Rapid screening of COVID-19 patients by White blood cells scattergrams, a study on 381 patients.

Complementary tools are warranted to increase the sensitivity of the initial testing for COVID-19. We identified a specific "sandglass" aspect on the white blood cells scattergram of COVID-19 patients reflecting the presence of circulating plasmacytoid lymphocytes. Patients were dichotomized as COVID-19 positive or negative based on RT-PCR and chest CT scan results. Sensitivity and specificity of the "sandglass" aspect were 85.9% and 83.5% respectively. The positive predictive value was 94.3%. Our findings provide a non-invasive and simple tool to quickly categorize symptomatic patients as either COVID-19 probable or improbable especially when RT-PCR and/or chest CT are not rapidly available.