SFTPD and susceptibility to pneumonia measurement: In acute respiratory distress syndrome patients, high LDH (> 350 IU/L) was associated with increased 60-day mortality8, and LDH was the most important variable for predicting mortality (AUC 0.854) among 12 variables (age, sex, pneumonia or not, sepsis or not, white blood cell, albumin, C-reactive protein, LDH, pulmonary surfactant-associated protein D, peptidase inhibitor 3, number of organ failures [none, one, two, and more than two], and PaO2/FIO2)9.