Table 1. Background subject characteristics.

Groups	N	Age	Plasma HIV RNA	CSF HIV RNA	Blood CD4+ T cells
		Median years (IQR)	Median Log10 (IQR)		Median cells/μL (IQR)
Cross-sectional study
NA, CD4<50	42	39 (36–49)	5.37 (4.88–5.61)	3.12 (2.30–3.81)	23 (10–40)
NA, CD4 50–199	49	39 (34–48)	4.92 (4.49–5.52)	4.92 (4.49–5.52)	130 (97–164)
NA, CD4 200–349	52	40 (33–50)	4.88 (4.30–5.35)	4.88 (4.30–5.35)	252 (230–300)
NA, CD4 >350	57	42 (34–48)	4.30 (3.74–4.85)	3.43 (2.92–3.92)	490 (400–630)
HAD	14	47 (38–53)	5.02 (4.73–5.38)	5.02 (4.73–5.38)	127 (35–160)
Treated-suppressed	85	47 (38–53)	1.30 (1.30–1.30)	1.30 (1.30–1.30)	530 (330–708)
HIV negative	204	36 (28–52)	NA	NA	NA
Longitudinal cohort study
All subjects	78	40 (34–47)	5.16 (3.98–5.57)	3.91 (3.25–4.44)	190 (70–270)
Normal CSF NFL	52	40 (34–46)	4.95 (4.33–5.39)	4.07 (3.41–4.60)	210 (125–275)
Elevated CSF NFL	26	42 (36–49)	5.43 (5.02–5.88)	3.71 (2.73–4.39)	150 (2

NA: Not available.