SFTPD and AIDS: SP-D levels were significantly higher in AIDS patients (median 577.79 ng/ml) compared to normal subjects (median 406.72 ng/ml; Kruskall Wallis p = 0.03) or HIV-infected individuals with CD4 count greater than 200 cells/μl (median 382.60 ng/ml; Kruskall Wallis p = 0.05) (Figure 1b).