Platelet size as a predictor for severity and mortality in COVID-19 patients: a systematic review and meta-analysis

Abstract

Background: Parameters reflecting platelet size can be sensitive indicators that circulating platelets are activated and COVID-19 patients are at increased risk of thrombosis. This systematic review aims to assess the association of mean platelet volume (MPV), platelet distribution width (PDW) and platelet-large cell ratio (P-LCR) with disease severity and mortality in COVID-19 patients. Methods: English and Chinese databases were searched electronically to identify studies reporting data on MPV, PDW or P-LCR in COVID-19 patients. Included articles underwent a quality rating. A meta-analysis was performed using the standard mean difference and interpreted as the common language effect size (CLES). Results: Twenty-two studies (11,906 patients) were included in the meta-analysis. Of these, 14 were rated poor and eight were fair. The MPV and P-LCR was significantly higher at hospital admission in severe patients compared to non-severe patients. The MPV, PDW and P-LCR were significantly higher at hospital admission in non-survivors compared to survivors. There was a marked increase in the probability of a severe COVID-19 patient presenting with higher P-LCR at hospital admission than a non-severe patient (CLES: 68.7% [95% CI: 59.8%, 76.5%]), when compared with MPV and PDW ((CLES: 59.2% [95% CI: 53.1%, 65.1%]) and (CLES: 55.9% [95% CI: 50.6%, 62.2%]), respectively). Conclusion: Severe COVID-19 disease is associated with the increased production of larger, younger platelets. When comparing MPV, PDW and P-LCR, P-LCR is the most important biomarker for evaluating platelet activity. P-LCR testing at hospital admission could identify COVID-19 patients with increased risk for thrombotic events, allowing preventative treatment.

Baseline Thrombocytopenia and Disease Severity Among COVID-19 Patients, Tibebe Ghion Specialized Hospital COVID-19 Treatment Center, Northwest Ethiopia

“…This leads to platelet consumption. 25 , 26 At admission, P-selectin expression was significantly increased in severe COVID-19 patients. 27 Rampotas Alexandros and Pavord Sue report that PLTs were aggregated in COVID-19 patients that showed the important role of platelets in thrombotic complications or respiratory failure in COVID-19 patients.…”

A Hybrid Feature Selection Approach to Screen a Novel Set of Blood Biomarkers for Early COVID-19 Mortality Prediction

“…The authors of [ 80 ] showed that COVID-19 positive cases with high P-LCR (95% CI, 1.40–6.41; p = 0.0046) were significantly associated with worse survivability. The authors of [ 81 ] proposed that P-LCR is the most important biomarker for evaluating platelet activity and could identify COVID-19 individuals with an increased risk of thrombotic events. In another study [ 82 ], the authors proposed the use of a cohort study, in which the values of the P-LCR parameter were significantly higher in COVID-19 individuals than in non-COVID-19 individuals.…”

A Composite Ranking of Risk Factors for COVID-19 Time-To-Event Data from a Turkish Cohort

“…Because platelet is a key regulator of thrombosis and inflammation, both present in severe COVID-19 patients, it is a good candidate for risk factor (Barrett et al, 2021). However, it is suggested that platelet/large-cell-cell ratio (PLCR) is a better marker than MPV and PDW (Daniels et al, 2021).…”

“…Because platelet is a key regulator of thrombosis and inflammation, both present in severe COVID-19 patients, it is a good candidate for risk factor (Barrett et al, 2021; Rohlfing et al, 2021; Delshad et al, 2021). However, it is suggested that platelet/large-cell-cell ratio (PLCR) (Daniels et al, 2021) is a better marker than MPV and PDW, and platelet-to-lymphocyte ratio (PLR) (Asan et al, 2021) is a better marker than platelet count. However, see counter conclusions in (Aydinyilmaz et al, 2021; Lippi et al, 2021).…”