The diagnostic and prognostic role of neutrophil-to-lymphocyte ratio in COVID-19: a systematic review and meta-analysis

Background: The world urgently requires surrogate markers to diagnose COVID-19 and predict its progression. The severity is not easily predicted via currently used biomarkers. Critical COVID-19 patients need to be screened for hyperinflammation to improve mortality but expensive cytokine measurement is not routinely conducted in most laboratories. The neutrophil-to-lymphocyte ratio (NLR) is a novel biomarker in patients with various diseases. We evaluated the diagnostic and prognostic accuracy of the NLR in COVID-19 patients.Methods: We searched for relevant articles in seven databases. The quantitative analysis was conducted if at least two studies were evaluating the NLR role in COVID-19.Results: We included 8,120 individuals, including 7,482 COVID-19 patients, from 32 articles. Patients with COVID-19 had significantly higher levels of NLR compared to negative individuals. Advanced COVID-19 stages had significantly higher levels of NLR than earlier stages.Expert Opinion: We found significantly higher levels of NLR in advanced stages compared to earlier stages of COVID-19 with good accuracy to diagnose and predict the disease outcome, especially mortality prediction. A close evaluation of critical SARS-CoV-2 patients and efficient early management are essential measures to decrease mortality. NLR could help in assessing the resource allocation in severe COVID-19 patients even in restricted settings.

P3130Relation between serum levels of long acting penicillin and the inflammatory markers: High sensitivity C-reactive protein and interleukin-6 in patients with chronic rheumatic heart disease

Background

There is evidence of a chronic inflammatory state in patients with chronic rheumatic valvular heart disease (RhD) as shown by high serum levels of high sensitivity C-reactive protein (CRP) and interleukin-6 (IL6). Despite the efficacy of long acting penicillin (LAP) in secondary prevention of rheumatic fever, its effect on this inflammatory state is still unknown

Objective

We sought to study the effect of (LAP) on the inflammatory markers, (CRP) and (IL-6), in patients with chronic rheumatic heart disease.

Methods

Eighty patients having (RhD) patients coming to our university hospitals outpatient clinic for rheumatic fever secondary prophylaxis by regular administration of (LAP) were enrolled in. the study. Patients were divided into to 3 groups: Group A; 70 patients with (RhD) already on prophylactic (LAP), Group B; 10 patients with (RhD) who have not yet started prophylactic (LAP), Group C; control group of 10 healthy individuals not known to have (RhD). Serum levels of (LAP), (IL6) and (CRP) were measured for the three groups.

Results

. Group A had significantly lower (IL6) levels than group B (25.22±33.50 vs. 126.1±33.76ng/ml, respectively, p<0.0001). (IL6) levels were significantly lower in control subjects compared to patients in group B (3.600±2.319, 25.22±33.50 ng/ml respectively, p<0.0001). However, IL6 levels in the control group were lower but non-significantly different compared to Group A . (CRP) level was lower in group A than group B (8419±4935 vs. 14400±3375mg/dl respectively, p=0.0002). (CRP) levels were significantly lower in control subjects compared to patients in group A and group B. (IL6) values were positively correlated with (CRP) values (r=0.6387, p<0.0001).

(CRP) level negatively correlated with Long acting penicillin level (r=−0.5277, p<0.0001). (IL-6) level negatively correlated with (LAP) level (r=−0.4401, p<0.0001). There was a highly significant difference between (LAP) level in compliant and non-compliant patients (1.045±1.270 vs. 0.0785±0.1057ng/ml, respectively, p value <0.0001).

There was also a highly significant difference between (CRP) level in compliant and non-compliant patients (7640±4558 vs. 13090±4717 mg/dl, respectively, p value 0.005).Moreover, there was a significant difference between (IL-6) levels in compliant and non-compliant patients (21.53±32.70 vs. 47.40±30.91 ng/ml, respectively, p value 0.03).

Conclusion

Serum (LAP) has a strong negative correlation with (IL-6) and (CRP) levels. Regular administration of (LAP) strongly ameliorates the inflammatory state seen in patients with (RhD).

Changes in creatine phosphokinase (CK) concentrations after minor and major surgeries in children

BACKGROUND

During surgery, damage occurs to muscles in the area of the operation. The few studies that have examined creatine phosphokinase (CK) values after surgery have been in adults. The only study in children was after cardiac surgery. Understanding the normal enzyme pattern of change may help to differentiate malignant hyperthermia, anaesthesia-induced rhabdomyolysis and elevated CK values resulting from inherited muscle disease in cases in which these are suspected. The aim of this study was to delineate the normal rise of CK after minor and major surgery in children.

METHODS

A total of 71 patients aged 1 month-17 yr were studied. From the cohort of 71 patients, 46 underwent elective surgery (14 major, 32 minor) and in 25 the surgery was designated as an emergency surgery (21 major, 4 minor). The anaesthesia protocol was similar for both groups with halothane induction and isoflurane maintenance. Owing to its possible effect on CK, succinylcholine was avoided during the study.

RESULTS

The mean values of CK concentration before and after surgery were 63.1 iu litre(-1) and 151.5 iu litre(-1), respectively. The median CK elevation (range) for the major and minor surgery groups was 43 iu litre(-1) (4-647) and 10 iu litre(-1) (-28 to 122), respectively (P<0.0001).

CONCLUSIONS

CK concentrations in the major surgery group were significantly higher than the minor surgery group. This profile can contribute to the evaluation of patients who present with the possibility of malignant hyperthermia, anaesthesia-induced rhabdomyolysis and underlying muscle disease. Any rise of CK concentration above what is expected should prompt further investigation.

Expression and purification of recombinant human receptor for advanced glycation endproducts in Escherichia coli

The receptor for advanced glycation endproducts (RAGE) is a multiligand receptor that binds a variety of structurally and functionally unrelated ligands, including advanced glycation endproducts (AGEs), amyloid fibrils, amphoterin, and members of the S100 family of proteins. The receptor has been implicated in the pathology of diabetes as well as in inflammatory processes and tumor cell metastasis. For the present study, the extracellular region of RAGE (exRAGE) was expressed as a soluble, C-terminal hexahistidine-tagged fusion protein in the periplasmic space of Escherichia coli. Proper processing and folding of the purified protein, predicted to contain three immunoglobulin-type domains, was supported by the results of electrospray mass spectroscopy and circular dichroism experiments. Sedimentation velocity experiments showed that exRAGE was primarily monomeric in solution. Binding to several RAGE ligands, including AGE-BSA, immunoglobulin light chain amyloid fibrils, and glycosaminoglycans, was demonstrated using pull-down, dot-blot, or enzyme-linked microplate assays. Using surface plasmon resonance, the interaction of exRAGE with AGE-BSA was shown to fit a two-site model, with KD values of 88 nM and 1.4 microM. The E. coli-derived exRAGE did not bind the advanced glycation endproduct Nepsilon-(carboxymethyl)lysine, as reported for the cellular receptor, and the possible role of RAGE glycosylation in recognition of this ligand is discussed. This new RAGE construct will facilitate detailed studies of RAGE-ligand interactions and provides a platform for preparation of site-directed mutants for future structure/function studies.

Kinetics of Src Homology 3 Domain Association with the Proline-rich Domain of Dynamins

Dynamin function is mediated in part through association of its proline-rich domain (PRD) with the Src homology 3 (SH3) domains of several putative binding proteins. To assess the specificity and kinetics of this process, we undertook surface plasmon resonance studies of the interaction between isolated PRDs of dynamin-1 and -2 and several purified SH3 domains. Glutathione S-transferase-linked SH3 domains bound with high affinity (K(D) approximately 10 nm to 1 microm) to both dynamin-1 and -2. The simplest interaction appeared to take place with the amphiphysin-SH3 domain; this bound to a single high affinity site (K(D) approximately 10 nm) in the C terminus of dynamin-1 PRD, as predicted by previous studies. Binding to the dynamin-2 PRD was also monophasic but with a slightly lower affinity (K(D) approximately 25 nm). Endophilin-SH3 binding to both dynamin-1 and -2 PRDs was biphasic, with one high affinity site (K(D) approximately 14 nm) in the N terminus of the PRD and another lower affinity site (K(D) approximately 60 nm) in the C terminus of dynamin-1. The N-terminal site in dynamin-2 PRD had a 10-fold lower affinity for endophilin-SH3. Preloading of dynamin-1 PRD with the amphiphysin-SH3 domain partially occluded binding of the endophilin-SH3 domain, indicating overlap between the binding sites in the C terminus, but endophilin was still able to interact with the high affinity N-terminal site. This shows that more than one SH3 domain can simultaneously bind to the PRD and suggests that competition probably occurs in vivo between different SH3-containing proteins for the limited number of PXXP motifs. Endophilin-SH3 binding to the high affinity site was disrupted when dynamin-1 PRD was phosphorylated with Cdk5, indicating that this site overlaps the phosphorylation sites, but amphiphysin-SH3 binding was unaffected. Other SH3 domains showed similarly complex binding characteristics, and substantial differences were noted between the PRDs from dynamin-1 and -2. For example, SH3 domains from c-Src, Grb2, and intersectin bound only to the C-terminal half of dynamin-2 PRD but to both the N- and C-terminal portions of dynamin-1 PRD. Thus, differential binding of SH3 domain-containing proteins to dynamin-1 and -2 may contribute to the distinct functions performed by these isoforms.

Temperature and cryoprotectant influence secondary quinone binding position in bacterial reaction centers

We have determined the first de novo position of the secondary quinone QB in the Rhodobacter sphaeroides reaction center (RC) using phases derived by the single wavelength anomalous dispersion method from crystals with selenomethionine substitution. We found that in frozen RC crystals, QB occupies primarily the proximal binding site. In contrast, our room temperature structure showed that QB is largely in the distal position. Both data sets were collected in dark-adapted conditions. We estimate that the occupancy of the QB site is 80% with a proximal: distal ratio of 4:1 in frozen RC crystals. We could not separate the effect of freezing from the effect of the cryoprotectants ethylene glycol or glycerol. These results could have far-reaching implications in structure/function studies of electron transfer in the acceptor quinone complex because the above are the most commonly used cryoprotectants in spectroscopic experiments.

Understanding Nonidealities of the Osmotic Pressure of Concentrated Bovine Serum Albumin

Previously Vilker et al. (J. Colloid Interface Sci. 79(2), (1981)) reported the osmotic pressure of concentrated bovine serum albumin (BSA) up to 475 g/L in 0.15 M sodium chloride at pH 4.5, 5.4, and 7.4. The authors used a semiempirical model based on Donnan theory to predict the osmotic pressure with good agreement. However, the formal application of a three-term virial expansion with the coefficients determined from the potential energy of interaction between BSA molecules resulted in poor agreement with their data. In this study, modeling of the osmotic pressure was reexamined using a free-solvent model that considered average solute-solvent and microion-solute interactions in a mole fraction concentration variable. The resulting fits were excellent for all three pH. The model is designed with no fitted parameters; however, the model results were highly sensitive to the selected hydration and microion binding. Therefore the hydration was further regressed from its initial estimate of 1 g H2O/g BSA (based on water-17O magnetic resonance studies of other globular proteins) to minimize the least-squares error between the predicted values and data. The resulting average hydration was determined to be 1.14 +/- 0.03 g H2O/g BSA for all pH values. However, the standard error in hydration for each pH was no greater than +/-0.0063 g H2O/g BSA. These results demonstrate that solvent-solute interaction and the concentration variable may be critical factors when evaluating osmotic pressure data of concentrated protein solutions. Copyright 1998 Academic Press.

Free-Solvent Model of Osmotic Pressure Revisited: Application to Concentrated IgG Solution under Physiological Conditions

The osmotic pressure measurements of bovine immuno-gamma globulin in phosphate-buffered solution at pH 7.4 and 0.13 M total salt concentration were extended to near saturation concentrations for ambient temperature. The osmotic pressure at the highest measured concentration of 424 g/L was 4.18 psi (28.3 kPa). A free-solvent model, considering solute-solvent interaction in the concentration variable, provided an excellent fit to observed osmotic pressure nonideality at even the highest protein concentration. The calculated mass of hydrated solvent compared with amounts determined from water-17O magnetic resonance for other globular proteins. This model provides an improved correlation to the data over virial equations (truncated to the third term) when only solute-solute interactions are considered. The use of mole fraction as the composition variable was critical in obtaining the excellent fit of the free-solvent model. A combination of the free-solvent correction for the concentration variable coupled with models incorporating solute-solute interaction, such as a virial expansion, will be necessary to generally describe the osmotic pressure of protein solutions for all concentrations. Copyright 1998 Academic Press. Copyright 1998Academic Press

Corticosteroid administration modifies ozone-induced increases in sheep airway blood flow

Recently, we have shown that exposure of intubated conscious sheep to 3 to 4 ppm ozone (O3) for 3 h increases bronchial blood flow (Qbr). The purpose of the present study was to assess the potential role of corticosteroids in modulating this increase. Six nasally intubated sheep were exposed to filtered room air, 3.5 ppm O3 on two separate occasions, and 3.5 ppm O3 plus methyl-prednisone, for 3 h. Qbr was measured using a chronically implanted 20 MHz pulsed Doppler flow probe. Qbr, mean aortic pressure, cardiac output, pulmonary artery pressure, arterial blood gases, and core temperature were monitored. After 3 h of 3.5 ppm O3, Qbr increased from 3.2 +/- 0.5 (mean +/- SEM) to 8.5 +/- 1.6 KHz, whereas bronchial vascular resistance (BVR) decreased from the baseline value of 43.6 +/- 8.0 to 15.0 +/- 3 mm Hg/KHz. With corticosteroids, baseline Qbr was 3.2 +/- 0.6 and BVR was 44.2 +/- 9.7; after 3 h of 3.5 ppm O3, Qbr was 3.3 +/- 0.5 KHz and BVR was 39.0 +/- 8.0 mm Hg/KHz. The two 3.5-ppm O3 exposures without corticosteroids were impressively reproducible. Except for Qbr and BVR, no other measured cardiovascular parameters were affected by O3. The results indicate that corticosteroids are capable of interfering with mediator, neurohumoral, or inflammatory cell mechanisms responsible for vasodilation of the airway microcirculation after O3 exposure, but do not specifically address the specific processes whereby this attenuation occurs.

Acute ozone exposure increases bronchial blood flow in conscious sheep

This study was initiated to determine the effects of ozone (O3) on sheep airway blood flow. Twenty-three nasally intubated sheep were exposed to filtered air (n = 5), 1 ppm O3 (n = 4), 2 ppm O3 (n = 5), 3 ppm O3 (n = 5), and 4 ppm O3 (n = 4) for 3 h. Bronchial artery flow (Qbr) was measured using a chronically implanted 20 MHz pulsed Doppler flow probe. Qbr, mean aortic pressure, cardiac output, pulmonary artery pressure, arterial blood gases, and core temperature were monitored during the period of the exposures. Exposure to 3 and 4 ppm O3 resulted in a significant increase in Qbr (103 and 204% change, respectively) without affecting any of the other cardiopulmonary parameters measured. These results indicate that O3 induces a dose dependent increase in Qbr which is the result of a vasodilation of the bronchial vasculature which is not dependent upon changes in blood gases or upstream driving pressure.