Diagnostic accuracy of antigen detection in urine and molecular assays testing in different clinical samples for the diagnosis of progressive disseminated histoplasmosis in patients living with HIV/AIDS: A prospective multicenter study in Mexico
Authors: Martínez-Gamboa Areli , Niembro-Ortega María Dolores , Torres-González Pedro , Santiago-Cruz Janeth , Velázquez-Zavala Nancy Guadalupe , Rangel-Cordero Andrea , Crabtree-Ramírez Brenda , Gamboa-Domínguez Armando , Reyes-Gutiérrez Edgardo , Reyes-Terán Gustavo , Lozano-Fernandez Víctor Hugo , Ahumada-Topete Víctor Hugo , Martínez-Ayala Pedro , Manríquez-Reyes Marisol , Ramírez-Hinojosa Juan Pablo , Rodríguez-Zulueta Patricia , Hernández-León Christian , Ruíz-Quiñones Jesús , Rivera-Martínez Norma Eréndira , Chaparro-Sánchez Alberto , Andrade-Villanueva Jaime , González-Hernández Luz Alicia , Cruz-Martínez Sofia , Flores-Barrientos Oscar , Gaytán-Martínez Jesús Enrique , Magaña-Aquino Martín , Cervantes-Sánchez Axel , Olivas-Martínez Antonio , Araujo-Meléndez Javier , del Rocío Reyes-Montes María , Duarte-Escalante Esperanza , Frías-De León María Guadalupe , Ramírez José Antonio , Taylor María Lucia , de León-Garduño Alfredo Ponce , Sifuentes-Osornio José 
Published: March 2021

Background
The progressive disseminated histoplasmosis (PDH) has been associated with severe disease and high risk of death among people living with HIV (PLWHIV). Therefore, the purpose of this multicenter, prospective, double-blinded study done in ten Mexican hospitals was to determine the diagnostic accuracy of detecting Histoplasma capsulatum antigen in urine using the IMMY ALPHA Histoplasma EIA kit (IAHE), clarus Histoplasma GM Enzyme Immunoassay (cHGEI IMMY) and MiraVista Histoplasma Urine Antigen LFA (MVHUALFA); as well as the Hcp100 and 1281-1283220SCAR nested PCRs in blood, bone-marrow, tissue biopsies and urine.

Methodology/Principal findings
We included 415 PLWHIV older than 18 years of age with suspicion of PDH. Using as diagnostic standard recovery of H. capsulatum in blood, bone marrow or tissue cultures, or histopathological exam compatible, detected 108 patients (26%, [95%CI, 21.78–30.22]) with proven-PDH. We analyzed 391 urine samples by the IAHE, cHGEI IMMY and MVHUALFA; the sensitivity/specificity values obtained were 67.3% (95% CI, 57.4–76.2) / 96.2% (95% CI, 93.2–98.0) for IAHE, 91.3% (95% CI, 84.2–96.0) / 90.9% (95% CI, 87.0–94.0) for cHGEI IMMY and 90.4% (95% CI, 83.0–95.3) / 92.3% (95% CI, 88.6–95.1) for MVHUALFA.
The Hcp100 nested PCR was performed on 393, 343, 75 and 297, blood, bone marrow, tissue and urine samples respectively; the sensitivity/specificity values obtained were 62.9% (95%CI, 53.3–72.5)/ 89.5% (95%CI, 86.0–93.0), 65.9% (95%CI, 56.0–75.8)/ 89.0% (95%CI, 85.2–92.9), 62.1% (95%CI, 44.4–79.7)/ 82.6% (95%CI, 71.7–93.6) and 34.9% (95%CI, 24.8–46.2)/ 67.3% (95%CI, 60.6–73.5) respectively; and 1281-1283220SCAR nested PCR was performed on 392, 344, 75 and 291, respectively; the sensitivity/specificity values obtained were 65.3% (95% CI, 55.9–74.7)/ 58.8% (95%CI, 53.2–64.5), 70.8% (95%CI, 61.3–80.2)/ 52.9% (95%CI, 46.8–59.1), 71.4% (95%CI, 54.7–88.2)/ 40.4% (95%CI, 26.4–54.5) and 18.1% (95%CI, 10.5–28.1)/ 90.4% (95%CI, 85.5–94.0), respectively.

Conclusions/Significance
The cHGEI IMMY and MVHUALFA tests showed excellent performance for the diagnosis of PDH in PLWHIV. The integration of these tests in clinical laboratories will certainly impact on early diagnosis and treatment.