Effects of cyanocobalamin on immunity in patients with pernicious anemia

Correlation of tuberculosis-related anemia severity with tuberculosis-induced inflammation in children: a six-year retrospective study

BACKGROUND

Anemia is a common complication of tuberculosis (TB), and there is evidence that its prevalence is higher in patients with TB. Although TB is very important in epidemiology, careful investigation of TB-related anemia in children has not been carried out systematically. This study aimed to describe the details of anemia in children with TB and its association with clinical characteristics and the severity of inflammation.

METHODS

In this retrospective study, we explored Hb levels in 103 children with pulmonary TB (PTB) and they were divided into anemic or non-anemic groups. Logistics regression analysis was used to study the associations between anemia and demographic characteristics. Spearman correlations analysis was performed to analyse the associations between the biochemical parameters and hemoglobin levels in blood.

RESULTS

The prevalence of anemia in children with TB was 37.9% (48.7% showed microcytic hypochromic anemia, and 5.1% showed normal cell anemia). Compared with the anemia (n = 39) group, the non-anemic group (n = 64) had longer fever duration and increased respiratory rate (P < 0.05). In logistic regression analysis, anemia was associated with lower levels of Alb and higher levels of WBC, CRP, LDH, and ESR (P < 0.05). Spearman correlations analysis showed a significant negative correlation between hemoglobin (Hb) levels and inflammatory markers. After one month of antitubercular therapy (ATT), the Hb levels of 76.9% children returned to normal.

CONCLUSIONS

Anemia is common among children with TB at diagnosis. The majority of children with TB-related anemia are mild to moderate microcytic hypochromic anemia. There is a strong correlation between the severity of anemia and the inflammation induced by TB. This suggests that anemia is a biomarker of the severity of TB in clinical practice among children.

Multiple Infections, Nutrient Deficiencies, and Inflammation as Determinants of Anemia and Iron Status during Pregnancy: The MINDI Cohort

In pregnant women with multiple infections, nutrient deficiencies, and inflammation (MINDI), the study of anemia and iron status is limited. For this cross-sectional study (n = 213 Panamanian indigenous women), we investigated if hemoglobin, anemia (Hb < 110 g/L), ferritin, serum iron, serum transferrin receptor, and hepcidin were associated with (1) maternal nutritional status and supplementation practices, (2) biomarkers of inflammation, and (3) presence/absence of infections. Hierarchical generalized linear and logistic regression models and dominance analyses identified the relative importance of these predictors. Anemia (38%), which was likely underestimated due to low plasma volume (95%), was associated with lower ferritin, vitamin A, and weight-for-height, suggesting anemia of undernutrition. Inflammation was not associated with Hb or anemia; nevertheless, higher CRP was associated with increased odds of low serum iron and higher ferritin and hepcidin, indicating iron restriction due to inflammation. The length of iron supplementation did not enter models for anemia or iron indicators, but a multiple nutrient supplement was associated with higher ferritin and hepcidin. Moreover, iron supplementation was associated with higher odds of vaginal trichomoniasis but lower odds of caries and bacterial vaginosis. The complex pathogenesis of anemia and iron deficiency in MINDI settings may require other interventions beyond iron supplementation.

Lack of vitamin B12 impairs innate and adaptive immunity of Cuban tree frog (Osteopilus septentrionalis) tadpoles

Vitamin B12 is a micronutrient required by a variety of organisms for healthy cellular functioning. Despite the systemic effects observed in cases of B12 deficiency, relatively little is known about how vitamin B12 affects immune health, especially in amphibians, which are declining at unprecedented rates. In this study, we tested how supplementing an algae diet with B12 affects the innate and adaptive immunity of Cuban tree frog (Osteopilus septentrionalis) tadpoles. We found that innate immunity, as measured by a bacterial killing assay, was significantly more robust in B12-supplemented tadpoles than control tadpoles, but no significant differences were found in natural antibody production or hematocrit between groups. Adaptive immunity, as measured by Aeromonas hydrophila-specific IgY antibodies, was significantly greater in tadpoles challenged with A. hydrophila and supplemented with B12 than in control tadpoles, those only challenged with A. hydrophila, and those only given B12. Our results suggest that vitamin B12 is an important factor in maintaining a functional immune system in tadpoles, which may also be true for all vertebrates.

Vitamins, microelements and the immune system: current standpoint in the fight against coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an acute respiratory disease associated with severe systemic inflammation. The optimal status of vitamins and microelements is considered crucial for the proper functioning of the immune system and necessary for successful recovery. Most patients with respiratory distress in COVID-19 are vitamin and microelement deficient, with vitamin D and Se deficiency being the most common. Anyway, various micronutrient supplements are widely and arbitrarily used for prevention or in the treatment of COVID-19. We aimed to summarise current knowledge about molecular and physiological mechanisms of vitamins (D, A, C, B₆, B₉ and B₁₂) and microelements (Se, Zn, Cu and Fe) involved in the immune system regulation in consideration with COVID-19 pathogenesis, as well as recent findings related to their usage and effects in the prevention and treatment of COVID-19. In the early course of the pandemic, several, mainly observational, studies reported an association of some micronutrients, such as vitamin C, D and Zn, with severity reduction and survival improvement. Still, emerging randomised controlled trials showed no effect of vitamin D on hospitalisation length and no effect of vitamin C and Zn on symptom reduction. Up to date, there is evidence neither for nor against the use of micronutrients in the treatment of COVID-19. The doses that exceed the recommended for the general population and age group should not be used, except in clinical trials. Benefits of supplementation are primarily expected in populations prone to micronutrient deficiencies, who are, as well, at a higher risk of worse outcomes in COVID-19.

Exploring the Immune-Boosting Functions of Vitamins and Minerals as Nutritional Food Bioactive Compounds: A Comprehensive Review

Food components have long been recognized to play a fundamental role in the growth and development of the human body, conferring protective functionalities against foreign matter that can be severe public health problems. Micronutrients such as vitamins and minerals are essential to the human body, and individuals must meet their daily requirements through dietary sources. Micronutrients act as immunomodulators and protect the host immune response, thus preventing immune evasion by pathogenic organisms. Several experimental investigations have been undertaken to appraise the immunomodulatory functions of vitamins and minerals. Based on these experimental findings, this review describes the immune-boosting functionalities of micronutrients and the mechanisms of action through which these functions are mediated. Deficiencies of vitamins and minerals in plasma concentrations can lead to a reduction in the performance of the immune system functioning, representing a key contributor to unfavorable immunological states. This review provides a descriptive overview of the characteristics of the immune system and the utilization of micronutrients (vitamins and minerals) in preventative strategies designed to reduce morbidity and mortality among patients suffering from immune invasions or autoimmune disorders.

The Potential Role of Vitamin B12 in the Prevention of COVID-19 Complications: A Narrative Review

The elderly are more prone to mortality from COVID-19 infection, as they are susceptible to develop acute respiratory distress syndrome (ARDS). For COVID-19 patients with ARDS caused by sepsis or septic shock, high-dose parenteral vitamin B12 appears to be a potential new treatment option. Vitamin B12 may play a substantial impact in COVID-19 morbidity and mortality reduction owing to its function in DNA synthesis, cellular control, improvement of anti-inflammatory immune responses, and decrease of pro-inflammatory responses. This review aims to assess the functional role of Vitamin B12 in COVID-19 in terms of its immunomodulatory effect, role in cellular and humoral immunity and maintaining the gut microbe homeostasis. From data inception to June 2021, accessible electronic databases were searched for research/review articles reporting on the function of Vitamin B12 in COVID-19. Scopus, Web of Science, PubMed, WHO worldwide research on COVID-19 and the clinical trials registration “https://clinicaltrials.gov/” were used to conduct the systematic search by using keywords: “COVID-19 and “Vitamin B12”. Also, based on these outcomes, it can be concluded that Vitamin B12 may have a potential role in preventing COVID-19 complications. Further, studies evaluating the role of Vitamin B12 in COVID-19 may open a new array of ideas on the optimal and the well-tolerated dose and timing of its administration in COVID-19 patients.

The Next-Generation of Combination Cancer Immunotherapy: Epigenetic Immunomodulators Transmogrify Immune Training to Enhance Immunotherapy

Cancer immunotherapy harnesses the immune system by targeting tumor cells that express antigens recognized by immune system cells, thus leading to tumor rejection. These tumor-associated antigens include tumor-specific shared antigens, differentiation antigens, protein products of mutated genes and rearrangements unique to tumor cells, overexpressed tissue-specific antigens, and exogenous viral proteins. However, the development of effective therapeutic approaches has proven difficult, mainly because these tumor antigens are shielded, and cells primarily express self-derived antigens. Despite innovative and notable advances in immunotherapy, challenges associated with variable patient response rates and efficacy on select tumors minimize the overall effectiveness of immunotherapy. Variations observed in response rates to immunotherapy are due to multiple factors, including adaptative resistance, competency, and a diversity of individual immune systems, including cancer stem cells in the tumor microenvironment, composition of the gut microbiota, and broad limitations of current immunotherapeutic approaches. New approaches are positioned to improve the immune response and increase the efficacy of immunotherapies, highlighting the challenges that the current global COVID-19 pandemic places on the present state of immunotherapy.

Nutritional management of diabetes mellitus during the pandemic of COVID-19: a comprehensive narrative review

Objectives

According to the recent epidemiological studies, patients with diabetes mellitus (DM) may be at higher risk of hospitalization due to COVID-19. Regarding the important role of nutrition on the immunity, the present review article aimed to outline nutritional support of DM during the outbreak of COVID-19 with a mechanistic insight.

Methods

Searches were performed in PubMed/MEDLINE, ScienceDirect, Scopus, and Google Scholar databases from 2000 until December 2020 using the following keywords. All relevant clinical and experimental studies published in English were included.

Results

Evidences revealed that hyperglycemia is a significant predictor of some viral infections including COVID-19 which can exacerbate the complications of DM. According to the literature review, adequate intake of dietary protein, fiber, essential fatty acids and some micronutrients especially vitamins D, C, B12, folate, zinc and selenium has beneficial effects on the prevention and treatment of COVID-19 in diabetic patients through modulation of innate and adaptive immune responses or direct effects on virus enzymes or the rate of cell entrance.

Conclusions

It is well understood that malnutrition may increase susceptibility to viral infections and disease progression. Therefore, considering nutritional status of diabetic patients and reasonable supplementation of the above mentioned nutrients can ameliorate the symptoms of COVID-19 in DM. However, further well-designed clinical trials are needed to determine their therapeutic dose.

The Influence of Nutritional Factors on Immunological Outcomes

Through food intake, humans obtain a variety of nutrients that are essential for growth, cellular function, tissue development, energy, and immune defense. A special interaction between nutrients and gut-associated lymphoid tissue occurs in the intestinal tract. Enterocytes of the intestinal barrier act as sensors for antigens from nutrients and the intestinal microbiota, which they deliver to the underlying immune system of the lamina propria, triggering an immune response. Studies investigating the mechanism of influence of nutrition on immunological outcomes have highlighted an important role of macronutrients (proteins, carbohydrates, fatty acids) and micronutrients (vitamins, minerals, phytochemicals, antioxidants, probiotics) in modulating immune homeostasis. Nutrients exert their role in innate immunity and inflammation by regulating the expression of TLRs, pro- and anti-inflammatory cytokines, thus interfering with immune cell crosstalk and signaling. Chemical substrates derived from nutrient metabolism may act as cofactors or blockers of enzymatic activity, influencing molecular pathways and chemical reactions associated with microbial killing, inflammation, and oxidative stress. Immune cell function appears to be influenced by certain nutrients that form parts of the cell membrane structure and are involved in energy production and prevention of cytotoxicity. Nutrients also contribute to the initiation and regulation of adaptive immune responses by modulating B and T lymphocyte differentiation, proliferation and activation, and antibody production. The purpose of this review is to present the available data from the field of nutritional immunology to elucidate the complex and dynamic relationship between nutrients and the immune system, the delineation of which will lead to optimized nutritional regimens for disease prevention and patient care.

Impact of daily-supervised administration of a package of iron and folic acid and vitamin B12 on hemoglobin levels among adolescent girls (12-19 years): a cluster randomized control trial

OBJECTIVE

The prevalence of anemia has remained high among Indian adolescent girls over the past decade, despite the ongoing iron and folic acid (IFA) supplementation program. This study was conducted to assess the impact of daily supplementation of a package of IFA with vitamin B₁₂ on hemoglobin levels among adolescent girls.

METHODS

A community-based cluster-randomized trial was conducted in the rural block of Faridabad District, Haryana, India in the year 2017. A total of 760 adolescent girls in the age group of 12-19 years with mild and moderate anemia were selected from government schools. Daily-supervised administration of iron and folic acid was conducted for 90 days: experimental group-IFA (iron (60 mg), folic acid (500) mcg), and cyanocobalamin (1000 mcg), control group-IFA and placebo. Hemoglobin, serum ferritin, and vitamin B₁₂ levels were assessed at baseline and endline.

RESULTS

Two-hundred adolescent girls completed 90 doses of daily supplementation. The mean hemoglobin (experimental group: 1.3 ± 1.0 g/dL, control group: 1.6 ± 1.2 g/dL, P = 0.004) and ferritin levels (experimental group: 18.6 ± 31.5 ng/mL, control group: 18.8 ± 35.0 ng/mL, P = 0.188) increased in both the control and experiment groups. Serum vitamin B₁₂ deficiency significantly reduced to 2.5% in the experimental group and ferritin deficiency alleviated in more than 96% of the girls post intervention.

CONCLUSIONS

Daily supplementation of IFA with/without vitamin B₁₂ for 90 days eliminated iron, vitamin B₁₂ deficiency and reduced the overall proportion of anemia by 53.5%. However, addition of vitamin B₁₂ to IFA supplementation had no impact on improving the hemoglobin levels among adolescent girls. The present study does not recommend provision of vitamin B₁₂ for prevention and treatment of anemia in this population group.

Evaluation of macular, retinal nerve fiber layer and choroidal thickness by optical coherence tomography in children and adolescents with vitamin B12 deficiency

PURPOSE

To investigate macular, Retinal Nerve Fiber Layer (RNFL) and choroidal thickness in children and adolescents with vitamin B₁₂ deficiency and no neurological examination finding.

METHODS

The study group includes of thirty-three children aged 8-17 years who were brought to the Pediatric outpatient clinic with the symptoms of fatigue and forgetfulness and whose Vitamin B₁₂ levels were detected < 200 pg/ml. The control group was the 30 children and adolescents applied to the same policlinic with various symptoms and whose Vitamin B₁₂ levels were found normal. Children and adolescents with chronic systemic/ocular disease history and myopia or hyperopia more than 4 diopters were not included in both groups. Spectral Domain-Optical Coherence Tomography (SD-OCT) was used for measurements.

RESULTS

Mean Macular thickness value was 261.2 ± 17.6 in the Vitamin B₁₂ deficiency group and 267.7 ± 17.4 in the control group. Mean value of Retinal Nerve Fiber Layer (RNFL) thickness was 103.5 ± 7.5 in the Vitamin B₁₂ deficiency group and 104.3 ± 8.9 in the control group. The mean values of Choroidal thickness were 360.1 ± 59.8 and 316.9 ± 95.4 in Vitamin B₁₂ deficiency and control groups, respectively. There was a statistically significant increase in choroidal thickness in Vitamin B₁₂ deficiency group compared to controls.

CONCLUSION

Statistically significant increase in the Choroidal thicknesses of children and adolescents with Vitamin B₁₂ deficiency is important in terms of shedding light on studies that will contribute to a better understanding of the relationship between vitamin B₁₂ and inflammation.

CLINICAL TRIAL REGISTRATION

This study is an observational study.

Anemia as a risk factor for tuberculosis: a systematic review and meta-analysis

BACKGROUND

Tuberculosis is a major public health problem caused by Mycobacterium tuberculosis, occurring predominantly in population with low socioeconomic status. It is the second most common cause of death from infectious diseases. Tuberculosis becomes a double burden among anemic patients. Anemia increases an individual's susceptibility to infectious diseases including tuberculosis by reducing the immunity level. Therefore, the purpose of this study was to determine whether anemia is a risk factor for tuberculosis.

METHOD

Relevant published articles were searched in electronic databases like PubMed, Google Scholar, EMBASE, and Cochrane Library using the following MeSH terms: risk factor, predictors, tuberculosis, TB, Anaemia, Anemia, hemoglobin, Hgb, and Hb. Articles written in the English, observational studies conducted on the incidence/prevalence of tuberculosis among anemic patients, or papers examined anemia as risk factors for tuberculosis were included. From those studies meeting eligibility criteria, the first author's name, publication year, study area, sample size and age of participants, study design, and effect measure of anemia for tuberculosis were extracted. The data were entered using Microsoft Excel and exported to Stata version 11 for analysis. The random-effects model was applied to estimate the pooled OR and HR, and 95% CI. The sources of heterogeneity were tested by Cochrane I-squared statistics. The publication bias was assessed using Egger's test statistics.

RESULTS

A total of 17 articles with a 215,294 study participants were included in the analysis. The odd of tuberculosis among anemic patients was 3.56 (95% CI 2.53-5.01) times higher than non-anemic patients. The cohort studies showed that the HR of tuberculosis was 2.01 (95% CI 1.70-2.37) times higher among anemic patients than non-anemic patients. The hazard of tuberculosis also increased with anemia severity (HR 1.37 (95% CI 0.92-2.05), 2.08 (95% CI 1.14-3.79), and 2.66 (95% CI 1.71-4.13) for mild, moderate, and severe anemia, respectively).

CONCLUSION

According to the current systematic review and meta-analysis, we can conclude that anemia was a risk factor for tuberculosis. Therefore, anemia screening, early diagnose, and treatment should be provoked in the community to reduce the burden of tuberculosis.

COVID-19's toll on the elderly and those with diabetes mellitus - Is vitamin B12 deficiency an accomplice?

COVID-19 exacts a disproportionate toll on both the elderly and those with diabetes; these patients are more likely to require costly intensive care, longer hospitalisation, and die from complications. Nations would thus find it extremely difficult to either lift or sustain socially, economically, and politically damaging restrictions that keep this group of people safe. Without a vaccine, there is thus an urgent need to identify potential modifiable risk factors which can help manage overall fatality or recovery rates. Case fatality rates are highly variable between (and even within) nations; nutritional differences have been proposed to account significantly for this disparity. Indeed, vitamin B12 deficiency is a common denominator between the elderly and those with diabetes. The question on hand thus lies on whether managing B12 deficiencies will impact COVID-19 fatality outcome or recovery rates. Herein, we review the latest evidence that shows that B12 deficiency associates in multiple areas very similar to where COVID-19 exerts its damaging effects: immunologically; microbiologically; haematologically; and through endothelial cell signalling-supporting the hypothesis that B12 deficiency is a potential modifiable risk factor in our fight against COVID-19.

Immunometabolism, Micronutrients, and Bariatric Surgery: The Use of Transcriptomics and Microbiota-Targeted Therapies

BACKGROUND

Obesity is associated with the gut microbiota and decreased micronutrient status. Bariatric surgery is a recommended therapy for obesity. It can positively affect the composition of the gut bacteria but also disrupt absorption of nutrients. Low levels of micronutrients can affect metabolic processes, like glycolysis, TCA cycle, and oxidative phosphorylation, that are associated with the immune system also known as immunometabolism.

METHODS

MEDLINE, PUBMED, and Google Scholar were searched. Articles involving gut microbiome, micronutrient deficiency, gut-targeted therapies, transcriptome analysis, micronutrient supplementation, and bariatric surgery were included.

RESULTS

Studies show that micronutrients play a pivotal role in the intestinal immune system and regulating immunometabolism. Research demonstrates that gut-targeting therapies may improve the microbiome health for bariatric surgery populations. There is limited research that examines the role of micronutrients in modulating the gut microbiota among the bariatric surgery population.

CONCLUSIONS

Investigations are needed to understand the influence that micronutrient deficiencies have on the gut, particularly immunometabolism. Nutritional transcriptomics shows great potential in providing this type of analysis to develop gut-modulating therapies as well as more personalized nutrition recommendations for bariatric surgery patients.

Micronutrients and bioactive compounds in the immunological pathways related to SARS-CoV-2 (adults and elderly)

The new coronavirus pandemic is affecting the entire world with more than 25 million confirmed cases in August 2020 according to the World Health Organization. It is known that the virus can affect several tissues and can progress to a respiratory failure in severe cases. To prevent the progression to this stage of the disease and minimize all the damage caused by coronavirus (SARS-CoV-2) the immune system must be in its integrity. A healthy nutritional status are fundamental to efficient immunological protection and consequently a good response to SARS-CoV-2. Micronutrients and bioactive compounds perform functions in immune cells that are extremely essential to stop SARS-CoV-2. Their adequate consumption is part of a non-pharmacological intervention to keep the immune system functioning. This review has as main objective to inform how micronutrients and bioactive compounds could act in the essential immunological pathways could stop SARS-CoV-2, focusing on the functions that have already established in the literature and transposing to this scenario.

The efficacy of a compounded micronutrient supplement on the incidence, duration, and severity of the common cold: A pilot randomized, double-blinded, placebo-controlled trial

Purpose

Viral upper respiratory infections are associated with significant health and economic impact. This study sought to determine the efficacy of routine immune system micronutrient supplementation on the incidence, duration and severity of common cold symptoms.

Methods

This pilot study was a randomized, double-blinded, placebo-controlled trial of N = 259 with asymptomatic participants aged 18 to 65 in two cold seasons of 2016 and 2017. The treatment group received an immune system targeted micronutrient caplet, while the placebo group received a micronized cellulose caplet externally identical to the treatment caplet. Weekly surveys were sent electronically to participants to document common cold incidence, duration and severity. Primary statistical results were obtained using mixed-effects logistic regressions to account for longitudinal measurements for participants.

Results

The odds of acquiring an upper respiratory infection, adjusted for potential confounders, was estimated to be 0.74 times lower in the treatment group (p = 0.14). The odds of reporting specific symptoms were statistically lower in the treatment arm compared to the placebo arm for runny nose (OR = 0.53, p = 0.01) and cough (OR = 0.51, p = 0.04). Shorter durations of runny nose and cough were also observed in the treatment arm compared to placebo (both p < 0.05). There was no significant difference in severity of symptoms in either group. The observed proportion of reported cold symptoms in the treatment group was lower compared to the placebo group between late January and February in two consecutive cold seasons. Given the physical, workplace and economic impact of upper respiratory infections, this low cost and low risk intervention should be further studied with more robust investigation and meticulous experimental design.

Breast milk vitamin B12 concentration and incidence of diarrhea and respiratory infections among infants in urban Tanzania: a prospective cohort study

Objective

A recent trial of vitamin B12 supplementation among Indian children 6–30 months found no effect on the incidence of diarrhea and respiratory infections. These results differ with studies in adults that showed improvement of the immune response following treatment with vitamin B12. We sought to determine how the adequacy of vitamin B12 concentrations in breast milk could act as immune modulator and protect against the incidence of diarrhea and respiratory infections of children up to 18 months in urban Tanzania.

Results

A prospective cohort study was undertaken to determine the association of breast milk vitamin B12 concentration with the incidence of acute respiratory infection and diarrhea among infants in urban Tanzania. A random sample of 491 women enrolled in a trial of multivitamins provided milk for B12 analysis at or around 6 weeks postpartum. Of 491 women, 345 had breast milk vitamin B12 inadequacy (< 310 pmol/L). Using generalized estimating equations, we found no overall association of milk vitamin B12 concentration with incident diarrhea and acute respiratory infections in infants. Studies measuring longitudinal changes of breast milk B12 concentration over time are needed to clarify the role of breast milk vitamin B12 in childhood infections.

A review of the effects of the anesthetic gas nitrous oxide on the immune system; a starting point for future experiences

Nitrous oxide is a common gas used as an anesthetic agent and analgesic medication in operating rooms. The gas inhibits vitamin B₁₂ dependent-methionine synthase, which converts L-homocysteine and 5-methyltetrahydrofolate to L-methionine and tetrahydrofolate, respectively, via a methylation process. The immune system has been frequently reported to be suppressed in anesthetized subjects during the postoperative period. Although previous reviews have focused on the pathophysiologic role of nitrous oxide, none of them has considered the harmful effects of nitrous oxide on the Defense system of the host. In this article, the authors review current studies on the effects of nitrous oxide on the immune system of both patients undergoing surgery and occupational exposure, as well as preclinical studies. Moreover, this paper opens a new horizon for future studies in the context of underlying mechanisms of nitrous oxide actions on the immune system.

Effect of Natural Compounds on NK Cell Activation

Natural killer (NK) cells are lymphocytes of the innate immune system that survey the body for stressed and abnormal cells. The integration of signals that they receive through various inhibitory and activating cell surface receptors controls their activation and ability to kill target cells and produce cytokines. In this manner, phenotypically and functionally distinct subsets of NK cells help protect against microbial infections and cancer and shape the adaptive immune response. NK cells can use two different mechanisms to kill their targets, either by cytotoxic granule exocytosis or by induction of death receptor-mediated apoptosis. Death ligands belong to the tumor necrosis factor (TNF) family of ligands. Upon release in close proximity to a cell slated for killing, perforin forms pores in the cell membrane of the target cell through which granzymes and associated molecules can enter and induce apoptosis. NK cells are also involved in antibody-dependent cellular toxicity via the CD16 receptor. In addition to target recognition, NK cells can be also activated by treatment with multiple compounds with stimulatory properties. Apart from interleukins, which belong to the best characterized group of NK cell-stimulating compounds, vitamins and constituents extracted from plants also display the ability to activate NK cells. The current review characterizes several groups of NK cell-activating compounds: vitamins belonging to classes A, B, C, D, and E, polysaccharides, lectins, and a number of phytochemicals used in cancer research, exhibiting stimulatory properties when applied to NK cells. Although in most cases the exact mechanism of action is not known, constituents described in this review seem to be promising candidates for NK cell-stimulating drugs.

Neglected tropical diseases and vitamin B12: a review of the current evidence

Vitamin B12 deficiency is an urgent public health problem that disproportionately affects individuals in low- and middle-income settings, where the burden of neglected tropical diseases (NTDs) is also unacceptably high. Emerging evidence supports a potential role of micronutrients in modulating the risk and severity of NTDs. However, the role of vitamin B12 in NTD pathogenesis is unknown. This systematic review was conducted to evaluate the evidence on the role of vitamin B12 in the etiology of NTDs. Ten studies were included in this review: one study using an in vitro/animal model, eight observational human studies and one ancillary analysis conducted within an intervention trial. Most research to date has focused on vitamin B12 status and helminthic infections. One study examined the effects of vitamin B12 interventions in NTDs in animal and in vitro models. Few prospective studies have been conducted to date to examine the role of vitamin B12 in NTDs. The limited literature in this area constrains our ability to make specific recommendations. Larger prospective human studies are needed to elucidate the role of vitamin B12 in NTD risk and severity in order to inform interventions in at-risk populations.

Unusual association between erythema nodosum and autoimmune atrophic gastritis

We report a case of a 46-year-old woman with a history of autoimmune atrophic gastritis and recurrent erythema nodosum (EN). Laboratory results showed iron-deficiency anaemia, positive antiparietal cell antibodies and marginal deficiency of vitamin B12. Although EN was refractory to general measures (rest and non-steroidal anti-inflammatory drugs) and corticosteroid therapy, it was successfully treated with vitamin B12 supplementation.

Micronutrient Supplementation does not Change Complement System Response to Heavy Training

We aimed to examine the micronutrient supplementation effect on complement system activity after heavy training. 24 male firefighters were randomly divided into supplemented and placebo groups, and tested for immunology-related parameters using venous blood samples in the fasting state pre- and post-5 weeks of nutritional supplementation. C3 and C4 complement components were determined in a nephelometer from immune complexes formed through specific human antisera and total haemolytic complement activity (CH100) was determined by enzyme immunoassay. Differences between pre- and post-supplementation were observed only for CH100 on placebo group (p=0.004; mean diff −26.92; 95%CI −43.58 to −10.25) and no interaction, treatment or time effects were observed for C3 and C4. Although interaction accounted for 8.8% of the total variance in CH100 (with time effect pre- vs post-accounting for 19.5% of the total variance), the treatment effect (supplemented vs placebo) was not significant. The absence of effects on the complement system response to supplementation during heavy training could be justified by the fact that: (i) nutritional supplements do not improve humoral innate immunity in well-fed subjects; (ii) selected supplements unlikely improve the innate immune system in situations of adequate nutritional status; and/or (iii) selected doses of supplementation were not sufficient to elicit immune changes.

Megaloblastic anemia presenting with massive reversible splenomegaly

Megaloblastic anemia (MA) is a common disorder with varied manifestations. It generally results in mild to moderate splenomegaly which is due to sequestration of macrocytic erythrocytes in spleen. Massive splenomegaly is generally seen in infections, myeloproliferative diseases, neoplasms, storage disorders or hematological conditions; but is not heard of and has rarely been reported in MA. We discuss a case of massive splenomegaly who presented with symptomatic anemia and was found to have MA. He was extensive evaluated for all other causes of massive splenomegaly which was normal. Further, after a therapeutic trial of MA he showed a regression in spleen size confirming that the massive splenomegaly was attributable to MA.

The influence of vitamin B12 supplementation on the level of white blood cells and lymphocytes phenotype in rats fed a low-protein diet

Protein malnutrition has a negative effect on body composition and some blood parameters, especially in the young growing organism. One of nutritional factors which could protect against negative consequences of protein deficiency may be B group vitamins. The aim of the study was to investigate the effect of vitamin B12 supplementation on the immune system in rats fed a standard and a low-protein diet. Rats were fed a control (20% of energy from protein) or a protein-deficient diet (4.5% of energy from protein). Half of animals in each group were additionally supplemented with vitamin B12 (300% of the daily intake). The white blood cells analysis and lymphocytes immunophenotyping (number and percentage) were performed. Low-protein diets caused disturbances in WBC and lymphocyte subpopulations in both short- (30-day) as well as long-term periods (90-day). Vitamin B12 supplementation significantly reduced the negative impact of protein malnutrition after 30 days, however had no effect on long-term malnutrition. Furthermore, vitamin B12 addition in rats fed a control diet did not affect the studied parameters. This observation opens the promise of use of vitamin B12 supplementation to improve immune system parameters in protein malnourished organisms.

High percentage of regulatory T cells before and after vitamin B12 treatment in patients with pernicious anemia

INTRODUCTION

In some previous studies, vitamin B12 treatment showed immunomodulatory effects and restored the immunological abnormalities in patients with pernicious anemia (PA). In the present study, peripheral blood T cell subsets, including regulatory T cells (T(reg)s), were examined before and after vitamin B12 treatment in PA patients.

PATIENTS AND METHODS

The percentages of CD4, CD8, Th1, Th2 and T(reg)s were examined in 23 PA patients before vitamin B12 treatment, in 23 other PA patients after vitamin B12 treatment and in 28 healthy controls.

RESULTS

The mean percentage of CD8+ T cells was significantly higher in the control group (23.0%; 95% CI, 20.4-25.6%) than in the pre- (16.0%; 95% CI, 12.1-20.0%) and posttreatment groups (15.2%; 95% CI, 11.8-18.6%; p < 0.05). The CD4/CD8 ratio was significantly lower in the control group (2.01; 95% CI, 1.66-2.34) than in the pre- (3.45; 95% CI, 2.55-7.80) and posttreatment groups (2.97; 95% CI, 2.22-3.72; p < 0.05). There was no significant difference in the mean Th1/Th2 ratio among these groups. There were significant increases in the mean percentage of T(reg)s in the pre- (6.29%; 95% CI, 5.04-7.54%) and posttreatment groups (7.77%; 95% CI, 6.34-9.20%) compared with the control group (4.18%; 95% CI, 3.92-4.47%; p < 0.05).

CONCLUSIONS

The percentage of T(reg)s was significantly higher in PA patients than in normal subjects, and this high T(reg) percentage was not different before and after vitamin B12 treatment. Other immunological alterations also did not recover after vitamin B12 treatment, so that these immunological changes appear to be the cause of PA and are not induced by vitamin B12 deficiency.

Sub-optimal vitamin B-12 levels among ART-naïve HIV-positive individuals in an urban cohort in Uganda

Malnutrition is common among HIV-infected individuals and is often accompanied by low serum levels of micronutrients. Vitamin B-12 deficiency has been associated with various factors including faster HIV disease progression and CD4 depletion in resource-rich settings. To describe prevalence and factors associated with sub-optimal vitamin B-12 levels among HIV-infected antiretroviral therapy (ART) naïve adults in a resource-poor setting, we performed a cross-sectional study with a retrospective chart review among individuals attending either the Mulago-Mbarara teaching hospitals' Joint AIDS Program (MJAP) or the Infectious Diseases Institute (IDI) clinics, in Kampala, Uganda. Logistic regression was used to determine factors associated with sub-optimal vitamin B-12. The mean vitamin B-12 level was 384 pg/ml, normal range (200-900). Sub-optimal vitamin B-12 levels (<300 pg/ml) were found in 75/204 (36.8%). Twenty-one of 204 (10.3%) had vitamin B-12 deficiency (<200 pg/ml) while 54/204 (26.5%) had marginal depletion (200-300 pg/ml). Irritable mood was observed more among individuals with sub-optimal vitamin B-12 levels (OR 2.5, 95% CI; 1.1-5.6, P=0.03). Increasing MCV was associated with decreasing serum B-12 category; 86.9 fl (± 5.1) vs. 83 fl (± 8.4) vs. 82 fl (± 8.4) for B-12 deficiency, marginal and normal B-12 categories respectively (test for trend, P=0.017). Compared to normal B-12, individuals with vitamin B-12 deficiency had a longer known duration of HIV infection: 42.2 months (± 27.1) vs. 29.4 months (± 23.8; P=0.02). Participants eligible for ART (CD4<350 cells/µl) with sub-optimal B-12 had a higher mean rate of CD4 decline compared to counterparts with normal B-12; 118 (± 145) vs. 22 (± 115) cells/µl/year, P=0.01 respectively. The prevalence of a sub-optimal vitamin B-12 was high in this HIV-infected, ART-naïve adult clinic population in urban Uganda. We recommend prospective studies to further clarify the causal relationships of sub-optimal vitamin B-12, and explore the role of vitamin B-12 supplementation in immune recovery.

The influence of sex and gender on the immune response

The immune system and its orchestrated response are affected by a multitude of endogenous and exogenous factors, modulators and challenges. One of the most frequent differences described in the immune response is its vigor and activity in females compared to males, leading to the consequent increase in autoimmune conditions seen in the female population as well as differences in the immune response to pathogens and viruses. The following review summarizes our present knowledge on sex differences in the immune response, detailing the hormonal and genetic effects that have been proposed as explanatory mechanisms. Sexual hormones, mostly estrogen but also progesterone and testosterone, affect immune cells quantitatively and qualitatively. Relevant research has focused on the impact of hormones on cytokine production by the different effector cells, as well as impact on immunoglobulin production by B lymphocytes and activity of granulocytes and NK cells. The biological aspects are complemented by research data on the possible modulatory role of the X chromosome. In addition to biological differences, the frequently neglected role of gender as an immunomodulator is introduced and explored. Gender affects all areas of human life and consequently affects the different steps of an immune response. Exposure to various types of antigens, access to health promotion programs and health care, as well as prioritization of health needs and household resource allocation all affect the different response of females and males to immunologic challenges.