Research
Anti-HTLV antibody profiling reveals an antibody signature for HTLV-I-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP)
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* Corresponding author: Steven Jacobson JacobsonS@ninds.nih.gov
1 Neurobiology and Pain Therapeutics Section, Laboratory of Sensory Biology, National Institute of Dental and Craniofacial Research, Bethesda, MD 20892, USA
2 Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892, USA
3 Metabolism Branch, National Cancer Institute National Institutes of Health, Bethesda, MD 20892, USA
4 Unité d'Epidémiologie et Physiopathologie des Virus Oncogènes, CNRS URA 3015, Département de Virologie, Institut Pasteur, Paris, 75015, France
5 The George Washington University Medical Center, Department of Microbiology, Immunology, and Tropical Medicine, Washington, DC 20037, USA
Retrovirology 2008, 5:96 doi:10.1186/1742-4690-5-96
Published: 20 October 2008Abstract
Background
HTLV-I is the causal agent of adult T cell leukemia (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Biomarkers are needed to diagnose and/or predict patients who are at risk for HAM/TSP or ATLL. Therefore, we investigated using luciferase immunoprecipitation technology (LIPS) antibody responses to seven HTLV-I proteins in non-infected controls, asymptomatic HTLV-I-carriers, ATLL and HAM/TSP sera samples. Antibody profiles were correlated with viral load and examined in longitudinal samples.
Results
Anti-GAG antibody titers detected by LIPS differentiated HTLV-infected subjects from uninfected controls with 100% sensitivity and 100% specificity, but did not differ between HTLV-I infected subgroups. However, anti-Env antibody titers were over 4-fold higher in HAM/TSP compared to both asymptomatic HTLV-I (P < 0.0001) and ATLL patients (P < 0.0005). Anti-Env antibody titers above 100,000 LU had 75% positive predictive value and 79% negative predictive value for identifying the HAM/TSP sub-type. Anti-Tax antibody titers were also higher (P < 0.0005) in the HAM/TSP compared to the asymptomatic HTLV-I carriers. Proviral load correlated with anti-Env antibodies in asymptomatic carriers (R = 0.76), but not in HAM/TSP.
Conclusion
These studies indicate that anti-HTLV-I antibody responses detected by LIPS are useful for diagnosis and suggest that elevated anti-Env antibodies are a common feature found in HAM/TSP patients.