Mean platelet volume to platelet count ratio as a laboratory indicator of mortality in pneumonia following ischemic stroke

Relationship of platelet counts, platelet volumes, and Curb-65 scores in the prognosis of COVID-19 patients

OBJECTIVES

This study investigated the relationship between 28-day mortality in patients with COVID-19 pneumonia and the CURB-65 score, platelet count (PLT), mean platelet volume (MPV), and MPV/PLT ratio (MPR).

METHODS

A total of 247 patients with COVID-19 pneumonia who presented to the emergency department between March 15, 2020 and May 15, 2020 were retrospectively analyzed. The age, gender, clinical presentation, history of chronic disease, thoracic computed tomography findings, MPV, PLT, MPR, CURB-65 scores, and 28-day mortality of patients were recorded.

RESULTS

The patients had a mean age of 51 years (IQR: 39-63 years) and 55.5% were females. The most common symptom was cough (30.4% of patients). The most common comorbidity was hypertension (13.4%), 49.8% of the cases showed intermediate involvement, and 7.7% of patients died within the first 28 days. The mean MPV was 9.71 ± 1.15, the mean PLT was 226.68 ± 83.82, and the mean MPR was 0.056 ± 0.12. There were significant correlations of 28-day mortality with the CURB-65 score, MPV, and MPR levels (p = 0.000, p = 0.034, and p = 0.034, respectively). No significant correlation was found between the PLT count and 28-day mortality (p = 0.105).

CONCLUSIONS

In addition to the CURB-65 score, MPV and MPR values can be used to predict 28-day mortality in patients with COVID-19 pneumonia.

Low value of platelet count to mean platelet volume ratio to diagnose chronic PJI: A case control study

INTRODUCTION

Numerous tests are being evaluated in order to aid the diagnosis of periprosthetic infections since it is a complicated and sometimes inconclusive process. The purpose of this study was to assess the diagnostic performance of platelet count to mean platelet volume ratio as a tool to aid the diagnosis of periprosthetic joint infections. The investigated questions were: "Is platelet count/mean platelet volume ratio more sensitive or specific than C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) in the diagnosis of periprosthetic joint infections?" and "Does platelet count/mean platelet volume ratio increase the accuracy of periprosthetic joint infection diagnosis?".

HYPOTHESIS

Platelet count/mean platelet volume ratio increases the accuracy of periprosthetic joint infection diagnosis.

MATERIALS AND METHODS

This study was performed retrospectively on patients who underwent revision hip or knee arthroplasty between 2016 and 2019. 62 patients with 33 aseptic (AR) and 29 septic revision (SR) who met our inclusion criteria were included. The sensitivity, specificity and diagnostic performance of CRP, ESR and platelet count/mean platelet volume values were analyzed and compared.

RESULTS

The demographic characteristics were similar between groups. Staphylococcus aureus and Staphylococcus epidermidis were the most commonly encountered microorganisms, while seven patients had negative cultures in SR group. ESR, CRP and platelet count/mean platelet volume values were significantly higher in SR group compared to AR group (p<0.01). ROC analysis for platelet count/mean platelet volume ratio revealed a cut-off value at 35.3 which provided 75.9% sensitivity and 78.8% specificity for periprosthetic joint infections. Platelet count/mean platelet volume ratio yielded lower sensitivity and similar specificity compared to ESR and CRP values. Platelet count/mean platelet volume had a lower area under curve value, indicating a poorer diagnostic performance compared to ESR and CRP.

DISCUSSION

The diagnostic performance of platelet count/mean platelet volume ratio is low and current findings do not support its usage to increase the accuracy of periprosthetic joint infections diagnosis.

LEVEL OF EVIDENCE

III; diagnostic case-control study.

Mean platelet volume/platelet count ratio predicts severe pneumonia of COVID-19

Background

Although platelet mean volume/platelet count ratio (MPR) is considered to be a crucial marker of inflammatory and infectious diseases, the relationship between MPR and novel coronavirus infectious disease 2019 (COVID‐19) remains unclear.

Methods

In this retrospective study, 85 patients with confirmed COVID‐19 were enrolled and divided into low and high MPR group. Data from repeated measures were compared by the generalized estimating equations. Cox regression analyses were performed to assess the impact of MPR on the incidence of severe pneumonia (SP), with inverse probability of treatment weighting (IPTW) used to reduce confounding bias. The primary outcome is the incidence of SP of COVID‐19.

Results

During follow‐up, 17 (20.0%) patients were developed to SP. Compared with mild patients, patients with SP developed showed a higher MPR level at baseline, day 1, day 2, and day 3 after admission (P = .005, P = .015, P = .009, and P = .032, respectively). Kaplan‐Meier method showed a higher incidence of SP in the high MPR group than the low MPR group (log‐rank test = 10.66, P = .001). After adjustment, high MPR was associated with an elevated incidence of SP (HR, 5.841, 95% CI, 1.566‐21.791, P = .009). The IPTW method also suggested that MPR was a significant factor related to the incidence of SP (HR, 8.337, 95% CI, 4.045‐17.182, P < .001).

Conclusion

High MPR level is an independent risk factor for severe pneumonia in patients with COVID‐19.

Platelets and Their Role in the Pathogenesis of Cardiovascular Events in Patients With Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality throughout the world with much recent and ongoing research focused on the occurrence of cardiovascular events (CVEs) during the infection, which are associated with adverse short-term and long-term survival. Much of the research directed at unraveling the pathogenesis of these events has been undertaken in the settings of experimental and clinical CAP caused by the dangerous, bacterial respiratory pathogen, Streptococcus pneumoniae (pneumococcus), which remains the most common bacterial cause of CAP. Studies of this type have revealed that although platelets play an important role in host defense against infection, there is also increasing recognition that hyperactivation of these cells contributes to a pro-inflammatory, prothrombotic systemic milieu that contributes to the etiology of CVEs. In the case of the pneumococcus, platelet-driven myocardial damage and dysfunction is exacerbated by the direct cardiotoxic actions of pneumolysin, a major pore-forming toxin of this pathogen, which also acts as potent activator of platelets. This review is focused on the role of platelets in host defense against infection, including pneumococcal infection in particular, and reviews the current literature describing the potential mechanisms by which platelet activation contributes to cardiovascular complications in CAP. This is preceded by an evaluation of the burden of pneumococcal infection in CAP, the clinical features and putative pathogenic mechanisms of the CVE, and concludes with an evaluation of the potential utility of the anti-platelet activity of macrolides and various adjunctive therapies.

Elevated mean platelet volume to platelet ratio predicts advanced fibrosis in chronic hepatitis C

OBJECTIVE

Chronic hepatitis C virus (HCV) infection is an important health problem that can cause liver cirrhosis and hepatocellular carcinoma. Recently, novel inflammatory markers from complete blood count have been used as a precursor of many clinical conditions. In this study, we investigated the role of hemogram parameters in predicting advanced liver fibrosis in chronic HCV patients.

METHODS

Patients who underwent percutaneous liver biopsy due to chronic HCV infection between 01.01.2011 and 01.08.2019 were included in this study. Liver biopsies were evaluated according to Ishak method. Patients were classified into those with mild fibrosis (F ≤ 2) and advanced fibrosis (F ≥ 3). Hemogram parameters of these groups were compared and their efficacy in predicting severe fibrosis was investigated.

RESULTS

Of the 81 chronic HCV patients, 38 cases were in the mild fibrosis group and 43 cases were in the severe fibrosis group. Mean platelet volume, mean platelet volume to lymphocyte ratio, mean platelet volume to platelet ratio, and red cell distribution width to platelet ratio of the severe fibrosis group were significantly higher than those of the mild fibrosis group (P < 0.05 for all). In the ROC curve analysis, mean platelet volume to platelet ratio showed the biggest area under the curve in the prediction of advanced fibrosis.

CONCLUSION

Mean platelet volume to platelet ratio may be an easy and practical biomarker to gain a preliminary insight into advanced fibrosis in chronic HCV patients.

Usefulness of mean platelet volume to platelet count ratio for predicting the risk of mortality in community-acquired pneumonia

INTRODUCTION

The association between mean platelet volume (MPV) to platelet count (PC) ratio and prognosis has been demonstrated in some diseases but not in community-acquired pneumonia (CAP). In this study, we evaluated the ability of MPV to PC ratio (MPR) to predict short-term mortality in CAP patients.

MATERIAL AND METHODS

We retrospectively analysed data archived over 10 years and stratified MPR values into quartiles. Relations between MPR (femtoliters/number of thousand platelets per microlitre) quartiles and 60-day mortality were examined. Logistic regression was performed to adjust for confounders, and the Kaplan-Meier method was used for survival analysis.

RESULTS

After adjusting for confounding factors, the odds ratios of 60-day mortality for CAP were 2.66 (95% CI: 2.04-3.46) for the fourth MPR quartile (range ≥ 5.19; p < 0.001) versus the first MPR quartile (range ≤ 2.45). Kaplan-Meier curves indicated that a higher MPR was associated with a higher risk of mortality among CAP patients, and this was confirmed by the log-rank test (p < 0.001).

CONCLUSIONS

Mean platelet volume to PC ratio was found to be positively correlated with short-term mortality. Our data indicate that MPR might be a significant predictive marker of the mortality in CAP. Further prospective studies are required to establish the exact role of MPR in CAP and other diseases.