Preanalytical Stability of Antibodies to Pathogenic Antigens

Abstract

Serologic testing for antibodies against epitopes from pathogens is a valuable tool for investigating the relationship between infection and disease. This study comprehensively evaluates the impact of preanalytic variation on antibody seropositivities to a selected set of antigens arising from delays in processing of blood samples, preprocessing storage temperature, and vacutainer type. We assessed peripheral blood collected from 29 volunteers in four different Vacutainer types [ethylenediaminoetetraacetic acid (EDTA), acid-citrate-dextrose (ACD), lithium heparin (LH), serum separator tubes (SST)], and stored at 4°C or room temperature for 0, 1, 2, 3, 4, 5, and 6 days before processing. Multiplex serology was used to determine antibody reactivity against 35 antigens derived from human papillomaviruses, human polyomaviruses, Epstein-Barr virus, and Cohen's κ statistic was used to measure agreement on seropositivity status between samples exposed to standard and nonstandard clinical practice conditions. For samples processed without delay, κ was not associated with storage-temperature ( value range 0.23 to 0.95) or vacutainer type ( value range, 0.35-0.89). Kappa did not significantly decline with increasing delays in processing for any vacutainer-type storage temperature combination ( slope range, 0.06-1.00). Antibodies to epitopes from various pathogenic infectious agents can be measured reliably from samples stored in SST, EDTA, ACD, or LH vacutainers at either room temperature or 4°C for up to 6 days before processing. Serologic testing is robust to several preanalytic options. These findings are particularly important for epidemiologic studies recruiting participants from remote settings where sample exposure to preanalytic conditions can vary considerably. .

Self-collection of capillary blood using Tasso-SST devices for Anti-SARS-CoV-2 IgG antibody testing

“…However, as shown here, antibodies tend to be stable analytes; the mean elapsed time between Tasso sample collection and processing was 72.7 hours, a relatively long period of time. Hodgkinson and colleagues also evaluated the effect of delayed processing and temperature on results from a multiplex immunoassay measuring antibodies against various infectious antigens and found their results to be stable at room temperature through 6 days [ 6 ]. Their results are consistent with our clinical experience evaluating the time-dependent stability of samples tested by antibody binding assays.…”

Stability of important antibodies for kidney disease: pre-analytic methodological considerations

“…Previous studies have demonstrated that antibody concentrations in the serum are stable at 4 °C for short times ( Hodgkinson et al, 2017 ; Rodriguez-Capote et al, 2016 ). Our study results agree with those of previous reports.…”

“…Previous studies have suggested that confounding methodological factors should be ruled out ( Chaigneau et al, 2007 ; Hodgkinson et al, 2017 ). To the best of our knowledge, no study has systematically described the methodology of sample preparation and storage with respect to important antibodies as blood biomarkers of kidney disease.…”

Effects of anticoagulants and Ficoll on human serum antibody reactivities and functions against Mycobacterium tuberculosis

“…Serum, which, unlike plasma, lacks fibrinogen and clotting factors, is traditionally used for antibody reactivity and functional assays. While prior studies by us and others show that the anticoagulants heparin and EDTA in plasma have little effect on antibody reactivities to M. tuberculosis and other mycobacterial antigens, little is known about the effects of ACD and CPT plasma on antibody reactivities, especially in the context of TB [7][8][9]. Furthermore, we and others previously showed that antibodies to M. tuberculosis antigens can have Fcgamma receptor (FcyR)-mediated functions, such as the uptake of M. tuberculosis into macrophages [1][2][3].…”