title: [Interrelationship between the duration of HIV infection, viral load and CD4 positive lymphocyte count].
abstract: BACKGROUND
  The decline in CD4+ lymphocytes occurs at different rates in patients with HIV infection. A longer duration of HIV infection and a higher level of viral replication, represented by the viral load, are associated with a lower CD4+ lymphocyte count. However, the interelationship between these variables is still not well known.
  
  
  METHODS
  107 HIV-infected patients for whom the date of infection was known, were included in a transversal study, in which the CD4+ lymphocyte count and the plasma viral load were analysed, the last using an isothermal amplification method (NASBA). Patients were not receiving antiretroviral drugs or suffered intercurrent infections at the time of the study.
  
  
  RESULTS
  The mean duration of HIV infection was 8.6 +/- 2.9 years. The mean CD4+ lymphocyte count was 366 +/- 264 x 10(6)/l. The mean plasma viraemia was 4.3 +/- 0.9 logs. In a linear regression model, the CD4+ lymphocyte count was explained in 21.7% of cases by the duration of HIV infection, meanwhile the viral load justified up to 36.2 of CD4+ cell variability. When both parameters were combined, up to 58.4% of CD4+ lymphocyte values were explained. In this model, changes of 1 log in viral load had a 4-fold higher effect on the CD4+ cell count than each year of HIV infection.
  
  
  CONCLUSIONS
  The duration of HIV infection and, particularly the viral load strongly influences the current CD4+ lymphocyte count, although other variables should exist (virus with syncytium-inducing phenotype, age of the patient and his immunegenetic repertoire) influencing the different decline seen in CD4+ T-cells.
authors.affiliation: Servicio de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid.
authors.forename: V
authors.initials: V
authors.lastname: Soriano
authors.forename: M
authors.initials: M
authors.lastname: Gómez-Cano
authors.forename: J
authors.initials: J
authors.lastname: Castilla
authors.forename: N
authors.initials: N
authors.lastname: Villalba
authors.forename: A
authors.initials: A
authors.lastname: Holguín
authors.forename: R
authors.initials: R
authors.lastname: Bravo
authors.forename: A
authors.initials: A
authors.lastname: Mas
authors.forename: M L
authors.initials: ML
authors.lastname: Pérez-Labad
authors.forename: J
authors.initials: J
authors.lastname: González-Lahoz
mesh_terms: D018791:CD4 Lymphocyte Count; D015658:HIV Infections / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D016019:Survival Analysis; D019562:Viral Load
vernacular_title: Interrelación entre la duración de la infección por el virus de la inmunodeficiencia humana, la viremia plasmática y la cifra de linfocitos CD4+.