Table 1. Untreated study donor characteristics.

Variable	Uninfected donors	HCV Rheumatoid Factor negative	HCV Rheumatoid Factor positive
Number	N = 23	N = 23	N = 20
Age, years	59 (42–83)	62 (28–72)	59 (50–64)
Plasma HCV RNA level, IU/mL		508,848 (69,124–3,507,690)	1,462,925 (316,393–6,530,280)b
Serum Albumin level, g/dL	4.1 (3.5–4.9)	3.8 (3.4–4.5)a	3.5 (2.4–4.3)a
Platelet count, x10 3 /uL	232 (160–345)	195 (123–400)	203 (81–323)
Serum AST level, U/L	19 (13–40)	38 (24–199)a	48 (26–282)a
Serum ALT level, U/L	20 (11–65)	46(17–316)a	51.5 (31–235)a
APRI	0.209 (0.084–0.520)	0.448 (0.148–2.44)a	0.619 (0.187–6.19)a
<0.4	22 (95.6%)	10 (43.5%)	6 (30%)
0.4–1.5	1 (4.4%)	10 (43.5%)	9 (45%)
>1.5		3 (13%)	5 (25%)
HCV genotype
1		21 (91.3%)	18 (90%)
2/3		2 (8.7%)	2 (10%)
Duration of HCV infection
1–10 years		2 (8.7%)	1 (5%)
>10 years		20 (86.9%)	16 (69.6%)
Unknown		1 (4.4)	3 (25.4%)
Sex
Male	23 (100%)	22 (95.6%)	20 (100%)
Female	0	1 (4.4%)
Ethnicity
Caucasian	6 (26.1%)	9 (39.1%)	5 (25.0%)
African American	16 (69.6%)	14 (60.9%)	14 (70.0%)
Hispanic White			1(5%)
Native Hawaiian	1 (4.3%)
Absolute CD19+ count (cells/uL)	219.8 (128.7–940.2)	243.55 (73.0–986)	210.6 (109–820.0)
RF level IU/mL			80% RF<100 IU/mL 20% RF >100 IU/mL

Values are expressed as median (range) for age, HCV RNA level, albumin, platelet, AST level, ALT level, APRI score, calculated as described previously [47], and absolute CD19+ count. Numbers and proportions of subjects within each category are given for HCV genotype, duration of HCV infection, sex, ethnicity and RF. Abbreviations: ALT, alanine aminotransferase; APRI, AST-to-Platelet ratio index; AST, aspartate aminotransferase; HCV, hepatitis C virus, and RF, rheumatoid factor. ^a p< .05 compared with uninfected donors; ^b p< .05 compared between HCV RF- and HCV RF+