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.

Endothelial dysfunction in rheumatic autoimmune diseases

Rheumatic autoimmune diseases have been associated with accelerated atherosclerosis and various types of vasculopathies. Atherosclerosis is an inflammatory condition which starts as a "response to injury" favoring endothelial dysfunction which is associated with increased expression of adhesion molecules, pro-inflammatory cytokines, pro-thrombotic factors, oxidative stress upregulation and abnormal vascular tone modulation. Endothelial dysfunction in rheumatic autoimmune diseases involves innate immune responses, including macrophages and dendritic cells expression of scavenger and toll-like receptors for modified or native LDL as well as neutrophil and complement activation, and dysregulation of adaptive immune responses, including proliferation of autoreactive T-helper-1 lymphocytes and defective function of dendritic and regulatory T cells. Specific differences for endothelial function among different disorders include: a) increased amounts of pro-atherogenic hormones, decreased amounts of anti-atherogenic hormones and increased insulin resistance in rheumatoid arthritis; b) autoantibodies production in systemic lupus erythematosus and antiphospholipid syndrome; c) smooth muscle cells proliferation, destruction of internal elastic lamina, fibrosis and coagulation and fibrinolytic system dysfunction in systemic sclerosis. Several self-antigens (i.e. high density lipoproteins, heat shock proteins, β2-glycoprotein1) and self-molecules modified by oxidative events (i.e. low density lipoproteins and oxidized hemoglobin) have been identified as targets of autoimmune responses. Endothelial dysfunction leads to accelerated atherosclerosis in rheumatoid arthritis, systemic lupus erythematosus and spondyloarthropaties whereas obliterative vasculopathy is associated with systemic sclerosis. In this paper, we will briefly review the most relevant information upon endothelial dysfunction and inflammatory mechanisms in atherosclerosis and we will summarize the similarities and differences in vascular disease patterns underlying different rheumatic autoimmune diseases.

Infection risk associated with anti-TNF-α agents: a review

INTRODUCTION

TNF-α is a pro-inflammatory cytokine known to a have a key role in the pathogenesis of chronic immune-mediated diseases. TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory or disease-modifying anti-rheumatic drugs (DMARDs) to treat chronic immune-mediated diseases.

AREAS COVERED

Patients receiving TNF-α inhibitors are at high risk of infections. Based on our experience, in this paper, we discuss the risk of infections associated with the administration of TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

EXPERT OPINION

Infliximab more so than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis (LTB) infection and the overall risk of opportunistic infections should be considered before beginning TNF-α inhibitor therapy. A careful medical history, Mantoux test and chest-x-ray should always be performed before prescribing TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitor treatment. Finally, patients who are at high risk of herpes zoster (HZ) reactivation would benefit from a second vaccination in adulthood when receiving TNF-α inhibitors.

The role of Th17 lymphocytes in the autoimmune and chronic inflammatory diseases

The emerging role of interleukin-17 as a hallmark proinflammatory cytokine of the adaptive immune system produced by a new T helper cell subset termed "Th17" has received considerable attention. In this review we will focus on recent information regarding IL-17 and its relevance in autoimmune and chronic inflammatory diseases.

IL-33/IL-31 Axis in Immune-Mediated and Allergic Diseases

Several allergic and immunologic diseases including asthma, food allergy (FA), chronic spontaneous urticaria (CSU), atopic dermatitis (AD), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), rheumatoid arthritis (RA), and Behçet's disease (BD) are characterized by the involvement of Th2 immunity. Several mediators lead to immunoglobulin (Ig)E production, thus including key cytokines such as interleukin (IL)-4, IL-5, and IL-13. Among them, IL-31 and IL-33 have been recently studied as novel biomarkers and future therapeutic targets for allergic and immunological disorders. IL-31 is a proinflammatory cytokine-it regulates cell proliferation and is involved in tissue remodeling. IL-33, acting through its receptor suppression of tumorigenity (ST2L), is an alarmin cytokine from the IL-1 family, whose expression is mediated by tissue damage. The latter has a pleiotropic effect, as it may modulate specific and innate immune cells functions. To date, several researchers have investigated the involvement of IL-31 and IL-33 in several allergic and immune-mediated diseases. Further studies are needed to understand the future applications of these molecules as novel therapeutic agents. This paper aims to give the readers a complete and updated review of IL-31 and IL-33 involvement among the most common autoimmune and allergic disorders.

Anti-TNF-alpha inhibitors: a new therapeutic approach for inflammatory immune-mediated diseases: an update upon efficacy and adverse events

The ongoing progresses in the knowledge of the pathogenic mechanisms of various inflammatory or immune-mediated diseases and the availability of innovative biotechnological approaches have lead to the development of new drugs which add to conventional treatments. TNF-alpha inhibitors (infliximab, adalimumab and etanercept) have demonstrated efficacy either as monotherapy or in combination with other anti-inflammatory or disease modifying anti-rheumatic drugs (DMARDs). The efficacy and safety profile of the TNF-alpha inhibitors can be considered, in general, as a class effect. Nevertheless, some differences may exist among the three agents. In this paper, we will briefly review the indications for the use of the three TNF-alpha inhibitors, the pre-treatment considerations and the reported adverse events.

TNF-α gene polymorphisms: association with disease susceptibility and response to anti-TNF-α treatment in psoriatic arthritis

The tumor necrosis factor-α (TNF-α) gene has been proposed as a major candidate gene in psoriatic arthritis (PsA). TNF-α is a therapeutic target for patients responding poorly to conventional treatments. We investigated the role of single-nucleotide polymorphisms (SNPs) at positions -238, -308, and +489 of the TNF-α gene in the genetic susceptibility to PsA, in the severity of the disease, and, finally, in the response to TNF-α inhibitors (adalimumab, etanercept, or infliximab). Fifty-seven Caucasian PsA patients and 155 healthy matched controls were studied. The SNP +489 variant allele A was significantly associated with PsA susceptibility (P=0.0136) and severity of clinical (Psoriasis Area and Severity Index score, American College of Rheumatology criteria, Disease Activity Score 28, and Disability Index Health Assessment Questionnaire) and laboratory (C-reactive protein and erythrocyte sedimentation rate) parameters (P-values ranging from 0.016 to 2.908 × 10(-12)). The difference in severity was accounted for by the differences between the AA and GA genotypes with respect to the GG genotype. The SNP +489A allele shows a trend of association with the response to PsA treatment with etanercept. These findings suggest a role of the SNP +489A allele in the susceptibility and severity of PsA.

Current views on diagnostic approach and treatment of lymphedema

Lymphedema is a chronic, progressive, and often debilitating condition. Primary lymphedema is a lymphatic malformation developing during the later stage of lymphangiogenesis. Secondary lymphedema is the result of obstruction or disruption of the lymphatic system, which can occur as a consequence of tumors, surgery, trauma, infection, inflammation, and radiation therapy. In this review, we report an update upon the diagnostic approach and the medical and surgical therapy for both primary and secondary lymphedema.

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.

Immunogenicity of infliximab and adalimumab: what is its role in hypersensitivity and modulation of therapeutic efficacy and safety?

INTRODUCTION

TNF-α inhibitors have demonstrated efficacy both as monotherapy and in combination with disease-modifying antirheumatic drugs (DMARDs) in the treatment of chronic inflammatory immune-mediated diseases such as rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, psoriasis and/or psoriatic arthritis, and may be administered off-label to treat disseminated granuloma annulare systemic lupus erythematosus and systemic sclerosis. There are several TNF-α inhibitors available for clinical use including infliximab, adalimumab, golimumab, certolizumab pegol and etanercept.

AREAS COVERED

infliximab and adalimumab can induce the development of anti-infliximab (anti-IFX) and anti-adalimumab (anti-ADA) monoclonal antibodies (mAbs). In this review, we discuss the impact of anti-IFX and anti-ADA mAbs upon efficacy and safety of these biological agents.

EXPERT OPINION

IgG/IgE neutralizing antibodies against infliximab and adalimumab decrease the possibility of achieving a minimal disease activity state or clinical remission, decrease drug survival, increase the need for doctors to prescribe a higher drug dosage and, finally, favor the occurrence of adverse events. Concomitant administration of DMARDs such as methotrexate or leflunomide prevents the development of neutralizing Abs against infliximab and adalimumab.

Influenza and pneumococcal vaccinations of patients with systemic lupus erythematosus: current views upon safety and immunogenicity

Systemic lupus erythematosus (SLE) is a chronic immune-mediated inflammatory multisystem disease. The onset of viral and bacterial infections may favor the exacerbation of the disease, amplify autoimmune processes and contribute to mortality and morbidity. The prevention of influenza and Streptococcus pneumoniae infections with vaccination should receive particular attention in SLE patients considering their elevated incidence, their high attack rate in epidemic periods, their potentially severe complications as well as the immunocompromised state of the host. The use of non-adjuvanted vaccine preparations should be preferred in order to avoid the onset of the "Autoimmune (auto-inflammatory) Syndrome Induced by Adjuvants" or "ASIA". In this review, we report that influenza and pneumococcal vaccinations in SLE patients are: 1) recommended to reduce the risk of development of these infections; 2) strongly suggested in elderly subjects and in those receiving high dose immunosuppressive treatments; 3) efficacious, even if specific immune responses may be lower than in the general population, as generally the humoral response fulfills the criteria for vaccine immunogenicity; and 4) safe in inactive disease although may favor a transient increase in autoantibody levels and rarely disease flares.

Free radicals and endothelial dysfunction: potential positive effects of TNF-α inhibitors

OBJECTIVES

During the last decade many new biological immune modulators have entered the market as new therapeutic principles. Tumor necrosis factor (TNF)-α is a pro-inflammatory cytokine known to a have a key role in the pathogenic mechanisms of various immune-mediated or inflammatory diseases. However, TNF-α also plays a key role in endothelial dysfunction and, thus, in the development and progression of atherosclerosis. What, then, is the potential therapeutic role of TNF-α inhibitors?

METHODS

We analysed the current literature concerning the administration of TNF-α inhibitors and their potential benefits upon endothelial function.

RESULTS

TNF-α inhibitors decrease the serum levels of inflammatory markers such as TNF-α itself, CRP, IL-6, and increased the tissue expression of endothelial NO synthase and the vasodilatory response to bradykinin.

DISCUSSION

TNF-α inhibitors may change the progression of endothelial dysfunction and, thus, slow down the atherosclerotic process.

Update upon efficacy and safety of TNF-α inhibitors

The ongoing progresses in the knowledge of the pathogenic mechanisms of various immune-mediated and inflammatory diseases as well as the availability of innovative biotechnological approaches have led to the development of new drugs that add to conventional treatments. Among these, tumor necrosis factor (TNF)-α inhibitors, that is, infliximab, adalimumab, etanercept, golimumab and certolizumab pegol, are now available for clinical use. This editorial discusses the recent indications of TNF-α inhibitors, the pretreatment considerations, the reported adverse events and, finally, the recommendations for its use in pregnancy.

Pharmacogenetics of etanercept: role of TNF-α gene polymorphisms in improving its efficacy

INTRODUCTION

During the last decade, many new biological immune modulators have entered the market as new therapeutic principles. Biologics, including TNF-α inhibitors, are the new frontier in the treatment of immune-mediated or inflammatory diseases, such as rheumatoid arthritis, systemic lupus erythematosus, Crohn's disease, ankylosing spondylitis, systemic sclerosis, disseminated granuloma annulare, psoriasis and/or psoriatic arthritis. TNF-α inhibitors have demonstrated efficacy and are well tolerated in large, randomized, controlled clinical trials. However, a substantial proportion of patients do not respond to these agents and potential adverse drug reactions may be associated with its use.

AREAS COVERED

Pharmacogenetics has the potential of increasing drug efficiency by identifying genetic factors responsible for lack of response or toxicities to TNF-α inhibitors. In this review, we analyze the influence of several polymorphisms upon the efficacy and safety of TNF-α inhibitors.

EXPERT OPINION

Several polymorphisms have been proven to influence the response to etanercept. Among them, single nucleotide polymorphisms (SNPs) -308 G/G, -857 C/T, +489 GG and GA, HLA-DRB1-encoding SE (allele *0404 and allele *0101) favor the response to etanercept, whereas SNP -308 A/A and TNFR1A AA decrease the response. Large clinical studies are needed to confirm the relevance of these associations in order to tailor treatment and to decrease unnecessary toxicity.

Potential use of TNF-α inhibitors in systemic sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by chronic inflammation and fibrosis of the skin, vascular abnormalities and variable involvement of organs. TNF-α has a central role in initial host response to infections and in the pathogenesis of various systemic immune-mediated diseases. Serum levels of TNF-α are elevated in patients with SSc and favor the development of pulmonary fibrosis and pulmonary arterial hypertension. Inflammatory arthritis can occur in patients with SSc. Infliximab and etanercept may improve the inflammatory arthritis and disability in SSc. TNF-α inhibitors reduce the systemic inflammation, improve the endothelial function decreasing the risk of pulmonary arterial hypertension progression and of acute cardiovascular and/or cerebrovascular events. Physicians need to be aware of the potential risks of tuberculosis reactivation and opportunistic infections. Randomized controlled trials with TNF-α inhibitors in patients with SSc are needed to confirm the potential role of these agents in the treatment of SSc.

Emerging biological drugs: a new therapeutic approach for Systemic Lupus Erythematosus. An update upon efficacy and adverse events

B-cells abnormalities leading to autoantibody production play a central role in Systemic Lupus Erythematosus (SLE) pathogenesis. B-cell targeted therapies, including anti-B lymphocyte stimulator (BLyS) and anti-CD20 monoclonal antibodies, are at forefront of new SLE treatments. Biologic agents targeting specific pathways (i.e. T-B lymphocyte interaction, cytokines and complement) have been also proposed as new tools for SLE treatment. In this review we will focus on biological drugs whose potential efficacy has been evaluated in open-label and randomized clinical trials.

Selective TNF-α inhibitor-induced injection site reactions

INTRODUCTION

During the last decade, many new biological immune modulators entered the market as new therapeutic principles. TNF-α is a pro-inflammatory cytokine known to a have a key role in the pathogenic mechanisms of various immune-mediated or inflammatory diseases. TNF-α blockers have demonstrated efficacy in large, randomized controlled clinical trials either as monotherapy or in combination with other anti-inflammatory or disease-modifying anti-rheumatic drugs.

AREAS COVERED

Although generally well tolerated and safe, potential adverse events may be associated with TNF-α inhibitor treatment. The authors will briefly review the potential adverse drug reactions and the immunological mechanisms of injection site reactions (ISRs) in patients treated with etanercept and adalimumab.

EXPERT OPINION

Patients treated with TNF-α inhibitors can develop ISR around the sites of injections. 'Type IV delayed type reaction' or 'recall ISRs'. Eosinophilic cellulitis or 'Wells syndrome', 'type III' and 'type I' reactions are reported. Long-term studies are necessary to determine the durability of response and the real risk of ISRs with golimumab and certolizumab pegol. Further studies are also necessary to evaluate the immunogenicity of these drugs.

Adalimumab for the treatment of immune-mediated diseases: an update on old and recent indications

Ongoing progress in understanding the pathogenic mechanisms regulating various immune-mediated and inflammatory diseases, as well as the availability of innovative biotechnological approaches, have lead to the development of new drugs that add to conventional treatments. Among these, tumor necrosis factor (TNF)-α inhibitors such as infliximab, adalimumab, etanercept, golimumab and certolizumab pegol, are now available for clinical use. Adalimumab is a fully recombinant human immunoglobulin G1 monoclonal antibody that specifically binds with high affinity to human TNF-α and inhibits its binding to TNF receptors. Adalimumab was approved by the U.S. FDA in 2002 and was granted approval from the European Medicines Agency in September 2003 for the treatment of moderate to severe rheumatoid arthritis and subsequently for the treatment of ankylosing spondylitis, chronic plaque psoriasis, psoriatic arthritis, juvenile idiopathic arthritis and Crohn's disease. In this paper, we will briefly review the structure and biological effects of TNF-α, the old and recent indications of adalimumab, the pretreatment considerations, the reported adverse events and finally, the recommendations for its use in pregnancy.

Genetic factors and systemic sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease of unknown etiology characterized by chronic inflammation and fibrosis of the skin, vascular abnormalities, and variable involvement of organs including kidneys, gastrointestinal tract, heart, and lungs. SSc shows a complex etiology in which both environmental and genetic factors seem to influence the onset and outcome of the disease. We provide an extensive overview of the genetic factors and epigenetic modifications and what their knowledge has revealed in terms of etiopathogenesis of SSc.

Basophils and Mast Cells in COVID-19 Pathogenesis

Basophils and mast cells are among the principal inducers of Th2 responses and have a crucial role in allergic and anti-parasitic protective immunity. Basophils can function as antigen-presenting cells that bind antigens on their surface and boost humoral immune responses, inducing Th2 cell differentiation. Their depletion results in lower humoral memory activation and greater infection susceptibility. Basophils seem to have an active role upon immune response to SARS-CoV-2. In fact, a coordinate adaptive immune response to SARS-CoV-2 is magnified by basophils. It has been observed that basophil amount is lower during acute disease with respect to the recovery phase and that the grade of this depletion is an important determinant of the antibody response to the virus. Moreover, mast cells, present in a great quantity in the nasal epithelial and lung cells, participate in the first immune response to SARS-CoV-2. Their activation results in a hyperinflammatory syndrome through the release of inflammatory molecules, participating to the "cytokine storm" and, in a longer period, inducing pulmonary fibrosis. The literature data suggest that basophil counts may be a useful prognostic tool for COVID-19, since their reduction is associated with a worse prognosis. Mast cells, on the other hand, represent a possible therapeutic target for reducing the airway inflammation characteristic of the hyperacute phase of the disease.

Anti-tumor necrosis factor-α treatment with infliximab for disseminated granuloma annulare

Granuloma annulare (GA) is a chronic inflammatory disease of unknown etiology characterized by the development of plaques preferentially localized to the distal extremities. Spontaneous remission and relapses are quite common and the course of GA is not easy to predict. Moreover, most therapeutic regimens have been used anecdotally and with variable success. We report the case of a 62-year-old White female patient affected by disseminated GA unsuccessfully treated with psoralen plus UVA photochemotherapy, prednisone, and cyclosporine (ciclosporin) who responded to the anti-tumor necrosis factor-α monoclonal antibody infliximab administered intravenously at a dosage of 5 mg/kg at weeks 0, 2, and 6 and thereafter at monthly intervals for 10 additional months. Most of the GA lesions improved within 8 weeks and then slowly resolved within 10 months of treatment. We suggest that infliximab may be proposed as an additional therapeutic option in the treatment of recalcitrant forms of disseminated GA.

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.

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.

Update upon the infection risk in patients receiving TNF alpha inhibitors

INTRODUCTION

TNF-α inhibitors can be administered either as monotherapy or in combination with other anti-inflammatory drugs or DMARDs in the treatment of chronic immune-mediated diseases.

AREAS COVERED

Patients receiving TNF-α inhibitors are at high risk of infections. An update is made on the risk of infection in patients receiving TNF-α inhibitors and the strategies for mitigating against the development of these serious adverse events.

EXPERT OPINION

Infliximab than etanercept appears to be responsible for the increased risk of infections. Re-activation of latent tuberculosis infection and the overall risk of opportunistic infections should be considered before beginning a course of TNF-α inhibitors. A careful medical history, Mantoux test/quantiferon-TB Gold In-tube Test and chest-X-ray should always be performed before starting TNF-α inhibitors. Particular attention should be paid to risk factors for Pneumocystis jirovecii infection. Hepatitis B and C virological follow-up should be considered during TNF-α inhibitors treatment. Finally, appropriate vaccinations for influenza, S. pneumoniae, and HBV should be administered to decrease the risk of infection, and patients who are at high risk of herpes zoster reactivation would benefit from a second vaccination in adulthood.

HLA-G expression in gastric carcinoma: clinicopathological correlations and prognostic impact

To analyze expression of human leukocyte antigen-G (HLA-G) in gastric adenocarcinoma and correlate its expression with histological and clinical variables. A continuous series of 94 unselected patients with gastric adenocarcinoma (stage I to III) were selected. All histological and clinical variables were collected including the intensity of intra- and peri-tumor lymphocytic infiltration. HLA-G expression was investigated using immunohistochemistry. All histological samples analyzed for HLA-G expression were taken from the primary gastric lesion and included non-neoplastic mucosa. Evaluation of HLA-G expression was performed on the transition zone between tumor and non-neoplastic mucosa, and the invasive front of the tumor and assessment was performed as follows: percentage of positive (strong expression vs weak) cells. A variable amount of HLA-G-positive tumor cells was found in 24 out of 94 cases (25.5%). No significant correlation was found between HLA-G expression and other clinicopathological variables (sex, age, stage, grade, histotype). The overall median survival was worse in patients with HLA-G-positive adenocarcinoma (24.3 months, CI95% 7.7-41.0) compared to those with HLA-G-negative tumors (66.3 months, CI95% 53.0-79.7; p < 0.0001). Two- and 5-year survival rates of HLA-G-negative patients were 88 and 44%, respectively, while were 42 and 11% in those HLA-G-positive. This trend was observed in all stages but was more marked in stage III. HLA-G expression is associated with poor survival in stage III gastric cancer patients and represents a possible immunoescape mechanism of cancer cells.