Table 1.

The effects of age, HIV infection and HAART initiation stratified by time of infection (perinatal vs adolescent or adult infection) on T- and B-cell subsets.

Cell subset	Effect of age	Effect of HIV	Effect of HAART
			Perinatal infection	Adolescent/adult infection
T cells (CD3+)
Naive (CD45RA+CCR7+)	↓ [14]	↓ [52,53]	↑ [78,82,83]	↔/↑ [80,84]
Central memory (CD45RA+CCR7−)	↑ [19,20,24]	↓ [52]	↔/↑ CD4+† [78,82] ↔/↓ CD8+† [78,82]	↑ [84]
Effector memory (CD45RA−CCR7+)	↑ [19,20,24]	↑ [53]	↔/↑ CD4+;† [78,82] ↔/↓ CD8+† [78,82]	?
Effector (CD45RA−CCR7−)	↔/↑ [19,24]	↑ [53]	?	↓ [84]
B cells (CD19+CD20+)
Naive (CD21+CD27−)	↔/↓ [29,31,35]	↑ [34,35]	?	↔/↑ [31,91]
Resting memory (CD21+CD27+)	↑ [28,29,31,34,36]	↓ [29]	↑ [35,93]	↑ [31,91,92]

Arrows indicate the change in each cell subset as an increase (↑), decrease (↓), no change (↔) or conflicting evidence (↔/↓ or ↔/↑).

^†Memory T-cell subsets were not evaluated based on CCR7 expression and were classified as total CD45RO⁺ memory cells.