HLA haplotypes in recurrent aphthous stomatitis: a mode of inheritance?

The aim of this study was to investigate the genetic association between recurrent aphthous stomatitis (RAS) and human leucocyte antigen (HLA) class I and II alleles and HLA haplotypes. Families selected had at least one child suffering from recurrent aphthous stomatitis in addition to one or both of the parents. HLA-A, -B and -DR alleles were typed in 29 families, 27 nuclear and two extended (121 subjects). HLA haplotypes of all family members with RAS were compared with those who were RAS negative. Although major histocompatibility complex class I and II gene analysis failed to demonstrate any significant association between RAS and HLA antigens, the study of HLA haplotypes revealed a significant association between HLA haplotypes and susceptibility to RAS. The results indicate that susceptibility to RAS segregates in families in association with HLA haplotypes.

Recurrent aphthous ulcers today: a review of the growing knowledge

Recurrent aphthous ulcers represent a very common but poorly understood mucosal disorder. They occur in men and women of all ages, races and geographic regions. It is estimated that at least 1 in 5 individuals has at least once been afflicted with aphthous ulcers. The condition is classified as minor, major, and herpetiform on the basis of ulcer size and number. Attacks may be precipitated by local trauma, stress, food intake, drugs, hormonal changes and vitamin and trace element deficiencies. Local and systemic conditions, and genetic, immunological and microbial factors all may play a role in the pathogenesis of recurrent aphthous ulceration (RAU). However, to date, no principal cause has been discovered. Since the aetiology is unknown, diagnosis is entirely based on history and clinical criteria and no laboratory procedures exist to confirm the diagnosis. Although RAU may be a marker of an underlying systemic illness such as coeliac disease, or may present as one of the features of Behcet's disease, in most cases no additional body systems are affected, and patients remain otherwise fit and well. Different aetiologies and mechanisms might be operative in the aetiopathogenesis of aphthous ulceration, but pain, recurrence, self-limitation of the condition, and destruction of the epithelium seem to be the ultimate outcomes. There is no curative therapy to prevent the recurrence of ulcers, and all available treatment modalities can only reduce the frequency or severity of the lesions.

Mouthrinses containing triclosan reduce the incidence of recurrent aphthous ulcers (RAU)

Triclosan, an antibacterial agent introduced in toothpastes and mouthrinses, has recently been shown to have anti-inflammatory and analgesic properties. The aim of the present double-blind cross-over study was to examine the effect of triclosan on the incidence of recurrent aphthous ulceration (RAU) when administered in mouthrinses. The study included 30 patients with a history of multiple recurrent aphthous ulcers. Three different triclosan-containing mouthrinses, differing only in their solubilizing agents were used and compared with a control rinse. The number of new ulcers, ulcer-free days and the severity of pain were recorded. The results showed that the patients experienced a significant decrease in the number of oral ulcers during the experimental period when the mouthrinses contained triclosan. It may thus be concluded that triclosan has the potential to reduce the number of aphthous ulcers presumably due to its anti-inflammatory properties.

Role of gamma delta T cells in pathogenesis and diagnosis of Behcet's disease

BACKGROUND

Behcet's disease (BD) is a multisystem disorder of unknown pathogenesis. The diagnosis is based on a set of international clinical criteria. Previous investigations have suggested that immunological cross-reactivity between peptides within streptococcal heat-shock proteins and human peptides might be involved in the pathogenesis of BD. We tested four peptides from mycobacterial heat-shock proteins to see if they specifically stimulated gamma delta T cells from BD patients. We then investigated this response to see whether it could be used as a laboratory test to diagnose BD.

METHODS

We used a T-cell proliferative test to assay responses to four mycobacterial 65 kDa heat-shock-protein peptides and to four homologous peptides derived from the sequence of the human 60 kDa heat-shock protein.

FINDINGS

We elicited significant gamma delta T-cell responses to the mycobacterial peptides in 25 (76%) of 33 patients with BD, compared with 2 (3.6%) of 55 controls with recurrent oral ulcers, systemic disease, or no disorders. The proportion of BD patients who had false-negative results decreased if the test was done during clinical manifestation of disease activity. There was a correlation between disease activity and T-cell responses. Four homologous peptides from human 60 kDa heat-shock protein also specifically stimulated T cells from patients with BD but with lower stimulation indices.

INTERPRETATION

Activation of peripheral-blood mononuclear cells with the four heat-shock-protein peptides elicited significant T-cell proliferative responses by the gamma delta subset of T cells, which may regulate alpha beta T cells. Because these peptides have a high specificity for BD, this assay can be used as a laboratory diagnostic test for BD.

Recurrent aphthous stomatitis. An update

Recurrent aphthous ulceration or recurrent aphthous stomatitis is the most common oral mucosal disease known to human beings. Despite much clinical and research attention, the causes remain poorly understood, the ulcers are not preventable, and treatment is symptomatic. The most common presentation is minor recurrent aphthous stomatitis: recurrent, round, clearly defined, small, painful ulcers that heal in 10 to 14 days without scarring. Major recurrent aphthous stomatitis lesions are larger (greater than 5 mm), can last for 6 weeks or longer, and frequently scar. The third variety of recurrent aphthous stomatitis is herpetiform ulcers, which present as multiple small clusters of pinpoint lesions that can coalesce to form large irregular ulcers and last 7 to 10 days. Diagnosis of all varieties is usually made after clinical examination. Many local and systemic factors have been associated with these conditions, and there is evidence that there may be a genetic and immunopathogenic basis for recurrent aphthous ulceration. Management of this condition depends on the clinical presentation and symptoms and includes analgesic, antimicrobial, and immunomodulatory drugs. As dental clinicians and researchers become better trained in oral medicine and stomatology, it is anticipated that the pathophysiology, prevention, and treatment of recurrent aphthous ulceration will improve in the future.

Recurrent aphthous ulceration in children--a review

The clinical presentation or recurrent aphthous ulceration in children is described together with current views on the aetiology and pathogenesis of the disease. Factors that predispose to this type of oral ulceration are discussed and a rational approach to the management of recurrent aphthous ulceration in children is proposed.

Increased production of tumour necrosis factor by peripheral blood leukocytes in patients with recurrent oral aphthous ulceration

Much evidence suggests that recurrent oral aphthous ulceration (RAU) is an immunologically mediated disease. Tumour necrosis factor has multiple biologic properties, some of which may be relevant to the pathogenesis of RAU. This study has assessed its production by peripheral blood leukocytes from aphthous patients in active and remission phases of disease and from patients with nonaphthous ulceration (diseased controls). Each ulcer patient was studied in parallel with a matched healthy control volunteer. A bioassay against the standard mouse fibrosarcoma line, L929, was used to assess the levels of tumour necrosis factor-alpha (TNF). Significantly greater amounts of TNF were released from unstimulated monocyte-enriched and monocyte-depleted leukocyte fractions in active RAU compared with those from healthy control donors, suggesting that this cytokine may be associated with RAU.

Peripheral lymphocyte subpopulations in recurrent aphthous ulceration

Peripheral lymphocyte subsets--T-helper (CD4+), T-suppressor/cytotoxic (CD8+), and naive/virgin T cells/natural killer cells (CD45RA)--were studied quantitatively in 30 patients with recurrent aphthous ulceration (RAU) and 29 sex- and age-matched RAU-free control donors. The CD4+ percentage was significantly lower in the patients than in the control group (P less than 0.0001), whereas CD8+ and CD4/CD8 ratio figures did not differ significantly between patients and controls. The CD45RA+ counts were significantly higher in the patient group (P less than 0.01). The study supports previous investigations with regard to the demonstration of immunologic disturbances in RAU patients. Whether the imbalance is primary or secondary with regard to the basic etiology remains to be resolved.

Treatment of aphthae with thalidomide

We report our experience in the treatment of major and minor aphthae with thalidomide. With doses of 100 to 300 mg daily for 3 months, a cure was obtained in 34% of cases, and marked improvement was evident in the rest. The follow-up period varied from 1 to 8 years. Two patients experienced dysesthesias, which disappeared when the medication was stopped. Thalidomide cannot be prescribed to women of childbearing potential because of its teratogenic potential.

Spontaneous migration and chemotactic activity of neutrophil polymorphonuclear leukocytes in recurrent aphthous ulceration

Chemotactic activity and spontaneous migration under agarose were assessed for peripheral blood neutrophil polymorphonuclear leukocytes from 22 patients with minor recurrent aphthous ulceration and 22 control subjects. The peptide N-formyl-L-methionyl-L-leucyl-L-phenylalanine was used as the standard chemotactic stimulus. Under the conditions of this study, no significant differences in either chemotaxis or spontaneous migration were evident between neutrophils from the patient and control groups.

The effects of a 0.2% chlorhexidine gluconate mouthrinse on plaque, toothstaining and candida in aphthous ulcer patients. A double-blind placebo-controlled cross-over study

Despite the known effectiveness of 0.2% chlorhexidine gluconate mouthwash in preventing plaque formation, relatively few studies have assessed adjunctive benefit to normal unsupervised oral hygiene measures. Furthermore, there have been few accurate measurements of toothstaining in the presence of normal oral hygiene and little data of effects on oral candidal carriage. This study was a double-blind placebo-controlled cross-over study of a 0.2% chlorhexidine gluconate mouthwash used 3 times daily on plaque, staining and candidal carriage in a group of recurrent aphthous ulcer suffers who maintained normal oral hygiene measures. At the end of 2 6-week treatment periods, baseline plaque scores were reduced by active and placebo mouthwashes. Chlorhexidine significantly reduced plaque compared to the placebo. Staining has markedly and significantly increased during chlorhexidine rinsing. Candidal carriage was present in 22.2% of this group and there was no significant effect of chlorhexidine on the mean number of candidal colonies. The distribution of plaque and staining by tooth was plotted and observationally studied. Baseline and placebo treatment plaque distributions indicated the considerable relevance of toothbrushing behaviour for plaque distribution. The effects of toothbrushing on plaque distribution were minimised during the use of chlorhexidine. Staining associated with chlorhexidine showed a distribution again suggesting the influence of toothbrushing. In conclusion, chlorhexidine has significant adjunctive effects on plaque inhibition in the presence of normal unsupervised oral hygiene, but toothbrushing did not prevent toothstaining.

Absence of circulating IgG immune complexes in minor recurrent aphthous ulceration

A monoclonal rheumatoid factor binding assay has been employed to detect IgG type immune complexes in sera from 21 patients with minor recurrent aphthous ulceration and 31 control subjects. In only one of the ulcer group patients was there a marginal elevation of immune complexes above the normal range, with no statistically significant difference between the patient and control groups. Assays of intrinsic serum rheumatoid factor and serum IgG, IgM and IgA levels also showed no significant differences between patient and control groups, with all mean values falling within the normal ranges.

Serum ferritin in recurrent oral ulceration

A sensitive radio-assay for ferritin was developed and used to examine serum ferritin levels in 105 patients with recurrent oral ulceration (ROU), 41 patients with Behçet's syndrome (BS), 42 with other ulcerative oral lesions, 35 patients with non-ulcerative oral lesions and in 78 controls. Ferritin levels increased with age and were significantly higher in males than females. The mean ferritin concentrations in male patients with ROU, BS or with other oral ulcers were significantly reduced in comparison with controls, and in female patients were significantly reduced in those with major aphthous ulcers. The prevalence of low serum ferritin levels was about 8% in patients with ROU, 15% in BS and 9.5% in patients with other ulcerative oral lesions, compared with less than 3% in patients with non-ulcerative oral disorders and in controls. Most of the iron-deficient patients were female. Serum ferritin levels did not directly correlate with serum iron levels and may be a more accurate indicator of iron deficiency. Furthermore, serum ferritin can distinguish between patients with true iron deficiency and those with secondary sideropenia. It is suggested that in a small number of patients, oral ulceration may be a presenting sign of iron deficiency, and that in a further small proportion of patients, ROU already present will be exacerbated by concurrent iron deficiency. Both groups will show a therapeutic response to correction of the iron deficiency. The results suggest that serum ferritin levels are a useful part of the haematological investigations in patients with ROU.

Immunological aspects of recurrent oral ulceration and Behçet's syndrome

Immunological factors play in recurrent oral ulceration (ROU) and Behçet's syndrome (BS) but these cannot be distinguished by means of antibodies and cell-mediated immune responses to oral mucosal antigens. However, HLA markers seem to differentiate ROU from BS. Immune complexes have now been found in about 55% of patients with BS and fewer patients with ROU, so that the transition from the focal ROU to the multifocal BS might be mediated by immune complexes. Immunopathological studies have shown that a vasculitis is the essential lesion in BS and this might be secondary to immune complexes inducing complement activation and damage. It is not clear at present whether the increased levels of C9 and C-reactive protein are a manifestation of acute phase reactants. C9 could be involved in complement dependent lysis and C-reactive protein in modulating the cell-mediated immune responses by its effect on T lymphocytes. It seems that at least two types of damaging immune mechanisms have been identified; cell-mediated and immune complex induced reactions and these might account for the association between ROU and BS.

Possibility of a viral etiology in recurrent aphthous ulcers and Behçet's syndrome

The clinical signs, laboratory data, and histological features of recurrent aphthous ulcers (RAU) and Behçet's syndrome suggest a viral etiology. In fact, there are reports of adenovirus isolations in herpetiform oral ulcers and on the isolation of a filterable agent in sporadic cases of Behçet's syndrome. However, isolation studies on the major and minor aphthous ulcers and more recent studies on Behçet's syndrome have been negative. A review of the literature on the role of viruses and autoimmunity in RAU and Behçet's syndrome is presented. Biopsy specimens of ulcerative lesions were grown in vitro for up to 300 days. Those cultures, along with leukocytes and body fluids, were examined by a variety of techniques for the presence of virus or viral antigens. Although a persistent or latent virus was not detected, these negative studies cannot exclude a viral etiology. In fact, the hypothesis of an infectious and viral etiology is still reasonable.

Nutritional deficiencies in recurrent aphthae

A series of 330 patients with recurrent aphthae was screened for deficiencies of iron, folate and vitamin B12. In 47 patients (14.2%) such deficiencies were found; 23 were deficient in iron, seven in folic acid, six in vitamin B12 and in addition 11 patients had combined deficiencies. Clinical examination of the aphthae was not helpful in identifying individual patients with a nutritional deficiency although patients with an associated glossitis or angular cheilitis were more likely to suffer from such deficiencies. Screening of the patients by examination of their peripheral blood alone (estimation of haemoglobin and absolute values, and blood film examination) detected only a proportion of those with deficiencies of iron or folic acid, although in this series such screening was able to identify the small number of cases with vitamin B12 deficiency. The 33 patients with a proven nutritional deficiency who were available for follow-up showed a favourable response to corrective therapy; 23 showed a complete remission of ulcers, 11 were improved and five were not helped. The significance of these findings is discussed. It is suggested that the results indicate the need for full haematological screening of all patients with recurrent aphthae.

[Inflammatory and systemic reactions of the mouth mucosa]

The field of oral medicine is fundamental to the practice of general medicine as well as dentistry, oral surgery, and other special fields of medicine concerned with diseases of organs beneath the oral cavity. Disorders of the oral mucosa may reflect many dermal and internal diseases, and may focus the physician's diagnostic attention to systemic pathological conditions which otherwise could be misdiagnosed. As to their morphological appearance, however, the oral mucosa shows other forms of reactivity than the skin. When the dermal and oral manifestations of many skin diseases are compared the influence of distinct local factors on the intraoral clinical picture becomes evident. This comparative view, as well as the dermatologist's practical experience that many dermatoses either spread to, or even are restricted to the oral mucosa, may explain why most dermatologists are very interested in oral diagnosis. In this report, the interdisciplinary view and some aspects of clinical stomatology are stressed which are of actual interest in oral diagnosis and therapy. The following topics are dealt with: Diseases with aphthous lesions, Allergic reactions to drugs, Pemphigus and pemphigoid disorders, Oral infections by Candida albicans, Melkersson-Rosenthal syndrome, Lingual anomalies of different types, Leukoplakias.