Cellular restoration in HIV infected persons treated with abacavir and a protease inhibitor: age inversely predicts naive CD4 cell count increase.
OBJECTIVE
To characterize early and later indices of cellular restoration among HIV-1 infected persons treated with abacavir and one protease inhibitor and to identify predictors of CD4 cell increases.


METHODS
Flow-cytometric analyses of lymphocyte phenotypes among 71 antiretroviral treatment naive adults in a 48 week treatment trial.


RESULTS
During the first 4 weeks of therapy, increases in naive and memory CD4 cells and in B cells were seen; naive CD8 cells increased while CD8 cells remained stable as memory CD8 cells decreased. During the second phase total CD4 and naive CD4 and CD8 cells increased while total CD8 and memory CD8 cells decreased. The numbers of CD4 cells that expressed CD28 increased from a median of 308 x 10(6)/l at baseline to 477 x 10(6)/l at week 48. Higher baseline plasma HIV-1 RNA levels predicted the magnitude of early CD4 (r = 0.35; P = 0.01), memory CD4 (r = 0.38; P = 0.001) and CD28 CD4 cell (r = 0.29; P = 0.01) restoration but was not related to second phase changes. Younger age predicted a greater second phase (but not first phase) increase in naive CD4 cells (r = -0.31; P = 0.03).


CONCLUSIONS
Higher baseline levels of HIV-1 replication determine the magnitude of first phase CD4 cell increases after suppression of HIV-1 replication. Second phase (primarily naive) CD4 cell increases are not related to HIV-1 replication but are inversely relate to age suggesting that thymic potential is a major determinant of long term cellular restoration in HIV-1 infected persons receiving antiretroviral therapy.
Lederman
M M
MM
Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Ohio 44106, USA.
McKinnis
R
R
Kelleher
D
D
Cutrell
A
A
Mellors
J
J
Neisler
M
M
Cooney
E
E
Haas
D W
DW
Haubrich
R
R
Stanford
J
J
Horton
J
J
Landay
A
A
Spreen
W
W
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D015224:Dideoxynucleosides / Q000494:pharmacology / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000188:drug therapy* / Q000276:immunology* / Q000473:pathology; D017320:HIV Protease Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D015497:HIV-1 / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D006801:Humans; D007156:Immunologic Memory / Q000187:drug effects / Q000276:immunology; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000032:analysis; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D000099227:Abacavir
D015703:Antigens, CD; D015224:Dideoxynucleosides; D017320:HIV Protease Inhibitors; D012367:RNA, Viral; D018894:Reverse Transcriptase Inhibitors; D000099227:Abacavir