N-protein presents early in blood, dried blood and saliva during asymptomatic and symptomatic SARS-CoV-2 infection
Shan et al.
The finding, in our words
A Simoa immunoassay detected SARS-CoV-2 nucleocapsid protein in venous and capillary blood and saliva with 98% negative and 90% positive agreement versus molecular testing across symptomatic, asymptomatic and pre‑symptomatic PCR‑positive individuals in days 1–7; N‑protein levels fell as spike‑IgG rose and correlated with saliva RT‑PCR Ct values and between matched saliva and capillary samples, enabling non‑invasive, swab‑independent sample collection for at‑home or point‑of‑care use.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
Capillary blood self-sampling achieved 98.3% agreement with venous samples for SARS-CoV-2 IgG antibodies and 100% for IgA among 60 participants, demonstrating accuracy for vaccine monitoring. Saliva self-collection proved feasible with excellent usability, offering a patient-centric alternative for decentralised immunogenicity assessment.
Capillary blood samples collected by staff or self-collected by participants showed strong correlation and clinically acceptable agreement with venipuncture for influenza haemagglutination inhibition titers. The small differences observed were not clinically meaningful, and adequate sample volume was achieved in most attempts, supporting the feasibility of decentralised serological testing.
In a cohort of 62 participants evaluating home self-collection with the TassoPlus device, 38 returned samples, with 29% excluded due to insufficient plasma volume below 200 ΔL. Although viral load measurements in adequate samples correlated well with conventional testing (r = 0.800), the high failure rate and missed detection in low-volume viremic samples indicate that further technical refinements are necessary before clinical adoption.
A study of decentralised patient-centric microsampling found that 82% of untrained participants, 47 of 57, successfully self-collected acceptable fingerstick blood in Microtainer tubes. All 46 tested samples yielded accurate HIV viral suppression results compared to venipuncture, though this remote monitoring approach is limited to US courier services and temperature conditions.
In 30 adult solid organ transplant recipients, capillary blood self-collected using the Tasso+ device showed 91% concordance with venous samples for detecting CMV DNAemia above the limit of detection, with excellent quantitative correlation (Spearman R² = 0.99). Most participants preferred self-collection over venipuncture, suggesting the device could enable decentralised viral monitoring, though sensitivity was lower (95% at 308 IU/mL).