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Rarely, however, a false positive heterophile antibody test may result from systemic lupus erythematosus, toxoplasmosis, rubella, lymphoma and leukemia. [ 7 ] However, the sensitivity is only moderate, so a negative test does not exclude EBV.
This type is also known as sandwich assay as the analyte is "sandwiched" between two antibodies.) Heterophile antibodies may thus give false positives (by bridging the capture and signal antibody) or false negatives (by blocking one or the other). Both detecting and deterring this interference is difficult in clinical medicine.
Complementarily, the false negative rate (FNR) is the proportion of positives which yield negative test outcomes with the test, i.e., the conditional probability of a negative test result given that the condition being looked for is present. In statistical hypothesis testing, this fraction is given the letter β.
The heterophile antibody test, or monospot test, works by agglutination of red blood cells from guinea pigs, sheep and horses. This test is specific but not particularly sensitive (with a false-negative rate of as high as 25% in the first week, 5–10% in the second, and 5% in the third). [26]
Antibody tests may give false negative (no antibodies were detected despite the presence of HIV) results during the window period, hence an interval of three weeks to six months between the time of HIV exposure and the production of measurable antibodies to HIV seroconversion is implemented. Most people develop detectable antibodies ...
In the most basic sense, there are four possible outcomes for a COVID-19 test, whether it’s molecular PCR or rapid antigen: true positive, true negative, false positive, and false negative ...
On the other hand, false-negative results are much more common, and a bigger concern, Labus says. Testing negative when you really have Covid could increase the likelihood that you spread the ...
Since the antibodies do not bridge between antigens, no agglutination occurs. Because no agglutination occurs, the test is interpreted as negative. In this case, the result is a false negative. The range of relatively high antibody concentrations within which no reaction occurs is called the prozone. [5]