Full blood count dynamics in immunologically naïve individuals with mild COVID-19: A prospective community cohort study

Résumé fourni par la source

PURPOSE: Full blood count (FBC) provides a range of cellular haematological parameters and serves as a routinely available basic immune profile. While FBC has been widely used to monitor moderate-to-severe COVID-19 in hospitalised settings, its temporal dynamics in mild, community-managed cases remain poorly characterised, despite these constituting the majority of global infections. METHODS: In a prospective cohort study, we tracked the cellular haematological profiles of 93 recently exposed, immunologically naïve individuals with mild COVID-19 and no underlying co-morbidities, recruited to the Integrated Network for Surveillance, Trials and Investigations into COVID-19 Transmission (INSTINCT) study. Blood samples were collected on D0, D7, D14 and D28 and subsequently aligned to infection-timepoints based on the day of first detected PCR positivity, and analysed using mixed-effects models. RESULTS: Over 30% of cases exhibited transient, clinically defined neutropenia (mean (95% CI): First PCR-Positive (FP) 2.47x109/L (2.26-2.68) vs convalescence 3.34 x109/L (2.98-3.7); p = 0.0013). Over 20% exhibited lymphopenia (FP 1.38x109/L (1.28-1.48) vs convalescence 1.79x109/L (1.79-2.01); p = 0.0013). Additionally, we observed a notable elevation in platelet count, peaking approximately two weeks after initial infection (mean (95% CI): FP + 14 283x109/L (254-311) vs convalescence 237x109/L (222-252); p = 0.0013). CONCLUSIONS: Transient neutropenia and lymphopenia occurred in approximately one-third and one-fifth of mild COVID-19 cases, respectively, and were followed by a delayed increase in platelet count. This study provides a descriptive, prospective dataset of full blood count parameters spanning early infection to convalescence in immunologically naïve individuals with mild SARS-CoV-2 infection. These data may support mathematical modelling of within-host cellular haematological dynamics and have potential clinical relevance for understanding typical trajectories of routine blood parameters during mild disease.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.