The study will investigate whether combination antiretroviral therapy of raltegravir and 3TC/ABC is effective and safe to use in tuberculosis (TB)/HIV co-infected adults receiving rifabutin-containing, first-line antituberculous treatment.

Hypothesis:Combination antiretroviral therapy of raltegravir and 3TC/ABC and is effective and safe to use in tuberculosis (TB)/HIV co-infected adults receiving rifabutin-based first-line antituberculous treatment.

This is a phase IIIB/IV, open-label, multi-center, single-arm descriptive pilot study of the efficacy and safety of RAL BID in combination with ABC/3TC QD in antiretroviral-naïve HIV-1 infected individuals with a presumptive or confirmed diagnosis of tuberculosis, without planned comparative analyses.

A goal of 40 subjects will be enrolled from 3 sites in the Russian Federation, including in our site, and receive RAL BID + 3TC/ABC QD for 48 weeks.

This study will include screening, treatment and follow-up periods. Screening period up to 28 days includes initial visits at Day -28 (screening) and Day -14 (switch to rifabutin). The second visit will be required if patient is initially on rifampin-based TB regimen that will need to be switched to rifabutin-based regimen.

Patients receiving rifampin-containing TB therapy will be switched to rifabutin (300 mg daily) a minimum of 14 days prior to initiation of antiretroviral therapy. Patients must not have received more than 45 days of tuberculosis therapy.

Treatment period from Day 1 to Week 48 includes 7 visits and a follow-up period (2-4 weeks after the Week 48 visit or Withdrawal visit) includes one visit for resolution of ongoing AEs (adverse events) and new SAEs (serious adverse events). Patients will therefore have 10 scheduled assessments: screening (Day -28; Day -14), baseline (Day 1), Weeks 4, 8, 12, 24, 36, and 48, and follow-up visit.

Inclusion Criteria:

• ART-naïve HIV infected patients
• Plasma HIV-1 RNA >1,000 copies/mL at screening
• CD4 cells 100-350 cells/mm3
• Have presumptive or confirmed diagnosis of Mycobacterium tuberculosis infection
• Receiving first-line antituberculosis treatment
• Documented negative results for the presence of HLA-B*5701 allele

Exclusion Criteria:

• Pregnancy and Breastfeeding
• Known allergy/sensitivity to study drugs or their formulations
• A condition (including but not limited to active alcohol or drug use) that, in the opinion of the investigator, may interfere with patient adherence or safety