Recombinant protein-based enzyme-linked immunosorbent assay and immunochromatographic tests for detection of immunoglobulin G antibodies to severe acute respiratory syndrome (SARS) coronavirus in SARS patients.
An enzyme-linked immunosorbent assay (ELISA) and a rapid immunochromatographic test for detection of immunoglobulin G (IgG) antibodies in severe acute respiratory syndrome (SARS) patients were developed by utilizing the well-characterized recombinant proteins Gst-N and Gst-U274. The ELISA detected IgG antibodies to SARS-CoV in all 74 convalescent-phase samples from SARS patients while weakly cross-reacting to only 1 of the 210 control sera from healthy donors. This finding thus led to a kit sensitivity, specificity, and accuracy of 100, 99.5, and 99.6%, respectively. The test thus provided a positive predictive value (PPV) of 98.7% and a negative predictive value (NPV) of 100%. In addition, the ELISA gave a positive delta of 5.4 and a negative delta of 3.6, indicating an excellent differentiation between positives and negatives. The same recombinant proteins were also applied to a newly developed platform for the development of a 15-min rapid test. The resulting rapid test has an excellent agreement of 99.6%, with a kappa value of 1.00, with the ELISA. Again, this rapid test was able to detect 100% of the samples tested (n = 42) while maintaining a specificity of 99.0% (n = 210). The PPV and NPV for the rapid test thus reached 95.3 and 100%, respectively.
Guan
Ming
M
Genelabs Diagnostics Pte, Ltd., Singapore, Republic of Singapore. guanming@mail.genelabs.com.sg
Chen
Hsiao Ying
HY
Foo
Shen Yun
SY
Tan
Yee-Joo
YJ
Goh
Phuay-Yee
PY
Wee
Shock Hwa
SH
D000914:Antibodies, Viral / Q000032:analysis / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D011237:Predictive Value of Tests; D011994:Recombinant Proteins / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology* / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D045169:Severe Acute Respiratory Syndrome / Q000175:diagnosis* / Q000276:immunology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D011994:Recombinant Proteins