New Inflammatory Marker Associated with Disease Activity in Rheumatoid Arthritis: The Systemic Immune-Inflammation Index

Association of the systemic immune-inflammation index with all-cause and cardiovascular mortality in individuals with rheumatoid arthritis

The systemic immune-inflammation index (SII), a metric reflecting systemic inflammatory response and immune activation, remains underexplored concerning its correlation with mortality among rheumatoid arthritis (RA) patients. This study aimed to delineate the association between SII and both all-cause and cardiovascular mortality within the cohort of American adults diagnosed with RA, utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999 to 2018. The investigation extracted data from NHANES cycles between 1999 and 2018, identifying RA patients through questionnaire responses. The SII was computed based on complete blood counts, employing the formula: (platelets × neutrophils) / lymphocytes. The optimal SII cutoff value for significant survival outcomes was determined using maximally selected rank statistics. Multivariable Cox proportional hazards models assessed the relationship between SII levels and mortality (all-cause and cardiovascular) among RA patients, with subgroup analyses examining potential modifications by clinical confounders. Additionally, restricted cubic spline (RCS) analyses were conducted to explore the linearity of the SII-mortality association. The study encompassed 2070 American adults with RA, among whom 287 exhibited a higher SII (≥ 919.75) and 1783 a lower SII (< 919.75). Over a median follow-up duration of 108 months, 602 participants died. After adjustments for demographic, socioeconomic, and lifestyle variables, a higher SII was associated with a 1.48-fold increased risk of all-cause mortality (hazard ratio [HR] = 1.48, 95% confidence interval [CI] 1.21-1.81, P < 0.001) and a 1.51-fold increased risk of cardiovascular mortality (HR = 1.51, 95% CI 1.04-2.18, P = 0.030) compared to a lower SII. Kaplan-Meier analyses corroborated significantly reduced survival rates within the higher SII cohort for both all-cause and cardiovascular mortality (Pall-cause mortality < 0.0001 and Pcardiovascular mortality = 0.0004). RCS analyses confirmed a positive nonlinear relationship between SII and mortality rates. In conclusion, the SII offers a straightforward indicator of the equilibrium between detrimental innate inflammation and beneficial adaptive immunity. Our investigation, utilizing a comprehensive and nationally representative sample, reveals that elevated SII levels independently forecast a greater risk of mortality from all causes, as well as cardiovascular-specific mortality, in individuals suffering from RA. These insights underscore the clinical relevance of the SII as an affordable and readily accessible biomarker. Its incorporation into regular clinical practice could significantly enhance the precision of risk assessment and forecasting for patients with RA, facilitating more tailored and effective management strategies. Specifically, patients with high SII levels could be identified for more stringent cardiovascular risk management, including closer monitoring, lifestyle interventions, and aggressive pharmacological treatments to mitigate their increased risk of mortality.

Association of dietary inflammatory index with immune-inflammatory biomarkers in rheumatoid arthritis patients: results from NHANES 1999-2018

Background

Synovial inflammation is the main reason for joint damage in patients with rheumatoid arthritis (RA). Diet is recognized as one of the therapeutic strategies to control the inflammatory activity in RA. However, few studies have investigated the association between diet and immune-inflammatory biomarkers in RA patients. Our study aims to examine the correlation between dietary inflammatory potential and systemic immune-inflammation Index (SII), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR) in the RA population.

Materials and methods

The National Health and Nutrition Examination Survey (NHANES) was the data source utilized in this study, spanning from 1999 to 2018. The study encompassed 2,500 RA participants in total. The dietary inflammatory potential was calculated by the dietary inflammation index (DII) score based on dietary recall interviews. The generalized multiple linear regression analyses were used to evaluate the relationship between DII and immune-inflammatory markers. Furthermore, subgroup analyses and restricted cubic spline models were performed.

Results

After full adjustments, there were significant positive correlations between DII levels and SII/NLR in RA patients (SII, β: 14.82, 95% CI: 5.14-24.50, p = 0.003; NLR, β: 0.04, 95% CI: 0.01-0.08, p = 0.005). It was noteworthy that inconsistent results were observed in the association between DII and SII as well as NLR in subgroups of red blood cell levels (Interaction p-value <0.001).

Conclusion

Pro-inflammatory dietary status in the RA population is significantly positively correlated with SII and NLR, influenced by variations in red blood cell levels.

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.

The relationship between disease activity with pan-immune-inflammatory value and systemic immune-inflammation index in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disease. Immune system cells have an important role in RA. Our aim was to investigate the relationship between disease activity, systemic immune-inflammation index (SII), and pan-immune-inflammation value (PIV) levels in RA patients. We planned to investigate whether these 2 measurements have an advantage over each other. About 67 patients diagnosed with RA and 49 healthy controls included in this study. RA was diagnosed based on 2010 ACR classification criteria. In this cross-sectional study, peripheral blood tests, C-reactive protein (CRP), hemogram, and erythrocyte sedimentation rate levels were noted after the physical examination of all participants. PIV was calculated with the formula: (neutrophil count × platelet count × monocyte count) / lymphocyte count. SII was calculated as follows: (neutrophil count × monocytes count) / lymphocyte count. The disease activity score 28 (DAS28) were noted in patients with RA. CRP values of active RA group were significantly higher than remission RA and control groups (P < .001), control and remission RA groups were similar (P = .86). PIV and SII are significantly higher in active RA than remission RA and control (P < .001, P < .001) higher in remission RA than control (P < .001, P < .001). Receiver operating characteristic curve analysis in predicting remission compared to the control group, CRP was not significant, PIV and SII was significant and PIV has higher sensitivity and sensitivity, a PIV value of > 217.31 have sensitivity 75.0% and specificity 85.7%. CRP, PIV, and SII are statistically significant in predicting active RA compared to the remission RA and control group. Our findings show that PIV, and SII are easy, inexpensive and reliable markers predicting remission in RA patients. CRP was not significant compared to remission RA and control group, PIV and SII was significant and PIV has higher sensitivity and specificity than SII in the remission group in RA. Patients with high disease activity, PIV, SII, and CRP levels were effective in showing disease activity compared to RA remission group and healthy controls.

Associations of perchlorate, nitrate, and thiocyanate exposure with arthritis and inflammation indicators in young and middle-aged adults, NHANES 2005-2016

Background

Perchlorates, nitrates, and thiocyanates are prevalent environmental chemicals. Their potential association with arthritis remains unexplored. This study aimed to investigate the link between perchlorate, nitrate, and thiocyanate exposure and arthritis, as well as the potential role of inflammation in this context.

Methods

Utilizing the National Health and Nutrition Examination Survey (NHANES) data spanning from 2005 to 2016, the study enrolled 6597 participants aged 20-59 (young and middle-aged), of which 1045 had arthritis. Employing multivariate logistic regression modeling, multiple linear regression models, restricted cubic spline analysis, Bayesian kernel machine regression (BKMR) modeling, and mediation analysis, we assessed these relationships.

Results

There was a significant positive association between elevated urinary thiocyanate levels and arthritis risk [1.19 (1.11, 1.28)]. This association held true across subgroups of osteoarthritis (OA) [1.24 (1.10, 1.40)] and rheumatoid arthritis (RA) [1.33 (1.15, 1.55)]. Thiocyanate levels displayed a dose-dependent relationship with arthritis risk, showing a linear trend (nonlinear P > 0.05). Conversely, perchlorate and nitrate did not exhibit associations with arthritis risk. BKMR outcomes highlighted a positive correlation between a mixture of perchlorate, nitrate, and thiocyanate and arthritis risk, with thiocyanate being the predominant predictors. Moreover, BKMR and generalized linear model analyses unveiled no significant synergistic effect of urinary perchlorate, nitrate, and thiocyanate on arthritis risk. Furthermore, thiocyanate exposure has been linked to elevated levels of inflammatory indicators (white blood cell, neutrophils, lymphocytes, and systemic immune-inflammatory index (SII)).

Conclusion

Heightened thiocyanate exposure may be linked to elevated arthritis risk, either single or in combined effects. Additionally, thiocyanate exposure is associated with heightened inflammation levels.

The diagnostic role of the systemic inflammation index in patients with immunological diseases: a systematic review and meta-analysis

The identification of novel, easily measurable biomarkers of inflammation might enhance the diagnosis and management of immunological diseases (IDs). We conducted a systematic review and meta-analysis to investigate an emerging biomarker derived from the full blood count, the systemic inflammation index (SII), in patients with IDs and healthy controls. We searched Scopus, PubMed, and Web of Science from inception to 12 December 2023 for relevant articles and evaluated the risk of bias and the certainty of evidence using the Joanna Briggs Checklist and the Grades of Recommendation, Assessment, Development, and Evaluation Working Group system, respectively. In 16 eligible studies, patients with IDs had a significantly higher SII when compared to controls (standard mean difference, SMD = 1.08, 95% CI 0.75 to 1.41, p < 0.001; I2 = 96.2%, p < 0.001; moderate certainty of evidence). The pooled area under the curve (AUC) for diagnostic accuracy was 0.85 (95% CI 0.82-0.88). In subgroup analysis, the effect size was significant across different types of ID, barring systemic lupus erythematosus (p = 0.20). In further analyses, the SII was significantly higher in ID patients with active disease vs. those in remission (SMD = 0.81, 95% CI 0.34-1.27, p < 0.001; I2 = 93.6%, p < 0.001; moderate certainty of evidence). The pooled AUC was 0.74 (95% CI 0.70-0.78). Our study suggests that the SII can effectively discriminate between subjects with and without IDs and between ID patients with and without active disease. Prospective studies are warranted to determine whether the SII can enhance the diagnosis of IDs in routine practice. (PROSPERO registration number: CRD42023493142).

Evaluation of systemic immune-inflammatory index in patients with wet age-related macular degeneration

CLINICAL RELEVANCE

The systemic immune-inflammatory index is a relatively new parameter and has been shown to increase in inflammatory diseases.

BACKGROUND

The primary aim of this study was to investigate the systemic immune-inflammatory index in patients with wet-type age-related macular degeneration. The secondary aim was to determine the relationship between best-corrected visual acuity, central macular thickness, subfoveal choroidal thickness, systemic immune-inflammatory index, platelet-to-lymphocyte ratio, and neutrophil-to-lymphocyte ratio.

METHODS

This study retrospectively analysed patients with wet-type age-related macular degeneration between 2018 and 2022. Demographic data and peripheral complete blood count were obtained from the electronic medical record system. The most recent best-corrected visual acuity, central macular thickness, and subfoveal choroidal thickness values (within one month) for complete blood count were obtained from case sheets and the optical coherence tomography digital image database. The systemic immune-inflammatory index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio were calculated. Age- and sex-matched controls were also generated.

RESULTS

Thirty-three patients (23 males, 10 females) with wet-type age-related macular degeneration and 43 controls (24 males, 19 females) were included. The groups were similar in terms of age and sex (78.0 ± 6.3 vs. 75.6 ± 6.6 years, p = 0.59; p = 0.38 for sex). The systemic immune-inflammatory index was higher in the wet-type age-related macular degeneration group (460.5 vs. 440.4); however, this difference was not statistically significant. When the correlations between the systemic immune-inflammatory index, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, best-corrected visual acuity (logMAR), central macular thickness, and subfoveal choroidal thickness were examined, there was only a moderate positive correlation between best-corrected visual acuity and platelet-to-lymphocyte ratio (r = 0.46, p = 0.007).

CONCLUSION

There were no differences in the systemic immune-inflammatory index, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio between the wet-type age-related macular degeneration and control groups. There was a positive correlation between the platelet-to-lymphocyte ratio and best-corrected visual acuity (logMAR). The systemic immune-inflammatory index was higher in patients with wet-type age-related macular degeneration than in the control group; however, this difference was not statistically significant.

Relationship of Complete Blood Count Derived Biomarkers With Methotrexate Resistance

Background Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation and joint damage. Among the therapeutic agents, methotrexate remains a cornerstone of initial treatment. Complete blood count (CBC)-derived biomarkers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammation index (SII), and systemic immune response index (SIRI) have been extensively studied in various diseases. Still, their specific role in RA patients undergoing methotrexate treatment has not been investigated. Objective This study aimed to investigate the relationship of CBC-derived biomarkers with methotrexate resistance in newly diagnosed rheumatoid arthritis patients. Methods We performed a comprehensive analysis of 54 RA patients, divided into methotrexate-resistant (MTXR) and methotrexate-sensitive (MTXS) groups. Analysis of variance (ANOVA) was used to assess differences in hematological biomarkers between groups. Standard t-tests were used to compare specific biomarkers between the MTXR and MTXS groups. The chi-squared test was used to compare categorical variables between groups. Pearson's correlation test was also used to examine correlations between these biomarkers and Disease Activity Score 28 (DAS28) in both groups. Receiver operating characteristic (ROC) curve analysis was performed for each biomarker to determine predictive ability. Results A statistically increased PLR ratio was observed in the MTXR group compared to the MTXS group. Significant correlations between DAS28 and NLR, PLR, SII, and SIRI were observed in the MTXR group. In contrast, these correlations were absent in the MTXS group. In addition to PLR, DAS28 and ESR were significantly higher in the MTXR group than in the MTXS group. None of these biomarkers showed prognostic value for methotrexate treatment outcomes. Conclusion PLR could be used as a biomarker for resistance to methotrexate treatment in a specific RA patient population. Increased PLR and ESR, together with higher DAS28, might be associated with a more pronounced inflammatory state in MTXR patients.

Is the C-reactive protein-to-albumin ratio the most remarkable simple inflammatory marker showing active disease in patients with axial spondyloarthritis, psoriatic arthritis, and rheumatoid arthritis?

OBJECTIVE

To learn which of the simple inflammation markers obtained from routine laboratory tests showed active disease best.

METHODS

The study included 256 patients (102 patients with axial spondyloarthritis [axSpA], 54 with psoriatic arthritis [PsA], and 100 with rheumatoid arthritis [RA]). The results of the routine laboratory tests requested during the outpatient clinic visits of the patients were noted. Inflammation-related ratio/indices were then calculated from these laboratory tests. Active and inactive diseases were defined according to the disease activity scores for each disease. Logistic regression and receiver operating characteristic (ROC) analyses were performed to determine the best laboratory marker(s) showing active disease and its cutoff value for all three diseases.

RESULTS

C-reactive protein to albumin ratio (CAR) was significantly higher in patients with active axSpA, PsA, and RA diseases than those with inactive diseases (p < 0.001, p = 0.006, and p < 0.001, respectively). In the logistic regression analysis, the CAR was the most important predictor of active disease in patients with axSpA, PsA, and RA. CAR had also showed the active disease at an acceptable level in axSpA and PsA and very well in RA. The cutoff values for active disease in axSpA, PsA, and RA were 0.75, 0.92, and 0.89, respectively.

CONCLUSION

CAR may be a promising simple laboratory marker to distinguish active disease in patients with axSpA, PsA, and RA. Key Points • Acute phase reactants and circulating blood cells have become an important target because of the search for a disease activity marker that can be used cheaply and quickly in the daily outpatient routine. • One or more of these simple markers have been previously discussed in various studies with different hypotheses. • We aimed to determine which of the inflammation markers obtained from routine laboratory tests showed active disease and to determine a cutoff value for this/these marker(s). • CAR was the most important simple laboratory marker to distinguish active disease in patients with axSpA, PsA, and RA. In addition, CAR showed the active disease at an acceptable level in axSpA and PsA, and very well in RA.

Anti-citrullinated protein antibodies as biomarkers in rheumatoid arthritis

INTRODUCTION

The serological biomarker anti-citrullinated protein antibodies (ACPAs) may have several functions but is especially important for the diagnosis of rheumatoid arthritis (RA) along with clinical symptoms.

AREAS COVERED

This review provides an overview of ACPAs, which are useful in RA diagnostics and may improve our understanding of disease etiology. PubMed was searched with combinations of words related to antibodies recognizing epitopes containing the post-translationally modified amino acid citrulline in combination with rheumatoid arthritis; cyclic citrullinated peptide, CCP, anti-CCP, anti-citrullinated protein antibodies, ACPA, citrullination, peptide/protein arginine deiminase, PAD, filaggrin, vimentin, keratin, collagen, perinuclear factor, EBNA1, EBNA2, and others. From this search, we made a qualitative extract of publications relevant to the discovery, characterization, and clinical use of these antibodies in relation to RA. We highlight significant findings and identify areas for improvement.

EXPERT OPINION

ACPAs have high diagnostic sensitivity and specificity for RA and recognize citrullinated epitopes from several proteins. The best-performing single epitope originates from Epstein-Barr Virus nuclear antigen 2 and contains a central Cit-Gly motif, which is recognized by ACPAS when located in a flexible peptide structure. In addition, ACPAs may also have prognostic value, especially in relation to early treatment, although ACPAs' main function is to aid in the diagnosis of RA.

The association between systemic immune-inflammation index and rheumatoid arthritis: evidence from NHANES 1999-2018

PURPOSE

We aimed to explore the relationship between the systemic immune-inflammation index (SII) and rheumatoid arthritis (RA) using NHANES from 1999 to 2018.

METHODS

We collected data from the NHANES database from 1999 to 2018. The SII is calculated from the counts of lymphocytes (LC), neutrophils (NC), and platelets (PC). The RA patients were derived from questionnaire data. We used weighted multivariate regression analysis and subgroup analysis to explore the relationship between SII and RA. Furthermore, the restricted cubic splines were used to explore the non-linear relationships.

RESULT

Our study included a total of 37,604 patients, of which 2642 (7.03%) had rheumatoid arthritis. After adjusting for all covariates, the multivariate logistic regression analysis showed that high SII (In-transform) levels were associated with an increased likelihood of rheumatoid arthritis (OR=1.167, 95% CI=1.025-1.328, P=0.020). The interaction test revealed no significant effect on this connection. In the restricted cubic spline regression model, the relationship between ln-SII and RA was non-linear. The cutoff value of SII for RA was 578.25. The risk of rheumatoid arthritis increases rapidly when SII exceeds the cutoff value.

CONCLUSION

In general, there is a positive correlation between SII and rheumatoid arthritis. Our study shows that SII is a novel, valuable, and convenient inflammatory marker that can be used to predict the risk of rheumatoid arthritis in US adults.