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Human T cell lymphotropic virus type 1 (HTLV‐1) proviral load of HTLV‐associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients according to new diagnostic criteria of HAM/TSP
Author(s) -
Grassi Maria Fernanda Rios,
Olavarria Viviailla,
Kruschewsky Ramon de Almeida,
Mascarenhas Rita Elizabeth,
Dourado Inês,
Correia Luis C.L.,
de CastroCosta Carlos Maurício,
GalvãoCastro Bernardo
Publication year - 2011
Publication title -
journal of medical virology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 121
eISSN - 1096-9071
pISSN - 0146-6615
DOI - 10.1002/jmv.22087
Subject(s) - tropical spastic paraparesis , asymptomatic , receiver operating characteristic , medicine , human t lymphotropic virus , virology , myelopathy , peripheral blood mononuclear cell , asymptomatic carrier , viral load , human t lymphotropic virus 1 , virus , serology , gastroenterology , immunology , biology , antibody , genetics , psychiatry , spinal cord , in vitro , t cell leukemia
A high human T‐cell lymphotropic virus type 1 (HTLV‐1) proviral load is described in HTLV‐1‐associated diseases, especially HAM/TSP. However, the cut‐off value to define high levels of HTLV‐1 proviral load is not well established. 281 HTLV‐1‐infected patients from the HTLV reference center in Salvador, Brazil, were followed from 2005 to 2008. Patients were classified as asymptomatic, possible‐, probable‐, and definite‐HAM/TSP, in accordance with diagnostic criteria proposed by De Castro‐Costa et al. (2006): AIDS Res Hum Retroviruses 22:931–935. HTLV‐1 proviral load was determined using real‐time PCR. A receiver operator characteristic (ROC) curve was constructed using only asymptomatic individuals and definite‐HAM/TSP patients. The ROC curve was used to predict the proviral load level that differentiates these two groups. Out of 281 patients, 189 were asymptomatic and 92 were diagnosed with HAM/TSP (22 possible, 23 probable, 47 definite). The mean HTLV‐1 proviral load was higher in possible‐ (89,104 ± 93,006 copies/10 6 PBMC), ‐probable (175,854 ± 128,083 copies/10 6 PBMC), and definite‐HAM/TSP patients (150,667 ± 122,320 copies/10 6 PBMC), when compared to asymptomatic individuals (27,178 ± 41,155 copies/10 6 PBMC) ( P < 0.0001). A comparison of all HAM/TSP groups showed the highest proviral loads in probable‐HAM/TSP patients, yet the differences in mean values were not statistically significant. The ROC curve suggested a value of 49,865 copies/10 6 PBMC, with 87% sensitivity (95% CI = 74–95) and 81% specificity (95% CI = 75–86), as the best proviral load cut‐off point to differentiate definite HAM/TSP patients from asymptomatic individuals. HTLV‐1 proviral loads are higher in groups of infected patients with neurological symptoms and may represent a relevant biological marker of disease progression. J. Med. Virol. 83:1269–1274, 2011. © 2011 Wiley‐Liss, Inc.