Distribution and reference interval establishment of neutral-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) in Chinese healthy adults.

BACKGROUND: Neutral-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) are associated with coronavirus disease 2019 (COVID-19) and many diseases, but there are few data about the reference interval (RI) of NLR, LMR, and PLR. METHODS: The neutrophil count, lymphocyte count, monocyte count, and platelet count of 404,272 Chinese healthy adults (>18 years old) were measured by Sysmex XE-2100 automatic hematology analyzer, and NLR, LMR, and PLR were calculated. According to CLSI C28-A3, the nonparametric 95% percentile interval is defined as the reference interval. RESULTS: The results of Mann-Whitney U test showed that NLR (p < .001) in male was significantly higher than that in female; LMR (p < .001) and PLR (p < .001) in male were significantly lower than that in female. Kruskal-Wallis H test showed that there were significant differences in NLR, LMR, and PLR among different genders and age groups (p < .001). The linear graph showed that the reference upper limit of NLR and PLR increased with age and the reference upper limit of LMR decreases with age in male population. In female population, the reference upper limit of NLR in 50-59 group, LMR in >80 group, and PLR in 70-79 group appeared a trough; the reference upper limit of NLR in >80 group, LMR in 50-59 group, and PLR in 40-49 group appeared peak. CONCLUSION: The establishment of RI for NLR, LMR, and PLR in Chinese healthy adults according to gender and age will promote the standardization of clinical application.

A low level of CD16pos monocytes in SARS-CoV-2 infected patients is a marker of severity.

OBJECTIVES: Severe forms of coronavirus disease 2019 (COVID-19) are characterized by an excessive production of inflammatory cytokines. Activated monocytes secrete high levels of cytokines. Human monocytes are divided into three major populations: conventional (CD14posCD16neg), non-classical (CD14dimCD16pos), and intermediate (CD14posCD16pos) monocytes. The aim of this study was to analyze whether the distribution of conventional (CD16neg) and CD16pos monocytes is different in patients with COVID-19 and whether the variations could be predictive of the outcome of the disease. METHODS: We performed a prospective study on 390 consecutive patients referred to the Emergency Unit, with a proven diagnosis of SARS-CoV 2 infection by RT-PCR. Using the CytoDiff™ reagent, an automated routine leukocyte differential, we quantified CD16neg and CD16pos monocytes. RESULTS: In the entire population, median CD16neg and CD16pos monocyte levels (0.398 and 0.054×109/L, respectively) were in the normal range [(0.3-0.7×109/L) and (0.015-0.065×109/L), respectively], but the 35 patients in the intensive care unit (ICU) had a significantly (p<0.001) lower CD16pos monocyte count (0.018 × 109/L) in comparison to the 70 patients who were discharged (0.064 × 109/L) or were hospitalized in conventional units (0.058 × 109/L). By ROC curve analysis, the ratio [absolute neutrophil count/CD16pos monocyte count] was highly discriminant to identify patients requiring ICU hospitalization: with a cut-off 193.1, the sensitivity and the specificity were 74.3 and 81.8%, respectively (area under the curve=0.817). CONCLUSIONS: Quantification of CD16pos monocytes and the ratio [absolute neutrophil count/CD16pos monocyte count] could constitute a marker of the severity of disease in COVID-19 patients.

Evaluation of simple and cost-effective immuno- haematological markers to predict outcome in hospitalized severe COVID-19 patients, with a focus on diabetes mellitus - A retrospective study in Andhra Pradesh, India.

BACKGROUND AND AIMS: COVID-19 pandemic has strained the health infrastructure globally, providing an opportunity to identify cost-effective biomarkers. We aimed to identify simple hematological prognostic markers in hospitalized severe COVID-19 patients with and without diabetes. METHODS: Retrospective study of RT-PCR confirmed hospitalized severe COVID-19 patients (total: n = 154 patients, including diabetic subset n = 57) were analyzed. Clinically applicable cut-offs were derived using receiver operating characteristic (ROC) curve analysis for total leucocyte count (TLC), absolute neutrophil count (ANC), neutrophil lymphocyte ratio (NLR), and derived neutrophil lymphocyte ratio (dNLR) in order to prognosticate the outcome. RESULTS: Among 154 severe COVID-19 patients, significant association with mortality was seen with respect to TLC(p < 0.001), ANC (p < 0.001), NLR(p < 0.001) and dNLR(p < 0.001). In the total cohort, applicable cut-offs based on ROC curve in predicting outcome were, for TLC 8950 cells/mm3 (area under curve (AUC)-0.764, odds ratio (OR)-7.53), ANC 7679 cells/mm3 (AUC-0.789, OR-8.14), NLR 5.13 (AUC-0.741, OR-4.77), dNLR 3.44 (AUC -0.741, OR-4.43) respectively.In diabetic subset, the cut-offs for TLC was 8950 cells/mm3 (AUC -0.762, OR-14.9), ANC 6510 cells/mm3 (AUC -0.773, OR-16.8), NLR 5.13(AUC -0.678, OR-6) and dNLR 3.25(AUC -0.685, OR-4.7) respectively. CONCLUSIONS: In severe COVID-19 patients irrespective of diabetes, a simple, applicable total leucocyte count cut-off, 8950 cells/mm3 , together with easily derived cut-offs for ANC, NLR, dNLR may serve as cost-effective prognosticators of clinical outcome. A normal TLC may be misleading in the intensive care and the above applicable cut-off for TLC serves as an early warning tool for high-risk identification and better in-hospital management. Even with similar or lower cut-offs, diabetics had a higher mortality.

Neutrophil-to-Lymphocyte Ratio as a Poor Prognostic Factor in Iranian COVID-19 Patients.

BACKGROUND: We aimed to accumulate evidence that suggests the potential role of neutrophil-to-lymphocyte ratio (NLR) in determining the prognostic factor for COVID-19 patients. METHODS: A cohort of COVID-19 hospitalized patients at the Ilam University of Medical Sciences was analyzed. Logistic regression models were performed to identify the potential role of NLR in determining the prognostic factor for COVID-19 patients. RESULTS: The total number of in-hospital mortality was 43/328 (13.1%). Multivariate analysis identified that there was a 26% higher risk of in-hospital death for each unit increase in NLR (Odds ratio [OR] = 1.08; 95% confidence interval [95% CI], 1.01 to 1.14; p = 0.0147). Multivariate analysis identified that there was an 8% higher risk of in-hospital death for each unit increase in NLR (Odds ratio [OR] = 1.08; 95% confidence interval [95% CI], 1.01 to 1.14; p = 0.0147). Compared with patients in the NLR < 5 group, the NLR of patients in the NLR ≥ 5 group had a 16-fold higher risk of mortality (OR = 16.04; 95% CI, 1.14 to 224.95; p = 0.0395) after adjustment for potential confounders. CONCLUSIONS: NLR is an independent risk factor of mortality COVID-19 patients.

Identification and characterization of neutrophil heterogeneity in sepsis.

BACKGROUND: Although the immune function of neutrophils in sepsis has been well described, the heterogeneity of neutrophils remains unclear during the process of sepsis. METHODS: In this study, we used a mouse CLP model to simulate the clinical scenario of patients with sepsis, neutrophil infiltration, abnormal distribution and dysfunction was analyzed. LPS was used to stimulate neutrophils in vitro to simulate sepsis; single-cell gene sequencing technology was used to explore the immunological typing. To explore the immunological function of immunosuppressive neutrophils, PD-L1 knockout neutrophils were cocultured with lymphocytes from wild-type mice. RESULTS: We found that neutrophils presented variant dysfunction at the late stage of sepsis, including inhibition of apoptosis, seriously damaged chemotaxis and extensive infiltration into the tissues. Single-cell RNA sequencing revealed that multiple subclusters of neutrophils were differentiated after LPS stimulation. The two-dimensional spatial distribution analysis showed that Foxp3+ T cells were much closer to Ly-6G than the CD4+ and CD8+ cells, indicating that infiltrated neutrophils may play immunomodulatory effect on surrounding T-regs. Further observations showed that LPS mediates PD-L1 over expression through p38α-MSK1/-MK2 pathway in neutrophils. The subsets of highly expressed PD-L1 exert immunosuppressive effect under direct contact mode, including inhibition of T cell activation and induction of T cell apoptosis and trans-differentiation. CONCLUSIONS: Taken together, our data identify a previously unknown immunosuppressive subset of neutrophils as inhibitory neutrophil in order to more accurately describe the phenotype and characteristics of these cells in sepsis.

Tobacco smoking confers risk for severe COVID-19 unexplainable by pulmonary imaging.

BACKGROUND: COVID-19 is a new pneumonia. It has been hypothesized that tobacco smoking history may increase severity of this disease in the patients once infected by the underlying coronavirus SARS-CoV-2 because smoking and COVID-19 both cause lung damage. However, this hypothesis has not been tested. OBJECTIVE: Current study was designed to focus on smoking history in patients with COVID-19 and test this hypothesis that tobacco smoking history increases risk for severe COVID-19 by damaging the lungs. METHODS AND RESULTS: This was a single-site, retrospective case series study of clinical associations, between epidemiological findings and clinical manifestations, radiographical or laboratory results. In our well-characterized cohort of 954 patients including 56 with tobacco smoking history, smoking history increased the risk for severe COVID-19 with an odds ratio (OR) of 5.5 (95% CI: 3.1-9.9; P = 7.3 × 10-8 ). Meta-analysis of ten cohorts for 2891 patients together obtained an OR of 2.5 (95% CI: 1.9-3.3; P < 0.00001). Semi-quantitative analysis of lung images for each of five lobes revealed a significant difference in neither lung damage at first examination nor dynamics of the lung damage at different time-points of examinations between the smoking and nonsmoking groups. No significant differences were found either in laboratory results including D-dimer and C-reactive protein levels except different covariances for density of the immune cells lymphocyte (P = 3.8 × 10-64 ) and neutrophil (P = 3.9 × 10-46 ). CONCLUSION: Tobacco smoking history increases the risk for great severity of COVID-19 but this risk is achieved unlikely by affecting the lungs.

High levels of SARS-CoV-2-specific T cells with restricted functionality in severe courses of COVID-19.

BACKGROUNDPatients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) differ in the severity of disease. We hypothesized that characteristics of SARS-CoV-2-specific immunity correlate with disease severity.METHODSIn this study, SARS-CoV-2-specific T cells and antibodies were characterized in uninfected controls and patients with different coronavirus disease 2019 (COVID-19) disease severity. SARS-CoV-2-specific T cells were flow cytometrically quantified after stimulation with SARS-CoV-2 peptide pools and analyzed for expression of cytokines (IFN-γ, IL-2, and TNF-α) and markers for activation, proliferation, and functional anergy. SARS-CoV-2-specific IgG and IgA antibodies were quantified using ELISA. Moreover, global characteristics of lymphocyte subpopulations were compared between patient groups and uninfected controls.RESULTSDespite severe lymphopenia affecting all major lymphocyte subpopulations, patients with severe disease mounted significantly higher levels of SARS-CoV-2-specific T cells as compared with convalescent individuals. SARS-CoV-2-specific CD4+ T cells dominated over CD8+ T cells and closely correlated with the number of plasmablasts and SARS-CoV-2-specific IgA and IgG levels. Unlike in convalescent patients, SARS-CoV-2-specific T cells in patients with severe disease showed marked alterations in phenotypical and functional properties, which also extended to CD4+ and CD8+ T cells in general.CONCLUSIONGiven the strong induction of specific immunity to control viral replication in patients with severe disease, the functionally altered characteristics may result from the need for contraction of specific and general immunity to counteract excessive immunopathology in the lung.FUNDINGThe study was supported by institutional funds to MS and in part by grants of Saarland University, the State of Saarland, and the Rolf M. Schwiete Stiftung.

COVID-19 in older adults: Retrospective cohort study in a tertiary hospital in Japan.

AIM: We aimed to describe the clinical characteristics, treatment and outcomes of patients with COVID-19 pneumonia, in particular older patients, admitted to tertiary and partner hospitals in Saitama, Japan. METHODS: We retrospectively reviewed the medical records of patients with COVID-19 pneumonia admitted to tertiary and partner hospitals in Saitama, Japan. Twenty-six patients with COVID-19 were categorized into two groups, i.e., older (≥75 years) and younger adults (≤74 years). We evaluated the clinical characteristics, comorbidities, symptoms, laboratory test results, treatments and outcomes of the patients. RESULTS: The majority of the older patients had comorbidities, such as dementia, cardiovascular disease and bone fractures. Comorbidities were significantly more frequent in older patients than younger patients. No association was found between age and body temperature or the incidence of respiratory failure. White blood cell count was significantly lower in older patients (P = 0.018) and the decrease in lymphocytes was greater in younger patients (P = 0.009). Computed tomography (CT) of all patients showed non-segmental, peripherally dominant ground-glass opacities consistent with COVID-19 pneumonia. In older patients, antiviral drugs, anticoagulants and anti-inflammatory drugs were administered on a compassionate use basis. The difference in mortality between the older and the younger patients was not statistically significant. CONCLUSIONS: In older patients, typical clinical symptoms and blood test changes were often absent; however, CT always contained typical findings of COVID-19, suggesting that CT may be a useful diagnostic tool. Our report illustrates that appropriate treatment, taking patient background into consideration, may improve their condition regardless of age. Geriatr Gerontol Int 2020; 20: 1044-1049.

Impaired immune and coagulation systems may be early risk factors for COVID-19 patients: A retrospective study of 118 inpatients from Wuhan, China.

The coronavirus disease 2019 (COVID-19) outbreak has become a global health threat and will likely be one of the greatest global challenges in the near future. The battle between clinicians and the COVID-19 outbreak may be a "protracted war."The objective of this study was to investigate the risk factors for in-hospital mortality in patients with COVID-19, so as to provide a reference for the early diagnosis and treatment.This study retrospectively enrolled 118 patients diagnosed with COVID-19, who were admitted to Eastern District of Renmin Hospital of Wuhan University from February 04, 2020 to March 04, 2020. The demographics and laboratory data were collected and compared between survivors and nonsurvivors. The risk factors of in-hospital mortality were explored by univariable and multivariable logistic regression to construct a clinical prediction model, the prediction efficiency of which was verified by receiver-operating characteristic (ROC) curve.A total of 118 patients (49 males and 69 females) were included in this study; the results revealed that the following factors associated with in-hospital mortality: older age (odds ratio [OR] 1.175, 95% confidence interval [CI] 1.073-1.287, P = .001), neutrophil count greater than 6.3 × 10 cells/L (OR 7.174, (95% CI 2.295-22.432, P = .001), lymphocytopenia (OR 0.069, 95% CI 0.007-0.722, P = .026), prothrombin time >13 seconds (OR 11.869, 95% CI 1.433-98.278, P = .022), D-dimer >1 mg/L (OR 22.811, 95% CI 2.224-233.910, P = .008) and procalcitonin (PCT) >0.1 ng/mL (OR 23.022, 95% CI 3.108-170.532, P = .002). The area under the ROC curve (AUC) of the above indicators for predicting in-hospital mortality were 0.808 (95% CI 0.715-0.901), 0.809 (95% CI 0.710-0.907), 0.811 (95% CI 0.724-0.898), 0.745 (95% CI 0.643-0.847), 0.872 (95% CI 0.804-0.940), 0.881 (95% CI 0.809-0.953), respectively. The AUC of combined diagnosis of these aforementioned factors were 0.992 (95% CI 0.981-1.000).In conclusion, older age, increased neutrophil count, prothrombin time, D-dimer, PCT, and decreased lymphocyte count at admission were risk factors associated with in-hospital mortality of COVID-19. The prediction model combined of these factors could improve the early identification of mortality risk in COVID-19 patients.

Clinical and laboratory findings from patients with COVID-19 pneumonia in Babol North of Iran: a retrospective cohort study.

BACKGROUND: In December 2019, China has experienced an outbreak of novel coronavirus disease 2019 (COVID-19). Coronavirus has now spread to all of the continents. We aimed to consider clinical characteristics, laboratory data of COVID-19 that provided more information for the research of this novel virus. METHODS: We performed a retrospective cohort study on the clinical symptoms and laboratory findings of a series of the 100 confirmed patients with COVID-19. These patients were admitted to the hospitals affiliated to Babol University of Medical Sciences (Ayatollah Rohani, Shahid Beheshti and Yahyanejad hospitals) form 25 February 2020 to 12 March 2020. RESULTS: Nineteen patients died during hospitalization and 81 were discharged. Non-survivor patients had a significantly higher C-reactive protein (CRP) (MD: 46.37, 95% CI: 20.84, 71.90; P = 0.001), white blood cells (WBCs) (MD: 3.10, 95% CI: 1.53, 4.67; P < 0.001) and lower lymphocyte (MD: -8.75, 95% CI: -12.62, -4.87; P < 0.001) compared to survivor patients Data analysis showed that comorbid conditions (aRR: 2.99, 95% CI: 1.09, 8.21, P = 0.034), higher CRP levels (aRR: 1.02, 95% CI: 1.01, 1.03, P = 0.044), and lower lymphocyte (aRR: 0.82, 95% CI: 0.73, 0.93, P = 0.003) were associated with increased risk of death. CONCLUSIONS: Based on our findings, most non-survivors are elderly with comorbidities. Lymphopenia and increased levels of WBCs along with elevated CRP were associated with increased risk of death. Therefore, it is best to be regularly assessed these markers during treatment of COVID-19 patients.