Hypovitaminosis D Is Associated with Higher Levels of Inflammatory Cytokines and with HAM/TSP in HTLV-Infected Patients.

Elaine Coutinho Netto,Alfredo Carlos Silva,Carlos Brites,Célia Pedroso

doi:10.3390/v13112223

Abstract

Recent studies have shown the effects of vitamin D on host response to infectious diseases. Some studies detected a high prevalence of hypovitaminosis D in HIV-infected patients, but scarce information exists for HTLV-1 infection. We conducted a cross-sectional study to evaluate the frequency of hypovitaminosis D in HTLV-1 patients and its relationship with their immune response in HTLV-infected patients and in age- and gender-matched controls at a Brazilian rehabilitation hospital. We compared vitamin D, interleukin-6 (IL-6), tumoral necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) levels across groups. Logistic regression was utilized to assess the association between hypovitaminosis D and cytokine levels. We enrolled 161 HTLV-infected subjects (129 HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, 32 asymptomatic HTLV carriers) and equal number of HTLV-negative controls. We observed a significantly higher prevalence of hypovitaminosis D in patients with HAM/TSP than in HTLV asymptomatic carriers (p < 0.001), or controls (p < 0.001). HAM/TSP patients also had higher levels of IL-6 and IFN-γ than asymptomatic carriers. Patients with HAM/TSP and hypovitaminosis D had higher levels of TNF-α than asymptomatic HTLV carriers. These findings suggest hypovitaminosis D plays a role in HAM/TSP pathogenesis, and it needs to be evaluated in further studies.

Highlights

The present study aims to evaluate the frequency of hypovitaminosis D and its relationship with clinical status and immune response in patients infected with HTLV
There was a significant difference in mean vitamin D levels between community ambulators HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients (27.5 ± 9.8 ng/mL) and community ambulators controls (31.2 ± 9.8 ng/mL, p = 0.015) as well as between wheelchair-restricted HAM/TSP
To the best of our knowledge, this is the first study to demonstrate an association between hypovitaminosis D and immune response in this population

Summary

Introduction

The importance of vitamin D in bone metabolism is well known, and the role of vitamin D deficiency in two major disorders of calcium metabolism (rickets in children and osteomalacia in adults) was recently recognized [1,2]. The expression of vitamin D receptors (VDR) in different organs (pancreas, brain, muscles, adipose tissue, colon, breast and immune cells) reinforces its importance in non-bony processes [3]. Many studies have linked vitamin D status to autoimmune diseases, type 1 diabetes mellitus, cardiovascular diseases, cancer and infections [1,2,3,4]. It has been estimated that more than 1 billion people have either 25-hydroxyvitamin D (25(OH)D) deficiency or insufficiency [2]. Routine screening for low 25 (OH) D levels and supplementation of vitamin D has become increasingly common [1,2,3,4,5]

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Conclusion