Lymphopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A systemic review and meta-analysis

Abstract

Objectives: Coronavirus Disease 2019 is a new respiratory and systemic disease which needs quick identification of potential critical patients. This meta-analysis aimed to explore the relationship between lymphocyte count and the severity of COVID-19. Methods: A comprehensive systematic literature search was carried out to find studies published from December 2019 to 22 March 2020 from five databases. The language of literatures included English and Chinese. Mean difference (MD) of lymphocyte count in COVID-19 patients with or without severe disease and odds ratio (OR) of lymphopenia for severe form of COVID-19 was evaluated with this meta-analysis. Results: Overall 13 case-series with a total of 2282 cases were included in the study. The pooled analysis showed that lymphocyte count was significantly lower in severe COVID-19 patients (MD -0.31 Â10 9 /L; 95%CI: -0.42 to -0.19 Â 10 9 /L). The presence of lymphopenia was associated with nearly threefold increased risk of severe COVID-19 (Random effects model, OR = 2.99, 95% CI: 1.31-6.82). Conclusions: Lymphopenia is a prominent part of severe COVID-19 and a lymphocyte count of less than 1.5 Â 10 9 /L may be useful in predicting the severity clinical outcomes.

Deep immune profiling of COVID-19 patients reveals patient heterogeneity and distinct immunotypes with implications for therapeutic interventions

“…Despite an apparent greater loss of CD8 compared to CD4 T cells, the frequency of these two lymphocyte populations correlated in the majority of patients (Figure 1G). These findings are consistent with previous reports of lymphopenia during COVID-19 disease (16)(17)(18)(19) but highlight a preferential impact on CD8 T cells. As a result of the decrease in T cells, the relative frequency of non-B and non-T cells in the PBMC was elevated ( Figure 1E).…”

“…Furthermore, D-dimer was associated with both WBC and PMN counts, although the later relationship was not significant (Figure S1B). IL-6 levels were variable across the 16 patients analyzed for suspected increased inflammation: normal in 1 patient, moderately elevated in 4 subjects (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) pg/ml), and high in 11 patients (21-738 pg/ml) ( Figure S1A). Thus, COVID-19 patients present with varied pre-existing comorbidities, complex clinical phenotypes, evidence of inflammation in many patients, and clinically altered leukocyte counts.…”

“…Moreover, although there is evidence of T cell activation in COVID-19 patients (15), some studies have found decreases in polyfunctionality (11,16) or cytotoxicity (11); however, this has not been observed in other similar studies (12). Furthermore, how this activation should be viewed in the context of COVID-19 lymphopenia (17)(18)(19) remains unclear.…”

Haematological factors of SARS-CoV-2 infection aggravation: a COVID'HEMOS study

“…Lymphopenia is a prominent part of severe Covid-19. A meta-analysis described lymphopenia<1.5 G/L predicting the severity clinical outcomes (30), however lymphopenia is de ned as under 1 G/L in our laboratory and more than 78% of our cohort exhibited lymphocytes level below 1.5 G/L (56% below 1G/L). Interestingly, our results suggest a non-signi cant relationship between lymphopenia and SARS-CoV-2 severity.…”

Clinical Features and Outcomes in Imported and Non-Imported Patients With COVID-19: A Retrospective, Multi-centre, Descriptive Study

“…20.4% patients received non-invasive ventilator mechanical ventilation for 3-20 days (median 8 days [ ). 3 (1.1%) patients used an invasive ventilator to assist ventilation for 3-20 days (median 17 [12][13][14][15][16][17][18][19]). Overall, there was no signi cant difference between the imported group and the non-imported group in all of these indicators.…”