title: Response to First-Line Ritonavir-Boosted Protease Inhibitors (PI/r)-Based Regimens in HIV Positive Patients Presenting to Care with Low CD4 Counts: Data from the Icona Foundation Cohort.
abstract: BACKGROUND
  There are no data comparing the response to PI/r-based regimens in people presenting for care with low CD4 counts or AIDS (LC).
  
  
  OBJECTIVE
  To compare the response to LPV/r-, DRV/r- or ATV/r-based cART regimens in LC initiating cART from ART-naive.
  
  
  METHODS
  We included people enrolled in Icona with either CD4 counts ≤350 cells/mm3 (low CD4-LC) or CD4 counts ≤200 cells/mm3 (very low CD4-VLC) and/or AIDS, starting their first PI/r-based regimen after 2008. Initial regimens were compared by intention-to-treat: i) time to viral failure (VF) (first of 2 consecutive VL>200 copies/mL after≥6 months); II) time to PI/r discontinuation/switching for any cause (TD) and for toxicity (TDT); III) treatment failure (TF) (VF or TD). Kaplan-Meier and Cox analyses were used.
  
  
  RESULTS
  1,362 LC patients were included (DRV/r 607; ATV/r 552; LPV/r 203); 813 VLC. In a median of 18 months (IQR:7-35), the 1-year probability of VF and TF were 2.8% (1.9-3.8) and 21.1% (18.7-23.4). In the adjusted analysis, patients initiating ATV/r had a 53% lower chance, and those initiating DRV/r a 61% lower chance of TD, as compared to LPV/r; the risk of TF was more likely in people starting LPV/r. Results were similar among VLC; in this subgroup LPV/r including regimens demonstrated a lower chance of VF.
  
  
  CONCLUSIONS
  We confirmed in LC a low chance of virological failure by 1 year, with small differences according to PI/r. However, larger differences were observed when comparing longer-term endpoints such as treatment failure. These results are important for people presenting late for care.
authors.affiliation: University of Milan, Department of Health Sciences, Clinic of Infectious and Tropical Diseases, ASST Santi Paolo e Carlo, Milan, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: d'Arminio Monforte
authors.affiliation: University College, London, United Kingdom.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Cozzi-Lepri
authors.affiliation: Spedali Riuniti, Bergamo, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Maggiolo
authors.affiliation: L Sacco Hospital, Milan, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Rizzardini
authors.affiliation: University of Cagliari, Cagliari, Italy.
authors.forename: Paolo Emilio
authors.initials: PE
authors.lastname: Manconi
authors.affiliation: San Raffaele Hospital, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Gianotti
authors.affiliation: Busto Arsizio Hospital, Varese, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Quirino
authors.affiliation: INMI L Spallanzani, Rome, Italy.
authors.forename: Carmela
authors.initials: C
authors.lastname: Pinnetti
authors.affiliation: University of Milan, Sacco Hospital, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Rusconi
authors.affiliation: University of Siena, Siena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: De Luca
authors.affiliation: INMI L Spallanzani, Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Antinori
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D005260:Female; D017320:HIV Protease Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006679:HIV Seropositivity / Q000097:blood / Q000188:drug therapy*; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D019438:Ritonavir / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D019380:Anti-HIV Agents; D017320:HIV Protease Inhibitors; D019438:Ritonavir