When Are False Positives Unacceptable?
by Marija (Masha) Zecevic
There are certain instances in which a false positive result of a diagnostic procedure is unacceptable. A result of a test is always a statistical probability with a more or less remote chance of the outcome not being correct.
In human health setting we can imagine several instances when a false positive has severe implications. For instance:
Public Health screening campaigns - a false positive result of a preliminary screening would overestimate the number of subjects that need to go for a confirmatory additional testing creating a large burden on the public health budget.
Human therapy – when treatment decisions can have serious or lethal implications in patients wrongly diagnosed.
But there are other instances as well, which go beyond the diagnosis and therapy of human diseases where for ethical or moral reasons a false positive event can mean disastrous consequences.
Justice system - a false positive result of a forensic procedure could determine imprisonment of an innocent person.
Labor law - an employee could lose a job in wrongly accused of drug use.
Sports medicine - a career could be destroyed if the athlete is found to have used illegal drugs to boost the performance.
It is this last use that one of our clients is targeting. HO.p.e has developed and validated an immunoassay able to discriminate samples from athletes who have used the growth hormone (hGH), a common performance enhancing drug.
The challenge in developing a reliable method of identified subjects who have used hGH is twofold: a) injected hGH has a short half-life in blood and b) recombinant hGH is identical to the one endogenously produces and common assay methods cannot discriminate the two forms.
A method based on the discrimination of the endogenous and exogenous form is available by multiple vendors but the uptake of hGH testing has been slow mainly driven by the poor precision of the available tests and serious implications of false positive results.
HO.p.e. ELISA kit is used for the differential quantification of the 22 kDa and 20/22 kDa Growth Hormone (GH) isoforms in human plasma in 96 well plates. This is a standard and accepted approach to discriminate between endogenous and exogenous hormone. The kit is an immunoenzimatic test based on proprietary antibodies against the 22 kDa and 20/22 kDa GH isoforms.
HO.p.e offers a kit with superior specificity, sensitivity and inter-and intra-assay precision.
In addition to sports medicine, HO.p.e kit can be used in human therapy, for instance to identify or monitor response to therapy in patients who have a dysfunction in the growth hormone pathways as is the case in Turner syndrome, congenital hypothyroidism or pituitary dysfunction.
