Secular trends in cryoglobulinemia mortality in the United States in the era of direct-acting antivirals

Abstract Background Hepatitis C virus (HCV) is the main etiology of cryoglobulinemia with mortality around 25%. Little is known on the changes in cryoglobulinemia mortality after the introduction of direct-acting antivirals (DAA) for treatment of HCV in 2014 in the US. Methods We calculated cryoglobulinemia mortality from 1999 to 2018. The proportionate mortality ratio (PMR) of cryoglobulinemia cases with HCV and those with autoimmune diseases were computed to assess the impact of introduction of DAA. Results We identified 1299 people aged ≥ 20 years who died with cryoglobulinemia between 1999 and 2018. The cryoglobulinemia mortality (deaths per million) declined from 1999 (0.4) to 2010 (0.22) and mildly increased from 2010 to 2014 (0.26), and then decreased abruptly from 2014 to 2018 (0.19). The proportion of cryoglobulinemia patients with HCV was 39% (118/302) in 2009–2013 and 26% (81/310) in 2014–2018, with a PMR of 0.67 (95% CI 0.50–0.89). By contrast, the proportion of cryoglobulinemia patients with systemic autoimmune diseases was 2.6% (8/302) in 2009–2013 and 4.2% (13/310) in 2014–2018, with a PMR of 1.58 (95% CI 0.66–3.82). Conclusion The changes in cryoglobulinemia mortality during the past two decades are mainly related to the aging and dying of the “baby boomer” cohort who had a high HCV prevalence and to the introduction of a DAA in 2014.