Association between serum total antioxidant status and flow-mediated dilation in patients with systemic lupus erythematosus: an observational study

Objective:

Endothelial dysfunction (ED) is a condition that involves increased oxidative stress and decreased total antioxidant status (TAS) levels. Systemic lupus erythematosus (SLE) is also associated with ED. We aimed to determine the association between serum TAS and ED as assessed by flow-mediated dilation (FMD) in patients with SLE.

Methods:

Thirty-four patients with stable SLE who were not undergoing any treatment and 39 healthy volunteers without any overt cardiovascular disease were included in this cross-sectional study. Doppler ultrasound was used to measure FMD to assess ED in the study groups. Serum TAS levels were measured using a TAS kit. High-sensitivity C-reactive protein (hs-CRP) and anticardiolipin antibody (aCLA) levels were also measured to assess the inflammatory state. The SLE group further was divided into 2 groups according to presence or absence of aCLA. SLE disease activity was assessed using the SLE disease activity index (SLEDAI). Regression analysis was used to define independent predictors.

Results:

The mean TAS levels were significantly lower in patients with SLE than in controls (1.60±0.11 versus 1.73±0.15 mmol/L, p<0.001). hs-CRP levels were significantly higher in patients with SLE than in controls (8.2±6.0 vs. 2.9±4.0 mg/L; p<0.001), particularly in SLE patients with positive aCLA when compared with SLE patients with negative aCLA (13.8±4.3 vs. 5.6±4.8 mg/L, p<0.001). The FMD percent was significantly lower in patients with SLE than in controls (8.1±4.9 vs. 10.6±4.7, p=0.04). There was a significant positive correlation between FMD and TAS in the SLE group (r=0.448, p=0.008) and the control group (r=0.367, p=0.03) and a significant negative correlation between FMD and serum hs-CRP (r=-0.368, p=0.04) in only the SLE group. In multiple linear regression analysis, TAS, hs-CRP and SLEDAI were independently correlated with FMD (ß=0.50, p=0.003; ß=-0.33, p=0.03; and ß=-0.36, p=0.03; respectively).

Conclusion:

Patients with SLE who have no overt cardiovascular disease are at increased risk for ED and this may be associated with underlying inflammation and impairment of TAS.

Ficolins and the lectin pathway of complement in patients with systemic lupus erythematosus

The complement system plays a pathophysiological role in systemic lupus erythematosus (SLE). This study aims to investigate whether an association exists between the ficolins that are part of the lectin complement pathway and SLE. EDTA plasma samples from 68 Danish SLE patients and 29 healthy donors were included in the study. Plasma concentrations of Ficolin-1, -2, and -3 were determined in specific sandwich ELISAs. Lectin pathway activity via Ficolin-3 was measured in ELISA on acetylated bovine serum albumin (acBSA) and measured as Ficolin-3 binding and deposition of C4, C3 and the terminal complement complex (TCC). SLE patients had increased levels of Ficolin-3, 21.6μg/ml as compared to 17.0μg/ml in healthy controls (P=0.0098). The Ficolin-1 plasma concentration was negatively correlated with SLE Disease Activity Index (SLEDAI) (Rho=-0.29, P=0.015) and positively correlated to the [Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index] (SDI) (Rho=0.27, P=0.026). The Ficolin-1 concentration was also associated with the occurrence of arterial (P=0.0053) but not venous thrombosis (P=0.42). Finally, deposition of C4, C3 and TCC in the Ficolin-3 pathway were all correlated to SLEDAI, respectively (P<0.0076). The Ficolin-1 association to SLEDAI and SDI as well as arterial thrombosis shown in this study suggests that Ficolin-1 may be a potential new biomarker for patients with SLE. Furthermore, Ficolin-3 mediated complement activation may be valuable in monitoring disease activity in SLE patients due to the high sensitivity for complement consumption in the assay independent of the Ficolin-3 concentration.

Association between mean platelet volume levels and inflammation in SLE patients presented with arthritis

BACKGROUND

Systemic lupus erythematosus (SLE) may be characterized by periods of remissions and chronic or acute relapses. The complexity of clinical presentation of the SLE patients leads to incorrect evaluation of disease activity. Mean platelet volume (MPV) has been studied as a simple inflammatory marker in several diseases. There is no study in the literature about MPV levels in adult SLE patients with arthritis.

OBJECTIVES

We aimed to investigate the MPV levels in the SLE population with arthritis during and between activations.

METHODS

The study consisted of 44 SLE patients with arthritis in activation period (Group 1), the same 44 SLE patients with arthritis in remission period (Group 2) and 44 healthy controls (Group 3). Erythrocyte sedimentation rate (ESR), creactive protein (CRP), white blood cell count, platelet count, and mean platelet volume (MPV) levels were retrospectively recorded from patient files.

RESULTS

The mean ages of the SLE subjects were 42 ± 16 years, while the mean ages of controls was 41 ± 17 years. MPV was significantly lower in Group 1(7.66±0.89fL) than in Group 2 (8.61±1.06 fL) and Group 3(8.62±1.11fL) (p<0.0001). The differences between groups reached statistical significance.

CONCLUSIONS

We suggest that MPV levels decrease in patients with arthritis of SLE activation when compared to the same patients in remission and healthy controls.

Characteristics of pleural effusions in systemic lupus erythematosus: differential diagnosis of lupus pleuritis

We investigated the clinical characteristics of pleural effusion in systemic lupus erythematosus (SLE). A prospective analysis of 17 SLE patients with pleural effusion (seven lupus pleuritis, eight transudative effusions and two parapneumonic effusions) was performed. Thirty non-SLE patients with pleural effusion were recruited as controls. A pleural fluid ANA titer ≥1:160 was found in 8/17 (47.1%) SLE patients and none of the 30 non-SLE patients (p = 0.0001). Pleural fluid to serum C3 ratios were significantly lower in SLE than in non-SLE (median (minimum-maximum) 0.29 (0.03-0.43) versus 0.52 (0.26-0.73), p = 0.0002). Among SLE patients, pleural fluid ANA titers ≥1:160 were more frequently found in patients with lupus pleuritis than in those with pleural effusion from causes other than lupus itself (85.7% versus 20.0%, p = 0.0152). Serum CRP levels were significantly increased in patients with lupus pleuritis compared with SLE patients with transudative pleural effusion (2.30 (0.30-5.66) versus 0.7 (0.12-1.47) mg/dl, p = 0.0062). In conclusion, pleural fluid ANA titer and serum CRP levels are significantly increased in lupus pleuritis.

Erythrocyte sedimentation rate and C-reactive protein: how best to use them in clinical practice

Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are markers of inflammatory conditions and have been used extensively by clinicians both in outpatient and inpatient settings. It is important to understand the physiologic principles behind these two tests so clinicians may use them appropriately. For example, fibrinogen (for which ESR is an indirect measure) has a much longer half-life than CRP, making ESR helpful in monitoring chronic inflammatory conditions, whereas CRP is more useful in diagnosis as well as in monitoring responses to therapy in acute inflammatory conditions, such as acute infections. Many factors can result in falsely high or low ESR and CRP levels, and it is important to take note of these. Therefore, if used wisely, ESR and CRP can be complementary to good history taking and physical examination in the diagnosis and monitoring of inflammatory conditions.

Recognition functions of pentameric C-reactive protein in cardiovascular disease

C-reactive protein (CRP) performs two recognition functions that are relevant to cardiovascular disease. First, in its native pentameric conformation, CRP recognizes molecules and cells with exposed phosphocholine (PCh) groups, such as microbial pathogens and damaged cells. PCh-containing ligand-bound CRP activates the complement system to destroy the ligand. Thus, the PCh-binding function of CRP is defensive if it occurs on foreign pathogens because it results in the killing of the pathogen via complement activation. On the other hand, the PCh-binding function of CRP is detrimental if it occurs on injured host cells because it causes more damage to the tissue via complement activation; this is how CRP worsens acute myocardial infarction and ischemia/reperfusion injury. Second, in its nonnative pentameric conformation, CRP also recognizes atherogenic low-density lipoprotein (LDL). Recent data suggest that the LDL-binding function of CRP is beneficial because it prevents formation of macrophage foam cells, attenuates inflammatory effects of LDL, inhibits LDL oxidation, and reduces proatherogenic effects of macrophages, raising the possibility that nonnative CRP may show atheroprotective effects in experimental animals. In conclusion, temporarily inhibiting the PCh-binding function of CRP along with facilitating localized presence of nonnative pentameric CRP could be a promising approach to treat atherosclerosis and myocardial infarction. There is no need to stop the biosynthesis of CRP.

C-reactive protein and the biology of disease

The C-reactive protein (CRP) is a plasma protein of hepatic origin, belonging to pentraxin family and forms a major component of any inflammatory reaction. A key component of the innate immunity pathway, the concentration of CRP may rapidly increase to levels more than 1,000-folds above normal values as a consequence to tissue injury or infection. Although functioning as a classical mediator of innate immunity, it functions via interaction of components of both humoral and cellular effector systems of inflammation. Initially considered as an acute-phase marker in tissue injury, infection and inflammation, it now has a distinct status of a disease marker in cardiovascular diseases and is well known of its clinical and pathological significance. The present torrent of studies in a large number of diseases and associated conditions has highly elucidated the role of CRP as a therapeutic and research reagent. In this review, we focus our attention to role of CRP in health and disease. The future prospect of this review lies in the applicability of CRP as a molecule in understanding and monitoring of the biology of disease.

Soluble urokinase plasminogen activator receptor levels reflect organ damage in systemic lupus erythematosus

Assessments of disease activity and organ damage in systemic lupus erythematosus (SLE) remain challenging because of the lack of reliable biomarkers and disease heterogeneity. Ongoing inflammation can be difficult to distinguish from permanent organ damage caused by previous flare-ups or medication side effects. Circulating soluble urokinase plasminogen activator receptor (suPAR) has emerged as a potential marker of inflammation and disease severity, and an outcome predictor in several disparate conditions. This study was done to evaluate suPAR as a marker of disease activity and organ damage in SLE. Sera from 100 healthy donors and 198 patients with SLE fulfilling the 1982 American College of Rheumatology classification criteria and/or the Fries criteria were analyzed for suPAR by enzyme immunoassay. Eighteen patients with varying degree of disease activity were monitored longitudinally. Disease activity was assessed by the SLE disease activity index 2000 and the physician's global assessment. Organ damage was evaluated by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). Compared with healthy control subjects, serum suPAR levels were elevated significantly in patients with SLE. No association was recorded regarding suPAR levels and SLE disease activity in cross-sectional or consecutive samples. However, a strong association was observed between suPAR and SDI (P < 0.0005). Considering distinct SDI domains, renal, neuropsychiatric, ocular, skin, and peripheral vascular damage had a significant effect on suPAR levels. This study is the first to demonstrate an association between serum suPAR and irreversible organ damage in SLE. Further studies are warranted to evaluate suPAR and other biomarkers as predictors of evolving organ damage.