Dataset Information

Superiority of a Novel Mp1p Antigen Detection Enzyme Immunoassay Compared to Standard BACTEC Blood Culture in the Diagnosis of Talaromycosis.

ABSTRACT:

Background

Talaromycosis is an invasive mycosis endemic in Southeast Asia and causes substantial morbidity and mortality in individuals with advanced human immunodeficiency virus (HIV) disease. Current diagnosis relies on isolating Talaromyces marneffei in cultures, which takes up to 14 days and is detectable only during late-stage infection, leading to high mortality.

Methods

In this retrospective case-control study, we assessed the accuracy of a novel Mp1p antigen-detecting enzyme immunoassay (EIA) in stored plasma samples of 372 patients who had culture-proven talaromycosis from blood or sterile body fluids (reference standard) and 517 individuals without talaromycosis (338 healthy volunteers; 179 with other infections). All participants were recruited between 2011 and 2017 in Vietnam.

Results

Of cases and controls, 66.1% and 75.4%, respectively, were male; the median age was 33 and 37, respectively. All cases were HIV infected; median CD4 count was 10 cells/μL. At an optical density cutoff of 0.5, the specificity was 98.1% (95% CI, 96.3%-99.0%); the sensitivity was superior to blood culture (86.3% [95% CI, 82.3%-89.5%] vs 72.8% [95% CI, 68.0%-77.2%]) (P < .001, McNemar test). The time to diagnosis was 6 hours vs 6.6 ± 3.0 days for blood culture. Paired plasma and urine testing in the same patients (n = 269) significantly increased sensitivity compared to testing plasma alone or testing urine alone (P < .001 and P = .02, respectively, McNemar test).

Conclusions

The Mp1p EIA is highly specific and is superior in sensitivity and time to diagnosis compared to blood culture for the diagnosis of talaromycosis. Paired plasma and urine testing further increases sensitivity, introducing a new tool for rapid diagnosis, enabling early treatment and potentially reducing mortality.

SUBMITTER: Thu NTM

PROVIDER: S-EPMC8282318 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundTalaromycosis is one of the most common opportunistic infections in human immunodeficiency virus (HIV) infected patients. However, few researches have explored the prevalence in Southern China and fully assessed the value of the Mp1p antigen screening for the diagnosis of talaromycosis.Methodology/principal findingsWe performed a cross-sectional study of HIV-infected antiretroviral therapy (ART)-naïve adult patients who were seen in 2018 at Guangzhou Eighth People's Hospital, Guangzhou Medical University. Serum samples collected from all the 784 enrolled patients were tested for Mp1p antigen using double-antibody sandwich enzyme-linked immunosorbent assay. A culture of pathogen was conducted in 350 clinically suspected patients to confirm talaromycosis. The overall prevalence of talaromycosis based on the Mp1p antigen detection was 11.4% (89/784) and peaked at 32.2% (75/233) in patients with CD4+ ≤50 Nr/μl. Logistic regression analysis found Mp1p antigen positive rate decreased with the increase in CD4+ counts (OR 0.982, 95% CI 0.977-0.987, P<0.01). The optimal cut-off point of the CD4+ count was 50 Nr/μl or less. Among the 350 patients received both fungal culture and Mp1p antigen detection, 95/350 (27.1%) patients were culture-positive for a Talaromyces marneffei, 75/350 (21.4%) patients were Mp1p antigen positive. The Mp1p antigen assay showed a good agreement to the culture of pathogen, and the sensitivity, specificity, positive predictive value, negative predictive value and kappa value was 71.6% (68/95), 97.3% (248/255), 90.7% (68/75), 90.2% (248/275), and 0.737, respectively. The screening accuracy of the Mp1p antigen assay in patients with CD4+ counts of ≤50 Nr/μl was superior to that in those with higher CD4+ counts.Conclusions/significanceMp1p antigen screening can be an effective tool for more efficient diagnosis of Talaromycosis, especially in HIV/AIDS patients with low CD4+ counts. Future validation studies are needed.

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