Levels of vitamin A and selenium of children with cystic echinococcosis in Aba Tibetan and Qiang and Garze Tibetan Autonomous Prefecture, Sichuan, China.

OBJECTIVE: The aim of this study was to review the levels of vitamin A and selenium in children with echinococcosis in Ganzi and Aba. METHODS: Twenty-six children with cystic echinococcosis and 104 apparently healthy controls from the Aba and Garze Tibetan Autonomous Prefecture of Sichuan province in China were recruited. The serum levels of selenium and vitamin A of the cases and controls were detected and stratified by sex and age. RESULTS: The results showed that the ratio of boys to girls was 1:1.36. Compared with the healthy controls, the vitamin A serum levels of the cases significantly declined. The rate of selenium deficiency was high in the cases, but there was no significant difference compared with the control group. Additionally, the lower the vitamin A serum level, the higher the risk for developing echinococcosis. CONCLUSIONS: To improve management strategies in children with cystic echinococcosis, or possibly to prevent the disease, children living in high-risk areas for cystic echinococcosis should be given supplemental vitamin A and encouraged to consume a vitamin A-rich diet containing paw-paw, carrot, palm oil, or fish. Children with vitamin A deficiency in high-risk areas should be screened for cystic echinococcosis.

Genetic variants in the HLA-DRB1 gene are associated with Kashin-Beck disease in the Tibetan population.

OBJECTIVE: To investigate the association between variants in the HLA-DRB1 gene and Kashin-Beck disease (KBD), as well as associations of selenium and iodine deficiencies with KBD in a Tibetan population. METHODS: Fourteen single-nucleotide polymorphisms (SNPs) were genotyped around the HLA-DRB1 gene, and HLA-DRB1 allele genotyping was performed in a discovery cohort, composed of 605 patients with KBD and 393 control subjects, and/or a replication cohort, composed of 290 patients with KBD and 295 controls. Plasma concentrations of selenium and iodine were measured and compared by t-test in 299 patients with KBD and 280 controls from the same villages. RESULTS: Four SNPs (rs6457617, rs6457620, rs9275295, and rs7745040) in the HLA-DRB1 gene locus were significantly associated with KBD in both the discovery cohort and replication cohort (combined cohort odds ratios [ORs] 1.307-1.402, P = 0.0039-0.0006). The protective haplotype GTCC and the risk haplotype ACGT, each generated by the 4 SNPs, showed a significant association with KBD (for GTCC, OR 0.77, P = 0.0031; for ACGT, OR 1.40, P = 0.0014). HLA-DRB1 allele genotyping revealed that the frequencies of HLA-DRB1*08 and *11 were significantly different between patients with KBD and controls (for HLA-DRB1*08, OR 0.731, P = 0.00564; for HLA-DRB1*11, OR 0.489, P = 0.000395). Moreover, plasma concentrations of selenium and iodine were significantly different between patients with KBD and controls from the same villages (P = 0.0013 and P = 1.84 × 10(-12) , respectively). CONCLUSION: These findings, obtained in plasma samples from Tibetan patients with KBD and healthy control subjects from the same regions, confirm the role of selenium and iodine deficiencies in the development of KBD. Moreover, genetic variants in the HLA-DRB1 gene significantly increase the susceptibility to KBD in this population.