Cytomegalovirus-specific IFN-gamma production is associated with protection against cytomegalovirus reactivation in HIV-infected patients on highly active antiretroviral therapy.
OBJECTIVE
To identify the predictors of cytomegalovirus reactivation in AIDS patients on highly active antiretroviral therapy (HAART).


METHODS
This prospective study enrolled cytomegalovirus-seropositive AIDS patients on or about to start HAART, who were not receiving anti-cytomegalovirus prophylaxis. Clinical and laboratory data were collected over 3.5 years at clinic visits, which coincided with the study visits.


METHODS
Blood was obtained at every study visit and was used for measurements of cytomegalovirus cell-mediated immunity (lymphocyte proliferation, IFN-gamma, IL-2, and IL-10 production), cytomegalovirus viral load, CD4 cell count, and HIV viral load. A logistic-normal model was used to analyse outcome data with repeated observations.


RESULTS
Twenty-six patients had 40 episodes of cytomegalovirus reactivation (positive cytomegalovirus viral load) during the study. Their immunological and virological parameters were compared with 26 randomly selected control individuals from the same cohort. The risk of cytomegalovirus reactivation significantly decreased with every 6-month increase in HAART duration [odds ratio (OR) 0.5; P = 0.02] and marginally increased with every log10 RNA copies/ml HIV viral load (OR 2; P = 0.07). CD4 cell counts, cytomegalovirus lymphocyte proliferation, IL-2, and IL-10 did not reach significance as predictors of cytomegalovirus reactivation. However, cytomegalovirus IFN-gamma production significantly decreased the risk of cytomegalovirus reactivation (OR 0.03; P = 0.04).


CONCLUSIONS
Cytomegalovirus-specific IFN-gamma has a unique value as an immunological predictor of cytomegalovirus reactivation, demonstrating the importance of cellular immune responses in the control of cytomegalovirus replication in HAART recipients.
Weinberg
Adriana
A
Department of Pediatrics, University of Colorado Health Sciences Center, Denver 80262, USA.
Wohl
David A
DA
MaWhinney
Samantha
S
Barrett
Rachel J
RJ
Brown
Darby G
DG
Glomb
Nick
N
van der Horst
Charles
C
D000328:Adult; D000368:Aged; D023241:Antiretroviral Therapy, Highly Active; D018791:CD4 Lymphocyte Count; D003587:Cytomegalovirus / Q000276:immunology / Q000502:physiology*; D003586:Cytomegalovirus Infections / Q000276:immunology / Q000821:virology*; D005260:Female; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology / Q000821:virology*; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000276:immunology; D016753:Interleukin-10 / Q000032:analysis; D007376:Interleukin-2 / Q000032:analysis; D008213:Lymphocyte Activation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D019562:Viral Load; D014775:Virus Activation
D007376:Interleukin-2; D016753:Interleukin-10; D007371:Interferon-gamma