1402. T Cell Clonal Expansion and Proviral Load Levels Among Human T Cell Lymphotropic Virus Type 1 (HTLV-1) Asymptomatic Carriers
Session: Oral Abstract Session: Host Susceptibility to Viral Infections
Sunday, October 23, 2011: 8:45 AM
Room: 156ABC
Background: Early prediction of Adult T Cell Leukemia (ATL) in HTLV-1 carriers can be difficult before a disease becomes clinically evident. In this study we aimed to determine the rate of T cell clonality among HTLV-1 asymptomatic carriers with different titers of proviral load (PL).

Methods: We first applied a sensitive SYBR Green real time PCR on mononuclear cells from cohort of 345 HTLV-1 serological positive asymptomatic subjects. PL was classified into three categories; low titer (≤50 copies/1000 PBMCs), intermediate titer (50-100 copies/1000 PBMCs) and high titer (≥100 copies/1000 PBMCs). Representative patients of each group were assessed for their T cell receptor rearrangements by TCRg multiplex PCR.

Results: Of the 345 patients tested for HTLV PL, 244 (70.7%) were classified as low PL, 41 (11.9%) had intermediate PL. and 60 (17.4%) had high PL. Of the 62 selected patients with low PL, oligoclonal and monoclonal populations were detected in 14 (22.6%) and 4 (6.5%), respectively. Of the 41 patients with intermediate PL, oligoclonal and monoclonal populations were detected in 14 (34.1%) and 5 (12.2%), respectively. Of the 60 patients with high PL, oligoclonal and monoclonal populations were detected in 21 (35.0%) and 23 (38.3%), respectively (p trend < 0.001).

Conclusion: Our results showed higher rate of oligoclonal and monoclonal T cell proliferation in HTLV-1 asymptomatic carriers particularly those who have PL of ≥ 100 copies/1000 PBMCs. Moreover, they provided evidence that both HTLV PL and clonality test are capable to accurately identify HTLV-1 asymptomatic carriers with a low preleukemic clone density who are likely to progress to ATL, hence facilitate disease staging.

Subject Category: V. Virology including clinical and basic studies of viral infections, including hepatitis

Walter Kleine-Neto1, Antonio Charlys da Costa, MSc.1, Ana Carolina Soares de Oliveira1, Yokuo Nukui2, Ester Sabino2 and Sabri Saeed Sanabani1, (1)Translational Medicine Department - Federal University of Sao Paulo, Sao Paulo, Brazil, (2)University of Sao Paulo, School of Medicine, Sao Paulo, Brazil


W. Kleine-Neto, None

A. C. D. Costa, None

A. C. S. D. Oliveira, None

Y. Nukui, None

E. Sabino, None

S. S. Sanabani, None

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