Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio, are they markers of COVID-19 severity or old age and frailty? A comparison of two distinct cohorts

Do Neutrophil-Lymphocyte Ratio and Platelet-Lymphocyte Ratio Need to Be Stratified for Age and Comorbidities in COVID-19 Disease? A Subgroup Analysis of Two Distinct Cohorts over Disease Course

Several studies described neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) as markers of COVID-19 severity. In a recently published study, age and frailty affected NLR and PLR more than disease severity. The study compared two distinct cohorts. The first comprised older frailer patients positive for SARS-CoV-2, with mild or asymptomatic disease, admitted to designated COVID-19 departments in a large geriatric medical center (GMC). The second cohort comprised COVID-19 patients admitted to a large general hospital (GH) for symptomatic disease. This was a follow-up study comparing a subgroup of patients who had NLR and PLR values measured a week after admission. Only 100 of 177 patients in the original GMC cohort had a second NLR test compared to almost all (287 of 289) patients in the general hospital (GH) cohort. The subgroup baseline characteristics did not change significantly from that of the original cohort. Disease symptoms were more prevalent in the GH cohort. In the GMC group, the median second NLR rose from 3.9 to 4.6, while in the GH cohort, the NLR value dropped from 3.5 to 2.8, enhancing the NLR differences between the groups. Smaller changes were observed in the second PLR. These results strengthen the prior results that age and frailty seem to have a stronger impact on NLR and PLR than disease severity.

The Prognostic Role of Platelet-to-Lymphocyte Ratio in Acute Coronary Syndromes: A Systematic Review and Meta-Analysis

This study aimed to investigate the potential prognostic role of the platelet-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). A systematic search of PubMed Central, Scopus, EMBASE, and the Cochrane Library from conception through 20 August 2023 was conducted. We used odds ratios (OR) as the effect measure with 95% confidence intervals (CIs) for dichotomous data and mean differences (MD) with a 95% CI for continuous data. If I2 was less than 50% or the p value of the Q tests was less than 0.05, a random synthesis analysis was conducted. Otherwise, a fixed pooled meta-analysis was performed. Nineteen studies fulfilled the eligibility criteria and were included in the meta-analysis. PLR was higher in MACE-positive (164.0 ± 68.6) than MACE-negative patients (115.3 ± 36.9; MD = 40.14; 95% CI: 22.76 to 57.52; p < 0.001). Pooled analysis showed that PLR was higher in AMI patients who died (183.3 ± 30.3), compared to survivors (126.2 ± 16.8; MD = 39.07; 95% CI: 13.30 to 64.84; p = 0.003). It was also higher in the ACS vs. control group (168.2 ± 81.1 vs. 131.9 ± 37.7; MD = 39.01; 95% CI: 2.81 to 75.21; p = 0.03), STEMI vs. NSTEMI cohort (165.5 ± 92.7 vs. 159.5 ± 87.8; MD = 5.98; 95% CI: -15.09 to 27.04; p = 0.58), and MI vs. UAP populations (162.4 ± 90.0 vs. 128.2 ± 64.9; MD = 18.28; 95% CI: -8.16 to 44.71; p = 0.18). Overall, our findings confirmed the potential prognostic role of the plate-let-to-lymphocyte (PLR) ratio in patients presenting with suspected acute coronary syndromes (ACS). Its use as a risk stratification tool should be examined prospectively to define its capability for evaluation in cardiovascular patients.