Most deaths from severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection occur in older subjects. We assessed the utility of serum inflammatory markers interleukin-6 (IL-6), C reactive protein (CRP), and ferritin (Roche, Indianapolis, IN), and SARS-CoV-2 immunoglobulin G (IgG), immunoglobulin M (IgM), and neutralizing antibodies (Diazyme, Poway, CA). In controls, non-hospitalized subjects, and hospitalized subjects assessed for SARS-CoV-2 RNA (n = 278), median IgG levels in arbitrary units (AU)/mL were 0.05 in negative subjects, 14.83 in positive outpatients, and 30.61 in positive hospitalized patients ( P <0.0001). Neutralizing antibody levels correlated significantly with IgG (r = 0.875; P <0.0001). Having combined values of IL-6 ≥10 pg/mL and CRP ≥10 mg/L occurred in 97.7% of inpatients versus 1.8% of outpatients (odds ratio 3,861, C statistic 0.976, P = 1.00 x 10 −12 ). Antibody or ferritin levels did not add significantly to predicting hospitalization. Antibody testing in family members and contacts of SARS-CoV-2 RNA positive cases (n = 759) was invaluable for case finding. Persistent IgM levels were associated with chronic COVID-19 symptoms. In 81,624 screened subjects, IgG levels were positive (≥1.0 AU/mL) in 5.21%, while IgM levels were positive in 2.96% of subjects. In positive subjects median IgG levels in AU/mL were 3.14 if <30 years of age, 4.38 if 30–44 years of age, 7.89 if 45–54 years of age, 9.52 if 55–64 years of age, and 10.64 if ≥65 years of age ( P = 2.96 x 10 −38 ). Our data indicate that: 1) combined IL-6 ≥10 pg/mL and CRP ≥10 mg/L identify SARS-CoV-2 positive subjects requiring hospitalization; 2) IgG levels were significantly correlated with neutralizing antibody levels with a wide range of responses; 3) IgG levels have significant utility for case finding in exposed subjects; 4) persistently elevated IgM levels are associated with chronic symptoms; and 5) IgG levels are significantly higher in positive older subjects than their younger counterparts.
【초록키워드】 neutralizing antibody, SARS-CoV-2, IgG, IgM, Antibody testing, Hospitalized, Hospitalization, Neutralizing antibodies, antibody, IL-6, Infection, interleukin-6, CRP, ferritin, severe acute respiratory syndrome Coronavirus, Severe acute respiratory syndrome, serum, Immunoglobulin G, Immunoglobulin, death, age, outpatients, SARS-CoV-2 RNA, Inflammatory marker, persistent, utility, Roche, COVID-19 symptoms, Coronavirus-2, Outpatient, Odds ratio, Contact, case finding, immunoglobulin M, Inpatients, Inpatient, C reactive protein, acute respiratory syndrome, acute respiratory syndrome coronavirus, subject, acute respiratory syndrome coronavirus-2, IgG levels, ferritin levels, older subjects, positive, MOST, controls, arbitrary units, identify, occurred, significantly, elevated, screened, median, subjects, occur, hospitalized patient, correlated, significantly higher, arbitrary unit, ferritin level, IgG level, older subject, 【제목키워드】 serology, inflammatory markers, Corona, hospitalizations,