Influence of IL28B Genetic Variation on the Phenotype Infection of HTLV-1

Influence of IL28B Genetic Variation on the Phenotype Infection of HTLV-1

Only 5 to 10% of patients infected with HTLV-1 develop a disease related to infection. The two most serious diseases are adult T-cell leukemia (ATL) and Tropical spastic paraparesis /HTLV-I-associated myelopathy (TSP / HAM). Factors influencing the development of TSP / HAM in the individual HTLV-1 are not yet completely understood. Patients TSP / HAM have a HTLV-1 proviral load (amount of virus) that is 6-10 times higher than seropositive asymptomatic.

Various studies have shown that the development of TSP / HAM in the subject HTLV-1 and its rapid evolution is partly attributed to the failure of the immune system that regulates viral replication and expression.

It has recently been shown that different versions of Single Nucleotide (human leukocyte antigen) rs12979860, located upstream of the gene for Interleukin 28B (IL28B), influenced the severity of infection with hepatitis C and effectiveness of treatment.

By analogy with hepatitis C, a Spanish (Treviño et al., 2012) examined this SNP(single nucleotide polymorphism) in 12 patients TSP / HAM and 29 asymptomatic HIV-positive. CT or TT genotype was statistically more frequent in the group TSP / HAM than in asymptomatic patients (80% versus 20%) and was associated with HTLV-1 proviral load higher.

We propose a broader group of patients in our population and Afro-Caribbean, to confirm the results of the latter study was conducted in a predominantly Latin American population.

Inclusion Criteria :

HAM/TSP Patient:

• Age over 18 years
• Whose HAM/TSP was diagnosed on the criteria of Belem (De Castro-Costa et al., 2006)
• Follow regular consultation of Neurology of the University Hospital of Fort-de-France,
• Affiliate a system of social security (or entitled Beneficiary)
• Having agreed to participate in research by signing the consent form.

HTLV-1 asymptomatic patient:

• Age over 18 years
• Follow regular consultation of Neurology of the University Hospital of Fort-de-France,
• Do not show clinical signs of neurological impairment (a pyramidal syndrome with functional impairment clinic, genito-sphincter, motor deficits suggestive of polymyositis belts)
• Affiliate a system of social security (or entitled Beneficiary)
• Having agreed to participate in research by signing the consent form.

Blood donors:

• Respecting the eligibility criteria for blood donation
• Affiliated with the social security system (or entitled Beneficiary)
• Having agreed to participate in research by signing the consent form
• Serology HTLV-1 negative at the time of blood donation

Exclusion Criteria :

HAM/TSP Patient:

• Featuring an intricate polypathology may cast doubt on the responsibility of HTLV-1 in neurological symptoms,
• Infected with HIV or HBV or HCV
• Not affiliated to a social security (or entitled beneficiary)
• Do not sign the form for obtaining consent.

HTLV-1 asymptomatic patient:

• Infected with HIV or HBV or HCV
• Not affiliated to a social security (or entitled beneficiary)
• Do not sign the form obtaining informed consent.

Blood donors:

• Do not meet the eligibility criteria for blood donation
• Not affiliated to a social security (or entitled beneficiary)
• Do not sign the form obtaining informed consent
• Serology HTLV-1 positive or doubtful