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Identifier

000445578

Title

Βιταμίνη D και ευπαθεία στις λοιμώξεις των βρεφών

Alternative Title

Vitamin D and susceptibility to infections in infants

Author

Ζαχαριουδάκη, Μαρία

Thesis advisor

Γαλανάκης, Εμμανουήλ

Reviewer

Σαμώνης, Γεώργιος
Τσατσάνης, Χρήστος
Δημητρίου, Ελένη
Κοφτερίδης, Διαμαντής
Παρασκάκης, Εμμανουήλ
Περδικογιάννη, Χρυσούλα

Abstract

Background: The role of Vitamin D in innate and adaptive immunity has been recently demonstrated. The biologic effects of vitamin D on target genes are exerted through its receptor (VDR). Vitamin D undergoes two activation processes; the first hydroxylation is conducted by the enzyme CYP2R1 and the second one by the enzyme CYP27B1. The metabolites circulate in plasma mainly bound to the vitamin D binding protein (VDBP). VDR and CYP27B1 are expressed on the majority of immune cells. Vitamin D pathway has recently been correlated to susceptibility to infections in different age groups. Infections constitute one of the major causes of morbidity and mortality in infancy. However, only a few data are published concerning the role of vitamin D in susceptibility to infections in this age group. Aim: In this study we explored the potential association of genetic variances in vitamin D pathway, vitamin D and VDBP serum levels and infections in infancy. Methods: Τhis prospective case-control study included infants 0-24 months with infection and age-matched healthy controls. The single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) gene (BsmI, FokI, ApaI, TaqI), vitamin D binding protein (VDBP) (Gc gene, rs7041, rs4588) and CYP27B1 (rs10877012) were genotyped by polymerase chain reaction and restriction fragment length polymorphism analysis. Serum V Vitamin D and susceptibility to infections in infants Ζacharioudaki Maria 5 vitamin D and VDBP levels were determined using Enzyme-linked Immunosorbent Assay (ELISA). Statistical analysis was conducted with non-parametric tests (twotailed Fisher exact test, Mann-Whiney test and Kruskal-Wallis tests) and Spearman’s correlation coefficient. Results: In total 132 infants were enrolled, of whom 40 with bacterial and 52 with viral infection, and 40 healthy controls. As compared to controls, ΤaqI was more frequent in infants with viral infection compared to controls (p= 0.03, OR 1.96, 95% CI 1.1 to 3.58). Moreover, Gc1F was more frequent in the control group compared to infants with viral infection (p=0.007, OR 2.7, 95%CI 1.3 to 5.6). No significant differences were found regarding the genetic profile for VDR and VDBP in infants with bacterial infection compared to the controls and also regarding CYP27B1 (rs10877012) between the studied groups. Serum 25(OH)Vitamin D and VDBP levels did not differ significantly between infants with viral infection compared to the control group neither between infants with bacterial infection compared to the control group. No significant difference was observed regarding serum 25(OH)Vitamin D and VDBP levels among infants with different genotypes for the studied SNPs of VDR, Gc and CYP27B1 genes. No significant correlation was revealed between serum 25(OH)Vitamin D and VDBP levels in the infants of the study. Conclusion: In this study we demonstrated that genetic variances in vitamin D pathway may modulate susceptibility to and severity of viral infections, in particular of viral respiratory tract infections, in infancy. TaqI was significantly more frequent in infants with acute viral infections compared to controls and Gc1F was more frequent in the control group compared to infants with acute viral infections. No significant difference was revealed regarding vitamin D and VDBP serum levels in the studied groups. Our findings further elucidate genetic susceptibility to viral infections and detection of SNPs of VDR and genetic variances of VDBP might help determine high-risk infants.

Language

Greek

Subject

Βακτηριακές λοιμώξεις

Βρέφη

Ιογενείς λοιμώξεις

Υποδοχέας Βιταμίνη D

Issue date

2022-03-30

Collection

School/Department--School of Medicine--Department of Medicine--Doctoral theses

Type of Work--Doctoral theses