1. Validation of a Host Gene Expression Test for Bacterial/Viral Discrimination in Immunocompromised Hosts
- Author
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Micah T. McClain, Julie M Steinbrink, Geoffrey S. Ginsburg, Thomas W. Burke, Christopher W. Woods, Ricardo Henao, Ephraim L. Tsalik, Sunil Suchindran, and Rachael E Mahle
- Subjects
0301 basic medicine ,Microbiology (medical) ,medicine.medical_treatment ,Gene Expression ,Host gene ,Logistic regression ,Immunocompromised Host ,03 medical and health sciences ,0302 clinical medicine ,Acquired immunodeficiency syndrome (AIDS) ,Humans ,Medicine ,030212 general & internal medicine ,Chemotherapy ,Bacteria ,business.industry ,Bacterial Infections ,medicine.disease ,Gene expression profiling ,Major Articles and Commentaries ,030104 developmental biology ,Infectious Diseases ,Quartile ,Virus Diseases ,Immunology ,Etiology ,Immunocompetence ,business - Abstract
Background Host gene expression has emerged as a complementary strategy to pathogen detection tests for the discrimination of bacterial and viral infection. The impact of immunocompromise on host-response tests remains unknown. We evaluated a host-response test discriminating bacterial, viral, and noninfectious conditions in immunocompromised subjects. Methods An 81-gene signature was measured using real-time–polymerase chain reaction in subjects with immunocompromise (chemotherapy, solid-organ transplant, immunomodulatory agents, AIDS) with bacterial infection, viral infection, or noninfectious illness. A regularized logistic regression model trained in immunocompetent subjects was used to estimate the likelihood of each class in immunocompromised subjects. Results Accuracy in the 136-subject immunocompetent training cohort was 84.6% for bacterial versus nonbacterial discrimination and 80.8% for viral versus nonviral discrimination. Model validation in 134 immunocompromised subjects showed overall accuracy of 73.9% for bacterial infection (P = .04 relative to immunocompetent subjects) and 75.4% for viral infection (P = .30). A scheme reporting results by quartile improved test utility. The highest probability quartile ruled-in bacterial and viral infection with 91.4% and 84.0% specificity, respectively. The lowest probability quartile ruled-out infection with 90.1% and 96.4% sensitivity for bacterial and viral infection, respectively. Performance was independent of the type or number of immunocompromising conditions. Conclusions A host gene expression test discriminated bacterial, viral, and noninfectious etiologies at a lower overall accuracy in immunocompromised patients compared with immunocompetent patients, although this difference was only significant for bacterial infection classification. With modified interpretive criteria, a host-response strategy may offer clinically useful diagnostic information for patients with immunocompromise.
- Published
- 2021