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Rodríguez Laboccetta C, Briceño Fernández VJ, Videla Garrido A, Posse GB, Cuestas ML, Nusblat AD. Histoplasma antigens as novel players for the development of new enzyme immunoassays for the serodiagnosis of histoplasmosis: A comparative study of their analytical performance. Med Mycol 2024; 62:myae023. [PMID: 38479779 DOI: 10.1093/mmy/myae023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/05/2024] [Accepted: 03/12/2024] [Indexed: 04/12/2024] Open
Abstract
Definitive diagnosis of histoplasmosis relies on culture and/or cytology/histopathology; however, these procedures have limited sensitivity and cultures are time-consuming. Antibodies detection by immunodiffusion has low sensitivity in immunocompromised individuals and uses histoplasmin (HMN), a crude antigenic extract, as reagent. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques to obtain standardized and specific reagents for diagnosing histoplasmosis. To compare the analytical performance of novel enzyme-linked immunosorbent assays (ELISAs) for antibodies testing for diagnosing histoplasmosis using different Histoplasma capsulatum antigens as reagents. The H. capsulatum 100 kDa protein (Hcp100), the M antigen and its immunoreactive fragment F1 were produced by DNA-recombinant techniques. Galactomannan was purified from both the yeast and mycelial cell walls (yGM and mGM, respectively). The analytical performance of the ELISA tests for the serological detection of antibodies against these antigens was evaluated and compared with those obtained using HMN as reagent. Antibodies detection by the Hcp100 ELISA demonstrated 90.0% sensitivity and 92.0% specificity, versus 43.3% sensitivity and 95.0% specificity of the M ELISA, 33.3% sensitivity and 84.0% specificity of the F1 ELISA, 96.7% sensitivity and 94.0% specificity of the yGM ELISA, 83.3% sensitivity and 88.0% specificity of the mGM ELISA, and 70.0% sensitivity and 86.0% specificity for the HMN ELISA. In summary, Hcp100 is proposed as the most promising candidate for the serodiagnosis of histoplasmosis. The primary immunoreactive element in HMN proved to be GM rather than the M antigen. Nevertheless, a higher incidence of cross-reactions was noted with GM compared to M.
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Affiliation(s)
- Carolina Rodríguez Laboccetta
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología (NANOBIOTEC). Buenos Aires, Argentina
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Víctor J Briceño Fernández
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología (NANOBIOTEC). Buenos Aires, Argentina
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Agustín Videla Garrido
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Gladys B Posse
- Laboratorio de Micología. Hospital Nacional Profesor Alejandro Posadas. Buenos Aires, Argentina
| | - María L Cuestas
- Universidad de Buenos Aires. CONICET. Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM). Buenos Aires, Argentina
| | - Alejandro D Nusblat
- Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología (NANOBIOTEC). Buenos Aires, Argentina
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Fernandes-Beraldo KR, Santos de Freitas-Xavier R, Pardini-Vicentini A. Fast and cost-effective protocol to produce Paracoccidioides spp. antigens. BIOMEDICA : REVISTA DEL INSTITUTO NACIONAL DE SALUD 2023; 43:170-180. [PMID: 37721912 PMCID: PMC10594581 DOI: 10.7705/biomedica.6874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 05/10/2023] [Indexed: 09/20/2023]
Abstract
INTRODUCTION The existing methods for Paracoccidioides spp. antigen production are problematic in terms of standardization, specificity, stability, repeatability, and reproducibility. OBJECTIVE To optimize the methodology for Paracoccidioides spp. antigen production and evaluate its applicability in paracoccidioidomycosis immunodiagnosis. MATERIALS AND METHODS The antigens were obtained from Paracoccidioides lutzii isolates (01, 66, and 8334), Paracoccidioides brasiliensis sensu stricto (113), and Paracoccidioides restripiensis (B-339). These fungi were grown at 36 °C ± 1 °C, on modified Fava-Netto agar, according to Freitas et al. (2018). Paracoccidioides lutzii antigens were obtained after , 10, and 20 days of culture, whereas P. brasiliensis and P. restripiensis antigens were obtained after 10 days. Antigens were evaluated in natura, 10 and 20 times concentrated. Antigenic capacity was evaluated using a double immunodiffusion assay against serum samples from patients with paracoccidioidomycosis, histoplasmosis, and aspergillosis, and random blood donors. RESULTS Cross-reactivity between Paracoccidioides spp. antigens was observed when P. brasiliensis, P. restrepiensis antigens, and P. lutzii antigens were evaluated with the polyclonal antibodies against P. lutzii and P. brasiliensis, respectively. No cross-reactivity was obtained for polyclonal antibodies against Histoplasma capsulatum, Aspergillus fumigatus, and random blood donors. The proposed protocol allowed stable, repeatable, and reproducible genus-specific antigen production at a low cost and in a short cultivation time. CONCLUSION The proposed protocol allowed us to obtain genus-specific antigens that can be developed and reproduced in all laboratories in Brazil and South America, where paracoccidioidomycosis is a neglected disease, contributing to an early diagnosis, especially in endemic regions, regardless of the species.
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Affiliation(s)
- Karolina Rosa Fernandes-Beraldo
- Laboratório Central, Universidade Federal de São Paulo, São Paulo, Brasil; Programa de Pós-Graduação em Ciências, Coordenadoria de Controle de Doenças, Secretaria de Estado da Saúde de São Paulo, São Paulo, Brasil.
| | - Roseli Santos de Freitas-Xavier
- Laboratório de Micologia Médica (LIM53), Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil.
| | - Adriana Pardini-Vicentini
- Programa de Pós-Graduação em Ciências, Coordenadoria de Controle de Doenças, Secretaria de Estado da Saúde de São Paulo, São Paulo, Brasil; Laboratório de Imunodiagnóstico das Micoses, Centro de Imunologia, Instituto Adolfo Lutz, São Universidade de São Paulo, São Paulo, Brasil.
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HTLV-1 and HTLV-2 infections in patients with endemic mycoses in São Paulo, Brazil: A cross-sectional, observational study. LANCET REGIONAL HEALTH. AMERICAS 2022; 15:100339. [PMID: 36778068 PMCID: PMC9904113 DOI: 10.1016/j.lana.2022.100339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background Brazil is a country endemic for human T-lymphotropic virus 1 and 2 (HTLV-1 and HTLV-2), systemic mycoses such as paracoccidioidomycosis (PCM) and histoplasmosis (HP), and aspergillosis (AP). The prevalence of HTLV-1/-2 infections in individuals with endemic mycoses in Latin America is unknown; however, an association between HTLV-1 and severe PCM and HP has been observed in Peru. Addressing this knowledge gap, we searched for HTLV-1/-2 antibodies in serum samples sent to the Instituto Adolfo Lutz, São Paulo, Brazil, for systemic mycosis diagnosis. Methods We used 387 sera from a biorepository that had seropositive results for Paracoccidioides spp. (G1, n=212), Histoplasma capsulatum (G2, n=95), Aspergillus spp. (G3, n=61), and at least two of these fungi (G4, n=19). We searched for the presence of HTLV-1/-2 antibodies using commercial immunoassays: enzyme immunoassay (HTLV-I+II Murex, Diasorin), western blotting (HTLV Blot 2.4, MP Biomedicals), and line immunoassay (INNO-LIA HTLV I/II, Fujirebio). Demographic characteristics were evaluated in each group. Findings Different regions in São Paulo were sampled. Most samples were from males (76.2%; p=0.001), except for G3, in which no sex bias was detected. Mean age differences were observed between groups: patients with PCM and HP had a similar mean age (42.8 and 42.0 years, respectively), while those with AP and co-fungal infection were older (55.1 and 52.8 years, respectively, (p<0.001). Noteworthy, males were older than females in G1 (p=0.005). Screening detected HTLV-1/2 antibodies in five samples (1.30%; 95% CI: 0.8-1.8%), with two borderline results. HTLV-1/2 was confirmed in two samples: 2/387 (0.52%; 0.063-1.85%): one HTLV-2, male, 42 years, from G1: 1/212 (0.47%; 0.012-2.60%), and one HTLV-1, male, 51 years, from G3: 1/61 (1.64%; 0.042-8.80%). Interpretation In the state of São Paulo, HTLV-1 and HTLV-2 seem to circulate in male patients with systemic mycoses, and since HTLV-1 could impact fungal disease severity, the identification of co-infection is important regardless of prevalence. Funding Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP), and Instituto Adolfo Lutz.
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Maciel IF, de Freitas-Xavier RS, Vicentini AP, Apoliano CF, Ruiz J, Dias ADS, Gimenes VFM, Benard G, Vasconcelos DM. Evaluation of IFN-γ secretion after stimulation with C. neoformans and C. gattii antigens in individuals with frequent exposure to the fungus. J Mycol Med 2021; 32:101230. [PMID: 34923245 DOI: 10.1016/j.mycmed.2021.101230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 10/19/2022]
Abstract
In this study we produced antigenic extracts from prototypical strains of C. neoformans (VNI-VNIV) and C. gattii (VGI-VGIV) and tested IFN-γ secretion by Elispot. Antigens from the eight Cryptococcus molecular types (VNI -VNIV and VGI - VGIV) were obtained after capsule reduction. IFN-γ secretion by Elispot method were stimulated with C. neoformans and C. gattii antigens. Peripheral blood mononuclear cells of fourteen healthy control subjects, being: five ecotourists, two mycologists, three poultry keepers, and four individuals without reports of exposure to the fungus. We observed a significant increase in IFN-γ secretion in the group of ecotourists, mycologists and bird keepers in relation to the group of individuals without reports of occupational exposures to these agents. Our results suggest the significant increase in IFN-γ secretion may be related to the continuous exposure of these groups of individuals to the fungus, as well as to the specific antigen memory immune response developed during exposure to Cryptococcus.
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Affiliation(s)
- Isabel Feitosa Maciel
- Laboratório de Imunologia em Imunodeficiências Primárias e Secundárias, LIM/56, do departamento de Dermatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil.
| | - Roseli Santos de Freitas-Xavier
- Laboratório de Micologia Médica, LIM/53, do Instituto de Medicina Tropical de São Paulo, da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | | | - Carlos Fernando Apoliano
- Laboratório de Imunologia em Imunodeficiências Primárias e Secundárias, LIM/56, do departamento de Dermatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | - Juliana Ruiz
- Laboratório de Imunologia em Imunodeficiências Primárias e Secundárias, LIM/56, do departamento de Dermatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | - Alana Dos Santos Dias
- Laboratório de Imunologia em Imunodeficiências Primárias e Secundárias, LIM/56, do departamento de Dermatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | - Viviane Favero Mazo Gimenes
- Laboratório de Micologia Médica, LIM/53, do Instituto de Medicina Tropical de São Paulo, da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | - Gil Benard
- Laboratório de Micologia Médica, LIM/53, do Instituto de Medicina Tropical de São Paulo, da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
| | - Dewton Moraes Vasconcelos
- Laboratório de Imunologia em Imunodeficiências Primárias e Secundárias, LIM/56, do departamento de Dermatologia do Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, SP, Brazil
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Toscanini MA, Nusblat AD, Cuestas ML. Diagnosis of histoplasmosis: current status and perspectives. Appl Microbiol Biotechnol 2021; 105:1837-1859. [PMID: 33587157 DOI: 10.1007/s00253-021-11170-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 02/03/2021] [Indexed: 11/29/2022]
Abstract
Histoplasmosis is a worldwide-distributed systemic mycosis caused by the dimorphic fungus Histoplasma capsulatum. Its clinical manifestations range from subclinical or mild respiratory illness to progressive disseminated histoplasmosis (PDH), a life-threatening disease, whose accurate diagnosis is still challenging and limited in many countries, where this disease is highly endemic. In this regard, Histoplasma antigen testing is now included in the WHO Essential Diagnostics List. The final diagnosis of histoplasmosis is established by culture and/or visualization of the yeast cells by cytology or histopathology using specific stains. However, both procedures have limited sensitivity to detect the disease and cultures are time-consuming. Antibody detection assays are effective for the subacute and chronic clinical forms of histoplasmosis. However, their sensitivity is low in the immunocompromised host. Several molecular "in-house" tests were also developed and showed promising results, but none of these tests are commercially available and their standardization and validation are still pending. Antigen detection assays have high sensitivity in PDH cases and are of great value for the follow-up of patients with histoplasmosis; however, cross-reactivity with other related fungi are common. In addition, this assay is expensive and only performed in few laboratories. Novel protein antigen candidates have been recently identified and produced by DNA-recombinant techniques in order to obtain standardized and specific reagents for the diagnosis of histoplasmosis, as opposed to the unspecific antigens or crude extracts currently used. This review describes the currently available assays, highlighting their strengths and limitations and reports the latest approaches to achieve reliable and rapid diagnostic tests for histoplasmosis. KEY POINTS: • PDH causes thousands of deaths per year globally. • Rapid accurate diagnosis of PDH is unfeasible in many regions. • Fast, accurate, and low-cost diagnostic alternatives are currently under development.
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Affiliation(s)
- María Agustina Toscanini
- Facultad de Farmacia y Bioquímica, CONICET, Instituto de Nanobiotecnología (NANOBIOTEC), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandro David Nusblat
- Facultad de Farmacia y Bioquímica, CONICET, Instituto de Nanobiotecnología (NANOBIOTEC), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Luján Cuestas
- CONICET, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Universidad de Buenos Aires, Buenos Aires, Argentina.
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Alvarado P, Pérez-Rojas Y, Zambrano EA, Gonzatti MI, Roschman-González A. Improved serodiagnosis of histoplasmosis by use of deglycosylated extracellular released antigens of Histoplasma capsulatum. J Microbiol Methods 2020; 175:105981. [PMID: 32534998 DOI: 10.1016/j.mimet.2020.105981] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/07/2020] [Accepted: 06/07/2020] [Indexed: 11/15/2022]
Abstract
The diagnosis of histoplasmosis depends on various approaches: direct clinical examination, fungus isolation from cultures of clinical samples, histopathological evaluation, and serological testing. In serodiagnostic assays, the Histoplasma capsulatum H and M antigenic glycoproteins have been extensively used. However, both antigens showed limitations attributed mainly to their cross-reactivity with glycoproteins from other pathogenic fungi, which compromises specificity, and generates false positives, misdiagnosis, and therapeutic failure. In this work, we deglycosylated extracellular released antigens from the Venezuelan 7090 H. capsulatum clinical isolate, using chemical and enzymatic methods and evaluated their effectiveness by indirect enzyme-linked immunosorbent assay (ELISA) with sera from patients with either histoplasmosis or PCM. Prior to deglycosylation, the extracellular released antigen showed 62% of sensitivity 66% of specificity and 68% of cross-reactivity with paracoccidioidomicosis sera. The chemically deglycosylated extracellular released antigen, for 8 or 18 h showed 72 and 52% sensitivity with 98% and 92% specificity, respectively. Moreover, cross-reactivity with Paracoccidioides decreased to 4 and 16%, following deglycosylation for 8 or 18 h, respectively. The enzymatically treated antigen showed 52% of sensitivity, 92% of specificity and 8% cross-reactivity against Paracoccidioides. Deglycosylation of the H. capsulatum antigen improves its specificity and decreases its cross-reactivity against Paracoccidioides when using indirect ELISA for serodiagnosis. Therefore, it is recommended to deglycosylate the fungal extracellular released antigen for clinical serodiagnosis, and to monitor humoral immune responses during therapy of patients with the different clinical forms of histoplasmosis.
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Affiliation(s)
- Primavera Alvarado
- Laboratorio de Micología, Instituto de Biomedicina "Dr. Jacinto Convit", Caracas, Venezuela.
| | - Yenis Pérez-Rojas
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Universidad Simón Bolívar, Venezuela
| | - Edgar Armando Zambrano
- Laboratorio de Bioquímica de Parásitos, Instituto de Biomedicina. "Dr. Jacinto Convit", Caracas, Venezuela
| | - Mary I Gonzatti
- Grupo de Bioquímica e Inmunología de Hemoparásitos, Universidad Simón Bolívar, Venezuela
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Toscanini MA, Maglio DG, Capece P, Posse G, Iovannitti CA, Nusblat AD, Cuestas ML. Histoplasma capsulatum 100-kilodalton antigen: recombinant production, characterization, and evaluation of its possible application in the diagnosis of histoplasmosis. Appl Microbiol Biotechnol 2020; 104:5861-5872. [PMID: 32377899 DOI: 10.1007/s00253-020-10570-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/11/2020] [Accepted: 03/20/2020] [Indexed: 11/29/2022]
Abstract
The goal of the present work was to develop a novel reagent with potential for histoplasmosis diagnosis. For this purpose, the genetic sequence of the 100 kDa protein of Histoplasma capsulatum (Hcp100) was cloned and expressed as a secretory protein in Pichia pastoris. After optimizing the culture conditions and purifying by immobilized metal ion affinity chromatography, the highest yield of Hcp100 reached approximately 1.3 mg/l with > 90% purity in shake flasks using basal salt medium supplemented with casamino acids after 72 h of methanol induction. To investigate its potential for diagnosis, its detection in urine samples using specific polyclonal antibodies as reagent was evaluated by dot blot in 6 patients with progressive disseminated histoplasmosis (PDH), of whom all had AIDS. Antigen was detected in urine from all 6 (100%) PDH patients. Urine samples from a pool of 20 healthy individuals did not react with the anti-Hcp100 antibodies. The dot blot assay performed in this study provides preliminary data of a simple technology that can be performed in medical institutions with limited resources to facilitate the rapid diagnosis of histoplasmosis, particularly the disseminated forms. Hence, use of these assays may provide a rapid diagnostic tool of PDH in endemic areas for histoplasmosis where PDH-related mortality is high, hastening treatment and improving patient survival. Finally, this novel antigen and its specific antibodies may provide an alternative diagnostic reagent to the largely unknown and poorly characterized polysaccharide antigens (HPA, galactomannan, histoplasmin) frequently used in the diagnostic tests. KEY POINTS: Few antigens are used as laboratory tools for the immunodiagnosis of histoplasmosis. P. pastoris was an excellent system for recombinant Hcp100 expression. Maximum expression levels of rHcp100 were achieved in BSM with 1% casamino acids. Dot blot assays with anti-rHcp100 antisera can be successfully used for diagnosing PHD.
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Affiliation(s)
- María A Toscanini
- Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología (NANOBIOTEC), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Daniel González Maglio
- Facultad de Farmacia y Bioquímica. Cátedra de Inmunología, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Estudios de la Inmunidad Humoral (IDEHU), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Paula Capece
- Laboratorio de Micología. Hospital Nacional Profesor Alejandro Posadas, Buenos Aires, Argentina
| | - Gladys Posse
- Laboratorio de Micología. Hospital Nacional Profesor Alejandro Posadas, Buenos Aires, Argentina
| | - Cristina A Iovannitti
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina
| | - Alejandro D Nusblat
- Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología (NANOBIOTEC), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María L Cuestas
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), Universidad de Buenos Aires. CONICET, Buenos Aires, Argentina.
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