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Inactivated pronase as the cause of false-positive results of serum cryptococcal antigen tests
1Division of Infectious Diseases, University of Colorado Health Sciences Center, Denver, CO, USA. Thomas.Stoeckli@chuv.hospvd.ch
Abstract:
Four patients who had acquired immunodeficiency syndrome and who were evaluated for headache within a 3-week period had false-positive results of serum cryptococcal antigen tests. This cluster of false-positive test results appeared to be due to inactivation of the pronase vial in the test kit, a cause that has not been reported previously.
Insights
A batch of false-positive serum cryptococcal antigen tests in four acquired immunodeficiency syndrome patients suggests a problem with the test kit. The likely cause was an inactivated pronase vial, a previously unreported issue.
Area of Science:
- Medical diagnostics
- Infectious disease testing
- Immunology
Background:
- Acquired immunodeficiency syndrome (AIDS) patients are susceptible to cryptococcal infections.
- Accurate diagnosis of cryptococcosis relies on sensitive serum cryptococcal antigen tests.
- False-positive test results can lead to unnecessary treatment and patient anxiety.
Purpose of the Study:
- To report a cluster of false-positive serum cryptococcal antigen test results in patients with acquired immunodeficiency syndrome.
- To identify the potential cause of these erroneous test results.
Main Methods:
- Retrospective review of four cases of acquired immunodeficiency syndrome patients presenting with headache.
- Analysis of serum cryptococcal antigen test results within a specific 3-week period.
- Investigation into the integrity and components of the diagnostic test kits used.
Main Results:
- Four patients with acquired immunodeficiency syndrome exhibited false-positive serum cryptococcal antigen test results.
- The cluster of false-positive results was linked to the inactivation of a pronase vial within the test kit.
- This specific cause of test kit malfunction had not been previously documented.
Conclusions:
- Inactivation of the pronase vial in serum cryptococcal antigen test kits can lead to false-positive results.
- This highlights the importance of quality control and potential batch-specific issues in diagnostic assays.
- Clinicians should be aware of this potential artifact, especially when interpreting results in high-risk populations like those with AIDS.
