Table 3.

Comparison of levels of anti-chromatin antibodies and gp70 IC in F₁ × NZB and F₁ × NZW backcross mice

Autoantibody trait	F1 × NZB		F1 × NZW
	H2d/z	H2d/d	H2d/z	H2z/z
Anti-chromatin, units/ml
Mean ± SEM	2.8 ± 0.71	0.45 ± 0.06	5.3 ± 1.03	4.4 ± 1.23
Median	0.93	0.33	2.2	2.1
25th percentile	0.53	0.18	1.2	0.55
75th percentile	3.6	0.58	4.3	4.6
gp70 IC μg/ml
Mean ± SEM	2.0 ± 0.43	1.8 ± 0.37	3.6 ± 0.57	1.2 ± 0.35
Median	0.50	0.55	2.0	0.25
25th percentile	0.11	0.11	0.55	0.00
75th percentile	2.5	2.0	5.0	1.5

Serum samples were obtained from 8-month-old animals, and a subset from each group was chosen to analyze for these autoantibodies. For the analysis of anti-chromatin antibodies, the data present samples from 69 F₁ × NZB and 89 F₁ × NZW backcross mice. For the analysis of gp70 IC, the data represent 131 F₁ × NZB and 80 F₁ × NZW backcross mice.