RESUMO
The prefusion Spike protein of SARS-CoV2 binds advanced glycation end product (AGE) glycated human serum albumin (HSA) and a higher mass, hyperglycosylated/glycated, IgG3, as determined by matrix assisted laser desorption mass spectrometry (MALDI-ToF MS). We set out to investigate if the total blood plasma of patients who had recovered from acute respiratory distress as a result of COVID-19, contained more glycated HSA and higher mass (glycosylated/glycated) IgG3 than those with only clinically mild or asymptomatic infections. A direct dilution and disulphide bond reduction method was development and applied to plasma samples from SARS-CoV2 seronegative (N = 30) and seropositive (N = 31) healthcare workers and 38 convalescent plasma samples from patients who had been admitted with acute respiratory distress syndrome (ARDS) associated with COVID-19. Patients recovering from COVID-19 ARDS had significantly higher mass, AGE-glycated HSA and higher mass IgG3 levels. This would indicate that increased levels and/or ratios of hyper-glycosylation (probably terminal sialic acid) IgG3 and AGE glycated HSA may be predisposition markers for development of ARDS as a result of COVID-19 infection. Furthermore, rapid direct analysis of plasma samples by MALDI-ToF MS for such humoral immune correlates of COVID-19 presents a feasible screening technology for the most at risk; regardless of age or known health conditions. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/21260186v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@12bfa69org.highwire.dtl.DTLVardef@45344forg.highwire.dtl.DTLVardef@16d4f7forg.highwire.dtl.DTLVardef@17e5c34_HPS_FORMAT_FIGEXP M_FIG C_FIG
RESUMO
The COVID-19 pandemic caused by the SARS-CoV-2 Coronavirus has stretched national testing capacities to breaking points in almost all countries of the world. The need to rapidly screen vast numbers of a countrys population in order to control the spread of the infection is paramount. However, the logistical requirement for reagent supply (and associated cost) of RT-PCR based testing (the current front-line test) have been hugely problematic. Mass spectrometry-based methods using swab and gargle samples have been reported with promise, but have not approached the task from a systematic analysis of the entire diagnostic process. Here, the pipeline from sample processing, the biological characteristics of the pathogen in human biofluid, the downstream bio- and physical-chemistry and the all-important data processing with clinical interpretation and reporting, are carefully compiled into a single high throughput and reproducible rapid process. Utilizing MALDI-ToF mass spectrometric detection to viral envelope glycoproteins in a systems biology - multidisciplinary team approach, we have achieved a multifaceted clinical MALDI ToF MS screening test, primarily (but not limited to) SARS-CoV-2, with direct applicable to other future epidemics/pandemics that may arise. The clinical information generated not only includes SARS-CoV-2 Coronavirus detection - (Spike protein fragments S1, S2b, S2a peaks), but other respiratory viral infections detected as well as an assessment of generalised oral upper respiratory immune response (elevated total Ig light chain peak) and a measure of the viral immune response (elevated intensity of IgA heavy chain peak). The advantages of the method include; 1) ease of sampling, 2) speed of analysis, and much reduced cost of testing. These features reveal the diagnostic utility of MALDI-ToF mass spectrometry as a powerful and economically-attractive global solution. Abstract graphic O_FIG O_LINKSMALLFIG WIDTH=183 HEIGHT=200 SRC="FIGDIR/small/20176669v1_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@1b84899org.highwire.dtl.DTLVardef@1a665e7org.highwire.dtl.DTLVardef@16c3f49org.highwire.dtl.DTLVardef@1aee6de_HPS_FORMAT_FIGEXP M_FIG C_FIG
