The purpose of this study is to determine the concentration of Rheumatic Factor (RF) and Anti-cyclic Citrullinated Peptide Antibody (ACPA) in serum and in Gingival Crevicular Fluid (GCF) and their dependence on the presence of periodontitis (P) and rheumatoid arthritis (RA). The study involved 81 patients divided into three groups: Group I – patients with P and without RA (with osteoarthritis) – 26 subjects; Group II – patients with P and RA – 30 subjects; Group III – patients with periodontal health (without P) and RA – 25 subjects. For all patients the levels of ACPA and RF (class IgM) have been analyzed by ELISA in serum and GCF. We found a significantly higher incidence of ACPA in the GCF positive individuals and significantly higher mean ACPA values in GCF in Group II patients compared to patients in Group I. We found a significant difference between the frequency of RF in the GCF positive patients in Group II compared to those in Group I as well as the RF in the GCF positive patients in Group II compared to those in Group III. In the study among the patients of Group II we found a significant correlation between the RF and ACPA concentrations in serum and the number of lost teeth. These results are associated with possible enhanced extraarticular synthesis of ACPA and RF in the periodontal tissues in patients with periodontitis and predisposed to RA. Evidence for the effect of RA on periodontitis is the correlation between the concentration of ACPA and RF in serum – biomarkers for RA and the number of lost teeth.

Bullous pemphigoid /BP/ is a chronic blistering disorder that can affect oral mucosa very rarely. This autoimmune disease typically has a gradual onset and a chronic progressive course with exacerbations and remissions. Against components located in the epithelial basement membrane are formed autoantibodies. It is important to perform an incisional biopsy to establish a definitive diagnosis. Direct immunofluorescent findings are identical in BMMP and BP. Indirect immunofluorescence shows circulating IgG antibodies against the components of basement membrane in the majority of cases with BP but very rarely in patients with BMMP. There is no correlation between antibody titer and disease severity in BP. The aim is to present a very rare case of bullous pemphygoid of oral mucosa histologically proved with immunostaining. We present a patient with clinically identified oral lesion-bullae with clear fluid content in buccal mucosa of maxilla. After the rupture of bullae it left painful, superficial, ulcerated areas of oral mucosa. Hystopathological examination revealed subepithelial blister formation with clean separation of the full thickness of the epithelium from the underlying connective tissue layer. Direct immunofluorescence revealed a continuous linear band of immunoreactants at the basement membrane area. This immune deposit consist mainly IgG and C3, localized in the basement membrane. Conclusion: The treatment depends on the severity of the disease, tendency of progression and the affected areas. Therefore the clinicians should thoroughly examine all mucosal sites in order to make a proper diagnosis. The chronically characteristic of this autoimmune disease can lead to significant morbidity to patients. The adverse effects from long-term use of corticosteroids and immunosuppressives agents can also contribute to morbidity. 1. INTRODUCTION Autoimmune diseases typically have a gradual onset and a chronic progressive course with exacerbations and remissions. Mucous membrane pemphigoid (cicatrial pemphigoid) and bullous pemphigoid represents a group of chronic, blistering, mucocutaneous autoimmune diseases in which tissue-bound autoantibodies are directed against components of the basement membrane of the epithelium. This condition has a heterogeneous origin, with autoantibodies being produced against any one of a variety of basement membrane components, all of which are with similar clinical manifestations. It is interesting that these oral lesions seldom exhibit tendency for scar formation [1-4]. Bullous pemphigoid (BP) and cicatrial pemphigoid(CP) have similar causes and microscopic features but a different distribution of lesions. The skin in all patients with BP demonstrates large thick-walled bullae, but oral mucosal lesions are less common [5, 6]. Bullous pemphigoid is the most common of the auto-immune blistering conditions, occurring at an estimated