Comparison of Pairwise Venous and Fingertip Plasma Using Quantitative Proteomics Based on Data-Independent Acquisition

Blood contains a great deal of health-related information and can be used to monitor human health status. Clinically, venous or fingertip blood is usually used for blood tests. However, the clinical application settings of the two sources of blood are unclear. In this study, the proteomes of pairwise venous plasma (VP) and fingertip plasma (FP) were analyzed, and the levels of 3797 proteins were compared between VP and FP. The Spearman's correlation coefficient for the relationship between protein levels of VP and FP ranges from 0.64 to 0.78 (p < 0.0001). The common pathways of VP and FP are related to cell-cell adhesion, protein stabilization, innate immune response, and complement activation, the classical pathway. The VP-overrepresented pathway is related to actin filament organization, while the FP-overrepresented pathway is related to the hydrogen peroxide catabolic process. ADAMTSL4, ADIPOQ, HIBADH, and XPO5 both in VP and FP are potential gender-related proteins. Notably, the VP proteome has a higher interpretation on age than the FP proteome, and CD14 is a potential age-related protein in VP but not in FP. Our study mapped the different proteomes between VP and FP, which can provide value for the standardization of clinical blood tests.