Lymphocyte transformation assay for C neoformans antigen is not reliable for detecting cellular impairment in patients with Neurocryptococcosis

BMC Infectious Diseases

Research Article

Vitor E Valenti¹  Luiz Carlos de Abreu²  Fernando LA Fonseca³  Dewton Moraes-Vasconcelos⁴  Monica SM Vidal⁴  Cinthia Pinhal⁴  Alberto JS Duarte⁴  Sônia Cavalcanti⁴  Matheus Toscano⁴  Anete SG Grumach⁵  Katya C Rocha⁶ 

[1]Departamento de Fonoaudiologia, Faculdade de Filosofia e Ciências, Universidade Estadual Paulista, UNESP, Av. Higyno Muzzi Filho, 737, 17.525-900, Marília, SP, Brazil

[2]Departamento de Morfologia e Fisiologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821, 09060-650, Santo André, SP, Brazil

[3]Departamento de Morfologia e Fisiologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821, 09060-650, Santo André, SP, Brazil

[4]Departamento de Ciências Biológicas, Universidade Federal de São Paulo, Rua Prof. Artur Riedel, s/n, Diadema, SP, Brazil

[5]Departamento de Patologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821. 09060-650 Santo André, SP, Brazil Av. Príncipe de Gales, 821, 09060-650, Santo André, SP, Brazil

[6]Laboratório de Dermatologia and Immunodeficiências, Departmento de Dermatologia, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Arnaldo, 455, 01246903, São Paulo, SP, Brazil

[7]Laboratório de Dermatologia and Immunodeficiências, Departmento de Dermatologia, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Arnaldo, 455, 01246903, São Paulo, SP, Brazil

[8]Departamento de Morfologia e Fisiologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821, 09060-650, Santo André, SP, Brazil

[9]Laboratório de Dermatologia and Immunodeficiências, Departmento de Dermatologia, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Arnaldo, 455, 01246903, São Paulo, SP, Brazil

[10]Departamento de Patologia, Faculdade de Medicina do ABC, Av. Príncipe de Gales, 821. 09060-650 Santo André, SP, Brazil Av. Príncipe de Gales, 821, 09060-650, Santo André, SP, Brazil

关键词: Lymphocytes;    Antigens;    Biases, Statistical;    Cryptococcus;    Methods;    Cryptococcus neoformans;   

DOI  :  10.1186/1471-2334-12-278

 received in 2012-01-30, accepted in 2012-10-17,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundCryptococcus neoformans causes meningitis and disseminated infection in healthy individuals, but more commonly in hosts with defective immune responses. Cell-mediated immunity is an important component of the immune response to a great variety of infections, including yeast infections. We aimed to evaluate a specific lymphocyte transformation assay to Cryptococcus neoformans in order to identify immunodeficiency associated to neurocryptococcosis (NCC) as primary cause of the mycosis.MethodsHealthy volunteers, poultry growers, and HIV-seronegative patients with neurocryptococcosis were tested for cellular immune response. Cryptococcal meningitis was diagnosed by India ink staining of cerebrospinal fluid and cryptococcal antigen test (Immunomycol-Inc, SP, Brazil). Isolated peripheral blood mononuclear cells were stimulated with C. neoformans antigen, C. albicans antigen, and pokeweed mitogen. The amount of 3H-thymidine incorporated was assessed, and the results were expressed as stimulation index (SI) and log SI, sensitivity, specificity, and cut-off value (receiver operating characteristics curve). We applied unpaired Student t tests to compare data and considered significant differences for p<0.05.ResultsThe lymphotoxin alpha showed a low capacity with all the stimuli for classifying patients as responders and non-responders. Lymphotoxin alpha stimulated by heated-killed antigen from patients with neurocryptococcosis was not affected by TCD4+ cell count, and the intensity of response did not correlate with the clinical evolution of neurocryptococcosis.ConclusionResponse to lymphocyte transformation assay should be analyzed based on a normal range and using more than one stimulator. The use of a cut-off value to classify patients with neurocryptococcosis is inadequate. Statistical analysis should be based on the log transformation of SI. A more purified antigen for evaluating specific response to C. neoformans is needed.

【 授权许可】

CC BY   
© Rocha et al.; licensee BioMed Central Ltd. 2012