Interleukin-7 levels may predict virological response in advanced HIV-1-infected patients receiving lopinavir/ritonavir-based therapy.
OBJECTIVE
To examine the relationship between levels of the T-cell regulatory cytokine interleukin-7 (IL-7) and CD4 cell counts during immune reconstitution and to assess its prognostic value in advanced HIV-1-infected patients receiving lopinavir/ritonavir-based therapy.


METHODS
Thirty-six HIV-1-infected adults who completed 48 weeks of follow-up visits were included in this prospective study. Patients having failed two or more antiretroviral therapy regimens were treated with lopinavir/ritonavir-based therapy. An enzyme-linked immunosorbent assay was used to determine IL-7 plasma levels, flow cytometry was used to analyse cell surface antigens, and polymerase chain reaction was used to quantify plasma HIV-1.


RESULTS
Pretreatment IL-7 levels were elevated in all patients (mean 11.0 pg/mL) and were negatively correlated with CD4 cell counts and age (r=-0.59, P<0.001 and r=-0.57, P<0.001, respectively). During the course of treatment, IL-7 levels decreased by 34% while CD4 cell numbers progressively increased by 88%. Multivariate regression analysis showed that only pretreatment IL-7 levels predicted viral load at 48 weeks when controlling for baseline CD4 cell counts, viral load and patient demographics.


CONCLUSIONS
These findings are consistent with regulation of T-cell recovery by IL-7, and suggest that IL-7 measurements might be used to predict virological response.
Boulassel
M R
MR
Immunodeficiency Service Division of Hematology, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada.
Smith
G H R
GH
Gilmore
N
N
Klein
M
M
Murphy
T
T
MacLeod
J
J
LeBlanc
R
R
Allan
J
J
René
P
P
Lalonde
R G
RG
Routy
J P
JP
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D005260:Female; D015658:HIV Infections / Q000097:blood / Q000188:drug therapy* / Q000276:immunology; D006801:Humans; D015851:Interleukin-7 / Q000097:blood*; D061466:Lopinavir; D018655:Lymphocyte Count; D008297:Male; D011446:Prospective Studies; D011744:Pyrimidinones / Q000627:therapeutic use*; D019438:Ritonavir / Q000627:therapeutic use*; D013601:T-Lymphocytes / Q000378:metabolism; D019562:Viral Load
D019380:Anti-HIV Agents; D015851:Interleukin-7; D011744:Pyrimidinones; D061466:Lopinavir; D019438:Ritonavir