@article {FakihP4784, author = {Dalia Fakih and Soulaima Chamat and Myrna Medlej-Hashim and Mirna Waked and Pascale Salameh and Grith Sorensen and Rania Jounblat}, title = {Polymorphism in SFTPD gene affects assembly and constitutional serum levels of surfactant protein D in a Lebanese population}, volume = {44}, number = {Suppl 58}, elocation-id = {P4784}, year = {2014}, publisher = {European Respiratory Society}, abstract = {Surfactant protein D (SP-D), an oligomeric lung-derived lectin, has essential roles in innate immunity. It can be measured in serum. Previous studies have shown that constitutional SP-D serum levels and the protein degree of multimerization are genetically influenced. We aimed to establish the distribution profile of serum constitutional SP-D in the Lebanese population and to investigate the genetic influence of single nucleotide polymorphism (SNP) rs721917 within SP-D gene (SFTPD) on its multimerization and its serum basal level. The C/T alleles at this SNP level lead respectively either to a threonine or methionine at position 11 of the SP-D protein. SP-D was measured by ELISA in serum taken from 97 healthy subjects. The p.Met11Thr SNP was genotyped. Different forms of SP-D were separated by gel filtration chromatography. Basal serum SP-D levels varied extensively, over a range of 108.3 ng/ml to 2995 ng/ml. The p.Met11Thr SNP was significantly associated with the serum SP-D levels (p=0.01). Individuals homozygous for the T wild-type allele had the highest mean SP-D serum levels (1423 ng/ml) compared to heterozygous individuals (1139 ng/ml) and homozygous individuals for the C allele (671.4 ng/ml). Serum from heterozygous individuals showed two different molecular weight peaks corresponding to different forms of SP-D of ratio high/low 1:07. However, data showed a remarkable predominance of the low molecular weight form of SP-D (ratio high/low 1:4.65) in serum of individuals carrying the CC genotype. Our preliminary findings validate previous observations of the influence of the p.Met11Thr SNP on assembly and serum concentration of SP-D.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/44/Suppl_58/P4784}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }