Abstract
Background:Vitamin D has been associated with the pathogenesis of infectious diseases.Objective:To perform a systematic review on the association of vitamin D and outcomes of HTLV (Human T-cell lymphotropic virus) infection.Methods:We searched PubMed, LILACs, Scielo, Embase and Cochrane Library for studies addressing vitamin D and HTLV infection. We included studies published in English since 1980. Studies associated with HIV, bone metabolism and not related to HTLV- associated myelopathy/ tropical spastic paraparesis (HAM/TSP) or adult T cell leukemia/lymphoma (ATL) were excluded.Results:Twenty-three studies were selected and sixteen studies were included in the review (eight experimental studies, three case reports, three cases series, one cross-sectional study and one review). Fourteen studies were focused on ATL, and two on HAM/TSP. The available data show thatin vitroexposure to 1,25(OH)2D inhibits proliferation of HTLV-infected lymphocytes in patients with ATL or HAM/TSP. It has been observed that hypercalcemia, the main cause of death in patients with ATL, is not associated with serum levels of 1,25(OH)2D or parathyroid hormone-related protein, but leukemia inhibitory factor/D factor seems to be an important factor for hypercalcemia pathogenesis. It was also demonstrated an association between the VDRApaIgene polymorphism and a decreased risk of HAM/TSP in HTLV positive individuals.Conclusion:Despite the small number and heterogeneity of the studies, this systematic review suggests that vitamin D play a role in the pathogenesis of HTLV-associated diseases.
Highlights
There is an increasing interest in the non-bony functions of vitamin D [1, 2]
Despite the small number and heterogeneity of the studies, this systematic review suggests that vitamin D play a role in the pathogenesis of HTLVassociated diseases
Initial observations suggested that the synthesis of 1,25(OH)2D and parathyroid hormonerelated protein (PTHrP) by HTLV-infected lymphocytes in patients with adult T cell leukemia/lymphoma (ATL) was associated with hypercalcemia, the main cause of death in patients with ATL, subsequent studies failed to show increased levels of 1,25(OH)2D and PTHrP [38, 41]
Summary
There is an increasing interest in the non-bony functions of vitamin D [1, 2]. The cholecalciferol, 25(OH)D3, is converted into its active form in the kidney, 1,25dihydroxycholecalciferol (1,25(OH)2D), by the enzyme 1-αhydroxylase. It has been demonstrated that immune cells express the vitamin D receptor (VDR) [1 - 4]. Vitamin D has an indirect effect on the immune activity of lymphocytes mediated by antigenpresenting cells (APC) paracrine action or promotes a direct. Some studies have observed that vitamin D stimulates the development of Th2 cells by increasing IL-4 synthesis, but this is a still controversial topic [13]. TCD8 + lymphocytes (cytotoxic T cells) recognize the peptides presented by nucleated cells They have higher levels of VDR expression compared to other immune cells. Some studies have observed the action of vitamin D on the expression of cytokines secreted by TCD8 + lymphocytes, such as IL-6, IL-12, TNF-α, IL-5 and TGF-β (transforming growth factor β) [16]. Vitamin D has been associated with the pathogenesis of infectious diseases
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
