Human AAT gene therapy delays disease progression in CIA mouse model. DBA/1 mice were intraperitoneally injected with rAAV8-CB-hAAT vector (2 × 1011 particles/mouse, n = 10) or saline (n = 10) two weeks before immunization with CII. Control group received saline. Mice were sacrificed on day 56 (EOS). (A) Serum levels of hAAT. hAAT protein serum levels in vector injected group were measured by ELISA (mean+SD). ↓ indicates the days of injection. (B) Anti-hAAT antibody levels. Serum anti-hAAT antibodies (anti-hAAT) were measured by ELISA using samples obtained at 56 days after immunization. Anti-hAAT antibodies were undetectable in the vector injected group. Each dot represents antibody level (arbitrary units) of an individual mouse. (C) Arthritis score. Each line represents the average score from hAAT treated group (open triangles, mean-SD) or control group (open circles, mean+SD, * p < 0.05 as determined by AUC analysis.) (D) Incidence of severe arthritis. Severe arthritis was defined by arthritic score > 3, (* p = 0.035 by logrank test.; 10 mice/group).