Yoon HY, et al. - Researchers investigated the prevalence and incidence of pulmonary alveolar proteinosis (PAP) by using nationwide claims data from the Korean Health Insurance Review and Assessment service. They recognized 182 cases (narrow, n = 82) with PAP-related codes from 2010 to 2016 and 89 new patients (narrow, n = 66) visited medical institutes between 2012 and 2015. PAP prevalence of 4.44 (narrow: 2.27) per 10⁶ population was identified revealing a low prevalence and incidence of PAP in Korea, similar to those noted in other countries. However, older diagnostic age, and a lower male-to-female ratio characterized Korean patients with PAP.