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.