γδ T cells in oral diseases.

OBJECTIVE: γδ T cells are a distinct subset of unconventional T cells, which link innate and adaptive immunity by secreting cytokines and interacting with other immune cells, thereby modulating immune responses. As the first line of host defense, γδ T cells are essential for mucosal homeostasis and immune surveillance. When abnormally activated or impaired, γδ T cells can contribute to pathogenic processes. Accumulating evidence has revealed substantial impacts of γδ T cells on the pathogenesis of cancers, infections, and immune-inflammatory diseases. γδ T cells exhibit dual roles in cancers, promoting or inhibiting tumor growth, depending on their phenotypes and the clinical stage of cancers. During infections, γδ T cells exert high cytotoxic activity in infectious diseases, which is essential for combating bacterial and viral infections by recognizing foreign antigens and activating other immune cells. γδ T cells are also implicated in the onset and progression of immune-inflammatory diseases. However, the specific involvement and underlying mechanisms of γδ T cells in oral diseases have not been systematically discussed. METHODS: We conducted a systematic literature review using the PubMed/MEDLINE databases to identify and analyze relevant literature on the roles of γδ T cells in oral diseases. RESULTS: The literature review revealed that γδ T cells play a pivotal role in maintaining oral mucosal homeostasis and are involved in the pathogenesis of oral cancers, periodontal diseases, graft-versus-host disease (GVHD), oral lichen planus (OLP), and oral candidiasis. γδ T cells mainly influence various pathophysiological processes, such as anti-tumor activity, eradication of infection, and immune response regulation. CONCLUSION: This review focuses on the involvement of γδ T cells in oral diseases, with a particular emphasis on the main functions and underlying mechanisms by which γδ T cells influence the pathogenesis and progression of these conditions. This review underscores the potential of γδ T cells as therapeutic targets in managing oral health issues.

Eosinophils in Oral Disease: A Narrative Review.

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Pulmonary insults exacerbate susceptibility to oral Listeria monocytogenes infection through the production of IL-10 by NK cells.

Most individuals who consume foods contaminated with the bacterial pathogen Listeria monocytogenes (Lm) develop mild symptoms, while others are susceptible to life-threatening systemic infections (listeriosis). Although it is known that the risk of severe disease is increased in certain human populations, including the elderly, it remains unclear why others who consume contaminated food develop listeriosis. Here, we used a murine model to discover that pulmonary coinfections can impair the host's ability to adequately control and eradicate systemic Lm that cross from the intestines to the bloodstream. We found that the resistance of mice to oral Lm infection was dramatically reduced by coinfection with Streptococcus pneumoniae (Spn), a bacterium that colonizes the respiratory tract and can also cause severe infections in the elderly. Exposure to Spn or microbial products, including a recombinant Lm protein (L1S) and lipopolysaccharide (LPS), rendered otherwise resistant hosts susceptible to severe systemic Lm infection. In addition, we show that this increase in susceptibility was dependent on an increase in the production of interleukin-10 (IL-10) from Ncr1+ cells, including natural killer (NK) cells. Lastly, the ability of Ncr1+ cell derived IL-10 to increase disease susceptibility correlated with a dampening of both myeloid cell accumulation and myeloid cell phagocytic capacity in infected tissues. These data suggest that efforts to minimize inflammation in response to an insult at the respiratory mucosa render the host more susceptible to infections by Lm and possibly other pathogens that access the oral mucosa.

An IL-17F.S65L Knock-In Mouse Reveals Similarities and Differences in IL-17F Function in Oral Candidiasis: A New Tool to Understand IL-17F.

Oropharyngeal candidiasis (OPC) is an opportunistic infection of the oral mucosa caused by the commensal fungus Candida albicans IL-17R signaling is essential to prevent OPC in mice and humans, but the individual roles of its ligands, IL-17A, IL-17F, and IL-17AF, are less clear. A homozygous IL-17F deficiency in mice does not cause OPC susceptibility, whereas mice lacking IL-17A are moderately susceptible. In humans, a rare heterozygous mutation in IL-17F (IL-17F.S65L) was identified that causes chronic mucocutaneous candidiasis, suggesting the existence of essential antifungal pathways mediated by IL-17F and/or IL-17AF. To investigate the role of IL-17F and IL-17AF in more detail, we exploited this "experiment of nature" by creating a mouse line bearing the homologous mutation in IL-17F (Ser65Leu) by CRISPR/Cas9. Unlike Il17f-/- mice that are resistant to OPC, Il17fS65L/S65L mice showed increased oral fungal burdens similar to Il17a -/- mice. In contrast to humans, however, disease was only evident in homozygous, not heterozygous, mutant mice. The mutation was linked to modestly impaired CXC chemokine expression and neutrophil recruitment to the infected tongue but not to alterations in oral antimicrobial peptide expression. These findings suggest mechanisms by which the enigmatic cytokine IL-17F contributes to host defense against fungi. Moreover, because these mice do not phenocopy Il17f-/- mice, they may provide a valuable tool to interrogate IL-17F and IL-17AF function in vivo in other settings.

The human microbiome in immunobullous disorders and lichen planus.

For several decades, there has been a significant growth in the incidence of autoimmune diseases. Studies indicate that genetic factors may not be the only trigger for disease development and that dysbiosis of the microbiome may be another mechanism involved in the pathogenesis of autoimmune diseases. The role of the microbiome in the development of common skin disorders such as psoriasis, atopic dermatitis, acne and rosacea is increasingly well understood. However, few studies have focused on lichen planus and the rare acquired immunobullous diseases, both mucocutaneous groups of disorders linked to skin, oral and gut microbiomes. This review provides an insight into the current understanding of how the microbiome may contribute to the development of autoimmunity and to the maintenance and exacerbation of acquired immunobullous and lichenoid diseases. These mechanisms may have implications for future preventive and therapeutic approaches.

"Oral Manifestations of Patients with Inherited Defect in Phagocyte Number or Function" a systematic review.

INTRODUCTION: Inherited phagocyte defects are one of the subgroups of primary immunodeficiency diseases (PIDs) with various clinical manifestations. As oral manifestations are common at the early ages, oral practitioners can have a special role in the early diagnosis. MATERIALS AND METHODS: A comprehensive search was conducted in this systematic review study and data of included studies were categorized into four subgroups of phagocyte defects, including congenital neutropenia, defects of motility, defects of respiratory burst, and other non-lymphoid defects. RESULTS: Among all phagocyte defects, 12 disorders had reported data for oral manifestations in published articles. A total of 987 cases were included in this study. Periodontitis is one of the most common oral manifestations. CONCLUSION: There is a need to organize better collaboration between medical doctors and dentists to diagnose and treat patients with phagocyte defects. Regular dental visits and professional oral health care are recommended from the time of the first primary teeth eruption in newborns.

Oral manifestations of allograft recipients immediately before and after kidney transplantation.

Objective: To identify the oral lesions of individuals with kidney disease immediately before and shortly after kidney transplantation, taking into account the immunosuppressive regimen, antiviral prophylaxis and type of transplantation.Methods: A prospective observational cohort study was carried from January 2017 to January 2018. Eighty individuals aged 18 years or older who were admitted for kidney transplantation were eligible to participate. Clinical data regarding medical history, immunosuppressive therapy, antiviral prophylaxis, laboratorial data and oral examination were performed by the same trained researcher, in three different moments: 24 hours before transplantation (1st time point), 15-20 days (2nd time point) and 45-60 days (3rd time point) after transplantation.Results: In the first, second and third time points, it was found that 3.7% (3/80), 23.7% (18/76) and 25.7% (19/74) of the participants showed oral soft tissue lesions. Ulcers and candidiasis were the most frequent oral lesions, and they were associated with the use of everolimus (p = .005) and azathioprine (p = .034), respectively. Less patients reported xerostomia after transplantation than before (p < .001).Conclusions: Oral lesions are common in the short term after renal transplantation and are particularly related to both toxicities of immunosuppressive drugs and immunosuppression.

Immunological methods for the diagnosis of oral mucosal diseases.

Immunological methods, which have been widely used in autoimmune blistering diseases (AIBDs) of the oral mucosa, can also be adopted as auxiliary diagnostic tools in oral lichen planus (OLP) and discoid lupus erythematosus (DLE). AIBDs, characterized by autoantibodies against structural proteins of keratinocytes or the basement membrane zone, clinically present as blisters and erosions of the oral mucosa. When atypical lesions occur, OLP or DLE may be confused with AIBDs. The improvement of diagnostic accuracy is necessary due to the significant differences in treatment and prognosis among these diseases. A variety of immunological methods are used for qualitative and quantitative detection of target antigens and autoantibodies. These methods can evaluate efficacy of treatment, monitor diseases and guide treatment decisions. In this review, we discuss the application of immunofluorescence, biochemical tests, and protein microarrays for AIBDs, OLP and DLE, as well as the differential diagnostic methods using immunological tests.

Mucous membrane pemphigoid and oral blistering diseases.

The autoimmune blistering disorders present with variable frequency in the oral cavity. Recognition of their key clinical features at presentation is important, as there are many causes of oral ulceration. Careful history-taking, clinical examination, an understanding of pathogenesis and appropriate investigations are essential. With the exception of the rare genodermatoses that may lead to blistering and oral ulceration, the majority of patients have an acquired disorder. These include the rare autoimmune blistering diseases mucous membrane pemphigoid (MMP), pemphigus vulgaris (PV), linear IgA disease, epidermolysis bullosa acquisita and paraneoplastic pemphigus. Important clinical differential diagnoses include erythema multiforme, which may be mistaken for PV in appearance, while oral lichen planus may be indistinguishable from MMP. Angina bullosa haemorrhagica may also present with tense haemorrhagic bullae, and in the absence of diagnostic tests, requires an astute clinical diagnosis based upon the history. Newer laboratory techniques have facilitated identification of target antigens and epitopes in the autoimmune blistering diseases, particularly in MMP. Current interest is in whether these relate to clinical presentation and outcomes. There have also been recent investigations into the use of saliva as an alternative medium to serum for the diagnosis of oral vesiculobullous lesions. Assessment of disease severity and measurement of quality of life at presentation and subsequent follow-up is paramount to interpreting therapeutic response. Furthermore, combining these scores with serological and/or salivary biomarkers is valuable in the assessment of clinical response. In this paper, we discuss MMP and its important differential diagnoses.

New Viral Facets in Oral Diseases: The EBV Paradox.

The oral cavity contributes to overall health, psychosocial well-being and quality of human life. Oral inflammatory diseases represent a major global health problem with significant social and economic impact. The development of effective therapies, therefore, requires deeper insights into the etiopathogenesis of oral diseases. Epstein-Barr virus (EBV) infection results in a life-long persistence of the virus in the host and has been associated with numerous oral inflammatory diseases including oral lichen planus (OLP), periodontal disease and Sjogren's syndrome (SS). There is considerable evidence that the EBV infection is a strong risk factor for the development and progression of these conditions, but is EBV a true pathogen? This long-standing EBV paradox yet needs to be solved. This review discusses novel viral aspects of the etiopathogenesis of non-tumorigenic diseases in the oral cavity, in particular, the contribution of EBV in OLP, periodontitis and SS, the tropism of EBV infection, the major players involved in the etiopathogenic mechanisms and emerging contribution of EBV-pathogenic bacteria bidirectional interaction. It also proposes the involvement of EBV-infected plasma cells in the development and progression of oral inflammatory diseases. A new direction for preventing and treating these conditions may focus on controlling pathogenic EBV with anti-herpetic drugs.

Characterization of Vibrio cholerae neuraminidase as an immunomodulator for novel formulation of oral allergy immunotherapy.

To improve current mucosal allergen immunotherapy Vibrio cholerae neuraminidase (NA) was evaluated as a novel epithelial targeting molecule for functionalization of allergen-loaded, poly(D,L-lactide-co-glycolide) (PLGA) microparticles (MPs) and compared to the previously described epithelial targeting lectins wheat germ agglutinin (WGA) and Aleuria aurantia lectin (AAL). All targeters revealed binding to Caco-2 cells, but only NA had high binding specificity to α-L fucose and monosialoganglioside-1. An increased transepithelial uptake was found for NA-MPs in a M-cell co-culture model. NA and NA-MPs induced high levels of IFN-γ and IL10 in naive mouse splenocytes and CCL20 expression in Caco-2. Repeated oral gavage of NA-MPs resulted in a modulated, allergen-specific immune response. In conclusion, NA has enhanced M-cell specificity compared to the other targeters. NA functionalized MPs induce a Th1 and T-regulatory driven immune response and avoid allergy effector cell activation. Therefore, it is a promising novel, orally applied formula for allergy therapy.

Immune checkpoints indoleamine 2,3-dioxygenase 1 and programmed death-ligand 1 in oral mucosal dysplasia.

BACKGROUND: Oral mucosal dysplasia is a histologic feature of potentially malignant disorders that is associated with the risk of transformation to carcinoma. Dysplastic cells use many strategies during their transformation to cancer, including escape from the immune mediated destruction. We hypothesized that adaptive immunity is inhibited by activation of distinct immune checkpoint molecules, such as indoleamine 2,3-dioxygenase 1 (IDO1) and programmed death-ligand 1 (PD-L1). METHODS: We collected 63 oral dysplasia samples from 47 patients. Nine biopsies from alveolar mucosa were taken during wisdom teeth extractions were used as healthy controls. Tissue samples were stained and scored for IDO1 and PD-L1. Additionally, dysplasia grades and inflammatory cell infiltration were evaluated. Eight patients were followed up to 36 months to evaluate dysplasia progression, inflammation, and immune checkpoint molecules expression. RESULTS: Dysplastic epithelium had significantly lower IDO1 expression than that of healthy controls. PD-L1 positive cells in the lamina propria were mainly in dysplastic samples and seldom in healthy controls. Dysplasia grade was associated negatively with epithelium IDO1 and positively with IDO1 and PD-L1 expression in the lamina propria. There was a positive association between dysplasia grade and level of inflammatory cell infiltration. During follow-up, dysplasia grade, inflammatory cell infiltration, and the immune checkpoint expression fluctuated over time. CONCLUSIONS: Immune checkpoint molecules IDO1 and PD-L1 are modulated during oral epithelial dysplastic changes, and their expression is associated with inflammatory cell infiltration in the lamina propria. As immune checkpoint molecules expression fluctuates over time, these molecules are not useful as biomarkers for oral mucosal dysplasia progression.

Prevalence of HIV-related oral manifestations and their association with HAART and CD4+ T cell count: a review.

HIV infection is one of the major health problem of the last decades. This disease causes a chronic infection that can lead to acquired immunodeficiency syndrome (AIDS). According to the Global AIDS update, released in 2016 by HIV department of World Health Organization (WHO) and by the Joint United Nations Program on HIV/AIDS (UNAIDS), at the end of 2015, 36.7 million people were infected by HIV: 34.9 million of these were adults and 1.8 million were children under 15 years of age. The same report shows that during 2015, 2.1 million of new infection cases have occurred all over the world and about 1.1 million people have died for HIV. The aim of this short review is to up-date of the main HIV-related oral manifestations and their correlation with HAART (Highly Active Antiretroviral Therapy) and CD4+ T-cell count. Despite that more than 20 years have elapsed, this classification still remains valid: even today, group 1 lesions are found in the majority of HIV-positive patients with oral manifestations. Group 1 includes the following conditions: oral candidiasis (pseudomembranous candidiasis, erythematous candidiasis, angle cheilitis), oral hairy leukoplakia, periodontal diseases (necrotizing gingivitis, necrotizing periodontitis, linear gingival erythema), Kaposi’s sarcoma, and non-Hodgkin’s lymphoma. Melanotic hyperpigmentation, HSV infection and HPV infection, which are included in group 2, are also common. Oral candidiasis, oral hairy leukoplakia, Kaposi’s sarcoma and HSV infection are the lesions that have seen the major drop in their incidence after the HAART introduction. The increase in CD4+ T-cell count is not significantly correlated to the decrease of every type of oral lesions, but it is statistically significant only in relation to oral candidiasis (p-value less than 0.001). Oral lesions are an important sign of immunodepression and with the introduction of HAART their incidence has strongly decreased, particularly in urban areas. Nevertheless, developing countries still have a high prevalence of these manifestations because of the persistence of many risk factors, like the difficulty to access treatment, poor oral hygiene, low socioeconomic status and late diagnosis.

The oral mucosa: A barrier site participating in tissue-specific and systemic immunity.

In the oral cavity, the immune system is constantly exposed to unique tissue-specific signals, including a rich community of commensal microbes and their metabolites, continuous tissue damage from mastication, and antigens from food and airborne particles. How this unique combination of signals participates in the training of specialized immunity at this site is not well understood, yet imbalance of local responses is linked to tissue-specific disease susceptibilities with the prototypic disease being periodontitis. However, the oral mucosa is also well recognized as a site where systemic inflammatory and autoimmune diseases often manifest, indicating that systemic immune deregulation is reflected in the function of the oral immune system. This commentary will discuss both aspects of compartmentalized and systemic immunity at the oral mucosa.

Immunohistopathological characterization and the impact of topical immunomodulatory therapy in oral chronic graft-versus-host disease: A pilot study.

OBJECTIVE: To characterize the immunohistopathological features of oral chronic graft-versus-host disease (cGVHD), and the impact of topical immunomodulatory therapy on the infiltrating cells. MATERIAL AND METHODS: Paired oral cGVHD biopsies obtained before (n = 12) and 1 month after treatment (n = 12) with topical dexamethasone (n = 8) or tacrolimus (n = 4) were characterized by immunohistochemistry using a panel of CD1a, CD3, CD4, CD8, CD20, CD31, CD62E, CD103, CD163, c-kit, and FoxP3. Controls included acute GVHD (aGVHD; n = 3), oral lichen planus (OLP; n = 5), and normal tissues (n = 5). RESULTS: Oral cGVHD specimens prior to treatment were mainly characterized by basal cell squamatization, lichenoid inflammation, sclerosis, apoptosis, and lymphocytic exocytosis. The infiltrating cells in oral cGVHD primarily consisted of CD3+ , CD4+ , CD8+ , CD103+ , CD163+ , and FoxP3+ cells, which were higher than in normal tissues. Topical dexamethasone or tacrolimus reduced neutrophilic exocytosis, basal cell squamatization, and lichenoid inflammation in oral cGVHD, and dexamethasone reduced the number of CD4+ and CD103+ cells. CONCLUSION: The high expression of CD3, CD4, CD8, CD103, CD163, and FoxP3 confirms that oral cGVHD is largely T-cell-driven with macrophage participation. The impact of topical immunomodulatory therapy was variable, reducing histological inflammatory features, but with a weak clinicopathological correlation. Topical dexamethasone reduced the expression of CD4 and CD103, which may offer novel therapeutic targets.

[Oral allergies]. / Les allergies orales.

Oral allergies to dental materials are a growing problem and remain poorly diagnosed by health professionals. The complaints of patients with oral allergy are various and include sensations of burning or stinging of the oral mucosa, sensations of dryness of the oral cavity, or general symptoms such as headache, dyspepsia, asthenia, arthralgia, and myalgia. Signs suggestive of oral allergy include erythema, edema, purpuric patches on the palate, ulcerations of the oral mucosa (canker sore), gingivitis, glossitis mimicking geographic tongue, angular cheilitis, peri-oral eczema or the presence of lichenoid reactions of the oral mucosa. The diagnosis of an allergy will include data from the anamnesis, the clinical examination, as well as the results of allergy tests: epicutaneous tests (patch tests) or cutaneous tests (prick tests), possibly completed by a blood test ( in vitro lymphoblastic transformation test ou LTT).

Les allergies orales aux matériaux dentaires représentent un problème croissant et demeurent peu diagnostiquées par les professionnels de la santé. Les plaintes des patients présentant une allergie buccale sont variées et compor tent des sensations de brûlures ou de picotements de la muqueuse buccale, des sensations de sécheresse de la cavité buccale ou des symptômes généraux de type céphalée, dyspepsie, asthénie, arthralgies, myalgies. Les signes qui peuvent faire suspecter une allergie de la cavité buccale sont la présence d'un érythème, d'un oedème ou piqueté purpurique du palais, des ulcérations de la muqueuse buccale (aphtes), une gingivite, une glossite dépapillante, une perlèche, un eczéma péribuccal ou encore la présence de réactions lichénoïdes de la muqueuse buccale. Le diagnostic d'une allergie comprendra les données de l'anamnèse, de l'examen clinique, ainsi que les résultats des tests d'allergies : tests épicutanés (patch tests) ou cutanés (prick tests), complétés éventuellement par un test sanguin (test de transformation lymphoblastique in vitro ou LTT).

The Oral Microbiome of Children: Development, Disease, and Implications Beyond Oral Health.

In the era of applied meta-omics and personalized medicine, the oral microbiome is a valuable asset. From biomarker discovery to being a powerful source of therapeutic targets and to presenting an opportunity for developing non-invasive approaches to health care, it has become clear that oral microbes may hold the answer for understanding disease, even beyond the oral cavity. Although our understanding of oral microbiome diversity has come a long way in the past 50 years, there are still many areas that need to be fine-tuned for better risk assessment and diagnosis, especially in early developmental stages of human life. Here, we discuss the factors that impact development of the oral microbiome and explore oral markers of disease, with a focus on the early oral cavity. Our ultimate goal is to put different experimental and methodological views into perspective for better assessment of early oral and systemic disease at an early age and discuss how oral microbiomes-at the community level-could provide improved assessment in individuals and populations at risk.

Spectrum of orocutaneous disease associations: Immune-mediated conditions.

There are a number of diseases that manifest both on the skin and the oral mucosa, and therefore the importance for dermatologists in clinical practice to be aware of these associations is paramount. In the following continuing medical education series, we outline orocutaneous disease associations with both immunologic and inflammatory etiologies.

Supportive care for patients undergoing immunotherapy.

Immune checkpoint inhibitors, a new class of cancer therapeutic agents, play an important role in the management of melanoma, NSCLC, and other malignancies. A workshop organized by three MASCC Study Groups: Oral Care, Skin Toxicities, and Neutropenia, Infection, and Myelosuppression during the MASCC Annual Meeting held in Adelaide, Australia on 23-25 June, 2016 focused on the new class of anti-cancer therapeutic agents. Topics in the workshop included the mechanism of action and clinical uses of immune anti-CTL4 and anti-PD1 antibodies, checkpoint inhibitor toxicities, including skin adverse events, gastrointestinal toxicities, oral complications, pulmonary toxicities, and endocrinological and immune-related infections. Checkpoint inhibitors have been approved for use in different malignancies including metastatic melanoma, advanced non-small cell lung cancer, metastatic renal cell carcinoma, refractory Hodgkin's lymphoma, metastatic bladder cancer, and advanced head and neck cancer, and the list continues to grow. In general, these agents seem to be better tolerated in most patients and less toxic compared to conventional chemotherapy. However, the toxicities here, termed immune-related adverse events (irAEs), are unique and different from what we have seen in the past. There is no prospective data on these toxicities, and guidelines or recommendations are currently based on symptomatic management from the ongoing clinical trials. Treating oncologists need to be aware and alert themselves to the subtleties in presentation and the big difference in the way we manage the irAEs. Although most irAEs are low-grade and manageable, they have the potential to be life-threatening and extremely severe if not promptly treated. Additionally, irAEs could even lead to death, if managed incorrectly. The MASCC workshop addressed the various irAEs, per organ system, clinical presentation, management recommendations, and individual toxicities.

Periodontal and other oral manifestations of immunodeficiency diseases.

The list of immunodeficiency diseases grows each year as novel disorders are discovered, classified, and sometimes reclassified due to our ever-increasing knowledge of immune system function. Although the number of patients with secondary immunodeficiencies (SIDs) greatly exceeds those with primary immunodeficiencies (PIDs), the prevalence of both appears to be on the rise probably because of scientific breakthroughs that facilitate earlier and more accurate diagnosis. Primary immunodeficiencies in adults are not as rare as once thought. Globally, the main causes of secondary immunodeficiency are HIV infection and nutritional insufficiencies. Persons with acquired immune disorders such as AIDS caused by the human immunodeficiency virus (HIV) are now living long and fulfilling lives as a result of highly active antiretroviral therapy (HAART). Irrespective of whether the patient's immune-deficient state is a consequence of a genetic defect or is secondary in nature, dental and medical practitioners must be aware of the constant potential for infections and/or expressions of autoimmunity in these individuals. The purpose of this review was to study the most common conditions resulting from primary and secondary immunodeficiency states, how they are classified, and the detrimental manifestations of these disorders on the periodontal and oral tissues.