Figure 3.

Onset, progression, severity and persistence of clinical disease. AR mice (N = 63; females = 34, males = 29) in the first four generations were followed for a minimum of 126 postnatal days (pnd) (average = 157 pnd) with a minimum of eight weekly readings (average = 12). The mice were scored on a weekly basis for the severity of clinical disease (see Materials and methods for details). (A) Histogram showing pnd at onset of clinical disease. While mice were classified as AR when they maintained a score of 2 for two consecutive readings, onset was designated as the first score ≥ 1. (B) Progression of cumulative clinical scores over time for selected AR mice. (C) The maximum numbers of paws affected are shown. Affected paws had a score ≥ 1. (D) The maximum severity of disease based on peak of cumulative clinical score is shown (mild = 2 to 5, moderate = 6 to 10 and severe = 11 to 16). (E) Chronic vs. resolving disease is shown. An AR mouse was classified as having chronic disease when it had a cumulative clinical score ≥ 2 for every weekly reading after onset. Resolving disease was deemed to have occurred when the cumulative joint score dropped below 2 and disease never recurred.