Phase IV, open, multicentre and single-arm study. 50 HIV infection naive patients with severe immunosuppression will be recruited to evaluate the efficacy and safety of elvitegravir / cobicistat / emtricitabine / tenofovir alafenamide as a first-line treatment.

The patients included in the study will be treated during 48 weeks and will have to perform the selection/basal visit, week 4 visit, week 8 visit, week 12 visit, week 24 visit, week 48 visit and follow up visit.

Inclusion Criteria:

• Patients able to give their written consent to participate in the study after having received information about the design, the purposes of the study, the possible risks that may arise from it and the possibility of withdrawing from it at any time. moment
• Adult patients (age ≥18 years) of both sexes
• Patients with HIV-1 infection with severe immunosuppression, defined by a concentration of CD4 + lymphocytes <200 cells / μL
• Patients who are allowed to perform a genotypic resistance test to inhibitors of intregrase, emtricitabine or tenofovir
• Creatinine clearance ≥ 30 ml / min before the start of treatment
• Alanine transaminase (ALT) / Aspartate transaminase (AST) levels not higher than five times normal levels, total bilirubin with normal values, neutrophils> 1000 cells / μL,> 50000 platelets / μL,> Hb level of 85 g / L and serum amylase levels <1 , 5 times higher normal limit before the start of treatment

Exclusion Criteria:

• Patient who undergoes a concomitant treatment not allowed. Patient with documented intolerance or hypersensitivity to the study medication, or who is contraindicated to use it, attending a technical file
• Patient receiving therapies with interferon, interleukin 2, cytotoxic chemotherapy or immunosuppressants at the baseline visit.
• Patients with neoplasms, an exception of skin cancer and anus cancer in situ (stage 0)
• Patient with any medical or psychological, sociological or geographical alteration, toxic habit (drugs, alcohol) that, a criterion of the researcher, may interfere in the fulfillment of the study by the patient. These conditions will be discussed with the patient before their inclusion in the trial
• Patients with any medical or psychological alteration that, a criterion of the investigator, an involuntary factor of the patient's ability to understand and complement the questionnaires and scales used in the study
• Patient in a treatment with any type of drug / product under investigation or who is participating in a clinical trial that uses a product under investigation, with the exception of studies in which the study treatment was completed more than 12 weeks ago
• Pregnant women, in breastfeeding period or with a positive pregnancy test in the selection period; women of childbearing age and sexually active who are not willing to use an adequate contraceptive method during the study and up to 3 months after the administration of the last dose of study treatment. Some women in adulthood have undergone permanent infertility procedures or amenorrheic procedures for less than 12 months
• Patients with severe hepatic impairment (Child-Pugh Class C).