Role of Vitamin D in the Clinical Course of Nasal Polyposis.

Vitamin D is a lipo-soluble hormone well known for its effects on calcium homeostasis and bone metabolism. Recently, there has been growing interest in the extraskeletal effects of vitamin D. In particular, recent studies have highlighted how vitamin D plays a fundamental role in immunomodulation processes in the context of both innate and adaptive immunity, with consequent anti-inflammatory and anti-oxidant effect in different immune-mediated pathologies, such as systemic sclerosis, psoriasis, atopic dermatitis and rheumatoid arthritis; as well as in various pro-inflammatory processes affecting the airways, including chronic rhinosinusitis with (CRSwNP) or without (CRSsNP) nasal polyposis. We analyze the role of vitamin D in the genesis and progression of CRSwNP/sNP and its supplementation as a safe and valid therapeutic strategy capable of improving the clinical outcome of standard therapies.

Vitamin D and Folate as Predictors of MMSE in Alzheimer's Disease: A Machine Learning Analysis.

Vitamin D (VD) and micronutrients, including folic acid, are able to modulate both the innate and the adaptive immune responses. Low VD and folic acid levels appear to promote cognitive decline as in Alzheimer's disease (AD). A machine learning approach was applied to analyze the impact of various compounds, drawn from the blood of AD patients, including VD and folic acid levels, on the Mini-Mental State Exam (MMSE) in a cohort of 108 patients with AD. The first analysis was aimed at predicting the MMSE at recruitment, whereas a second investigation sought to predict the MMSE after a 4 year follow-up. The simultaneous presence of low levels of VD and folic acid allow to predict MMSE, suggestive of poorer cognitive function. Such results suggest that the low levels of VD and folic acid could be associated with more severe cases of cognitive impairment in AD. It could be hypothesized that simultaneous supplementation of VD and folic acid could slow down the progression of cerebral degeneration at least in a subset of AD individuals.

Hygiene hypothesis and autoimmune diseases: A narrative review of clinical evidences and mechanisms.

Since the start of the "modern era", characterized by the increase in urbanization, a progressive attention to hygiene and autoimmune conditions has considerably grown. Although these diseases are often multifactorial, it was demonstrated that environment factors such as pollution, diet and lifestyles may play a crucial role together with genetic signature. Our research, based on the newest and most significant literature of this topic, highlights that the progressive depletion of microbes and parasites due to increased socioeconomic improvement, may lead to a derangement of immunoregulatory mechanisms. Moreover, special attention was given to the complex interplay between microbial agents, as gut microbiome, diet and vitamin D supplementation with the aim of identifying promising future therapeutic options. In conclusion, autoimmunity cannot be limited to hygiene-hypothesis, but from the point of view of precision medicine, this theory represents a fundamental element together with the study of genomics, the microbiome and proteomics, in order to understand the complex functioning of the immune system.

Vitamin D and Microbiota: Is There a Link with Allergies?

There is increasing recognition of the importance of both the microbiome and vitamin D in states of health and disease. Microbiome studies have already demonstrated unique microbial patterns in systemic autoimmune diseases such as inflammatory bowel disease, rheumatoid arthritis, and systemic lupus erythematosus. Dysbiosis also seems to be associated with allergies, in particular asthma, atopic dermatitis, and food allergy. Even though the effect of vitamin D supplementation on these pathologies is still unknown, vitamin D deficiency deeply influences the microbiome by altering the microbiome composition and the integrity of the gut epithelial barrier. It also influences the immune system mainly through the vitamin D receptor (VDR). In this review, we summarize the influence of the microbiome and vitamin D on the immune system with a particular focus on allergic diseases and we discuss the necessity of further studies on the use of probiotics and of a correct intake of vitamin D.

Vitamin D and Covid-19: an update on evidence and potential therapeutic implications.

The world is now experiencing its third major epidemic of coronavirus (CoV) infections began in Wuhan, Hubei, China, in late 2019 and named COVID-19. After an initial explosive outbreak of pneumonia of unknown etiology in China, the disease spread first to neighboring Asian countries and then worldwide. Patients with COVID-19 presented with a constellation of symptoms such as fever, dry cough, dyspnea, sore throat, and nasal congestion and radiological findings showed bilateral lung glassy opacities. Vitamin D has many mechanisms by which it reduces the risk of microbial infection and death, including physical barrier, cellular natural immunity, and adaptive immunity. Vitamin D supplementation has shown favorable effects in viral infections including influenza and HIV. The effects of vitamin D supplementation during covid 19 infection remain controversial. Looking ahead, clinical studies are needed to define better cut offs for vitamin D levels and, finally, which dosage is the best.

Emerging role of vitamin D in autoimmune diseases: An update on evidence and therapeutic implications.

Vitamin D plays a key role in in calcium homeostasis and, thus, provides an important support in bone growth by aiding in the mineralization of the collagen matrix. However, vitamin D performs various immunomodulatory, anti-inflammatory, antioxidant and anti-fibrotic actions. Autoimmune diseases result from an aberrant activation of the immune system, whereby the immune response is directed against harmless self-antigens. Does vitamin D play a role in the pathophysiology of autoimmune diseases? And, if so, what is its role? In the last decade, researchers' interest in vitamin D and its correlations with autoimmune diseases has considerably increased. We conducted a literature review, covering the period January 1, 2009 through March 30, 2019, in PubMed. We analyzed more than 130 studies in order to find a correlation between vitamin D levels and its effect upon several autoimmune diseases. The analysis demonstrated an inverse association between vitamin D and the development of several autoimmune diseases, such as SLE, thyrotoxicosis, type 1 DM, MS, iridocyclitis, Crohn's disease, ulcerative colitis, psoriasis vulgaris, seropositive RA, polymyalgia rheumatica. International multicenter study could allow us to confirm the data already present in the literature in the single clinical studies and to evaluate when to effectively supplement vitamin D in patients who do not take corticosteroids.

Two year sublingual immunotherapy affects serum leptin.

BACKGROUND: It has been demonstrated that serum leptin is elevated in females with allergic rhinitis. Recently, it has been reported that one course of sublingual immunotherapy (SLIT) does not affect serum leptin levels. OBJECTIVE: The aim of this study was to evaluate the serum leptin levels in a cohort of patients with pollen-induced allergic rhinitis, before and after two pre-seasonal SLIT courses. METHODS: Forty-one patients (22 males and 19 females, median age 39 years) with AR, due to pollen allergy, and 34 healthy subjects (16 males and 18 females, median age 43 years) were included in the study. Blood sampling for assessing serum leptin was performed in all subjects before and after the second SLIT course. RESULTS: All patients were responders to SLIT. Serum leptin was significantly increased only in males (p=0.0056) after the second SLIT course. CONCLUSION: This preliminary study shows that at least two pre-seasonal SLIT courses were required to induce significant modifications in serum leptin levels, but it occurred only in males. Some hypotheses might be outlined, including a leptin protective effect, however further studies must clarify this issue.

Soluble serum HLA-G and HLA-A, -B, -C molecules in patients with seasonal allergic rhinitis exposed to pollens.

BACKGROUND: Allergic rhinitis (AR) is characterized by a Th2 polarized immune response and soluble HLA (sHLA) molecules play an immunomodulatory role in this response. Previously, it has been reported that these molecules are increased in sera of patients with pollen-induced allergic rhinitis studied outside the pollen season. To date, however, no study has investigated there in AR patients during the pollen season. OBJECTIVE: The aim of this study was to evaluate serum sHLA-G and sHLA-A, -B, -C levels in both AR patients and healthy controls. METHODS: 60 symptomatic allergic patients were enrolled. A group of 50 healthy subjects was included as a control. Serum sHLA-G and sHLA-A, -B, -C levels were determined by an immunoenzymatic method. Allergy severity was assessed by VAS for symptoms and drug use. RESULTS: Allergic patients had significantly higher levels of both sHLA-G (p<0.001) and sHLA-A, -B, -C (p=0.001) than normal controls. In addition, there was a very strong correlation between sHLA-G levels and clinical severity. CONCLUSION: The present study confirms evidence that serum sHLA-G and sHLA-A, -B, -C molecules are significantly increased in patients with pollen-induced AR also during the pollen season. Moreover, sHLA-G might be considered as a biomarker for assessing clinical severity.

Serum adiponectin levels in patients with pollen-induced allergic rhinitis.

BACKGROUND: Several studies have outlined a possible relationship between an increased body mass index and respiratory allergic diseases, such as asthma and rhinitis. OBJECTIVE: The aim of the study was to evaluate the serum adiponectin levels in a cohort of patients with pollen-induced allergic rhinitis, enrolled outside the pollen season, and in a group of healthy controls. METHODS: The study included 41 patients with moderate-severe persistent allergic rhinitis due to a pollen allergy and 34 normal subjects. All subjects were prospectively and consecutively evaluated. A skin prick test and blood sampling for assessing serum adiponectin levels were performed in all subjects. RESULTS: The comparison between allergic patients and normal subjects, globally considered without gender distinction, showed slightly higher values in the allergic population. After analysing genders separately, allergic patients show significantly higher levels than normal males (p = 0.0134), whereas the comparison between allergic and normal females was not significant (p = 0.1419). In addition, in normal males adiponectin serum levels are significantly related with age (p = 0.0123). CONCLUSION: This preliminary study provides the first evidence of significantly higher adiponectin serum levels in male patients with pollen-induced allergic rhinitis as compared to normal male subjects.