HSPA5 and Osteopenia: Anti-GRP78 autoantibody prevalence was significantly greater in the subjects who had both emphysema and osteopenia (50.7% vs. 25%, OR 3.1, 95%CI = 1.8–5.4, p<0.0001), and even more so among those with both emphysema and osteoporosis (80.0% vs. 29.6%, OR 9.5, 95%CI = 2.6–34.7, p<0.0001).