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Clinical and Diagnostic Laboratory Immunology, November 2004, p. 1105-1110, Vol. 11, No. 6
1071-412X/04/$08.00+0 DOI: 10.1128/CDLI.11.6.1105-1110.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
Establishing Phenotypic Features Associated with Morbidity in Human T-Cell Lymphotropic Virus Type 1 Infection
G. E. A. Brito-Melo,1,2,3* J. G. Souza,2 E. F. Barbosa-Stancioli,3 A. B. F. Carneiro-Proietti,4 B. Catalan-Soares,4 J. G. Ribas,5 G. W. Thorum,4 R. D. R. Rocha,2 O. A. Martins-Filho,2 and Grupo Interdisciplinar de Pesquisas em HTLV
Laboratório de Imunologia das Faculdades Federais Integradas de Diamantina (FAFEID),1 Laboratório de Doença de Chagas, CPqRR-FIOCRUZ/BH,2 Departamento de Microbiologia, ICB/UFMG,3 Fundação HEMOMINAS,4 Hospital Sarah Kubitschek, Belo Horizonte, Minas Gerais, Brazil5
Received 22 September 2003/ Returned for modification 1 March 2004/ Accepted 23 July 2004
The human T-cell lymphotropic virus type 1 (HTLV-1) is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HT). Although it is widely believed that virus infection and host immune response are involved in the pathogenic mechanisms, the role of the immune system in the development and/or maintenance of HT remains unknown. We performed an analysis of the peripheral blood leukocyte phenotype for two different subcohorts of HTLV-1-infected individuals to verify the existence of similar immunological alterations, possible laboratory markers for HT. The leukocyte population balance, the activation status of the T lymphocytes, and the cellular migratory potential of T lymphocytes, monocytes, and neutrophils were evaluated in the peripheral blood of HTLV-1-infected individuals classified as asymptomatic individuals, oligosymptomatic individuals, and individuals with HT. Data analysis demonstrated that a decreased percentage of B cells, resulting in an increased T cell/B cell ratio and an increase in the CD8+ HLA-DR+ T lymphocytes, exclusively in the HT group could be identified in both subcohorts, suggesting its possible use as a potential immunological marker for HT for use in the laboratory. Moreover, analysis of likelihood ratios showed that if an HTLV-1-infected individual demonstrated B-cell percentages lower than 7.0%, a T cell/B cell ratio higher than 11, or a percentage of CD8+ HLA-DR+ T lymphocytes higher than 70.0%, this individual would have, respectively, a 12-, 13-, or 22-times-greater chance of belonging to the HT group. Based on these data, we propose that the T cell/B cell ratios and percentages of circulating B cells and activated CD8+ T lymphocytes in HTLV-1-infected patients are important immunological indicators which could help clinicians monitor HTLV-1 infection and differentiate the HT group from the asymptomatic and oligosymptomatic groups.
* Corresponding author. Mailing address: Laboratório de Imunologia, Departamento de Ciências Básicas, Faculdades Federais Integradas de Diamantina (FAFEID), Rua da Glória 187, Centro, CEP 39100-000, Diamantina, Minas Gerais, Brazil. Phone: 55 38 3531-1811. Fax: 55 38 3531-1030. E-mail: britomelogea{at}hotmail.com.
Contributing members of the Grupo Interdisciplinar de Pesquisas em HTLV are listed in Acknowledgments.
Clinical and Diagnostic Laboratory Immunology, November 2004, p. 1105-1110, Vol. 11, No. 6
1071-412X/04/$08.00+0 DOI: 10.1128/CDLI.11.6.1105-1110.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.
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