Role of platelet-to-lymphocyte count ratio (PLR), as a prognostic indicator in COVID-19: A systematic review and meta-analysis

Prognostic Significance of NLR and PLR in COVID-19: A Multi-Cohort Validation Study

INTRODUCTION

Recent studies have highlighted the prognostic value of easily accessible inflammatory markers, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) for predicting severe outcomes in patients affected by Coronavirus disease 2019 (COVID-19). Our study validates NLR and PLR cut-off values from a prior cohort at IRCCS Policlinico San Matteo (OSM) of Pavia, Italy, across two new cohorts from different hospitals. This aims to enhance the generalizability of these prognostic indicators.

METHODS

In this retrospective cohort study, conducted at Milan's Ospedale Luigi Sacco (OLS) and IRCCS Ospedale Maggiore Policlinico (OMP) hospitals, we assess the predictive capacity of NLR and PLR for three main outcomes-non-invasive ventilation (NIV) or continuous positive airway pressure (CPAP) usage, invasive ventilation (IV), and death-in patients with COVID-19 at admission. For each outcome, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were computed separately for male and female cohorts. Distinct NLR and PLR cut-off values were used for men (7.00, 7.29, 7.00 for NLR; 239.22, 248.00, 250.39 for PLR) and women (6.36, 7.00, 6.28 for NLR; 233.00, 246.45, 241.54 for PLR), retrieved from the first cohort at OSM.

RESULTS

A total of 3599 patients were included in our study, 1842 from OLS and 1757 from OMP. OLS and OMP sensitivity values for both NLR and PLR (NLR: 24-67%, PLR: 40-64%) were inferior to specificity values (NLR: 64-76%, PLR: 55-72%). Additionally, PPVs generally remained lower (< 63%), while NPVs consistently surpassed 68% for PLR and 72% for NLR. Finally, both PLR and NLR exhibited consistently higher NPVs for more severe outcomes (> 82%) compared to NPVs for CPAP/NIV.

CONCLUSIONS

Consistent findings across diverse patient populations validate the reliability and applicability of NLR and PLR cut-off values. High NPVs emphasize their role in identifying individuals less likely to experience severe outcomes. These markers not only aid in risk stratification but also guide resource allocation in emergencies or limited-resource situations.

Association of PADI2 and PADI4 polymorphisms in COVID-19 host severity and non-survival

Background

Enzymes of the peptidylarginine deiminase family (PADs) play a relevant role in the pathogenesis of COVID-19. However, the association of single nucleotide polymorphisms (SNPs) in their genes with COVID-19 severity and death is unknown.

Methodology

We included 1045 patients who were diagnosed with COVID-19 between October 2020 and December 2021. All subjects were genotyped for PADI2 (rs1005753 and rs2235926) and PADI4 (rs11203366, rs11203367, and rs874881) SNPs by TaqMan assays and their associations with disease severity, death, and inflammatory biomarkers were evaluated.

Results

291 patients presented had severe COVID-19 according to PaO2/FiO2, and 393 had a non-survival outcome. Carriers of the rs1005753 G/G genotype in the PADI2 gene presented susceptibility for severe COVID-19, while the heterozygous carriers in rs11203366, rs11203367, and rs874881 of the PADI4 gene showed risk of death. The GTACC haplotype in PADI2-PADI4 was associated with susceptibility to severe COVID-19, while the GCACC haplotype was a protective factor. The GCGTG haplotype was associated with severe COVID-19 but as a protective haplotype for death. Finally, the GTACC haplotype was associated with platelet-to-lymphocyte ratio (PLR), the GCACC haplotype with neutrophil-to-hemoglobin and lymphocyte and the GCGTG haplotype as a protective factor for the elevation of procalcitonin, D-dimer, CRP, LCRP, NHL, SII, NLR, and PLR.

Conclusions

Our results suggest that the haplotypic combination of GTACC and some individual genotypes of PADI2 and PADI4 contribute to the subjects' susceptibility for severity and death by COVID-19.

Prognostic Value of D-dimer to Lymphocyte Ratio (DLR) in Hospitalized Coronavirus Disease 2019 (COVID-19) Patients: A Validation Study in a National Cohort

BACKGROUND

This study aimed to validate the role of the D-dimer to lymphocyte ratio (DLR) for mortality prediction in a large national cohort of hospitalized coronavirus disease 2019 (COVID-19) patients.

METHODS

A retrospective, multicenter, observational study that included hospitalized patients due to SARS-CoV-2 infection in Spain was conducted from March 2020 to March 2022. All biomarkers and laboratory indices analyzed were measured once at admission.

RESULTS

A total of 10,575 COVID-19 patients were included in this study. The mean age of participants was 66.9 (±16) years, and 58.6% (6202 patients) of them were male. The overall mortality rate was 16.3% (n = 1726 patients). Intensive care unit admission was needed in 10.5% (n = 1106 patients), non-invasive mechanical ventilation was required in 8.8% (n = 923 patients), and orotracheal intubation was required in 7.5% (789 patients). DLR presented a c-statistic of 0.69 (95% CI, 0.68-0.71) for in-hospital mortality with an optimal cut-off above 1. Multivariate analysis showed an independent association for in-hospital mortality for DLR > 1 (adjusted OR 2.09, 95% CI 1.09-4.04; p = 0.03); in the same way, survival analysis showed a higher mortality risk for DLR > 1 (HR 2.24; 95% CI 2.03-2.47; p < 0.01). Further, no other laboratory indices showed an independent association for mortality in multivariate analysis.

CONCLUSIONS

This study confirmed the usefulness of DLR as a prognostic biomarker for mortality associated with SARS-CoV-2 infection, being an accessible, cost-effective, and easy-to-use biomarker in daily clinical practice.

The Role of Platelet Parameters in Predicting the Disease Severity of COVID-19 Patients: A Hospital-Based Study

Background and objective Globally, a large number of people have been impacted by the extremely contagious coronavirus disease 2019 (COVID-19) infection, and several pieces of literature were published on hematological parameter changes in this infection, particularly focusing on leucocytes. In this study, we have analyzed the platelet parameters and platelet-leucocyte ratios in COVID-19 patients and correlated them with the disease severity. Methods The COVID-19 patients who were hospitalized during the second peak of the pandemic were assessed. The platelet count and indices, platelet to lymphocyte ratio (PLR), neutrophil to platelet ratio (NPR), and clinical severity of each patient were analyzed. The significance of parameters and clinical severity was evaluated using analysis of variance (ANOVA) and the Kruskal Wallis test. A bivariate analysis was performed to assess the strength of the association. Receiver operating characteristic (ROC) curves were plotted to detect the predictive value of parameters for disease severity. Results The data of 132 COVID-19 patients has been evaluated. The average mean age was 45.60 ± 15.76 years with slight female predominance. Thrombocytopenia was found in 33% of cases with the majority of them being mild. Age, platelet distribution width (PDW), and PLR and NPR parameters were significantly (p-value <0.05) associated with disease severity. ROC curves showed age, PDW, PLR, NPR, absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) had significant prediction values for clinical severity. Conclusions Platelet parameters may not accurately reflect the severity of the disease, but when combined with leucocyte parameters and their ratios (PLR and NPR), they offer important information about disease severity.

The Characteristics and Laboratory Findings of SARS-CoV-2 Infected Patients during the First Three COVID-19 Waves in Portugal-A Retrospective Single-Center Study

Background and Objectives: Given the wide spectrum of clinical and laboratory manifestations of the coronavirus disease 2019 (COVID-19), it is imperative to identify potential contributing factors to patients' outcomes. However, a limited number of studies have assessed how the different waves affected the progression of the disease, more so in Portugal. Therefore, our main purpose was to study the clinical and laboratory patterns of COVID-19 in an unvaccinated population admitted to the intensive care unit, identifying characteristics associated with death, in each of the first three waves of the pandemic. Materials and Methods: This study included 337 COVID-19 patients admitted to the intensive care unit of a single-center hospital in Lisbon, Portugal, between March 2020 and March 2021. Comparisons were made between three COVID-19 waves, in the second (n = 325) and seventh (n = 216) days after admission, and between discharged and deceased patients. Results: Deceased patients were considerably older (p = 0.021) and needed greater ventilatory assistance (p = 0.023), especially in the first wave. Differences between discharged and deceased patients' biomarkers were minimal in the first wave, on both analyzed days. In the second wave significant differences emerged in troponins, lactate dehydrogenase, procalcitonin, C-reactive protein, and white blood cell subpopulations, as well as platelet-to-lymphocyte and neutrophil-to-lymphocyte ratios (all p < 0.05). Furthermore, in the third wave, platelets and D-dimers were also significantly different between patients' groups (all p < 0.05). From the second to the seventh days, troponins and lactate dehydrogenase showed significant decreases, mainly for discharged patients, while platelet counts increased (all p < 0.01). Lymphocytes significantly increased in discharged patients (all p < 0.05), while white blood cells rose in the second (all p < 0.001) and third (all p < 0.05) waves among deceased patients. Conclusions: This study yields insights into COVID-19 patients' characteristics and mortality-associated biomarkers during Portugal's first three COVID-19 waves, highlighting the importance of considering wave variations in future research due to potential significant outcome differences.

[Early prediction of severe COVID-19 in patients with Sjögren's syndrome]

OBJECTIVE

To investigate the predictive value of blood cell ratios and inflammatory markers for adverse prognosis in patients with primary Sjögren's syndrome (PSS) combined with coronavirus disease 2019 (COVID-19).

METHODS

We retrospectively collected clinical data from 80 patients with PSS and COVID-19 who visited the Rheumatology and Immunology Department of the First Affiliated Hospital of Nanchang University from December 2022 to February 2023. Inclusion criteria were (1) meeting the American College of Rheumatology (ACR) classification criteria for Sjögren's syndrome; (2) confirmed diagnosis of COVID-19 by real-time reverse transcription polymerase chain reaction or antigen testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); (3) availability of necessary clinical data; (4) age > 18 years. According to the clinical classification criteria of the "Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (trial the 10th Revised Edition)", the patients were divided into the mild and severe groups. Disease activity in primary Sjögren' s syndrome was assessed using the European League Against Rheumatism (EULAR) Sjögren' s syndrome disease activity index (ESSDAI). Platelet-lymphocyte ratio (PLR), C-reactive protein-lymphocyte ratio (CLR), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and other laboratory data were compared between the two groups within 24-72 hours post-infection.

RESULTS

The mild group consisted of 66 cases with an average age of (51. 52±13. 16) years, and the severe group consisted of 14 cases with an average age of (52.64±10.20) years. Disease activity, CRP, platelets, PLR, and CLR were significantly higher in the severe group compared with the mild group (P < 0.05). Univariate analysis using age, disease activity, CRP, platelets, PLR, and CLR as independent variables indicated that disease activity, CRP, PLR, and CLR were correlated with the severity of COVID-19 (P < 0.05). Multivariate logistic regression analysis further confirmed that PLR (OR=1.016, P < 0.05) and CLR (OR=1.504, P < 0.05) were independent risk factors for the severity of COVID-19 in the critically ill patients. Receiver operator characteristic (ROC) curve analysis showed that the area under the curve (AUC) for PLR and CLR was 0.708 (95%CI: 0.588-0.828) and 0.725 (95%CI: 0.578-0.871), respectively. The sensitivity for PLR and CLR was 0.429 and 0.803, respectively, while the highest specificity was 0.714 and 0.758, respectively. The optimal cutoff values for PLR and CLR were 166.214 and 0.870, respectively.

CONCLUSION

PLR and CLR, particularly the latter, may serve as simple and effective indicators for predicting the prognosis of patients with PSS and COVID-19.

Accurate and efficient estimation of local heritability using summary statistics and the linkage disequilibrium matrix

Existing SNP-heritability estimators that leverage summary statistics from genome-wide association studies (GWAS) are much less efficient (i.e., have larger standard errors) than the restricted maximum likelihood (REML) estimators which require access to individual-level data. We introduce a new method for local heritability estimation-Heritability Estimation with high Efficiency using LD and association Summary Statistics (HEELS)-that significantly improves the statistical efficiency of summary-statistics-based heritability estimator and attains comparable statistical efficiency as REML (with a relative statistical efficiency >92%). Moreover, we propose representing the empirical LD matrix as the sum of a low-rank matrix and a banded matrix. We show that this way of modeling the LD can not only reduce the storage and memory cost, but also improve the computational efficiency of heritability estimation. We demonstrate the statistical efficiency of HEELS and the advantages of our proposed LD approximation strategies both in simulations and through empirical analyses of the UK Biobank data.

It's in the blood: a review of the hematological system in SARS-CoV-2-associated COVID-19

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global healthcare crisis. While SARS-CoV-2-associated COVID-19 affects primarily the respiratory system, patients with COVID-19 frequently develop extrapulmonary manifestations. Notably, changes in the hematological system, including lymphocytopenia, neutrophilia and significant abnormalities of hemostatic markers, were observed early in the pandemic. Hematological manifestations have since been recognized as important parameters in the pathophysiology of SARS-CoV-2 and in the management of patients with COVID-19. In this narrative review, we summarize the state-of-the-art regarding the hematological and hemostatic abnormalities observed in patients with SARS-CoV-2-associated COVID-19, as well as the current understanding of the hematological system in the pathophysiology of acute and chronic SARS-CoV-2-associated COVID-19.

The Role of Aspartate Aminotransferase-to-Lymphocyte Ratio Index (ALRI) in Predicting Mortality in SARS-CoV-2 Infection

COVID-19 has a mortality rate exceeding 5.4 million worldwide. The early identification of patients at a high risk of mortality is essential to save their lives. The AST-to-lymphocyte ratio index (ALRI) is a novel biomarker of survival in patients with hepatocellular carcinoma, an organ susceptible to SARS-CoV-2 infection. For this study, the prognostic value of ALRI as a marker of COVID-19 mortality was evaluated. For this purpose, ALRI was compared with the main biomarkers for COVID-19 mortality (neutrophil-to-lymphocyte ratio [NLR], systemic immune-inflammation index [SII], platelet-to-lymphocyte ratio [PLR], lactate dehydrogenase (LDH)/lymphocyte ratio [LDH/LR]). A retrospective cohort of 225 patients with SARS-CoV-2 infection and without chronic liver disease was evaluated. In the non-survival group, the ALRI, NLR, SII, and LDH/LR were significantly higher than in the survival group (pcorrected < 0.05). ALRI had an area under the curve (AUC) of 0.81, a sensitivity of 70.37%, and a specificity of 75%, with a best cut-off value >42.42. COVID-19 patients with high ALRI levels had a mean survival time of 7.8 days. Multivariate Cox regression revealed that ALRI > 42.42 (HR = 2.32, 95% CI: 1.35-3.97; pcorrected = 0.01) was a prognostic factor of COVID-19 mortality. These findings prove that ALRI is an independent predictor of COVID-19 mortality and that it may help identify high-risk subjects with SARS-CoV-2 infection upon admission.

The Prognostic Role of Platelet-to-Lymphocyte Ratio in Acute Coronary Syndromes: A Systematic Review and Meta-Analysis

This study aimed to investigate the potential prognostic role of the platelet-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). A systematic search of PubMed Central, Scopus, EMBASE, and the Cochrane Library from conception through 20 August 2023 was conducted. We used odds ratios (OR) as the effect measure with 95% confidence intervals (CIs) for dichotomous data and mean differences (MD) with a 95% CI for continuous data. If I2 was less than 50% or the p value of the Q tests was less than 0.05, a random synthesis analysis was conducted. Otherwise, a fixed pooled meta-analysis was performed. Nineteen studies fulfilled the eligibility criteria and were included in the meta-analysis. PLR was higher in MACE-positive (164.0 ± 68.6) than MACE-negative patients (115.3 ± 36.9; MD = 40.14; 95% CI: 22.76 to 57.52; p < 0.001). Pooled analysis showed that PLR was higher in AMI patients who died (183.3 ± 30.3), compared to survivors (126.2 ± 16.8; MD = 39.07; 95% CI: 13.30 to 64.84; p = 0.003). It was also higher in the ACS vs. control group (168.2 ± 81.1 vs. 131.9 ± 37.7; MD = 39.01; 95% CI: 2.81 to 75.21; p = 0.03), STEMI vs. NSTEMI cohort (165.5 ± 92.7 vs. 159.5 ± 87.8; MD = 5.98; 95% CI: -15.09 to 27.04; p = 0.58), and MI vs. UAP populations (162.4 ± 90.0 vs. 128.2 ± 64.9; MD = 18.28; 95% CI: -8.16 to 44.71; p = 0.18). Overall, our findings confirmed the potential prognostic role of the plate-let-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). Its use as a risk stratification tool should be examined prospectively to define its capability for evaluation in cardiovascular patients.

Predictive value of hematological indices on incidence and severity of pulmonary embolism in COVID-19 patients

BACKGROUND

Pulmonary thromboembolism (PTE) is a common complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which raises the COVID-19 disease's fatality rate from 3% to 45%. Nevertheless, due to fairly indistinguishable clinical symptoms and a lack of validated clinical prediction models, PTE diagnosis in COVID-19 patients is challenging. This study aims to investigate the applicability of hematological indices to predict PTE incidence and its severity in SARS-CoV-2 patients.

METHODS

A retrospective cohort study was conducted on hospitalized patients with a confirmed diagnosis of SARS-CoV-2 infection who underwent CT angiography to assess probable PTE in them. The correlation between complete blood count parameters 1 day before CT angiography and CT angiography outcomes, and simplified pulmonary embolism severity index (s-PESI) was investigated.

RESULTS

We discovered that among individuals with a probable PTE, males and those with higher platelet-to-lymphocyte (PLR) and neutrophil-to-lymphocyte (NLR) ratios had a greater likelihood of PTE incidence (p < .001, .027, and .037, respectively). PLR was a significant and independent predictor of PTE with a p value of .045. Moreover, a higher neutrophil count was associated with a higher s-PESI score in COVID-19 patients developing PTE (p: .038).

CONCLUSIONS

Among hematological indices, NLR and more precisely PLR are cost-effective and simply calculable markers that can assist physicians in determining whether or not COVID-19 patients with clinically probable PTE require CT angiography and the higher neutrophil count can be employed as an indicator of PTE severity in COVID-19 patients. Further large multicenter and prospective studies are warranted to corroborate these observations.

Hematological parameters and their predictive value for assessing disease severity in laboratory-confirmed COVID-19 patients: a retrospective study

BACKGROUND

The coronavirus disease 19 (COVID-19) infection has spread globally and caused a substantial amount of mortality and morbidity. Early detection of severe infections will improve care and reduce deaths. The use of hematological parameters in predicting COVID-19 disease severity, patient outcomes, and early risk stratification is limited. Therefore, the study was aimed at determining hematological parameters and their predictive value for assessing disease severity in laboratory-confirmed COVID-19 patients in Northwest Ethiopia.

METHODS

A retrospective cross-sectional study was conducted at the University of Gondar comprehensive specialized hospital and Tibebe Ghion comprehensive specialized referral hospital on 253 patients diagnosed with COVID-19 and admitted between March 2021 and February 2022. Data were extracted, and entered into Epi-data 4.2.0.0, and analyzed using SPSS version 25 software. Hematological parameters were provided as the median and interquartile range (IQR). Categorical variables were represented by their frequency, and the χ2 test was applied to compare observed results with expected results. The receiver-operating curve (ROC) was used to establish the predictive value of hematological parameters for COVID-19 severity. A p-value < 0.05 was considered statistically significant.

RESULTS

On a total of 253 patients, there were 43.87% severe cases, with a mortality rate of 26.9%. The ROC analysis showed the optimal cutoff values for hematological parameters were ANC (3370), lymphocyte (680), NLR (9.34), PLR (290.77), platelets (332,000), and WBCs (4390.65). The area under the curve (AUC) values for NLR (0.679) and ANC (0.631) were high, with the highest sensitivity and specificity, and could potentially be used to predict COVID-19 severity.

CONCLUSION

This study proved that high NLR and high ANC have prognostic value for assessing disease severity in COVID-19. Thus, assessing and considering these hematological parameters when triaging COVID-19 patients may prevent complications and improve the patient's outcome.

Prognostic Value of Routine Biomarkers in the Early Stage of COVID-19

Various biomarkers like certain complete blood cell count parameters and the derived ratios including neutrophil-lymphocyte ratio are commonly used to evaluate disease severity. Our study aimed to establish if baseline levels of complete blood cell count-derived biomarkers and CRP, measured before any treatment which can interfere with their values, could serve as a predictor of development of pneumonia and the need for hospitalization requiring oxygen therapy. We retrospectively analyzed the laboratory data of 200 consecutive patients without comorbidities, who denied usage of medications prior to blood analysis and visited a COVID-19 ambulance between October and December 2021. Multivariate regression analysis extracted older age, elevated CRP and lower eosinophil count as significant independent predictors of pneumonia (p = 0.003, p = 0.000, p = 0.046, respectively). Independent predictors of hospitalization were higher CRP (p = 0.000) and lower platelet count (p = 0.005). There was no significant difference in the neutrophil-lymphocyte and platelet-lymphocyte ratios between examined groups. Individual biomarkers such as platelet and eosinophil count might be better in predicting the severity of COVID-19 than the neutrophil-lymphocyte and platelet-lymphocyte ratios.

Hematological ratios in coronavirus disease 2019 patients with and without invasive mechanical ventilation

Patients with the most severe form of coronavirus disease 2019 (COVID-19) often require invasive ventilation. Determining the best moment to intubate a COVID-19 patient is complex decision and can result in important consequences for the patient. Therefore, markers that could aid in clinical decision-making such as hematological indices are highly useful. These markers are easy to calculate, do not generate extra costs for the laboratory, and are readily implemented in routine practice. Thus, this study aimed to investigate differences in the ratios calculated from the hemogram between patients with and without the need for invasive mechanical ventilation (IMV) and a control group. This was an observational retrospective analysis of 212 patients with COVID-19 that were hospitalized between April 1, 2020 and March 31, 2021 who were stratified as IMV (n = 129) or did not require invasive mechanical ventilation (NIMV) (n = 83). A control group of 198 healthy individuals was also included. From the first hemogram of each patient performed after admission, the neutrophil-to-lymphocyte ratio (NLR), the derived NLR (d-NLR), the lymphocyte-to-monocyte ratio, the platelet-to-lymphocyte ratio, the neutrophil-to-platelet ratio (NPR), and the systemic immune-inflammation index (SII) were calculated. All hematological ratios exhibited significant differences between the control group and COVID-19 patients. NLR, d-NLR, SII, and NPR were higher in the IMV group than they were in the NIMV group. The hematological indices addressed in this study demonstrated high potential for use as auxiliaries in clinical decision-making regarding the need for IMV.

Accurate and Efficient Estimation of Local Heritability using Summary Statistics and LD Matrix

Existing SNP-heritability estimation methods that leverage GWAS summary statistics produce estimators that are less efficient than the restricted maximum likelihood (REML) estimator using individual-level data under linear mixed models (LMMs). Increasing the precision of a heritability estimator is particularly important for regional analyses, as local genetic variances tend to be small. We introduce a new estimator for local heritability, "HEELS", which attains comparable statistical efficiency as REML (\emph{i.e.} relative efficiency greater than 92%) but only requires summary-level statistics -- Z-scores from the marginal association tests plus the empirical LD matrix. HEELS significantly improves the statistical efficiency of the existing summary-statistics-based heritability estimators-- for instance, HEELS produces heritability estimates that are more than 3-fold and 7-times less variable than GRE and LDSC, respectively. Moreover, we introduce a unified framework to evaluate and compare the performance of different LD approximation strategies. We propose representing the empirical LD as the sum of a low-rank matrix and a banded matrix. This approximation not only reduces the storage and memory cost of using the LD matrix, but also improves the computational efficiency of the HEELS estimation. We demonstrate the statistical efficiency of HEELS and the advantages of our proposed LD approximation strategies both in simulations and through empirical analyses of the UK Biobank data.

Clinical utility of haematological inflammatory biomarkers in predicting 30-day mortality in hospitalised adult patients with COVID-19

Coronavirus disease 2019 (COVID-19) is a multisystem disease affecting respiratory, cardiovascular, gastrointestinal, neurological, immunological and haematological systems. The most important indices that have been studied are platelet (PLT) indices in addition to the PLT count and red blood cell distribution width (RDW). This retrospective study included 95 patients with COVID-19 and was conducted at the Hospital Isolation, Scientific and Medical Research Centre and Clinical Pathology Department at Zagazig University Hospitals, Egypt over 6 months from March to August 2021. All patients on admission had a full blood count, which included white blood cell (WBC) count, haemoglobin, RDW, PLT count and its indices in addition to PLT-to-WBC ratio (PWR) and PLT-to-lymphocyte ratio (PLR), which were calculated for all the study patients. There were significant linear correlations for higher levels of the PLR, PWR and RDW and mortality rate (p = 0.03, p < 0.001 and p < 0.001 respectively). Moreover, on multivariable analysis the RDW, PLT count and PWR levels were independent prognostic predictors for mortality with a hazard ratio [HR] of 1.25 (95% confidence interval [CI] 1.09-1.44, p = 0.002), 1.00 (95% CI 0.99-1.00, p = 0.03) and 2.3 (95% CI 1.21-4.48, p = 0.01) respectively. The RDW and PLT indices are accessible predictors that can be valuable prognostic factors for survival assessment and risk stratification of COVID-19.

Pathways of Coagulopathy and Inflammatory Response in SARS-CoV-2 Infection among Type 2 Diabetic Patients

Chronic inflammation and endothelium dysfunction are present in diabetic patients. COVID-19 has a high mortality rate in association with diabetes, partially due to the development of thromboembolic events in the context of coronavirus infection. The purpose of this review is to present the most important underlying pathomechanisms in the development of COVID-19-related coagulopathy in diabetic patients. The methodology consisted of data collection and synthesis from the recent scientific literature by accessing different databases (Cochrane, PubMed, Embase). The main results are the comprehensive and detailed presentation of the very complex interrelations between different factors and pathways involved in the development of arteriopathy and thrombosis in COVID-19-infected diabetic patients. Several genetic and metabolic factors influence the course of COVID-19 within the background of diabetes mellitus. Extensive knowledge of the underlying pathomechanisms of SARS-CoV-2-related vasculopathy and coagulopathy in diabetic subjects contributes to a better understanding of the manifestations in this highly vulnerable group of patients; thus, they can benefit from a modern, more efficient approach regarding diagnostic and therapeutic management.

Clinical Significance and Diagnostic Utility of NLR, LMR, PLR and SII in the Course of COVID-19: A Literature Review

Nowadays, society is increasingly struggling with infectious diseases that are characterized by severe course and even death. Recently, the whole world has faced the greatest epidemiological threat, which is COVID-19 caused by SARS CoV-2 virus. SARS CoV-2 infection is often accompanied by severe inflammation, which can lead to the development of different complications. Consequently, clinicians need easily interpreted and effective markers of inflammation that can predict the efficacy of the treatment and patient prognosis. Inflammation is associated with changes in many biochemical and hematological parameters, including leukocyte counts and their populations. In COVID-19, changes in leukocytes count populations such as neutrophils, lymphocytes or monocytes are observed. The numerous research confirm that indicators like neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), platelets-to-lymphocyte ratio (PLR) and systemic inflammatory index (SII) may prove effective in assessment patient prognosis and choosing optimal therapy. Therefore, in this review, we would like to summarize the latest knowledge about the diagnostic utility of systemic inflammatory ratios - NLR, LMR, PLR and SII in patients with COVID-19. We focused on the papers evaluating the diagnostic utility of inflammatory ratios using ROC curve published in the recent 3 years. Identification of biomarkers associated with inflammation would help the selection of patients with severe course of COVID-19 and high risk of death.

Demographic and Social Patterns of the Mean Values of Inflammatory Markers in U.S. Adults: A 2009-2016 NHANES Analysis

Several studies have reported on the negative implications of elevated neutrophil-to-lymphocyte ratio (NLR) and elevated platelet-to-lymphocyte ratio (PLR) levels associated with outcomes in many surgical and medical conditions, including cancer. In order to use the inflammatory markers NLR and PLR as prognostic factors in disease, a normal value in disease-free individuals must be identified first. This study aims (1) to establish mean values of various inflammatory markers using a healthy and nationally representative U.S. adult population and (2) to explore heterogeneity in the mean values by sociodemographic and behavioral risk factors to better specify cutoff points accordingly. The National Health and Nutrition Examination Survey (NHANES) of aggregated cross-sectional data collected from 2009 to 2016 was analyzed; data extracted included markers of systemic inflammation and demographic variables. We excluded participants who were under 20 years old or had a history of an inflammatory disease such as arthritis or gout. Adjusted linear regression models were used to examine the associations between demographic/behavioral characteristics and neutrophil counts, platelet counts, lymphocyte counts, as well as NLR and PLR values. The national weighted average NLR value is 2.16 and the national weighted average PLR value is 121.31. The national weighted average PLR value for non-Hispanic Whites is 123.12 (121.13-125.11), for non-Hispanic Blacks it is 119.77 (117.49-122.06), for Hispanic people it is 116.33 (114.69-117.97), and for participants of other races it is 119.84 (116.88-122.81). Non-Hispanic Blacks and Blacks have significantly lower mean NLR values (1.78, 95% CI 1.74-1.83 and 2.10, 95% CI 2.04-2.16, respectively) as compared with that of non-Hispanic Whites (2.27, 95% CI 2.22-2.30, p < 0.0001). Subjects who reported a non-smoking history had significantly lower NLR values than subjects who reported any smoking history and higher PLR values than current smokers. This study provides preliminary data for demographic and behavioral effects on markers of inflammation, i.e., NLR and PLR, that have been associated with several chronic disease outcomes, suggesting that different cutoff points should be set according to social factors.

Plasma-induced nanoparticle aggregation for stratifying COVID-19 patients according to disease severity

Stratifying patients according to disease severity has been a major hurdle during the COVID-19 pandemic. This usually requires evaluating the levels of several biomarkers, which may be cumbersome when rapid decisions are required. In this manuscript we show that a single nanoparticle aggregation test can be used to distinguish patients that require intensive care from those that have already been discharged from the intensive care unit (ICU). It consists of diluting a platelet-free plasma sample and then adding gold nanoparticles. The nanoparticles aggregate to a larger extent when the samples are obtained from a patient in the ICU. This changes the color of the colloidal suspension, which can be evaluated by measuring the pixel intensity of a photograph. Although the exact factor or combination of factors behind the different aggregation behavior is unknown, control experiments demonstrate that the presence of proteins in the samples is crucial for the test to work. Principal component analysis demonstrates that the test result is highly correlated to biomarkers of prognosis and inflammation that are commonly used to evaluate the severity of COVID-19 patients. The results shown here pave the way to develop nanoparticle aggregation assays that classify COVID-19 patients according to disease severity, which could be useful to de-escalate care safely and make a better use of hospital resources.

COVID-19 in elderly: Correlations of viral load, clinical course, laboratory parameters, among patients vaccinated with CoronaVac

SARS-CoV-2 virus was initially identified in Wuhan, China, in December 2019 and a global pandemic was declared in March 2020 by World Health Organization. COVID-19 disease is characterized with severe pneumonia and hypoxemia, especially in the elderly population. The elderly population was primarily vaccinated with CoronaVac, which is a whole virion inactivated vaccine (Sinovac Biotech, China) in Turkey. This study aimed to investigate the association of viral load and laboratory parameters with the severity of the disease and vaccination status in elderly (older than 60 years old) COVID-19 patients. The age range of the patients was 61-97 years old with a mean of 71.80. Vaccinated patients had a lower viral load (P = 0.253) in nasopharyngeal swabs during breakthrough COVID-19 infection compared to unvaccinated ones and were hospitalized for a shorter period of time in hospital wards (P = 0.035). A lower number of patients were vaccinated in both moderate (n = 33, 29.20%) and severe/critical group (n = 46, 34.07%) (P = 0.412). Only 17 (32.08%) vaccinated patients were hospitalized in an intensive care unit (ICU), whereas 36 (67.92%) of the ICU patients were unvaccinated (P = 0.931). Severe/critical patients had higher c-reactive protein (CRP), platelet-to-lymphocyte ratio (PLR), fibrinogen, ferritin, and lactate dehydrogenase (LDH) levels compared to the moderate group on the admission day (P < 0.05). Our study suggested that elderly patients vaccinated with CoronaVac had a shorter stay in hospitals and according to our results CRP, PLR, fibrinogen, ferritin, and LDH levels could be used to determine the severity of the infections.

THE IMPORTANCE OF INFLAMMATORY MARKERS IN PREDICTION OF MORTALITY IN COVID-19 PATIENTS

ÖZET GİRİŞ: Çin’de 2019 Aralık ayı sonunda ortaya çıkan COVID-19 kısa sürede tüm dünyaya yayılarak Dünya Sağlık Örgütü tarafından 11 Mart 2020’de pandemi olarak kabul edilmiştir. Pandemi hala değişen varyantlarıyla ve vaka sayılarıyla güncelliğini korumaktadır. Bu çalışmada COVID-19 tanılı yatan hastalarda 1. ve 5. gün bakılan hematolojik, inflamatuvar ve biyokimyasal belirteçlerin mortaliteyi öngörmede önemini belirlemeyi amaçladık. GEREÇ ve YÖNTEM: Araştırma retrospektif ve kesitsel çalışma olarak tasarlanmıştır. Çalışmaya 1 Kasım 2020-30 Nisan 2021 tarihleri arasında Kahramanmaraş Sütçü İmam Üniversitesi Hastanesi’ne COVID-19 şüpheli semptomları ile başvuran COVID-19 RT-PCR testi ile tanısı doğrulanarak yatışı yapılan 18 yaş üstü 200 hasta dahil edilmiştir. Hastaların yaş, cinsiyet, eşlik eden komorbid hastalıkları, 1. ve 5. gün laboratuvar parametreleri ve sonlanım durumları kaydedildi. Hastalar taburcu ve ölen şeklinde iki gruba ayrıldı. BULGULAR: Çalışmaya alınan 200 hastanın %75’i (n=150) taburcu olan, %25’i ise (n=50) 28 gün içinde ölen hastalardan oluşmaktaydı. Hastaların %63.5 (n=127) erkek, %36.5’i (n=73) kadındı. Hastaların yaş ortalaması 63±17.2 yıldı. Hastaların %50.5’i hafif, %31’i orta, %18.5’i ise ağır klinik tabloya sahipti. COVID-19 hastalarının prognozunu etkileyen faktörleri belirlemek amacıyla lojistik regresyon analizi yapıldı. Prognoz ile ilişkili faktörler erkek cinsiyet, diyabetes mellitus, KOAH, hipertansiyon varlığı, ateş, nefes darlığı ve öksürük olarak bulundu. Hastaların 1. ve 5.gün bakılan lenfosit (lenfopeni), C-Reaktif Protein (CRP), Prokalsitonin (PCT),nötrofil7lenfosit oranı (NLO), platelet /lenfosit oranı (PLO), D-Dimer değerleri tanı anında ve takiplerde mortalite öngörücüsü olarak tespit edildi (p

Platelet-to-lymphocyte ratio and mean platelet volume-to-platelet count ratio for predicting mortality in critical COVID-19 patients

Introduction: Defining the markers that can be used in clinical practice for predicting the mortality of critical patients will be cautionary for taking necessary measures in high-risk cases. Although there are a large number of studies conducted during the pandemic, no mortality marker to predict the prognosis of intensive care unit (ICU) patients with COVID-19 has yet been defined. Platelet indices can be easily evaluated with a complete blood count (CBC) analysis, one of the most accessible tests worldwide. This study aimed to evaluate the role of platelet indices such as mean platelet volume (MPV), platelet distribution width (PDW), plateletcrit (PCT), platelet-to-lymphocyte ratio (PLR), and MPV-to-platelet count ratio (MPV/PLT) in predicting the mortality of ICU patients with COVID-19. Material and Method: This single-center, retrospective, cross-sectional study included 201 critical COVID-19 patients over 18 years of age who were hospitalized in ICU between August 2020 and February 2021. Patients were divided into two groups as survivors and non-survivors. The relationship of MPV, PDW, PCT, PLR, and MPV/PLT parameters evaluated at ICU admission with mortality was investigated. Results: There was no significant difference between the survivor and non-survivor groups in terms of platelet count, MPV, PCT, and PDW. The comparison of the platelet ratios revealed higher PLR and MPV/PLT ratio in the non-survivor group than in the survivor group (p

Evaluation of simple laboratory parameters in SARS-CoV-2 infection: the role of ratios

BACKGROUND

The real predictive prognostic capacity of cellular indices (or ratios) is unclear in SARS-CoV-2 infection. This study aimed to assess the prognostic role of previously well-known laboratory indices and new ones in hospitalized COVID-19 patients.

METHODS

A retrospective observational study from March to May 2022 evaluated laboratory indices on admission (neutrophil to lymphocyte-, derived neutrophil to lymphocyte-, platelet to lymphocyte-, CRP to lymphocyte-, CRP to albumin-, fibrinogen to lymphocyte-, d-dimer to lymphocyte-, ferritin to lymphocyte-, LDH to lymphocyte-, and IL-6 to lymphocyte ratios), in patients hospitalized due to SARS-CoV2 infection to determine the association with mortality, admission to an intensive care unit (ICU), need for non-invasive mechanical ventilation (NIMV), orotracheal intubation (OTI), or combined event at 30 days follow-up.

RESULTS

A total of 1113 COVID-19 patients were evaluated with a mean age of 64.1 ± 15.9 years (58.49% male), 166 (14.91%) patients died, 58 (5.21%) required ICU admission, 73 (6.56%) needed NIMV, 46 (4.23%) needed OTI, and 247 (22.19%) presented the combined event. All the ratios evaluated in this study showed statistical significance in the univariate analysis for mortality and combined event; however, only d-dimer to lymphocyte ratio >0.6 presented an independent association in the multivariate analysis for 30-day mortality (adjusted OR 2.32; p = .047) and 30-day combined event (adjusted OR 2.62; p = .014).

CONCLUSIONS

Laboratory indices might be a potential biomarker for better prognosis stratification in hospitalized COVID-19 patients. d-Dimer to lymphocyte ratio presents an independent association for 30-day mortality and 30-day adverse outcomes in hospitalized COVID-19 patients.

Systemic Inflammatory Biomarkers and Chest CT Findings as Predictors of Acute Limb Ischemia Risk, Intensive Care Unit Admission, and Mortality in COVID-19 Patients

Background: Numerous tools, including inflammatory biomarkers and lung injury severity scores, have been evaluated as predictors of thromboembolic events and the requirement for intensive therapy in COVID-19 patients. This study aims to verify the predictive role of inflammatory biomarkers [monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), systemic inflammatory index (SII), Systemic Inflammation Response Index (SIRI), and Aggregate Index of Systemic Inflammation (AISI)] and the CT Severity Score in acute limb ischemia (ALI) risk, intensive unit care (ICU) admission, and mortality in COVID-19 patients.; Methods: The present study was designed as an observational, analytical, retrospective cohort study and included all patients older than 18 years of age with a diagnosis of COVID-19 infection, confirmed through real time-polymerase chain reaction (RT-PCR), and admitted to the County Emergency Clinical Hospital of Targu-Mureș, Romania, and Modular Intensive Care Unit of UMFST “George Emil Palade” of Targu Mures, Romania between January 2020 and December 2021. Results: Non-Survivors and “ALI” patients were associated with higher incidence of cardiovascular disease [atrial fibrillation (AF) p = 0.0006 and p = 0.0001; peripheral arterial disease (PAD) p = 0.006 and p < 0.0001], and higher pulmonary parenchyma involvement (p < 0.0001). Multivariate analysis showed a high baseline value for MLR, NLR, PLR, SII, SIRI, AISI, and the CT Severity Score independent predictor of adverse outcomes for all recruited patients (all p < 0.0001). Moreover, the presence of AF and PAD was an independent predictor of ALI risk and mortality. Conclusions: According to our findings, higher MLR, NLR, PLR, SII, SIRI, AISI, and CT Severity Score values at admission strongly predict ALI risk, ICU admission, and mortality. Moreover, patients with AF and PAD had highly predicted ALI risk and mortality but no ICU admission.

Chest CT Severity Score and Systemic Inflammatory Biomarkers as Predictors of the Need for Invasive Mechanical Ventilation and of COVID-19 Patients' Mortality

Background: Numerous tools, including inflammatory biomarkers and lung injury severity scores, have been evaluated as predictors of disease progression and the requirement for intensive therapy in COVID-19 patients. This study aims to verify the predictive role of inflammatory biomarkers [monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), systemic inflammatory index (SII), Systemic Inflammation Response Index (SIRI), Aggregate Index of Systemic Inflammation (AISI), and interleukin-6 (IL-6)] and the total system score (TSS) in the need for invasive mechanical ventilation (IMV) and mortality in COVID-19 patients. Methods: The present study was designed as an observational, analytical, retrospective cohort study and included all patients over 18 years of age with a diagnosis of COVID-19 pneumonia, confirmed through real time-polymerase chain reaction (RT-PCR) and radiological chest CT findings admitted to County Emergency Clinical Hospital of Targu-Mureș, Romania, and Modular Intensive Care Unit of UMFST “George Emil Palade” of Targu Mures, Romania between January 2021 and December 2021. Results: Non-Survivors patients were associated with higher age (p = 0.01), higher incidence of cardiac disease [atrial fibrillation (AF) p = 0.0008; chronic heart failure (CHF) p = 0.01], chronic kidney disease (CKD; p = 0.02), unvaccinated status (p = 0.001), and higher pulmonary parenchyma involvement (p < 0.0001). Multivariate analysis showed a high baseline value for MLR, NLR, SII, SIRI, AISI, IL-6, and TSS independent predictor of adverse outcomes for all recruited patients. Moreover, the presence of AF, CHF, CKD, and dyslipidemia were independent predictors of mortality. Furthermore, AF and dyslipidemia were independent predictors of IMV need. Conclusions: According to our findings, higher MLR, NLR, SII, SIRI, AISI, IL-6, and TSS values at admission strongly predict IMV requirement and mortality. Moreover, patients above 70 with AF, dyslipidemia, and unvaccinated status highly predicted IMV need and fatality. Likewise, CHF and CKD were independent predictors of increased mortality.

Platelet Indices and Platelet to Lymphocyte Ratio (PLR) as Markers for Predicting COVID-19 Infection Severity

Background

Novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (or coronavirus disease 2019; COVID-19) has caused a large number of infections across the globe. Numerous markers are being used to predict the severity of infection. This study was undertaken to assess the utility of platelet count, mean platelet volume (MPV), platelet distribution width (PDW), and platelet lymphocyte ratio (PLR) as markers of severity and mortality among patients with COVID-19 infection.

Methodology

This is a retrospective study conducted in a tertiary care center in India from April 2021 to June 2021. Patients admitted with COVID-19 infection were included in the study. Based on the severity, patients were categorized into the mild and severe (moderate severity included) groups. Platelet count, MPV, PDW, and PLR done at admission were studied and correlated with the disease severity and mortality.

Statistics

The independent t-test was used to compare the variables. The receiver operating characteristic (ROC) curve was done to identify the cut-off value. Statistical analysis was performed using SPSS 18 software (SPSS Inc. Released 2009. PASW Statistics for Windows, Version 18.0. Chicago: SPSS Inc).

Results

One hundred patients admitted with COVID-19 infection were studied. 51 patients had a mild and 49 had a severe infection. The mean PLR was 141.40 among patients with mild illness and 252.6 with severe infection (P<0.001). The mean PLR among survivors was 104.4 (SD-23.56) and among nonsurvivors was 302.78 (SD-34.5) (P<0.001). There was no statistically significant difference between the two groups with respect to platelet count, MPV, and PDW.

Conclusion

PLR was found to be a reliable marker of severity and mortality among patients with COVID-19 illness.

Correlation Between Platelet-Lymphocyte Ratio and Neutrophil-Lymphocyte Ratio in Patients with Uterine Leiomyoma: A Cross-Sectional Study

The inflammatory reaction has been proven to be a key factor in the pathogenesis of uterine leiomyoma. The platelet-lymphocyte ratio (PLR) and the neutrophil-lymphocyte ratio (NLR) are inexpensive and reliable inflammatory biomarkers. However, evidence of the relationship between PLR and NLR in patients with uterine leiomyoma is limited. This study aimed to explore the relationship between PLR and NLR in patients with incident uterine leiomyoma. This cross-sectional study included 763 patients with uterine leiomyoma who were first diagnosed in our hospital between January 2016 and December 2016. Patient characteristics were collected for univariate analysis, smooth curve fitting, and multivariate piecewise linear regression. Overall, 722 patients with an average age of 40.16 ± 5.99 years were included. The average PLR was 161.22 ± 65.33. Univariate analysis revealed a significant positive correlation between PLR and NLR (P < 0.0001). In addition, the non-linear relationship between the PLR and NLR was tested using smooth curve fitting after adjusting for potential confounding factors. The multivariate piecewise linear regression model showed that there was a significant positive correlation between PLR and NLR in both PLR <226.45 (β 0.01, 95% CI: 0.01, 0.01;P < 0.0001) and >226.45 (β 0.00, 95% CI: 0.00, 0.00; P=0.0026). In conclusion, PLR and NLR are positively correlated in patients with uterine leiomyoma. This result clarifies the promoting role of inflammation in the occurrence of uterine leiomyoma.

The GNB3 c.825C>T (rs5443) polymorphism and protection against fatal outcome of corona virus disease 2019 (COVID-19)

Background and aims: Albeit several factors which influence the outcome of corona virus disease (COVID-19) are already known, genetic markers which may predict the outcome of the disease in hospitalized patients are still very sparse. Thus, in this study, we aimed to analyze whether the single-nucleotide polymorphism (SNP) rs5443 in the gene GNB3, which was associated with higher T cell responses in previous studies, might be a suitable biomarker to predict T cell responses and the outcome of COVID-19 in a comprehensive German cohort.

Methods: We analyzed the influence of demographics, pre-existing disorders, laboratory parameters at the time of hospitalization, and GNB3 rs5443 genotype in a comprehensive cohort (N = 1570) on the outcome of COVID-19. In a sub cohort, we analyzed SARS-CoV-2-specific T cell responses and associated GNB3 rs5443 genotypes. We investigated the influence of all factors on COVID-19 fatality in multivariable analysis.

Results: We found a younger patient age, normotension or absence of diabetes mellitus or cardiovascular diseases, normal blood cell counts, and low inflammatory markers at hospital admission were protective factors against fatal course of disease. In addition, the rs5443 TT genotype was significantly associated with protection against COVID-19 fatality (OR: 0.60, 95% CI: 0.40–0.92, p = 0.02). We also observed significantly increased SARS-CoV-2-specific T cell responses in rs5443 TT genotype carriers (p = 0.01). Although we observed a significant association of the factors described previously in univariate analysis, only a younger age of the patients, normal blood cell counts, and the GNB3 rs5443 TT genotype remained independent predictors against COVID-19 fatality in multivariable analysis.

Conclusion: Immutable predictors for COVID-19 fatality are relatively rare. In this study we could show that the TT genotype of the SNP rs5443 in the gene GNB3 is associated with protection against COVID-19 fatality. It was as well correlated to higher SARS-CoV-2-specific T cell responses, which could result in a milder course of disease in those patients. Based on those observations we hereby provide a further prognostic biomarker, which might be used in routine diagnostics as a predictive factor for COVID-19 mortality already upon hospitalization.

The Neutrophil-to-Lymphocyte Ratio and the Platelet-to-Lymphocyte Ratio as Predictors of Mortality in Older Adults Hospitalized with COVID-19 in Peru

Background

The prognostic value of the neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) in patients with COVID-19 is rarely described in older adults. We aimed to estimate the prognostic value of NLR and PLR, determining the mortality of adults over 60 years of age hospitalized for COVID-19 in three hospitals in Peru from March to May 2020.

Methods

We performed a secondary analysis of data from a retrospective cohort carried out in Lambayeque, Peru, from March 18 to May 13, 2020. Older adults hospitalized for COVID-19 were included. The outcome variable was in-hospital mortality by all causes, while the exposure variable was the NLR and PLR (categorized in tertiles and numerically, performing a logarithmic transformation). We included sociodemographic variables, comorbidities, vital functions, laboratory markers, and treatment received during hospital stay. We evaluated the association between NLR and PLR using the hazard ratio (HR) in a Cox regression model. We estimated HR with their respective 95% confidence intervals (95% CI). We estimated cumulative/dynamic time-dependent ROC curves and reported area under the curve ROC (AUC-ROC) for 15-, 30-, and 60-day mortality with their respective simultaneous confidence intervals (confidence bands (CB)). Also, we estimated an optimal cut-off point based on the maximally selected rank statistics.

Results

A total of 262 hospitalized older adults were analyzed, 71.8% (n = 188) of whom were male with a median age of 70 years (interquartile range: 65-78). The mean NLR and PLR were 16.8 (95% CI: 14.9-18.7; SD: 15.5) and 50.3 (95% CI: 44.6-55.9; SD: 46.3), respectively. The mortality rate was 68.7% (95% CI: 62.7-74.3). The adjusted Cox regression analysis showed that the high NLR (adjusted HR (aHR) = 2.12; 95% CI: 1.43-3.14) and PLR (aHR = 1.90; 95% CI: 1.30-2.79) tertiles were associated with a higher risk of mortality. The maximum AUC-ROC values at 60 days of follow-up for NLR and PLR were 0.713 (95%CB: 0.627-0.800) and 0.697 (95%CB: 0.583-0.754), respectively.

Conclusions

The NLR and PLR are predictors of higher risk of mortality, and these results suggest that both could be reliable and practical markers for the identification of older adults at high risk of mortality by COVID-19. NLR and PLR have prognostic value, with an AUC greater than 0.5; however, by themselves, they are weak prognostic markers. It is important to carry out future studies incorporating these two markers into preexisting models or designing new ones considering them.

Haematological Traits in Symptomatic and Asymptomatic COVID-19 Positive Patients for Predicting Severity and Hospitalization

Objective

Materials and Methods

Results

Conclusion

Significance of hemogram‐derived ratios for predicting in‐hospital mortality in COVID‐19: A multicenter study

Background

To address the problem of resource limitation, biomarkers having a potential for mortality prediction are urgently required. This study was designed to evaluate whether hemogram‐derived ratios could predict in‐hospital deaths in COVID‐19 patients.

Materials and Methods

This multicenter retrospective study included hospitalized COVID‐19 patients from four COVID‐19 dedicated hospitals in Sylhet, Bangladesh. Data on clinical characteristics, laboratory parameters, and survival outcomes were analyzed. Logistic regression models were fitted to identify the predictors of in‐hospital death.

Results

Out of 442 patients, 55 (12.44%) suffered in‐hospital death. The proportion of male was higher in nonsurvivor group (61.8%). The mean age was higher in nonsurvivors (69 ± 13 vs. 59 ± 14 years, p < 0.001). Compared to survivors, nonsurvivors exhibited higher frequency of comorbidities, such as chronic kidney disease (34.5% vs. 15.2%, p ≤ 0.001), chronic obstructive pulmonary disease (23.6% vs. 10.6%, p = 0.011), ischemic heart disease (41.8% vs. 19.4%, p < 0.001), and diabetes mellitus (76.4% vs. 61.8%, p = 0.05). Leukocytosis and lymphocytopenia were more prevalent in nonsurvivors (p < 0.05). Neutrophil‐to‐lymphocyte ratio (NLR), derived NLR (d‐NLR), and neutrophil‐to‐platelet ratio (NPR) were significantly higher in nonsurvivors (p < 0.05). After adjusting for potential covariates, NLR (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.009‐1.08), d‐NLR (OR 1.08; 95% CI 1.006‐1.14), and NPR (OR 1.20; 95% CI 1.09‐1.32) have been found to be significant predictors of mortality in hospitalized COVID‐19 patients. The optimal cut‐off points for NLR, d‐NLR, and NPR for prediction of in‐hospital mortality for COVID‐19 patients were 7.57, 5.52 and 3.87, respectively.

Conclusion

Initial assessment of NLR, d‐NLR, and NPR values at hospital admission is of good prognostic value for predicting mortality of patients with COVID‐19.

Plasma Levels and Renal Handling of Amino Acids Contribute to Determination of Risk of Mortality or Feed of Ventilation in Patients with COVID-19

COVID-19 infection may lead to serious complications, e.g., need for mechanical ventilation or death in some cases. A retrospective analysis of patients referred to our COVID Emergency Department, indiscriminately, was performed. A routine lab analysis measured amino acids in plasma and urine of patients. Data of surviving and deceased patients and those requiring or not requiring mechanical ventilation were compared, and logistic regression analyses have been performed. Deceased patients were older, had higher blood glucose, potassium, AST, LDH, troponin, d-dimer, hsCRP, procalcitonin, interleukin-6 levels (p < 0.05 for all). They had lower plasma serine, glycine, threonine, tryptophan levels (p < 0.01), higher tyrosine and phenylalanine levels (p < 0.05), and higher fractional excretion of arginine, methionine, and proline (p < 0.05) than survivors. In a regression model, age, severity score of COVID-pneumonia, plasma levels of threonine and phenylalanine were predictors of in-hospital mortality. There was a difference in ventilated vs. non-ventilated patients in CT-scores, glucose, and renal function (p < 0.001). Using logistic regression, CT-score, troponin, plasma level, and fractional excretion of glycine were predictors of ventilation. Plasma levels and renal excretion of certain amino acids are associated with the outcome of COVID-19 infection beside other parameters such as the CT-score or age.

Neutrophile-to-Lymphocyte Ratio (NLR) Identifies Patients with Coronavirus Infectious Disease 2019 (COVID-19) at High Risk for Deterioration and Mortality—A Retrospective, Monocentric Cohort Study

Among people infected with SARS-CoV-2, the determination of clinical features associated with poor outcome is essential to identify those at high risk of deterioration. Here, we aimed to investigate clinical phenotypes of patients hospitalized due to COVID-19 and to examine the predictive value of the neutrophil-to-lymphocyte ratio (NLR) in a representative patient collective of the Swiss population. We conducted a retrospective monocentriccohort study with patients hospitalized due to COVID-19 between 27 February and 31 December 2020. Data were analyzed descriptively, using the binary logistic regression model, proportional odds logistic regression model, competing risk analysis, and summary measure analysis. A total of 454 patients were included in our study. Dyspnea, elevated respiratory rate, low oxygen saturation at baseline, age, and presence of multiple comorbidities were associated with a more severe course of the disease. A high NLR at baseline was significantly associated with disease severity, unfavorable outcome, and mortality. In non-survivors, NLR further increased during hospital stay, whereas in survivors, NLR decreased. In conclusion, our data emphasize the importance of accurate history taking and clinical examination upon admission and confirm the role of baseline NLR as a surrogate marker for increased disease severity, unfavorable outcome, and mortality in patients hospitalized due to infection with SARS-CoV-2.

Neutrophil-to-Lymphocyte Ratio (NLR) Is a Promising Predictor of Mortality and Admission to Intensive Care Unit of COVID-19 Patients

The neutrophil-to-lymphocyte ratio (NLR) is an inflammatory marker predicting the prognosis of several diseases. We aimed to assess its role as a predictor of mortality or admission to the intensive care unit in COVID-19 patients. We retrospectively evaluated a cohort of 411 patients with COVID-19 infection. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) of patients with COVID-19 were compared. The median age of our sample was 72 years (interquartile range: 70−75); 237 were males. Hypertension, diabetes and ischemic heart disease were the most common comorbidities. The study population was subdivided into three groups according to NLR tertiles. Third-tertile patients were older, showing significantly higher levels of inflammatory markers; 133 patients (32%) died during hospitalization, 81 of whom belonged to the third tertile; 79 patients (19%) were admitted to ICU. NLR showed the largest area under the curve (0.772), with the highest specificity (71.9%) and sensitivity (72.9%), whereas CRP showed lower sensitivity (60.2%) but slightly higher specificity (72.3%). Comparisons between NLR and CRP ROC curves were significantly different (p = 0.0173). Cox regression models showed that the association between NLR and death was not weakened after adjustment for confounders. Comparisons of ROC curves showed no significant differences between NLR, PLR, and CRP. Cox regression analysis showed that NLR predicted the risk of admission to ICU independently of demographic characteristics and comorbidities (HR: 3.9597, p < 0.0001). These findings provide evidence that NLR is an independent predictor of mortality and a worse outcome in COVID-19 patients and may help identify high-risk individuals with COVID-19 infection at admission.

Fever, Tachypnea, and Monocyte Distribution Width Predicts Length of Stay for Patients with COVID-19: A Pioneer Study

(1) Background: Our study investigated whether monocyte distribution width (MDW) could be used in emergency department (ED) settings as a predictor of prolonged length of stay (LOS) for patients with COVID-19. (2) Methods: A retrospective cohort study was conducted; patients presenting to the ED of an academic hospital with confirmed COVID-19 were enrolled. Multivariable logistic regression models were used to obtain the odds ratios (ORs) for predictors of an LOS of >14 days. A validation study for the association between MDW and cycle of threshold (Ct) value was performed. (3) Results: Fever > 38 °C (OR: 2.82, 95% CI, 1.13−7.02, p = 0.0259), tachypnea (OR: 4.76, 95% CI, 1.67−13.55, p = 0.0034), and MDW ≥ 21 (OR: 5.67, 95% CI, 1.19−27.10, p = 0.0269) were robust significant predictors of an LOS of >14 days. We developed a new scoring system in which patients were assigned 1 point for fever > 38 °C, 2 points for tachypnea > 20 breath/min, and 3 points for MDW ≥ 21. The optimal cutoff was a score of ≥2. MDW was negatively associated with Ct value (β: −0.32 per day, standard error = 0.12, p = 0.0099). (4) Conclusions: Elevated MDW was associated with a prolonged LOS.

Prothrombotic Milieu, Thrombotic Events and Prophylactic Anticoagulation in Hospitalized COVID-19 Positive Patients: A Review

The Coronavirus Disease 2019 (COVID-19) pandemic has resulted in significant morbidity and mortality worldwide. Although initial reports concentrated on severe respiratory illness, emerging literature has indicated a substantially elevated risk of thromboembolic events in patients with COVID-19 disease. Pro-inflammatory cytokine release has been linked to endothelial dysfunction and activation of coagulation pathways, as evident by elevated D-dimer levels and deranged coagulation parameters. Both macrovascular and microvascular thromboses have been described in observational cohort and post-mortem studies. Concurrently, preliminary data have suggested the role of therapeutic anticoagulation in preventing major thromboembolic complications in moderately but not critically ill patients. However, pending results from randomized controlled trials, clear guidance is lacking regarding the intensity and duration of anticoagulation in such patients. Herein, we review the existing evidence on incidence and pathophysiology of COVID-19 related thromboembolic complications and guide anticoagulation therapy based on current literature and societal consensus statements.

Neutrophil-to-lymphocyte ratio versus platelet-to-lymphocyte ratio in predicting clinical outcomes in acute methanol poisoning

Acute methanol poisoning is a global health concern. This study was designed to compare the prognostic roles of neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and their combination in the prediction of clinical outcomes in methanol-intoxicated patients as well as to evaluate their associations with all initial patients' characteristics. We conducted a cross-sectional study among methanol-intoxicated patients. A total of 109 patients were enrolled in the study. Thirty-four (31%) patients died during hospital admission while 30 (27.5%) patients developed visual loss. Most of the unfavorable findings were evident in patients with high NLR and PLR. Neutrophil-to-lymphocyte ratio and PLR can excellently differentiate between survivors and non-survivors with an area under the curve (AUC) of 0.991 vs 0.923, respectively. Platelet-to-lymphocyte ratio showed an accepted discrimination ability to differentiate between patients who developed and patients who did not develop visual loss, AUC of 0.734, however, NLR showed no discrimination, AUC of 0.558. We concluded that NLR and PLR can serve as valuable tools in risk-stratifying patients and prognosticating outcomes in acute methanol poisoning. Platelet-to-lymphocyte ratio is superior to NLR as a predictive factor in patients with permanent visual impairment. However, a combination of NLR with PLR can develop a more powerful prediction for overall clinical outcomes.