Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood

Luisa F. López, Oliver Keatinge Clay, Diego H. Cáceres, Beatriz L. Gómez

Research output: Contribution to conferenceAbstract

Abstract

Objective: Histoplasmosis is an important cause of mortality in persons living with HIV and AIDS (PLWHA), especially in countries where patients have limited access to antiretroviral therapies and diagnostic testing. In PLWHA, the progressive disseminated form of histoplasmosis (PDH) can be fatal without treatment. Early diagnosis is critical for providing proper treatment, however, current diagnosis by culture can take weeks and serology may be falsely negative early in infection or as a result of immunosuppression in these patients. Detection of Histoplasma antigen in patient specimens improves sensitivity and timeliness of diagnosis, but the current method by enzyme immunoassay must be performed by highly trained personnel in specialty laboratories. Recently, the development of the lateral flow technology has provided a method that is simple to use and can be performed in a setting closer to the patient. In this study, a lateral flow assay (LFA) was evaluated for the detection of Histoplasma antigen in sera. Methods: Using a MiraVista Diagnostics LFA for detection of Histoplasma antigen, we evaluated 47 serum samples: 19 from patients with AIDS and culture-proven PDH and 28 from patients with other fungal and bacterial infections, as well as healthy people. LFA devices were read by human eye and automated reader. Results: When the LFA test was read by human eye, sensitivity was 95% and specificity was 82%. Using an automated reader, sensitivity was 89% and specificity was 89%. The Kappa index compared human eye and automated reader was 0.87. Cross-reactions were observed principally in samples from patients with proven diagnosis of paracoccidioidomycosis. Conclusion: The MiraVista Diagnostics LFA had high analytical performance and good agreement between human eye and automated reader. This LFA allows Histoplasma antigen testing with minimal laboratory equipment and infrastructure requirements. Based on these results, this new method is a viable option for rapid diagnosis of PDH. LFA provides highly sensitive results in <1 hour, being faster and more sensitive for PDH than other immunological assays, such as ELISA (three to five hours; >90% sensitivity), immunodiffusion and complement fixation (two days; ∼65% sensitivity), and conventional microbiological tests, including histopathologic examination (one to two days; ∼75% sensitivity) and culture (two to four weeks; ∼80% sensitivity). Prompt diagnosis of PDH could impact public health by initiating early treatment thereby reducing mortality.
Original languageEnglish (US)
PagesS1-S159
Number of pages1
DOIs
StatePublished - Jun 5 2018
Event20th Congress of the International Society for Human and Animal Mycology - Amsterdam, Netherlands
Duration: Jun 30 2018Jul 4 2018
https://www.isham2018.org/en/Home_10_6_12.html

Conference

Conference20th Congress of the International Society for Human and Animal Mycology
Abbreviated title20th Congress ISHAM
CountryNetherlands
CityAmsterdam
Period6/30/187/4/18
Internet address

Cite this

López, L. F., Clay, O. K., Cáceres, D. H., & Gómez, B. L. (2018). Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood. S1-S159. Abstract from 20th Congress of the International Society for Human and Animal Mycology, Amsterdam, Netherlands. https://doi.org/10.1093/mmy/myy036
López, Luisa F. ; Clay, Oliver Keatinge ; Cáceres, Diego H. ; Gómez, Beatriz L. / Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood. Abstract from 20th Congress of the International Society for Human and Animal Mycology, Amsterdam, Netherlands.1 p.
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abstract = "Objective: Histoplasmosis is an important cause of mortality in persons living with HIV and AIDS (PLWHA), especially in countries where patients have limited access to antiretroviral therapies and diagnostic testing. In PLWHA, the progressive disseminated form of histoplasmosis (PDH) can be fatal without treatment. Early diagnosis is critical for providing proper treatment, however, current diagnosis by culture can take weeks and serology may be falsely negative early in infection or as a result of immunosuppression in these patients. Detection of Histoplasma antigen in patient specimens improves sensitivity and timeliness of diagnosis, but the current method by enzyme immunoassay must be performed by highly trained personnel in specialty laboratories. Recently, the development of the lateral flow technology has provided a method that is simple to use and can be performed in a setting closer to the patient. In this study, a lateral flow assay (LFA) was evaluated for the detection of Histoplasma antigen in sera. Methods: Using a MiraVista Diagnostics LFA for detection of Histoplasma antigen, we evaluated 47 serum samples: 19 from patients with AIDS and culture-proven PDH and 28 from patients with other fungal and bacterial infections, as well as healthy people. LFA devices were read by human eye and automated reader. Results: When the LFA test was read by human eye, sensitivity was 95{\%} and specificity was 82{\%}. Using an automated reader, sensitivity was 89{\%} and specificity was 89{\%}. The Kappa index compared human eye and automated reader was 0.87. Cross-reactions were observed principally in samples from patients with proven diagnosis of paracoccidioidomycosis. Conclusion: The MiraVista Diagnostics LFA had high analytical performance and good agreement between human eye and automated reader. This LFA allows Histoplasma antigen testing with minimal laboratory equipment and infrastructure requirements. Based on these results, this new method is a viable option for rapid diagnosis of PDH. LFA provides highly sensitive results in <1 hour, being faster and more sensitive for PDH than other immunological assays, such as ELISA (three to five hours; >90{\%} sensitivity), immunodiffusion and complement fixation (two days; ∼65{\%} sensitivity), and conventional microbiological tests, including histopathologic examination (one to two days; ∼75{\%} sensitivity) and culture (two to four weeks; ∼80{\%} sensitivity). Prompt diagnosis of PDH could impact public health by initiating early treatment thereby reducing mortality.",
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López, LF, Clay, OK, Cáceres, DH & Gómez, BL 2018, 'Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood' 20th Congress of the International Society for Human and Animal Mycology, Amsterdam, Netherlands, 6/30/18 - 7/4/18, pp. S1-S159. https://doi.org/10.1093/mmy/myy036

Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood. / López, Luisa F.; Clay, Oliver Keatinge; Cáceres, Diego H.; Gómez, Beatriz L.

2018. S1-S159 Abstract from 20th Congress of the International Society for Human and Animal Mycology, Amsterdam, Netherlands.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood

AU - López, Luisa F.

AU - Clay, Oliver Keatinge

AU - Cáceres, Diego H.

AU - Gómez, Beatriz L.

PY - 2018/6/5

Y1 - 2018/6/5

N2 - Objective: Histoplasmosis is an important cause of mortality in persons living with HIV and AIDS (PLWHA), especially in countries where patients have limited access to antiretroviral therapies and diagnostic testing. In PLWHA, the progressive disseminated form of histoplasmosis (PDH) can be fatal without treatment. Early diagnosis is critical for providing proper treatment, however, current diagnosis by culture can take weeks and serology may be falsely negative early in infection or as a result of immunosuppression in these patients. Detection of Histoplasma antigen in patient specimens improves sensitivity and timeliness of diagnosis, but the current method by enzyme immunoassay must be performed by highly trained personnel in specialty laboratories. Recently, the development of the lateral flow technology has provided a method that is simple to use and can be performed in a setting closer to the patient. In this study, a lateral flow assay (LFA) was evaluated for the detection of Histoplasma antigen in sera. Methods: Using a MiraVista Diagnostics LFA for detection of Histoplasma antigen, we evaluated 47 serum samples: 19 from patients with AIDS and culture-proven PDH and 28 from patients with other fungal and bacterial infections, as well as healthy people. LFA devices were read by human eye and automated reader. Results: When the LFA test was read by human eye, sensitivity was 95% and specificity was 82%. Using an automated reader, sensitivity was 89% and specificity was 89%. The Kappa index compared human eye and automated reader was 0.87. Cross-reactions were observed principally in samples from patients with proven diagnosis of paracoccidioidomycosis. Conclusion: The MiraVista Diagnostics LFA had high analytical performance and good agreement between human eye and automated reader. This LFA allows Histoplasma antigen testing with minimal laboratory equipment and infrastructure requirements. Based on these results, this new method is a viable option for rapid diagnosis of PDH. LFA provides highly sensitive results in <1 hour, being faster and more sensitive for PDH than other immunological assays, such as ELISA (three to five hours; >90% sensitivity), immunodiffusion and complement fixation (two days; ∼65% sensitivity), and conventional microbiological tests, including histopathologic examination (one to two days; ∼75% sensitivity) and culture (two to four weeks; ∼80% sensitivity). Prompt diagnosis of PDH could impact public health by initiating early treatment thereby reducing mortality.

AB - Objective: Histoplasmosis is an important cause of mortality in persons living with HIV and AIDS (PLWHA), especially in countries where patients have limited access to antiretroviral therapies and diagnostic testing. In PLWHA, the progressive disseminated form of histoplasmosis (PDH) can be fatal without treatment. Early diagnosis is critical for providing proper treatment, however, current diagnosis by culture can take weeks and serology may be falsely negative early in infection or as a result of immunosuppression in these patients. Detection of Histoplasma antigen in patient specimens improves sensitivity and timeliness of diagnosis, but the current method by enzyme immunoassay must be performed by highly trained personnel in specialty laboratories. Recently, the development of the lateral flow technology has provided a method that is simple to use and can be performed in a setting closer to the patient. In this study, a lateral flow assay (LFA) was evaluated for the detection of Histoplasma antigen in sera. Methods: Using a MiraVista Diagnostics LFA for detection of Histoplasma antigen, we evaluated 47 serum samples: 19 from patients with AIDS and culture-proven PDH and 28 from patients with other fungal and bacterial infections, as well as healthy people. LFA devices were read by human eye and automated reader. Results: When the LFA test was read by human eye, sensitivity was 95% and specificity was 82%. Using an automated reader, sensitivity was 89% and specificity was 89%. The Kappa index compared human eye and automated reader was 0.87. Cross-reactions were observed principally in samples from patients with proven diagnosis of paracoccidioidomycosis. Conclusion: The MiraVista Diagnostics LFA had high analytical performance and good agreement between human eye and automated reader. This LFA allows Histoplasma antigen testing with minimal laboratory equipment and infrastructure requirements. Based on these results, this new method is a viable option for rapid diagnosis of PDH. LFA provides highly sensitive results in <1 hour, being faster and more sensitive for PDH than other immunological assays, such as ELISA (three to five hours; >90% sensitivity), immunodiffusion and complement fixation (two days; ∼65% sensitivity), and conventional microbiological tests, including histopathologic examination (one to two days; ∼75% sensitivity) and culture (two to four weeks; ∼80% sensitivity). Prompt diagnosis of PDH could impact public health by initiating early treatment thereby reducing mortality.

U2 - 10.1093/mmy/myy036

DO - 10.1093/mmy/myy036

M3 - Abstract

SP - S1-S159

ER -

López LF, Clay OK, Cáceres DH, Gómez BL. Application of real-time PCR assays for the diagnosis of histoplasmosis using three molecular targets in human FFPE tissues and whole-blood. 2018. Abstract from 20th Congress of the International Society for Human and Animal Mycology, Amsterdam, Netherlands. https://doi.org/10.1093/mmy/myy036