The Role of Molecular Tests in the Diagnosis of Disseminated Histoplasmosis

Vasconcellos, Izadora Clezar da S.; Lana, Daiane Flores Dalla; Pasqualotto, Alessandro C.

doi:10.3390/jof6010001

Cited by 23 publications

(22 citation statements)

References 32 publications

(50 reference statements)

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“…The majority of PCR tests for the diagnosis of histoplasmosis have been developed in house and none of them has been commercialized. They have been recently reviewed in several reports with different purposes [31,38,46]. Most developed methods targeted specific multicopy regions of the ribosomal DNA or the single-copy Hcp100 gene and were performed by using conventional, nested or qPCR formats.…”

Section: Dna Based Detection Methodsmentioning

confidence: 99%

“…The sensitivity and specificity of these assays depends on the type of sample analyzed, the clinical characteristics of patients and the PCR format used for DNA detection. These tests showed an excellent analytical performance (overall sensitivity of 95% and specificity of 99%) when testing samples of HIV patients [38], but sensitivity decreased when testing blood and serum samples from immunocompetent patients [31,46]. Panfungal or broad-range PCRs are used when there is not a clear suspicion of the fungus involved in the infection, since universal primers are used to detect any fungal DNA in the clinical sample.…”

Section: Dna Based Detection Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Laboratory Diagnosis of Histoplasmosis: An Update

Buitrago¹,

Valero²

2020

Histoplasma and Histoplasmosis

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Early diagnosis of histoplasmosis is essential to establish a suitable antifungal therapy and reduce morbidity and mortality rates. However, laboratory diagnosis remains challenging due to the low availability of proper methods and the lack of clinical suspicion. Conventional diagnosis is still largely used even though limitations are well known. Isolating the fungus is time consuming and requires manipulation in BSL3 facilities, while direct visualization and histopathology techniques show low sensitivity and need skilled personnel. New approaches based on the detection of antibodies and antigens have been developed and commercialized last years. Although sensitivity and specificity of these methods is variable, antigen detection has been recently listed as an essential diagnostic test for AIDS patients due to its excellent performance. DNA detection methods are recognized as promising tools but there is still a lack of consensus among laboratories and there are not commercial tests available. Not all methods are widely available, thus most laboratories combine classical and other tests in order to overcome aforementioned limitations. In this chapter, we review the diagnostic pipeline currently available for the diagnosis of histoplasmosis in microbiological laboratories, from conventional to new developed tests. Most recent approaches are introduced and future perspectives are discussed.

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Section: Dna Based Detection Methodsmentioning

confidence: 99%

Section: Dna Based Detection Methodsmentioning

confidence: 99%

Laboratory Diagnosis of Histoplasmosis: An Update

Buitrago¹,

Valero²

2020

Histoplasma and Histoplasmosis

View full text Add to dashboard Cite

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“…Initial PCR is done for the 18-S rDNA, then PCR is done on that amplified product to detect a more specific product for H. capsulatum . Because amplification of an already amplified product occurs, there is an increased risk of contamination [ 70 , 71 ]. Early studies of nested PCR mechanisms testing for both H. capsulatum rDNA and a 100-kDa-like protein unique to Histoplasma (later named Hcp100 ) suggested excellent specificity, although they were limited by DNA extraction capabilities [ 70 ].…”

Section: Diagnosis Of Histoplasmosismentioning

confidence: 99%

Current and New Perspectives in the Diagnosis of Blastomycosis and Histoplasmosis

Linder

Kauffman

2020

JoF

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The diagnosis of blastomycosis and histoplasmosis can be difficult for clinicians who rarely see infections caused by these environmentally restricted dimorphic fungi. Historically, the diagnosis of blastomycosis has been established by culture and sometimes by histopathologic identification. Currently, antigen detection in urine and serum has been shown to aid in the rapid diagnosis of blastomycosis, and newer antibody assays are likely to contribute to our diagnostic capability in the near future. The gold standard for the diagnosis of histoplasmosis has been culture of the organism from involved tissues, aided in some patients by histopathological verification of the typical yeast forms in tissues. Antigen detection has contributed greatly to the ability of clinicians to rapidly establish the diagnosis of histoplasmosis, especially in severely ill and immunocompromised patients, and antibody testing for Histoplasma capsulatum provides important adjunctive diagnostic capability for several forms of both acute and chronic histoplasmosis. For both of these endemic mycoses, novel molecular tests are under active investigation, but remain available in only a few reference laboratories. In this review, we provide a synopsis of diagnostic test options that aid in establishing whether a patient has blastomycosis or histoplasmosis.

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“…An important point was the increased sensitivity obtained by testing more than one sample per patient in cases with extra-pulmonary involvement (Gago et al, 2014). Overall, although the diagnostic yield seem variable depending on the disease stage, clinical form, and type of specimen, PCR based techniques may be the answer to provide the much desired rapid results, particularly to diagnose severe cases in non-endemic locations (Vasconcellos et al, 2019).…”

Section: Molecular Alternatives To Diagnose Histoplasmosismentioning

confidence: 99%

Timely Diagnosis of Histoplasmosis in Non-endemic Countries: A Laboratory Challenge

Buitrago

Martín-Gómez

2020

Front. Microbiol.

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Human histoplasmosis is a fungal infection caused by the inhalation of microconidia of the thermally dimorphic fungi Histoplasma capsulatum. Autochthonous cases of histoplasmosis have been diagnosed in almost every country, but it is considered an endemic infection in specific areas of the world. Many of them are popular travel destinations or the source of migratory movements. Thus, the vast majority of the registered cases in non-endemic countries are imported. They correspond to people having been exposed to the fungus in endemic locations as immigrants, expatriates, transient workers or tourists, with reported cases also associated to organ donation. Misdiagnosis and delays in initiation of treatment are not uncommon in cases of imported histoplasmosis. They are associated to high fatality-rates specially in patients with compromised cellular immunity in which progressive disseminated forms develop. The diagnosis of this infection in non-endemic countries is hampered by the lack of clinical suspicion and a dearth of available diagnostic tools adequate to offer rapid and accurate results. Non-culture-based assays such as nucleic-acid amplification tests present as a suitable alternative in this situation, offering improved sensitivity and specificity, shortened turnaround time, and increased biosafety by avoiding culture manipulation. In non-endemic regions, molecular techniques are being used mainly in laboratories from countries that have registered an increase in the incidence of imported cases. However, the number of published techniques is limited and lack consensus. Efforts are currently under way to standardize nucleic acid amplificationbased techniques for its implementation in areas registering a rising number of imported cases.

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The Role of Molecular Tests in the Diagnosis of Disseminated Histoplasmosis

Cited by 23 publications

References 32 publications

Laboratory Diagnosis of Histoplasmosis: An Update

Laboratory Diagnosis of Histoplasmosis: An Update

Current and New Perspectives in the Diagnosis of Blastomycosis and Histoplasmosis

Timely Diagnosis of Histoplasmosis in Non-endemic Countries: A Laboratory Challenge

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