Systemic immune-inflammation index is associated with white matter hyperintensity volume

Association between the systemic immune-inflammation index and GnRH antagonist protocol IVF outcomes: a cohort study

RESEARCH QUESTION

What is the relationship between the systemic immune-inflammation index (SII) and IVF outcomes in women undergoing a gonadotrophin-releasing hormone (GnRH) antagonist protocol?

DESIGN

This retrospective cohort study analysed clinical data and blood samples collected before oocyte retrieval from participants undergoing IVF with the GnRH antagonist protocol. Logistic regression and generalized additive models were used to examine the association between SII quartiles and continuous SII values and IVF outcomes.

RESULTS

Higher SII values correlated negatively with biochemical pregnancy, clinical pregnancy, live birth and implantation rates, and positively with early pregnancy loss, independent of age, body mass index, anti-Müllerian hormone and stimulation parameters. The most significant adverse outcomes were observed in the highest SII quartile. A non-linear relationship was identified between log-transformed SII and IVF outcomes, with an inflection point at an SII of approximately 6.72, indicating a threshold effect.

CONCLUSIONS

Elevated SII is associated with poorer IVF outcomes in women after the GnRH antagonist protocol, suggesting its potential as a predictive marker in IVF treatments. Further research is needed to confirm these findings and explore the underlying mechanisms.

Relationship of neutrophil/lymphocyte ratio with cerebral small vessel disease and its common imaging markers

BACKGROUND

High neutrophil/lymphocyte ratio (NLR) is associated with poor prognosis in ischemic stroke. However, the role of NLR in cerebral small vessel disease (CSVD) is controversial. Herein, we evaluated the value of NLR in identifying CSVD and its relationship with the common imaging markers of CSVD.

METHODS

A total of 667 patients were enrolled in this study, including 368 in the CSVD group and 299 in the non-CSVD group. Clinical, laboratory, and imaging data were collected. The relationship of NLR with CSVD and common imaging markers of CSVD were analyzed with univariate and multivariate logistic regression analysis. The predictive value of NLR was assessed with the receiver operating characteristic curve.

RESULTS

NLR (odds ratio [OR] = 1.929, 95% confidence interval [CI] =  1.599-2.327, p < .001) was an independent risk factor for CSVD. NLR was also independently associated with moderate to severe white matter hyperintensity (WMH) (OR = 2.136, 95% CI = 1.768-2.580, p < .001), moderate to severe periventricular WMH (OR = 2.138, 95% CI = 1.771-2.579, p < .001), and moderate to severe deep WMH (OR = 1.654, 95% CI = 1.438-1.902, p < .001), moderately to severely enlarged perivascular spaces (EPVS) (OR = 1.248, 95% CI = 1.110-1.402, p < .001), moderately to severely EPVS in the basal ganglia (OR = 1.136, 95% CI = 1.012-1.275, p = .030), and moderately to severely EPVS in the centrum semiovale (OR = 1.140, 95% CI = 1.027-1.266, p = .014). However, NLR was not statistically significantly associated with lacune. The optimal cutoff point of NLR in predicting CSVD was 2.47, with sensitivity and specificity of 84.2% and 66.9%, respectively (p < .01). The diagnostic effect was maximized when NLR was combined with other risk factors.

CONCLUSIONS

NLR is an independent risk factor for CSVD and is independently associated with common imaging markers of CSVD. NLR may serve as a valid and convenient biomarker for assessing CSVD.

Blood urea nitrogen to albumin ratio is associated with cerebral small vessel diseases

Blood urea nitrogen (BUN) to albumin ratio (BAR) is a comprehensive parameter that reflects renal, inflammatory, nutritional, and endothelial functions. BAR has been shown to be associated with various cancers, pneumonia, sepsis, and pulmonary and cardiovascular diseases; however, few studies have been conducted on its association with cerebrovascular diseases. In this study, we evaluated the association between BAR and cerebral small vessel disease (cSVD) in health check-up participants. We assessed consecutive health check-up participants between January 2006 and December 2013. For the cSVD subtype, we quantitatively measured the volume of white matter hyperintensity (WMH) and qualitatively measured the presence of lacune and cerebral microbleeds (CMBs). The BAR was calculated by dividing BUN by albumin as follows: BAR = BUN (mg/dl)/albumin (g/dl). A total of 3012 participants were evaluated. In multivariable linear regression analysis, BAR showed a statistically significant association with WMH volume after adjusting for confounders [β = 0.076, 95% confidence interval (CI): 0.027-0.125]. In multivariable logistic regression analyses, BAR was significantly associated with lacunes [adjusted odds ratio (aOR) = 1.20, 95% CI: 1.00-1.44] and CMBs (aOR = 1.28, 95% CI: 1.06-1.55). BAR was associated with all types of cSVD in the health check-up participants.

Monocyte to high-density lipoprotein cholesterol ratio is associated with cerebral small vessel diseases

BACKGROUND

Inflammation is a major pathological mechanism underlying cerebrovascular disease. Recently, a new inflammatory marker based on the ratio between monocyte count and high-density lipoprotein (HDL) cholesterol has been proposed. In this study, we evaluated the relationship between monocyte-to-HDL cholesterol ratio (MHR) and cerebral small vessel disease (cSVD) lesions in health check-up participants.

METHODS

This study was a retrospective cross-sectional study based on a registry that prospectively collected health check-up participants between 2006 and 2013. Three cSVD subtypes were measured on brain magnetic resonance imaging. White matter hyperintensity (WMH) volume, and lacunes and cerebral microbleeds (CMBs) were quantitatively and qualitatively measured, respectively. The MHR was calculated according to the following formula: MHR = monocyte counts (× 103/μL) / HDL cholesterol (mmol/L).

RESULTS

In total, 3,144 participants were evaluated (mean age: 56 years, male sex: 53.9%). In multivariable analyzes adjusting for confounders, MHR was significantly associated with WMH volume [β = 0.099, 95% confidence interval (CI) = 0.025 to 0.174], lacune [adjusted odds ratio (aOR) = 1.43, 95% CI = 1.07-1.91], and CMB (aOR = 1.51, 95% CI = 1.03-2.19). In addition, MHR showed a positive quantitative relationship with cSVD burden across all three subtypes: WMH (P < 0.001), lacunes (P < 0.001), and CMBs (P < 0.001).

CONCLUSIONS

High MHR was closely associated with cSVD in health check-up participants. Because these associations appear across all cSVD subtypes, inflammation appears to be a major pathological mechanism in the development of various cSVDs.

HLA-C*07:01 and HLA-DQB1*02:01 protect against white matter hyperintensities and deterioration of cognitive function: A population-based cohort study

BACKGROUND

Neuroinflammation and aberrant immune regulation are increasingly implicated in the pathophysiology of white matter hyperintensities (WMH), an imaging marker of cerebrovascular pathologies and predictor of cognitive impairment. The role of human leukocyte antigen (HLA) genes, critical in immunoregulation and associated with susceptibility to neurodegenerative diseases, in WMH pathophysiology remains unexplored.

METHODS

We performed association analyses between classical HLA alleles and WMH volume, derived from MRI scans of 38 302 participants in the UK Biobank. To identify independent functional alleles driving these associations, we conducted conditional forward stepwise regression and lasso regression. We further investigated whether these functional alleles showed consistent associations with WMH across subgroups characterized by varying levels of clinical determinants. Additionally, we validated the clinical relevance of the identified alleles by examining their association with cognitive function (n = 147 549) and dementia (n = 460 029) in a larger cohort.

FINDINGS

Four HLA alleles (DQB1*02:01, DRB1*03:01, C*07:01, and B*08:01) showed an association with reduced WMH volume after Bonferroni correction for multiple comparisons. Among these alleles, DQB1*02:01 exhibited the most significant association (β = -0.041, 95 % CI: -0.060 to -0.023, p = 1.04 × 10-5). Forward selection and lasso regression analyses indicated that DQB1*02:01 and C*07:01 primarily drove this association. The protective effect against WMH conferred by DQB1*02:01 and C*07:01 persisted in clinically relevant subgroups, with a stronger effect observed in older participants. Carrying DQB1*02:01 and C*07:01 was associated with higher cognitive function, but no association with dementia was found.

INTERPRETATION

Our population-based findings support the involvement of immune-associated mechanisms, particularly both HLA class I and class II genes, in the pathogenesis of WMH and subsequent consequence of cognitive functions.

The association between systemic immune-inflammation index and in vitro fertilization outcomes in women with polycystic ovary syndrome: a cohort study

BACKGROUND

As a novel prognostic and inflammatory marker, the systemic immune-inflammation index (SII) has come to the foreground in recent years. SII may be used as an indicator reflecting the progressive inflammatory process in patients with polycystic ovary syndrome (PCOS). This study aimed to evaluate the correlation between SII and assisted reproductive outcomes in PCOS patients.

RESULTS

A total of 966 women undergoing in vitro fertilization (IVF) procedure with PCOS were included in the study. The SII was calculated as platelet count (/L) × neutrophil count (/L)/lymphocyte count (/L). Participants were divided into four groups according to SII quartiles calculated at baseline, and the differences of clinical and laboratory outcomes between these four groups were compared. Moreover, a univariate linear regression model was used to evaluate the associations between SII and the outcomes. Patients in the highest SII quartile (Q4) had lower antral follicle count (AFC), estradiol (E2), and progesterone (P) levels on the day of human chorionic gonadotropin (HCG) start compared with the lower three SII quartiles (Q1-Q3). Moreover, our analysis demonstrated that women in the lower SII quartiles had a higher rate of available embryos and blastocyst formation compared with those in the highest SII quartile. Logarithm of SII correlated negatively with available embryo rate, but not with number of available embryos. Additionally, the results of our multivariate logistic regression analyses indicated that the highest SII quartile was negatively associated with biochemical pregnancy rate (BPR), clinical pregnancy rate (CPR), live birth rate (LBR), and implantation rate (IR). A non-linear relationship between the SII and number of available embryos, with a negative relationship seen to the right of the inflection point was also found.

CONCLUSIONS

The interplay among thrombocytosis, inflammation, and immunity could influence assisted reproductive outcomes in PCOS patients. In this regard, SII may serve as a valuable marker for exploring potential correlations.

Early Human Pathophysiological Responses to Exertional Hypobaric Decompression Stress

INTRODUCTION: Consistent blood biomarkers of hypobaric (altitude) decompression stress remain elusive. Recent laboratory investigation of decompression sickness risk at 25,000 ft (7620 m) enabled evaluation of early pathophysiological responses to exertional decompression stress.METHODS: In this study, 15 healthy men, aged 20-50 yr, undertook 2 consecutive (same-day) ascents to 25,000 ft (7620 m) for 60 and 90 min, breathing 100% oxygen, each following 1 h of prior denitrogenation. Venous blood was sampled at baseline (T0), immediately after the second ascent (T8), and next morning (T24). Analyses encompassed whole blood hematology, endothelial microparticles, and soluble markers of cytokine response, endothelial function, inflammation, coagulopathy, oxidative stress, and brain insult, plus cortisol and creatine kinase.RESULTS: Acute hematological effects on neutrophils (mean 72% increase), eosinophils (40% decrease), monocytes (37% increase), and platelets (7% increase) normalized by T24. Consistent elevation (mean five-fold) of the cytokine interleukin-6 (IL-6) at T8 was proinflammatory and associated with venous gas emboli (microbubble) load. Levels of C-reactive protein and complement peptide C5a were persistently elevated at T24, the former by 100% over baseline. Additionally, glial fibrillary acidic protein, a sensitive marker of traumatic brain injury, increased by a mean 10% at T24.CONCLUSIONS: This complex composite environmental stress, comprising the triad of hyperoxia, decompression, and moderate exertion at altitude, provoked pathophysiological changes consistent with an IL-6 cytokine-mediated inflammatory response. Multiple persistent biomarker disturbances at T24 imply incomplete recovery the day after exposure. The elevation of glial fibrillary acidic protein similarly implies incomplete resolution following recent neurological insult.Connolly DM, Madden LA, Edwards VC, D'Oyly TJ, Harridge SDR, Smith TG, Lee VM. Early human pathophysiological responses to exertional hypobaric decompression stress. Aerosp Med Hum Perform. 2023; 94(10):738-749.

Systemic immune-inflammation index and progression of white matter hyperintensities of presumed vascular origin. A longitudinal population study in community-dwelling older adults living in rural Ecuador

BACKGROUND

Information on the association between the systemic immune-inflammation index (SII) and white matter hyperintensities (WMH) of presumed vascular origin is confined to cross-sectional studies. We sought to evaluate the impact of SII on WMH progression in community-dwelling older adults.

METHODS

Following a longitudinal prospective study design, participants of a population-based cohort received baseline blood tests to calculate the SII (platelets x neutrophils / lymphocytes x 109 L) together with clinical interviews and brain MRIs. Participants with follow-up brain MRI were included in the analysis. Poisson regression models adjusted for demographics and cardiovascular risk factors were fitted to assess the incidence rate ratio of WMH progression by levels of the SII.

RESULTS

Across 246 study participants (mean age: 65.5 ± 5.9 years; 55% women), the mean SII was 434.7 ± 193.8 × 109 L, and WMH progression was found in 101 (41%) individuals after a mean of 7.3 ± 1.5 years. A multivariate Poisson regression model showed increased WMH progression rate among individuals in the fourth quartile of the SII compared with those in the first quartile (IRR: 1.87; 95% C.I.: 1.02-3.41).

CONCLUSIONS

Study results provided novel evidence of an independent association between the SII and WMH progression. The SII may be able to identify individuals at high risk of WMH progression.

Investigating the Prognostic Role of Peripheral Inflammatory Markers in Mild Cognitive Impairment

Growing evidence suggests that neuroinflammation plays a critical role in the pathogenesis of neurodegenerative diseases. Peripheral markers of inflammation, including blood cell counts and their ratios, such as the neutrophil-to-lymphocyte ratio (NLR), have been reported as an easily accessible and reliable proxy of central nervous system inflammation. However, the role of peripheral inflammation in dementia and Mild Cognitive Impairment (MCI) still needs to be clarified. In the current study, we aimed to assess the prognostic role of the NLR and other peripheral markers of inflammation in a sample of 130 amnestic MCI, followed up for two to five years. The Mini-Mental state examination (MMSE) score at baseline and follow-up visits was used to assess global cognitive status at each visit and the degree of cognitive decline over time. Baseline peripheral markers of inflammation included blood cell counts and ratios, specifically the NLR, the platelet-to-lymphocyte ratio (PLR), the monocyte-to-lymphocyte ratio (MLR), and the systemic immune inflammation index (SII). After classifying subjects into CONVERTERS and non-CONVERTERS (respectively, patients converting to dementia and subjects showing stability at the last available follow-up), we compared peripheral markers of inflammation among groups ed correlated them with cognitive measures, testing the ability of significant factors to predict conversion to dementia. In our cohort, CONVERTERS showed lower baseline MMSE scores (p-value = 0.004) than non-CONVERTERS. In addition, CONVERTERS had statistically elevated NLR (p-value = 0.005), PLR (p-value = 0.002), and SII levels (p-value = 0.015), besides a lower number of lymphocytes (p-value = 0.004) compared with non-CONVERTERS. In a logistic regression analysis, baseline MMSE scores and NLR predicted conversion to dementia. Tertiles analysis showed that MCI with the highest NLR values had a higher conversion risk. Our study supports the hypothesis that a dysregulation of peripheral inflammation involving both lymphocytes and neutrophils may play a role in the pathogenesis of dementia, even at the early stages of neurodegeneration, as in the MCI condition.

Systemic Immune-Inflammation Index is Associated with Cerebral Small Vessel Disease Burden and Cognitive Impairment

OBJECTIVE

This study sought to explore the associations of the systemic immune-inflammation index (SII) with total cerebral small vessel disease (CSVD) burden and cognitive impairment.

METHODS

We enrolled 201 patients in the retrospective study with complete clinical and laboratory data. The SII was calculated as platelet count × neutrophil count/lymphocyte count. Cognitive function was evaluated by the Mini-Mental State Examination (MMSE). Total CSVD burden was assessed based on magnetic resonance imaging. We performed logistic regression models, Spearman correlation, and mediation analysis to evaluate the associations of SII with CSVD burden and cognitive impairment.

RESULTS

After adjustment for confounding factors in the multivariate binary logistic regression model, elevated SII (odds ratio [OR], 3.263; 95% confidence interval [CI], 1.577-6.752; P = 0.001) or severe CSVD burden (OR, 2.794; 95% CI, 1.342-5.817; P = 0.006) was significantly associated with the risk of cognitive impairment. Correlation analyses revealed that SII levels were negatively associated with MMSE scores (rs = -0.391, P < 0.001), and positively associated with the total CSVD burden score (rs = 0.361, P < 0.001). Moreover, SII was significantly related to the severity of the CSVD burden (OR, 2.674; 95% CI, 1.359-5.263; P = 0.004). The multivariable-adjusted odds ratios (95% CI) in highest tertile versus lowest tertile of SII were 8.947 (3.315-24.145) for cognitive impairment and 4.945 (2.063-11.854) for severe CSVD burden, respectively. The effect of higher SII on cognitive impairment development was partly mediated by severe CSVD burden.

CONCLUSION

Elevated SII is associated with severe CSVD burden and cognitive impairment. The mediating role of severe CSVD burden suggests that higher SII may contribute to cognitive impairment through aggravating CSVD burden.

Systemic immune-inflammation index predicts postoperative delirium in elderly patients after surgery: a retrospective cohort study

Background

Postoperative delirium (POD) is a common complication among elderly patients after surgery. It is unclear whether the systemic immune-inflammation index (SII) can be a predictor of POD. We explored the prognostic value of the SII in predicting POD in elderly patients undergoing non-neurosurgery and non-cardiac surgery in a large retrospective cohort.

Methods

We enrolled elderly patients undergoing non-neurosurgery and non-cardiac surgery between January 2014 and August 2019. Univariate and multivariate logistic regression analyses were performed to explore the correlation between POD and the SII value as both a continuous and categorical variable. Then, propensity score matching (PSM) analysis was applied to eliminate the confounding effect of covariates and prove our results. Subgroup analyses were then performed to discover the association between the SII and POD in different subgroups.

Results

A total of 29,608 patients with a median age of 70 years (IQR: 67–74) were enrolled in the retrospective cohort. The cut-off value of the SII was 650, which was determined by the receiver operating characteristic (ROC) curve. The ORs of an SII value > 650 was 2.709 (95% CI:2.373–3.092, P < 0.001), 1.615 (95% CI:1.384–1.882, P < 0.001), 1.855 (95% CI:1.602–2.146, P < 0.001), and 1.302 (95% CI:1.106–1.531, P = 0.001) for prediction of POD in univariate model and three multivariate regression models. After PSM, the OR of an SII value > 650 was 1.301 (95% CI: 1.062–1.598, P = 0.011). The subgroup analysis indicated that the SII indicates a significantly increased risk of POD in patients with Hb < 130 g/L, 4*10⁹/L < WBC ≤ 10*10⁹/L, albumin < 39 g/L, or duration of MAP < 60 mmHg ≥ 5 min. The SII was found to be a useful prognostic predictor of POD for patients of different ages, sexes, and ASA classifications.

Conclusions

The SII had a predictive value for POD in patients undergoing non-neurosurgery and non-cardiac surgery. As an index generated from routine blood tests, the SII has advantages regarding cost and time. After further validation, the SII may provide a new option for POD prediction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03418-4.