Background Early Kinetics of SARS‐CoV‐2 viral load (VL) in plasma determined by quantitative RT‐PCR was evaluated as a predictor of poor clinical outcome in a prospective study and assessed in a retrospective validation cohort. Methods Prospective observational single‐centre study including consecutive adult patients hospitalised with COVID‐19 between November 2020 and January 2021. Serial plasma samples were obtained until discharge. Quantitative RT‐PCR was performed to assess SARS‐CoV‐2 VL. The main outcomes were in‐hospital mortality, admission to the Intensive Care Unit (ICU) and their combination (Poor Outcome). Relevant Viremia (RV), established in the prospective study, was assessed in a retrospective cohort including hospitalised COVID‐19 patients from April 2021‐May 2022, in which plasma samples were collected according to clinical criteria. Results Prospective cohort: 57 patients were included. RV was defined as at least a two‐fold increase in VL within ≤2 days or a VL>300 copies/mL, in the first week. Patients with RV (N=14; 24.6%) were more likely to die than those without RV (35.7% vs 0%), needed ICU admission (57% vs 0%) or had Poor Outcome (71.4% vs 0%), (p<0.001 for the three variables) Retrospective cohort: 326 patients were included, 18.7% presented RV. Patients with RV compared with patients without RV had higher rates of ICU‐admission [OR 5.6 (95%CI,2.1‐15.1); p=0.001], mortality [OR 13.5 (95%CI,6.3‐28.7); p<0.0001] and Poor Outcome [OR 11.2 (95%CI,5.8‐22); p<0.0001] Conclusion Relevant SARS‐CoV‐2 viremia in the first week of hospitalisation was associated with higher in‐hospital mortality, ICU admission, and Poor Outcome. Findings observed in the prospective cohort were confirmed in a larger validation cohort. This article is protected by copyright. All rights reserved.

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Objective: Primary Sjogrens syndrome (pSS) is an inflammatory autoimmune disorder characterized by damage of exocrine glands and linked to IFN responses and the induction of autoreactive adaptive immune cells. However, the role of innate immune cells in pSS pathology remains understudied. Methods: We studied differential phenotypical characteristics of different NK cell, conventional dendritic cell (cDC) and monocyte subsets in the blood and salivary glands from pSS individuals. Transcriptional patterns of circulating cDC and Mo from pSS and healthy controls were also compared. Finally, in vivo alterations in these cell populations in the salivary gland were investigated in a mouse model. Results: Here, we identified CD16+ CD56hi NK cells enriched in pSS patients which associates with higher natural cytotoxic function and increased proportions of circulating CD64+ CD1c+ cDC exhibiting antiviral transcriptional IFN signatures. CD64hi cDC and NK cell were detected infiltrated into the salivary glands from pSS patients and a murine SS model. CD1c+ cDC from patients with pSS expressed high levels of ligands for activating NK receptors and increased ability to activate NK cells ex vivo. Finally, the antiviral RIG-I and DDX60 sensors regulated the expression of NK cell receptor ligands on CD1c+ cDC. Conclusions: Therefore, the interplay of CD1c+ cDCs and NK cells could contribute to pSS pathology.