Development and evaluation of an enzyme-linked immunosorbent assay to detect Histoplasma capsulatum antigenuria in immunocompromised patients.
Histoplasma capsulatum infection causes significant morbidity and mortality in human immunodeficiency virus-infected individuals, particularly those in countries with limited access to rapid diagnostics or antiretroviral therapies. The fungus easily disseminates in persons with AIDS, resulting in progressive disseminated histoplasmosis (PDH), which can progress rapidly to death if undiagnosed. The availability of a simple, rapid method to detect H. capsulatum infection in less developed countries where the infection is endemic would dramatically decrease the time to diagnosis and treatment of PDH. We have developed an antigen-capture enzyme-linked immunosorbent assay (ELISA) to detect PDH antigenuria in infected patients. The assay uses polyclonal antibodies against H. capsulatum as both capture and detection reagents, and a standard reference curve is included to quantify antigenuria and ensure reproducibility. We evaluated this assay using specimens collected from patients with AIDS and culture-proven histoplasmosis in a Guatemalan clinic (n = 48), from healthy persons (n = 83), and from patients with other, nonhistoplasmosis diseases (n = 114). The ELISA demonstrated a sensitivity of 81% and a specificity of 95% in detecting H. capsulatum antigen in urine. This assay relies on simple technology that can be performed in institutions with limited resources. Use of this test will facilitate rapid diagnosis of PDH in countries where mortality is high, expediting treatment and likely reducing PDH-related mortality.
Scheel
Christina M
CM
Division of Foodborne, Bacterial and Mycotic Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd. NE, Mailstop G-11, Atlanta, GA 30333, USA. cscheel@cdc.gov
Samayoa
Blanca
B
Herrera
Alejandro
A
Lindsley
Mark D
MD
Benjamin
Lynette
L
Reed
Yvonne
Y
Hart
John
J
Lima
Sandra
S
Rivera
Blanca E
BE
Raxcaco
Gabriella
G
Chiller
Tom
T
Arathoon
Eduardo
E
Gómez
Beatriz L
BL
D000328:Adult; D000368:Aged; D000818:Animals; D000908:Antibodies, Fungal; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006166:Guatemala; D015658:HIV Infections / Q000150:complications; D006658:Histoplasma / Q000276:immunology / Q000302:isolation & purification*; D006660:Histoplasmosis / Q000175:diagnosis*; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D012680:Sensitivity and Specificity; D014556:Urine / Q000382:microbiology*; D055815:Young Adult
D000908:Antibodies, Fungal