RESUMO
BACKGROUND: Cryptococcosis is a potentially life-threatening fungal disease caused by encapsulated yeasts of the genus Cryptococcus, mostly C. neoformans or C. gattii. Cryptococcal meningitis is the most frequent clinical manifestation in humans. Neutralizing autoantibodies (auto-Abs) against granulocyte-macrophage colony-stimulating factor (GM-CSF) have recently been discovered in otherwise healthy adult patients with cryptococcal meningitis, mostly caused by C. gattii. We hypothesized that three Colombian patients with cryptococcal meningitis caused by C. neoformans in two of them would carry high plasma levels of neutralizing auto-Abs against GM-CSF. METHODS: We reviewed medical and laboratory records, performed immunological evaluations, and tested for anti-cytokine auto-Abs three previously healthy HIV-negative adults with disseminated cryptococcosis. RESULTS: Peripheral blood leukocyte subset levels and serum immunoglobulin concentrations were within the normal ranges. We detected high levels of neutralizing auto-Abs against GM-CSF in the plasma of all three patients. CONCLUSIONS: We report three Colombian patients with disseminated cryptococcosis associated with neutralizing auto-Abs against GM-CSF. Further studies should evaluate the genetic contribution to anti-GM-CSF autoantibody production and the role of the GM-CSF signaling pathway in the immune response to Cryptococcus spp.
Assuntos
Criptococose , Cryptococcus neoformans , Meningite Criptocócica , Adulto , Humanos , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Meningite Criptocócica/diagnóstico , Autoanticorpos , Colômbia , Criptococose/diagnósticoRESUMO
Abstract Background: The yeasts species determination is fundamental not only for an accurate diagnosis but also for establishing a suitable patient treatment. We performed a concordance study of five methodologies for the species identification of oral isolates of Candida in Colombia. Methods: Sixty-seven Candida isolates were tested by; API® 20C-AUX, Vitek®2 Compact, Vitek®MS, Microflex® and a molecular test (panfungal PCR and sequencing). The commercial cost and processing time of the samples was done by graphical analysis. Results: Panfungal PCR differentiated 12 species of Candida, Vitek®MS and Microflex® methods identified 9 species, and API® 20C-AUX and Vitek®2 Compact methods identified 8 species each. Weighted Kappa (wK) showed a high agreement between Panfungal PCR, Vitek®MS, Microflex® and API® 20C-AUX (wK 0.62-0.93). The wK that involved the Vitek®2 Compact method presented moderate or good concordances compared with the other methods (wK 0.56-0.73). Methodologies based on MALDI TOF MS required 4 minutes to generate results and the Microflex® method had the lowest selling price. Conclusion: The methods evaluated showed high concordance in their results, being higher for the molecular methods and the methodologies based on MALDI TOF. The latter are faster and cheaper, presenting as promising alternatives for the routine identification of yeast species of the genus Candida.
Resumen Introducción: La clasificación a nivel de especies de las levaduras del género Candida de origen clínico es fundamental para el diagnóstico y la instauración de un adecuado tratamiento para el paciente. Se realizó un estudio de concordancia de cinco metodologías usadas para la identificación de aislamientos orales de Candida spp en Colombia. Métodos: Sesenta y siete aislamientos de Candida spp fueron identificados a nivel de especie utilizando; API® 20 C AUX‚ Vitek® 2 Compact, MALDI TOF (Vitek® MS y Microflex®) y una prueba molecular, PCR Panfungal y secuenciación. Un análisis del costo comercial y tiempo de procesamiento de las muestras por cada método fue realizado mediante el análisis gráfico de ambas variables. Resultados: La PCR Panfungal y secuenciación diferenció 12 especies de Candida‚ los métodos Vitek® MS y Microflex® identificaron 9 especies y los métodos API® 20 C AUX y Vitek® 2 Compact identificaron 8 especies. El análisis de Kappa ponderado (wK) demostró una concordancia alta entre los métodos PCR Panfungal y secuenciación‚ Vitek® MS‚ Microflex® y API® 20 C AUX‚ concordancias agrupadas en las categorías buena y muy buena (wK 0.62 - 0.93); los Kp que involucraron el método Vitek® 2 Compact presentaron concordancias moderadas o buenas frente a los otros métodos (wK 0.56 - 0.73). Las metodologías basadas en MALDI TOF MS requirieron 4 minutos para generar un resultado y el método Microflex® fue el método que en nuestro medio presentó el menor precio de venta del servicio. Conclusión: Los métodos evaluados presentaron una alta concordancia en sus resultados‚ siendo más alta para los métodos moleculares y las metodologías basadas en MALDI TOF MS; estas últimas son metodologías más rápidas, económicas y precisas, las cuales se presentan como alternativas prometedoras para la identificación rutinaria de especies de levaduras del género Candida.
Assuntos
Adulto , Humanos , Candida/isolamento & purificação , Candidíase Bucal/diagnóstico , Reação em Cadeia da Polimerase/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Fatores de Tempo , Candidíase Bucal/microbiologia , Técnicas de Tipagem Micológica/métodos , ColômbiaRESUMO
We determined the value of culture and serological tests used to diagnose histoplasmosis. The medical records of 391 histoplasmosis patients were analyzed. Diagnosis of the mycosis was assessed by culture, complement fixation, and immunodiffusion tests; 310 patients (79.5%) were male, and 184 patients (47.1%) were infected with human immunodeficiency virus (HIV). Positivity value for cultures was 35.7% (74/207), reactivity of serological tests was 95.2% (160/168), and a combination of both methodologies was 16.9% (35/207) for non-HIV patients. Positivity value for cultures was 75.0% (138/184), reactivity of serological tests was 92.4% (85/92), and a combination of both methodologies was 26.0% (48/184) for HIV/acquired immunodeficiency syndrome (AIDS) patients; 48.1% (102/212) of extrapulmonary samples from HIV/AIDS patients yielded positive cultures compared with 23.1% (49/212) in non-HIV patients. Lymphocyte counts made for 33.1% (61/184) of HIV/AIDS patients showed a trend to low CD4+ numbers and higher proportion of positive cultures. These results indicate that culture is the most reliable fungal diagnostic method for HIV/AIDS patients, and contrary to what is generally believed, serological assays are useful for diagnosing histoplasmosis in these patients.