1Division of Rheumatology, Department of Internal Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Brazil
2Department of Internal Medicine, Universidade Federal de Santa Maria, Brazil
3Department of Genetics, Universidade Federal do Rio Grande do Sul, Brazil
4Laboratory of Clinical Pathology, Hospital de Clínicas de Porto Alegre, Brazil
- Odirlei André Monticielo, Serviço de Reumatologia do Hospital de Clínicas de Porto Alegre - HCPA, Rua Ramiro Barcelos, 2350 – Largo Eduardo Zaccaro Faraco, Sala 645, 6° andar, Porto Alegre, Rio Grande do Sul, Brazil - 90035-903 Email: omonticielo{at}yahoo.com.br
Vitamin D deficiency has been described in systemic lupus erythematosus (SLE). BsmI VDR (vitamin D receptor) gene polymorphism was associated with SLE in Asian patients. Studies in Brazilian populations have not been realized. A case-control study with 195 SLE patients and 201 healthy controls was conducted to investigate the influence of BsmI and FokI VDR gene polymorphisms on susceptibility to SLE. In addition, 25-hydroxyvitamin D [25(OH)D] was measured in SLE patients to evaluate possible associations with VDR polymorphic variants and clinical and laboratory expressions of disease. Genotyping was performed by RFLP-PCR. The measurement of 25(OH)D was performed by chemiluminescence. There was no statistically significant difference in genotype and allelic frequencies of BsmI and FokI polymorphisms between European-derived cases and controls. The mean serum levels of 25(OH)D were 25.51 ± 11.43 ng/ml in SLE patients. According to genotype distribution, 25(OH)D concentrations were significantly higher in patients carrying the FokI f/f genotype compared with patients carrying the F/F genotype (31.6 ± 14.1 ng/ml versus 23.0 ± 9.2 ng/ml, p = 0.004), reinforcing its role in the functional activity of VDR. This feature may be considered in future clinical and experimental studies involving vitamin D measurements. Therefore, genetic-specific definitions of ideal levels of vitamin D in SLE need to be established in future studies.
- 25-hydroxyvitamin D
- BsmI polymorphism
- FokI polymorphism
- genetics and immunology
- systemic lupus erythematosus
- vitamin D
- vitamin D receptor
- Received February 9, 2011.
- Accepted August 5, 2011.
- © The Author(s), 2011. Reprints and permissions: http://www.sagepub.co.uk/journalsPermissions.nav