HIV treatment guidelines and value of CD4 count at ART initiation: data analysis of a cohort of HIV patients enrolled in Italy when their CD4 count was >500 cells/mm3

Background: Aim was to evaluate the influence of guidelines changes on the probability of starting ART at different CD4+ levels in patients enrolled in ICONA in 1996-2010.
Methods: Patients with CD4 count>500 cells/mm3 at enrolment were included. We used the DHHS guidelines to define temporal cut-offs at which recommendations were modified (1996, 2000, 2002, 2003, 2004, 2008 and 2009). Patients' follow-up accrued-up from enrolment to date of starting ART or last follow-up. Person-years (PY) with CD4 count in pre-defined categories (< 200, 200-350, 350-500 and >500) and number of patients initiating ART at each level were counted. Poisson regression analysis was used to estimate relative rates of initiating ART at a certain level of CD4 and calendar period.
Results: We studied 2705 patients, median age 35 years, 29% females, 34% infected heterosexually, median CD4 count at enrollment 672 (range:501-1466) cells/mm3 and viral load (VL) 9,800 (IQR:1,800-34,920) copies/mL. PY at risk were: 25%(1996-1999), 19%(2000-2001), 10% (2002), 9%(2003), 25%(2004-2007), 5%(2008) 8%+(2009). Both current levels of CD4 count and VL showed strong gradients of association with the probability of starting ART: the rates were 93/%PY in patients with VL>100,000 vs. 7%/PY in those with VL< =10,000 copies/mL., 72/%PY in patients with CD4 count 200-350 vs. 20/%PY in those with 351-500 cells/mm3. The figure shows relative rates according to current CD4 levels and calendar periods.

CD4 table
[CD4 table]


Conclusion: we show an increased probability of initiating ART with a CD4 count 201-350/mm3 starting from 2008 and a low probability of starting ART at counts >500 cells/mm3 constant over time.

S. Lo Caputo1, A. Cozzi-Lepri2, A. Antinori3, M. Galli4, P.L. Viale5, A. Lazzarin6, G. Carosi7, L. Sighinolfi8, M. Montroni9, A. d'Arminio Monforte10
1S.M. Annunziata Hospital, Infectious Disease Clinic, florence, Italy, 2University College London, london, United Kingdom, 3INMI Lazzaro Spallanzani, Roma, Italy, 4Dipartimento Scienze Cliniche- Università di Milano Ospedale Luigi Sacco, Milano, Italy, 5Clinica Malattia Infettive Ospedale Sant'Orsola Università degli Studi Bologna, Bologna, Italy, 6Clinica Malattie Infettive Osp. San Raffaele, milano, Italy, 7Istituto Malattie Infettive Università di Brescia, Brescia, Italy, 8U.O. Malattie Infettive Azienda Ospedaliera Universitaria Arcispedale S. Anna, Ferrara, Italy, 9Clinica Malattie Infettive Università degli Studi Ancona, Ancona, Italy, 10Clinica Malattie Infettive - Ospedale San Paolo, Milano, Italy