SFTPD and hypersensitivity pneumonitis: Whereas elevated-GMAb HP patients without aPAP complication (n = 4) presented with higher lymphocyte counts in BAL (p = 0.016), and higher serum levels of KL-6 (p = 0.003), and SP-D (p = 0.007) than those of low-GMAb subjects (n = 40).