Search

The importance of reactive oxygen species (ROS) in innate immunity was first recognized in professional phagocytes undergoing a 'respiratory burst'upon activation. This robust oxygen consumption is related to a superoxide-generating enzyme, the phagocytic NADPH oxidase (Nox2-based or phox). The oxidase is essential for microbial killing, since patients lacking a functional oxidase suffer from enhanced susceptibility to microbial infections. ROS derived from superoxide attack bacteria in the isolated niche of the neutrophil phagosome. The oxidase is electrogenic, alters ion currents across membranes, induces apoptosis, regulates cytokine production, influences gene expression, and promotes formation of extracellular traps. Recently, new homologues of Nox2 were discovered establishing the Nox family of NADPH oxidases that encompasses seven members. Nox1 is highly expressed in the colon epithelium, and can be induced by LPS or IFN- gamma. Nox4 was implicated in innate immunity since LPS induces Nox4-dependent ROS generation. Duox1 and Duox2 localize to the apical plasma membrane of epithelial cells in major airways, salivary glands, and the gastrointestinal tract, and provide extracellular hydrogen peroxide to lactoperoxidase to produce antimicrobial hypothiocyanite ions. Th1 and Th2 cytokines regulate expression of dual oxidases in human airways and may thereby act in host defense or in proinflammatory responses.

It was established that every patient carried out through the oral osteoplastic operation needs immunoprophylaxis to avoid postoperative complications. It doesn't depend on the initial level of the immunity. Asa casual prophylaxis Licopid is recommented. But only one prophylaxis willbenot enough if the anamnesis has any chronical oralfacial disease. The great attention should be taken to the immunocorrection.

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that cell-mediated immunological mechanisms are involved in pathogenesis. The objective of this study was to investigate the expression of CD44 isoforms including CD44s, CD44v5, and CD44v6 in biopsy specimens and saliva from OLP patients. Thirty-one OLP patients and 30 healthy subjects were enrolled in this study. Immunohistochemical methods were used to detect the expression of CD44 isoforms in oral epithelia, and enzyme-linked immunosorbent assay (ELISA) was performed to measure levels of salivary CD44 isoforms. Our results demonstrated that expression of CD44v6 in oral epithelia from OLP patients was significantly decreased in comparison to controls (p = 0.021). Levels of salivary CD44s and CD44v5 from OLP patients were significantly higher than those from controls (p = 0.007 and p = 0.002, respectively). In summary, our findings provided additional evidence that the pathological stress, such as chronic inflammation, altered the expression of CD44 isoforms in oral epithelia and saliva of OLP patients.

Background: Cow's milk allergy (CMA) is the most common food allergy in infants and young children, affecting 2% to 3% of the general population. Most studies have shown the prognosis of developing tolerance to cow's milk to be good, with most outgrowing their allergy by age 3 years., Objective: To define the natural course of CMA and identify the factors that best predict outcome in a large referral population of children with CMA., Methods: Clinical history, test results, and final outcome were collected on 807 patients with IgE-mediated CMA. Patients were considered tolerant after they passed a challenge or experienced no reactions in the past 12 months and had a cow's milk IgE (cm-IgE) level <3 kU/L., Results: Rates of resolution were 19% by age 4 years, 42% by age 8 years, 64% by age 12 years, and 79% by 16 years. Patients with persistent allergy had higher cm-IgE levels at all ages to age 16 years. The highest cm-IgE for each patient, defined as peak cm-IgE, was found to be highly predictive of outcome (P < .001). Coexisting asthma (P < .001) and allergic rhinitis (P < .001) were also significant predictors of outcome., Conclusion: The prognosis for CMA in this population is worse than previously reported. However, some patients developed tolerance during adolescence, indicating that follow-up and re-evaluation of CMA patients is important in their care. cm-IgE level is highly predictive of outcome., Clinical Implications: The increasing potential for persistence of CMA, along with cm-IgE level's effect on prognosis, should be considered when counseling families regarding expected clinical course.

We examined how dietary melibiose affected the T-helper (Th) cell responses induced by an orally fed antigen in ovalbumin (OVA)-specific T cell receptor transgenic mice (OVA 23-3). Dietary melibiose markedly decreased the Th2 type responses as shown by a significant decrease in the interleukin (IL)-4 production and T cell proliferative response induced by sensitization from the 7-d oral administration of OVA. It was additionally observed that the Th1 type responses tended to decrease. We therefore examined the effect of melibiose feeding on the induction of immunological tolerance induced by the oral administration of an antigen (oral tolerance). The Th cell responses induced in BALB/c mice by subcutaneous immunization with OVA were suppressed by the prior oral administration of OVA. Such responses in the OVA-fed and immunized mice were further diminished by dietary melibiose. These results suggest that dietary melibiose strongly affected the Th cell responses to an ingested antigen, and further demonstrate the potential of melibiose to enhance the induction of oral tolerance.

Primary infection of oral epithelial cells by HIV-1, if it occurs, could promote systemic infection. Most primary systemic infections are associated with R5-type HIV-1 targeting the R5-specific coreceptor CCR5, which is not usually expressed on oral keratinocytes. Because coinfection with other microbes has been suggested to modulate cellular infection by HIV-1, we hypothesized that oral keratinocytes may up-regulate CCR5 in response to the oral endogenous pathogen Porphyromonas gingivalis by cysteine-protease (gingipains) activation of the protease-activated receptors (PARs) or LPS signaling through the TLRs. The OKF6/TERT-2-immortalized normal human oral keratinocyte line expressed CXCR4, whereas CCR5 was not detectable. When exposed to P. gingivalis ATCC 33277, TERT-2 cells induced greater time-dependent expression of CCR5-specific mRNA and surface coreceptors than CXCR4. By comparing arg- (Rgp) and lys-gingipain (Kgp) mutants, a mutant deficient in both proteases, and the action of trypsin, P. gingivalis Rgp was strongly suggested to cleave PAR-1 and PAR-2 to up-regulate CCR5. CCR5 was also slightly up-regulated by an isogenic gingipain-deficient mutant, suggesting the presence of a nongingipain-mediated mechanism. Purified P. gingivalis LPS also up-regulated CCR5. Blocking TLR2 and TLR4 receptors with Abs attenuated induction of CCR5, suggesting LPS signaling through TLRs. P. gingivalis, therefore, selectively up-regulated CCR5 by two independent signaling pathways, Rgp acting on PAR-1 and PAR-2, and LPS on TLR2 and TLR4. By inducing CCR5 expression, P. gingivalis coinfection could promote selective R5-type HIV-1 infection of oral keratinocytes.

The normal flora of the head and neck exists in a delicate balance within tightly regulated ecologic niches, counterbalanced by a highly efficient innate immune system of the host. Invasion by the normal oral flora is rare when mucosal defenses remain intact. An understanding of the indigenous microflora and the innate mucosal defense mechanisms is necessary for an appropriate evaluation of infections and therapies in this area.

Cystic fibrosis (CF) patients who are chronically infected with Pseudomonas aeruginosa make serum antibodies to bacterial surface LPS as well as other pseudomonas antigens. This study investigated the feasibility of using oral fluid samples for the detection of pseudomonas antibodies in CF patients and compared these results with corresponding serum antibodies. Most strains of P. aeruginosa produce two forms of LPS molecule, termed A-band (described as a common antigen) and B-band (O-serotype-specific antigen), apparently bound to a common core oligosaccharide moiety. A-band LPS was demonstrated in 45 out of 49 clinical isolates of P. aeruginosa by SDS-PAGE and immunoblotting with a specific antibody. Oral fluids were collected from 17 adult CF patients, all of whom were sputum culture positive for P. aeruginosa (13 also provided serum samples), 11 primary ciliary dyskinesia (PCD) patients and 37 healthy volunteers. Antibodies to A-band LPS were detected by immunoblotting in all of the CF patients' oral fluids but 10 of the volunteer samples gave weak reactions with immunoblotting. Six of the PCD patients gave a weak reaction with A-band antibodies and only one demonstrated antibodies to core LPS. In a quantitative ELISA, 15 of the 17 CF patients' oral fluids were shown to contain antibodies to A-band LPS, whilst none of the volunteer samples contained antibodies to A-band LPS. All serum samples from the CF patients were positive by both methods. Thus this is a sensitive procedure for the detection of antibodies to A-band LPS of P. aeruginosa in oral fluid and serum from patients with CF.

Histo-blood group antigen (HBGA) phenotypes have been associated with susceptibility to human noroviruses (HuNoVs). Our aims were: (i) to determine the patterns of A/H HBGA expression in buccal and intestinal tissues of gnotobiotic (Gn) pigs; (ii) to determine if virus-like particles (VLPs) of HuNoV genogroup I (GI) and GII bind to A- or H-type tissues; (iii) to compare A/H expression and VLP binding patterns and confirm their binding specificities by blocking assays; (iv) to develop a hemagglutination inhibition test using buccal cells from live pigs to determine the Gn pig's A/H phenotype and to match viral strains with previously determined HuNoV VLP binding specificities; and (v) to determine the A/H phenotypes and compare these data to the infection outcomes of a previous study of 65 Gn pigs inoculated with HuNoV GII/4 strain HS66 and expressing A and/or H or neither antigen on their buccal and intestinal tissues (S. Cheetham, M. Souza, T. Meulia, S. Grimes, M. G. Han, and L. J. Saif, J. Virol. 80:10372-10381, 2006). We found that the HuNoV GI/GII VLPs of different clusters bound to tissues from four pigs tested (two A+ and two H+). The GI/1 and GII/4 VLPs bound extensively to duodenal and buccal tissues from either A+ or H+ pigs, but surprisingly, GII/1 and GII/3 VLPs bound minimally to the duodenum of an A+ pig. The VLP binding was partially inhibited by A-, H1-, or H2-specific monoclonal antibodies, but was completely blocked by porcine mucin. Comparing the A/H phenotypes of 65 HS66-inoculated Gn pigs from our previous study, we found that significantly more A+ and H(+) pigs (51%) than non-A+ and non-H+ pigs (12.5%) shed virus. From the 22 convalescent pigs, significantly more A+ or H+ pigs (66%) than non-A+ or H+ pigs (25%) seroconverted.

Toll-like receptor (TLR) family members are pattern-recognition receptors and very important molecules in innate immunity. Although TLRs are originally type I transmembrane receptors, soluble forms of TLRs are detected in human plasma and milk. This study showed that soluble TLR2 (sTLR2) is detected in human parotid saliva. Western blotting with anti-TLR2 antibodies (Abs) showed that three polypeptides are detected as sTLR2 with molecular weights of 55, 40 and 27kDa, respectively. Parotid saliva neutralized the binding of anti-TLR2 polyclonal Ab to cell-surface TLR2 on THP-1, a human monocytic cell line. Immunohistochemical analysis revealed that TLR2 is expressed in serous and interlobular ductal cells of human salivary gland. Human salivary gland cell lines, AZA3 and HSY, constitutively expressed TLR2. Parotid saliva augmented IL-8 production of THP-1 cells stimulated with a synthetic TLR2 ligand, Pam(3)Cys-Ser-(Lys)(4) (Pam(3)CSK(4)). Depletion of sCD14 from parotid saliva by immunoprecipitation eliminated the augmentation of IL-8 production, indicating that the augmentable effects depended on sCD14 in parotid saliva. On the other hand, preincubation of Pam(3)CSK(4) with parotid saliva abrogated the augmentation of IL-8 production, indicating that sTLR2 in saliva bound to Pam(3)CSK(4) and neutralized its function. These results suggest that parotid saliva modulates the TLR2-mediated immune responses with binary mechanisms via sTLR2 and sCD14 in the oral cavity.

Human saliva not only lubricates the oral cavity, making possible functions such as swallowing and speaking, but it also helps to maintain integrity of the hard tissues of the teeth. In addition to secretory immunoglobulins saliva contains several less specific antibacterial systems. This innate defense system includes: lysozyme, lactoferrin, peroxidase system, histatins, mucins, and other polypeptides with basic side chains. Some proteins of innate defense system have bactericidal or bacteriostatic effects; some can cause aggregation of oral bacteria resulting in their increased clearance from oral cavity.

Objective: It is known that immune functions are altered in various ways by obesity. However, changes in the intestinal immune system resulting from obesity remain poorly understood. Oral tolerance is a system that suppresses antigen specific immune responses to orally administrated antigens. The intestinal immune system is intimately associated with the oral tolerance system, that acts to prevent allergic and inflammatory diseases. In this study we investigated the effect of obesity on induction of oral tolerance to ovalbumin (OVA) in an animal model of obesity., Research Methods and Procedures: Obese mice induced by a high fat diet and control mice were allowed free access for 3 days to a 1%-ovalbumin (OVA) solution in drinking water. After continuous feeding of the antigen, all the mice were immunized by two intraperitoneal injections of OVA administered 7 days apart., Results: In the control mice, induction of oral tolerance caused an increase in antigen specific IgG1 levels and a decrease in IgG2a levels. In contrast, the IgG1/IgG2a ratio was reversed in obese mice. OVA-specific IL-2 production was suppressed by antigen feeding in both the control and obese mice; however, suppression of OVA-specific IL-10 was observed only in the control mice. Although OVA-specific IgA and IgM were not affected by antigen feeding, the obese groups of mice had significantly lower titers of antibodies., Discussion: These findings suggest that obesity may affect induction of oral tolerance following antigen feeding and that these changes may be related to the inflammatory reaction.

Signaling of RANK (receptor activator of nuclear factor kappa B) through its ligand RANKL appears critical in osteolysis associated with aseptic loosening (AL). The purpose of this study was to investigate the role of RANK in a murine osteolysis model developed in RANK knockout (RANK(-/-)) mice. Ultra high molecular weight polyethylene (UHMWPE) debris was introduced into established air pouches on RANK(-/-) mice, followed by implantation of calvaria bone from syngeneic littermates. Wild type C57BL/6 (RANK(+/+)) mice injected with either UHMWPE or saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Results showed that UHMWPE stimulation induced strong pouch tissue inflammation in RANK(-/-) mice, as manifested by inflammatory cellular infiltration, pouch tissue proliferation, and increased gene expression of IL-1beta, TNFalpha, and RANKL. However, the UHMWPE-induced inflammation in RANK(-/-) mice was not associated with the osteoclastic bone resorption observed in RANK(+/+) mice. In RANK(+/+) mice subjected to UHMWPE stimulation, a large number of TRAP(+) cells were found on the implanted bone surface, where active osteoclastic bone resorption was observed. No TRAP(+) cells were found in UHMWPE-containing pouch tissues of RANK(-/-) mice. Consistent with the lack of osteoclastic activity shown by TRAP staining, no significant UHMWPE particle-induced bone resorption was found in RANK(-/-) mice. A well preserved bone collagen content (Van Gieson staining) and normal plateau surface contour [microcomputed tomography (microCT)] of implanted bone was observed in RANK(-/-) mice subjected to UHMWPE stimulation. In conclusion, this study provides the evidence that UHMWPE particles induce strong inflammatory responses, but not associated with osteoclastic bone resorption in RANK(-/-) mice. This indicates that RANK signaling is essential for UHMWPE particle-induced osteoclastic bone resorption, but does not participate in UHMWPE particle-induced inflammatory response.

Background: The Whey Acidic Protein domain is an evolutionarily conserved motif found in a number of proteins, the best studied of which are antiproteinases involved in the innate immune defence of multiple epithelia. We recently characterised the WFDC2 gene which encodes a two WAP domain-containing protein, initially suggested as a marker for epididymis, and showed that it is highly expressed in the lung and salivary gland. The precise location of WFDC2 protein in these sites has not been described., Methods: We used immunohistochemistry to localise WFDC2 in normal tissues of the respiratory tract, naso- and oropharynx, as well as in chronically inflamed lung from Cystic Fibrosis and a range of pulmonary carcinomas. We have complemented these studies with molecular analysis of WFDC2 gene expression in primary human lung cell cultures., Results: WFDC2 is expressed in some epithelial cells of the upper airways as well as in mucous cells and ducts of submucosal glands. No staining was seen in peripheral lung. Intense staining is found in major salivary glands and in minor glands of the nose, sinuses, posterior tongue and tonsil. Studies with the related protein Secretory Leukocyte Protease Inhibitor (SLPI) show that although both proteins are expressed in similar tissues, the precise cellular localisation differs. Significant increases in expression and localisation of WFDC2 are seen in patients with Cystic Fibrosis. SLPI expression was greatly reduced in the same samples. In cultures of tracheobronchial epithelial cells, expression of WFDC2 and SLPI are differentially regulated during differentiation yet WFDC2 is not induced by pro-inflammatory mediators. The majority of adenocarcinomas stain with WFDC2 whilst a significant minority of squamous, small cell and large cell carcinomas exhibit focal staining. There is no clear association with tumour grade., Conclusion: We believe that these studies support the hypothesis that WFDC2 may be a component of the innate immune defences of the lung, nasal and oral cavities and suggest that WFDC2 functions in concert with related WAP domain containing proteins in epithelial host defence. We also suggest that WFDC2 re-expression in lung carcinomas may prove to be associated with tumour type and should be studied in further detail.

Feeding myelin oligodendrocyte glycoprotein (MOG) followed by immunization results in induction of oral tolerance evidenced by the amelioration of experimental autoimmune encephalomyelitis (EAE). Oral tolerization is characterized by the suppression of Th1 responses and up-regulation of Th2 responses and TGF-beta. To identify the costimulatory molecules and cell types involved in cytokine-mediated suppression we examined wild type mice and mice deficient for either CD86 (CD86-/-) or B cells (muMT). Oral tolerance was found in CD86-/- mice evidenced by amelioration of disease severity, decreased proliferative responses and IFN-gamma production and increased IL-4. TGF-beta was not up-regulated in CD86-/- or muMT mice but was increased in wild type mice. Analysis of the gut associated lymphoid tissue (GALT) of different mouse strains (C57BL/6 and PLJxSJL F1) fed distinct myelin antigens (MOG and myelin basic protein, MBP) showed that TGF-beta was increased in wild type mice of both strains by 3 days post-immunization and further increased with time. In contrast, no up-regulation of TGF-beta was found in the GALT of CD86-/- or muMT mice. These results demonstrate that CD86 is not required for oral tolerization and that both CD86 and B cells are important for the up-regulation of TGF-beta following oral antigen.

Antimicrobial peptides or host defence peptides are endogenous peptide antibiotics, which have been confirmed as an essential part of the immune system. Apart from direct killing of bacteria, a role for the peptides in antiviral and immunomodulatory functions has recently been claimed. In this chapter we have focused on the host contact with microbes, where these host defence peptides are key players. The interplay with commensals and pathogens in relation to antimicrobial peptide expression is discussed, with specific emphasis on the respiratory and the alimentary systems. A possible novel difference in epithelial interactions between commensals and pathogens is considered in relation to disease.

Introduction: The aim of this work was to evaluate the influence of HIV infection on the catabolism of glycoconjugates in oral cavity, by determination the activity of lysosomal exoglycosidases in resting whole saliva HIV positive patients., Material and Methods: Sample of resting whole saliva from HIV infected patients (divided into two groups, depending on lymphocyte CD4+ number in peripheral blood) and the control-HIV negative group were analyzed for exoglycosidases activity. Determinations the activities (muKat/kg of protein) of lysosomal exoglycosidases were performed according to Chatteriee et al., modified Zwierz et al. The protein content (mg/ml) was determined by the Lowry method. Statistical analysis was performed using packet Statistica 6.0. Results were expressed as the mean and SD. P values less than 0.05 were considered significant., Results: Exoglycosidases activities were not statistically dependent on immunological status of HIV patients. We obtained insignificant increase activities of HEX, HEX A and GALp and insignificant decrease activity of HEX B along with the reduction of the CD4+ number. In both HIV positive groups the activities of HEX B were statistically lower and GALp statistically higher in comparison to the control. In the case of HEX A significant differences could be observed between patients with low immunological status and the control group., Conclusions: HIV infection intensifies catabolism glycoconiugates in saliva and changes activities of HEX, its isoenzymes A and B and beta-galactosidase. It may change susceptibility the cells lining oral cavity to viral and bacterial infections.

Despite structural and functional differences between the initial sites of contact with allergens in the gastrointestinal and nasal tracts, few animal models have examined the influence of the mucosal routes of sensitization on host reactivity to food or environmental antigens. We compared the oral and nasal routes of peanut sensitization for the development of a mouse model of allergy. Mice were sensitized by administration of peanut proteins in the presence of cholera toxin as adjuvant. Antibody and cytokine responses were characterized, as well as airway reactivity to nasal challenge with peanut or unrelated antigens. Oral sensitization promoted higher levels of IgE, but lower IgG responses, than nasal sensitization. Both orally and nasally sensitized mice experienced airway hyperreactivity on nasal peanut challenge. The peanut challenge also induced lung eosinophilia and type 2 helper T-cell-type cytokines in orally sensitized mice. In contrast, peanut challenge in nasally sensitized mice promoted neutrophilia and higher levels of lung MAC-1(+) I-A(b low) cells and inflammatory cytokines. In addition, nasal but not oral, sensitization promoted lung inflammatory responses to unrelated antigens. In summary, both oral and nasal peanut sensitization prime mice for airway hyperreactivity, but the initial mucosal route of sensitization influences the nature of lung inflammatory responses to peanut and unrelated allergens.

Background: Recently allergic reactions to legumes mediated by Bet v 1-homologous food allergens were described for soy and peanut. In this study we assessed allergic reactions to another legume, to mungbean seedlings, and identified its Bet v 1-homologous allergen Vig r 1., Methods: Ten patients were selected who had a history of allergic reactions to mungbean seedlings and a respiratory allergy to birch pollen. The Bet v 1 homologue in mungbean seedlings, Vig r 1, was cloned by a PCR strategy, expressed in Escherichia coli, and purified by preparative SDS-PAGE. In all sera, specific IgE against birch pollen, Bet v 1, Bet v 2, Vig r 1, and the Bet v 1 homologues in soy (Gly m 4) and cherry (Pru av 1) was determined by CAP-FEIA. Cross-reactivity of specific IgE with Vig r 1, Bet v 1, Gly m 4, and Pru av 1 was assessed by immunoblot inhibition. Expression of Vig r 1 during development of mungbean seedlings and under wounding stress was analysed by immunoblotting. The Vig r 1 double band was analysed by matrix-assisted laser desorption/ionization time-of-flight and liquid chromatography/tandem mass spectrometry (LC/MS/MS)., Results: All patients were sensitized to birch pollen and Bet v 1, 20% to Bet v 2, and 90% to Gly m 4. Seventy percent of the patients showed IgE binding to a double band at 15 kDa in mungbean extract that was inhibited after pre-incubation of sera with rBet v 1. PCR cloning revealed that the mungbean homologue of Bet v 1 had a molecular weight of 16.2 kDa, a calculated pI of 4.6% and 42.8% amino acid sequence identity with Bet v 1. MS analysis confirmed similarity of the double band with the deduced Vig r 1 sequence, but also indicated the existence of other Vig r 1 isoforms. ImmunoCAP analysis detected IgE against Vig r 1 in 80% of the sera. IgE binding to Vig r 1 was inhibited with Gly m 4 in six of six and with rPru av 1 in four of six patients. Vig r 1 expression occurred during development of seedlings and was increased by wounding stress., Conclusions: Food allergy to mungbean seedlings can be caused by primary sensitization to birch pollen and is mediated by Vig r 1 in the majority of the patients with birch pollen-related allergy to mungbean seedlings.

On the basis of the data of immunological investigations of 142 workers of metallurgical (melting shops of Zestaphoni's Farroalloy Plant) and chemical (electrolytic shops of manganese and dioxide manganese of Farroalloy Plant and "Azoti") production it was found that during parodontitis among studied contingent local resistance of mouth cavity and humoral immunity are changed, the compound of lysozyme and amylase in saliva is lowered, in the layers of saliva and blood is revealed the misbalance of immunoglobulin's system. First of all was established, that during parodontitis among the studied workers autoimmune processes are developed directed against the I-st type collagen and the tissue of gum. Changes of local and common homeostasis as well as the changes of intensity of autoimmune process are in direct correlation with the severity of parodontitis and the pollution of production environment with the spray of manganese dioxide.

Viral coinfection in the oral cavity associated to HIV infection was evaluated in 180 children from birth to 13 years of age of both sexes. The oral examinations were performed at the Pediatric AIDS Outpatient Clinic, São Lucas Hospital and Clinic Hospital, both in Porto Alegre, Brazil and at the School of Dental Medicine, University Hospital Center, State University of New York at Stony Brook, USA. The aim of this study was to identify the presence of viral infections in the oral cavity. PCR technique was used to determine opportunistic viral infections caused by CMV, EBV, and HSV in mucosal swabs. A high frequency of viral infection was detected in the oral cavity of HIV-infected children determined by the PCR technique. HIV-infected children with viruses had a favorable CD4+ T lymphocyte count and unfavorable viral load.

Background: Oral allergy syndrome (OAS) is often associated with pollen-induced rhinitis, and there are preferential associations between causative substances. If OAS and rhinitis are both immunoglobulin (Ig)E-mediated and there are cross-reacting proteins, it is expected that similar reactions can be elicited in the nose and mouth. In order to test this hypothesis we performed a series of 'cross-challenges' with foods and pollens in both the nose and the mouth., Methods: Nine patients with ascertained OAS due to vegetables and rhinitis due to pollens were studied. On the first day a nasal challenge with pollen extracts and an oral challenge with fresh food was carried out. After a week, washout nasal challenge with food and an oral challenge with pollens were performed. Immediate symptoms, mucosal tryptase and soluble eosinophil cationic protein (ECP) were assessed after each challenge., Results: The administration of pollen into the nose and food into the mouth elicited symptoms as expected, but the cross-challenge had no clinical effect. In parallel, tryptase and ECP increased after nasal challenge with pollens, whereas foods did not elicit a measurable response., Conclusion: The cross-reactivity between foods and pollens, when evaluated at the shock organ, was not clinically evident. This data can be explained with a low concentration of cross-reagent epitopes in pollen extracts and food homogenized because of degradation. The different behaviour upon challenge suggests that different immunological mechanisms may act in the nose and mouth.

Unlabelled: Geographic position and local plants of the country influence the profile of sensitization of the population to airborne allergens. The aim of this study was to evaluate the sensitization pattern to pollen and food allergens in adult patients with pollinosis in Lithuania. 101 patients (age 16-63 years) suffering from seasonal allergic rhinitis and 23.8% of them also diagnosed with concomitant seasonal asthma were investigated. Oral allergy syndrome (OAS) was diagnosed in 29.7% of cases. The sensitization to 21 species of tree-, grass- and weed-pollen and plant food allergens was determined by positive skin prick and prick-prick test. In serum levels of total IgE and timothy and orchard grass specific IgE were determined by immunoenzyme assay. 52.5% of patients suffered from spring-summer pollinosis. 91.2% of patients were sensitized to grass-pollen allergens, 79.3% -to tree pollen-allergens. 74.7% of patients were allergic to weeds. Pollinosis starting in the spring and lasting more than sixteen weeks was associated with increased probability of OAS (OR=7.1, p<0.001 and OR=3.1, p=0.01). Sensitization to hazelnut (OR=8.6, p=0.009), birch (OR=9.6, p=0.07), lamb's quarters (OR=5.2, p=0.04) allergens and twofold and more increase in serum IgE (OR=4.8, p=0.03) were considered the significant risk factors for pollinosis with OAS. More than two times elevated serum IgE increased the probability of seasonal asthma (OR=3.4, p=0.03). Sensitization to ragweed was associated with decreased risk for asthma (OR=0.26, p=0.03)., Conclusions: Our data indicate that more than a half of patients (52.5%) had pollinosis symptoms during spring and summer seasons because of multiple sensitivity to pollen allergens. Sensitization to hazelnut, birch, lamb's quarters allergens, more than two times elevated serum IgE are significant risk factors for pollinosis with OAS. More than two times elevated serum IgE increased the probability of seasonal asthma, but sensitization to ragweed was associated with decreased risk for pollinosis with asthma.

Intraepithelial lymphocytes (IELs) are considered to drive immune surveillance of the epithelial layer to the mucosa, which is initially exposed to exogenous antigens. However, how IELs are activated by orally administered antigens remains unclear. To clarify this mechanism, we fed ovalbumin (OVA) to T cell receptor transgenic (TCR-Tg) mice with OVA-specific MHC class II-restricted TCR and found that the cytotoxic activity of IELs was increased against both NK and LAK target cells, but notably reduced after depleting CD8 + IELs. Cytoplasmic staining showed that the production of IFN-gamma and IL-2 was increased in mice fed with OVA both in the supernatant of cultured IELs with immobilized anti-CD3 mAb and in fresh CD4+ IELs. In contrast, the cytotoxic activity against NK and LAK target cells and the production of IL-2 and IFN-gamma was decreased in splenic T cells from mice fed with OVA. However, when the splenic T cells from these mice were cultured with OVA and IL-2, IFN-gamma production recovered. The decreased response demonstrated the clonal anergy of T cells. Furthermore, tumor growth was enhanced in TCR-Tg mice carrying an OVA-transfected counterpart A20 B cell lymphoma (OVA-A20) and fed with OVA. These results indicate that the oral administration of soluble antigens can activate CD4+ IELs in an antigen-specific manner but induces hyporesponsiveness in the spleen. In addition, Th1-type cytokines produced by activated CD4+ IEL might provide a bystander effect on the cytotoxic activity of IELs.

It remains unclear how and where unresponsiveness to fed antigens is induced. This "oral tolerance" is probably necessary to prevent the array of immune effector mechanisms required to counteract pathogens of the mucosae from being misdirected against food antigens or commensal flora. It will obviously be important to dissect where, when, and how such immunological homeostasis is maintained in the gut, but it will also be necessary to determine whether similar inductive and effector mechanisms are required for the therapeutic applications of oral tolerance systemically. This may be influenced by anatomical and microenvironmental effects on the phenotype and/or activation state of the antigen-presenting cell (APC), which presents orally delivered antigen. Fed antigen passes from the intestinal lumen either via the villus epithelium and M cells in the Peyer's patches (PP) or the mucosal lamina propria to the organized lymphoid tissues of the PP and mesenteric lymph nodes (MLN). In addition, there is evidence that mucosally administered antigen also gains access directly to peripheral lymphoid organs. Each of these sites contains distinctive populations of APCs and has unique local microenvironments that may influence the immune response in different ways. We propose that feeding antigen in high doses may induce clonal anergy, deletion, or altered differentiation because it gains direct access to resting APCs in the T cell areas of both the gut-associated lymphoid tissues (GALT) and peripheral lymphoid organs, with presentation occurring in the absence of productive costimulation. By contrast, low doses of tolerizing antigen may be taken up and presented preferentially by APCs in the GALT, where the local environment may favor the induction of regulatory T cells. This is consistent with our own and others findings, using adoptive transfer of TcR tg T cells. These studies have shown that antigen-specific CD4(+) T cells are activated simultaneously in all peripheral and gut-associated lymphoid organs after feeding high doses of proteins, but that this may be more restricted to local tissues when lower doses are used. Another level of anatomical control is imposed within lymphoid organs, where migration of T cells through distinct anatomical compartments can affect their differentiation. We find that, in contrast to orally primed T cells, orally tolerized T cells are unable to migrate into B cell follicles during their initial exposure to antigen. This affects their differentiation as upon subsequent challenge with antigen in adjuvant, tolerized T cells can be found in follicles but are unable to provide the B cell help that primed T cells can deliver. We hypothesize that the initial defective migration of tolerized T cells prevents them from receiving signals from antigen-specific B cells in follicles and results in abortive differentiation. Thus, both gross and fine anatomical location of fed antigen presentation may be important in mucosal immunoregulation.

Oral tolerance was first detailed almost 100 years ago, and since then, it has been shown repeatedly that feeding a wide variety of nonpathogenic antigens can inhibit subsequent systemic immune responses. All systemic immune responses are susceptible, but the degree and scope of the suppression depends on the nature and dose of the fed antigen. Oral tolerance has been described in most mammals, including humans, and it may be the homeostatic mechanism that prevents hypersensitivity to food antigens, as is found in celiac disease. A similar process may prevent the aberrant immune responses to commensal bacteria that occur in inflammatory bowel disease. The ability of oral tolerance to modulate experimental models of autoimmune and inflammatory disease has led to clinical trials in such diseases as rheumatoid arthritis, multiple sclerosis, and type I diabetes, with only variable success. Despite intense research, the exact mechanisms responsible for the systemic tolerance and the reasons why tolerance is the default response to many fed antigens remain controversial. Early studies suggested that CD8(+) "suppressor" T cells were important, but it is now accepted that it may involve either anergy/deletion of CD4(+) T cells, or the induction of regulatory CD4(+) T cells that produce IL-10 and/or TGFbeta. There may also be a role for CD4(+) CD25(+) T(reg), but how and when all these different mechanisms operate is still unclear. The ability of fed antigens to induce tolerance probably reflects their uptake by "quiescent" antigen-presenting cells in the intestine, with presentation to specific CD4(+) T cells in the absence of costimulation, or with the involvement of inhibitory costimulatory molecules. Dendritic cells in the Peyer's patches or mucosal lamina propria are the most likely APCs involved, but it remains to be determined exactly where these interactions occur and what the precise nature of the relevant dendritic cells is.

The innate immune response is of pivotal importance in defending the mucosal barriers of the body against pathogenic attack. The list of proteins that contribute to this defense mechanism is constantly being updated. In this review we introduce a novel family of secreted proteins, palate, lung, and nasal epithelium clones (PLUNCs), that are expressed in the mouth, nose and upper airways of humans, mice, rats and cows. In humans, PLUNC genes are located in a compact cluster on chromosome 20, with similar loci being found in synteneic locations in other species. The protein products of this gene cluster are predicted to be structural homologues of the human lipopolysaccharide binding proteins, lipopolysaccharide binding-protein (LBP) and bacterial permeability-increasing protein (BPI), which are known mediators of host defense against Gram-negative bacteria. On the basis of these observations we outline why we believe PLUNC proteins mediate host defense functions in the oral, nasal and respiratory epithelia.

The alanine-rich repeating region (A-region) in the surface protein antigen (PAc) of Streptococcus mutans has received much attention as an antigenic component for vaccines against dental caries. The PAc (residue 361-386) peptide in the A-region possesses a multiple binding motif (L- -V-K- -A) to various HLA-DR molecules and a B-cell core epitope (- Y- - -L- -Y- - - -) that recognizes the inhibiting antibody to S. mutans. In the present study, we investigated the immunogenicity of the PAc (361-386) peptide in humans and regulators of induction of the anti-PAc (361-386) peptide IgA antibody (aPPA) in saliva. The PAc (361-386) peptide was confirmed as an ideal peptide antigen for induction of the inhibiting antibody to S. mutans in 151 healthy human subjects (36.6 +/- 12.6 years old) by quantitative analyses of oral bacteria and ELISA, as the aPPA titre in human saliva decreased significantly in an age-dependent manner. Homozygous DRB1*0405 and 1502, and heterozygous DRB1*0405/1502 showed a negative association with production of aPPA and tended to reduce the number of total streptococci in saliva. In contrast, the DRB1*1501 allele was significantly correlated with a high level of induction of the antibodies, and also tended to reduce lactobacilli and mutans streptococci. Further, peptide immunogenicity was confirmed in NOD-SCID mice grafted with human peripheral blood mononuclear cells. Our results indicate that the interplay between regulators such as age, DRB1 genotype, cytokines, and peptide immunogenicity may provide a potential means for developing a vaccine useful for the prevention of dental caries as well as their diagnosis.

The mouths of three human infants were examined from birth to age 2 years to detect colonization of Actinomyces naeslundii genospecies 1 and 2. These bacteria did not colonize until after tooth eruption. The diversity of posteruption isolates was determined by ribotyping. Using immunoblotting and enzyme-linked immunosorbent assay, we determined the reactivity of secretory immunoglobulin A (SIgA) antibodies in saliva samples collected from each infant before and after colonization against cell wall proteins from their own A. naeslundii strains and carbohydrates from standard A. naeslundii genospecies 1 and 2 strains. A. naeslundii genospecies 1 and 2 carbohydrate-reactive SIgA antibodies were not detected in any saliva sample. However, SIgA antibodies reactive with cell wall proteins were present in saliva before these bacteria colonized the mouth. These antibodies could be almost completely removed by absorption with A. odontolyticus, a species known to colonize the human mouth shortly after birth. However, after colonization by A. naeslundii genospecies 1 and 2, specific antibodies were induced that could not be removed by absorption with A. odontolyticus. Cluster analysis of the patterns of reactivity of postcolonization salivary antibodies from each infant with antigens from their own strains showed that not only could these antibodies discriminate among strains but antibodies in saliva samples collected at different times showed different reactivity patterns. Overall, these data suggest that, although much of the salivary SIgA antibodies reactive with A. naeslundii genospecies 1 and 2 are directed against genus-specific or more broadly cross-reactive antigens, species, genospecies, and possibly strain-specific antibodies are induced in response to colonization.

We evaluated the relationships between oral and pharyngeal hypersensitivity to fruits and vegetables (oral allergy syndrome) and birch pollinosis in 2003 in Sapporo. 1. Of 153 patients with birch pollinosis (seasonal nasal or ocular symptom and CAP positive [birch pollen CAP score 2 or more]), 65 patients (42%) have episode of oral allergy syndrome (OAS). And that rate in 2003 was higher than in 1992 and was equal to in 1998. 2. Among birch pollinosis patients, the higher the CAP score of birch pollen, the higher the prevalences of OAS were found to be. 3. Among birch pollinosis patients, female have OAS much more than male. 4. Among birch pollinosis patients in 1998, patients who visited to ENT clinic for medical consultation of birch pollinosis in March and April have OAS much more than patients who visited in May and June.

Oral health is influenced by oral microbial flora, which are concentrated in dental plaque. Dental plaque provides a microhabitat for organisms and an opportunity for adherence of the organisms to either the tooth surface or other microorganisms. In critically ill patients, potential pathogens can be cultured from the oral cavity. These microorganisms in the mouth can translocate and colonize the lung, resulting in ventilator-associated pneumonia. The importance of oral care in the intensive care unit has been noted in the literature, but little research is available on mechanical or pharmacological approaches to reducing oral microbial flora via oral care in critically ill adults. Most research in oral care has been directed toward patients' comfort; the microbiological and physiological effects of tooth brushing in the intensive care unit have not been reported. Although 2 studies indicated reductions in rates of ventilator-associated pneumonia in cardiac surgery patients who received chlorhexidine before intubation and postoperatively, the effects of chlorhexidine in reducing ventilator-associated pneumonia in other populations of critically ill patients or its effect when treatment with the agent initiated after intubation have not been reported. In addition, no evaluation of the effectiveness of pharmacological and mechanical interventions relative to each other or in combination has been published. Additional studies are needed to develop and test best practices for oral care in critically ill patients.

Avid mouthing, the propensity of infants to suck objects and put them in their mouths, is a pattern characteristic of the first 2-3 years of life, with its most intensive manifestation occurring during the first year. Although traditional accounts explain infant mouthing as a source of sensual gratification and/or environmental exploration, these proximate hypotheses are inconsistent with the high costs of mouthing, including choking, poisoning, and exposure to pathogens. We propose that mouthing serves to proactively expose the naive gastrointestinal tract to environmental antigens and commensal bacteria while under the sheltering umbrella of breastfeeding. Mouthing functions to accurately calibrate the developing immune system, including antibody production and mucosal immunity, to the local disease ecology. The critical exposure period is not open-ended, as failure to expose the gut to an adequate number of antigens early in life is associated with an increased risk of allergies, asthma, and atopy. Weaning initiates a number of immune changes that may program the neonatal immune system into certain life-long responses.

Antimicrobial peptides (AMPs) are components of complex host secretions, acting synergistically with other innate defence molecules to combat infection and control resident microbial populations throughout the oral cavity and respiratory tract. AMPs are directly antimicrobial, bind lipopolysaccharide (LPS) and lipoteichoic acid, and are immunomodulatory signals. Pathogenic and commensal organisms display a variety of resistance mechanisms, which are related to structure of cell wall components (e.g. LPS) and cytoplasmic membranes, and peptide breakdown mechanisms. For example, LPS of the AMP-resistant cystic fibrosis pathogen Burkholderia cepacia is under-phosphorylated and highly substituted with charge-neutralising 4-deoxy-4-aminoarabinose. Additionally, host mimicry by addition of phosphorylcholine contributes to resistance in oral and respiratory organisms. Porphyromonas gingivalis, Pseudomonas aeruginosa and other pathogens produce extracellular and membrane-bound proteases that degrade AMPs. Many of these bacterial properties are environmentally regulated. Their modulation in response to host defences and inflammation can result in altered sensitivity to AMPs, and may additionally change other host-microbe interactions, e.g. binding to Toll-like receptors. The diversity and breadth of antimicrobial cover and immunomodulatory function provided by AMPs is central to the ability of a host to respond to the diverse and highly adaptable organisms colonising oral and respiratory mucosa.

It has recently been shown that human salivary glands constitutively express CD14, an important molecule in innate immunity, and that a soluble form of CD14 is secreted in saliva. The concentration of CD14 in parotid (a serous gland) saliva was comparable to that in normal serum and 10-fold the amount in whole saliva, although the physiological function of saliva CD14 remained unclear. Actinobacillus actinomycetemcomitans is a periodontopathic bacterium and is able to invade oral epithelial cells. The present study showed that upon exposure to live A. actinomycetemcomitans Y4 for 2 h, human oral epithelial HSC-2 cells produced interleukin-8 (IL-8) for a further 24 h and whole saliva augmented the production induced by A. actinomycetemcomitans Y4. Parotid saliva showed a more pronounced effect on the production of IL-8 than whole saliva. Neither saliva preparation itself had IL-8-inducing activity. Parotid saliva exhibited antibacterial activity against a low concentration of A. actinomycetemcomitans Y4, but recombinant CD14 did not show the activity. The internalization of A. actinomycetemcomitans Y4 into HSC-2 cells was inhibited by cytochalasin B, indicating that the process was actin dependent, and depletion of CD14 from parotid saliva inhibited the invasion and, as a consequence, inhibited production of IL-8. Furthermore, human recombinant CD14 augmented invasion and IL-8 production. These results suggest that saliva CD14 promoted the invasion of oral epithelial cells by A. actinomycetemcomitans and consequently augmented the production of IL-8, playing an important role in innate immunity in the oral cavity.

We evaluated different approaches for diagnosing measles virus (MV) infection in unvaccinated children and in healthy contact persons (n=194) during a measles epidemic in The Netherlands. MV RNA was detected by reverse-transcriptase polymerase chain reaction in throat-swab specimens from 93% of the patients with clinical symptoms. MV RNA was detected from 5 days before until 12 days after the onset of symptoms. Most patients (88%) also secreted MV RNA in their urine until 5 weeks after the onset of symptoms. Oral fluid proved to be the most practical specimen for the simultaneous detection of MV-specific IgM antibody and viral RNA, which, together, confirmed 93% of measles cases. Viral RNA was also detected in oropharyngeal specimens from 3 healthy contact persons with serological proof of MV infection. The results of this study emphasize the feasibility of combined detection of viral RNA and MV-specific IgM antibodies in oropharyngeal specimens for the diagnosis of clinical and subclinical MV infection.

Objective: In a previous study, we screened 149 subjects and established four groups high or low for salivary killing of oral bacteria, and for aggregation and live and dead adherence of oral bacteria (as a combined factor). Caries scores were significantly lower in both High Aggregation-Adherence groups. In this study we looked at the effects of those differences in salivary function on the quantity and diversity of oral biofilm streptococci., Design: Subjects from those four groups were recalled for collection of overnight oral biofilm from buccal upper central incisors, lingual lower central incisors, buccal upper and lower first molars, and lingual upper and lower first molars. At each site, groups were compared for total biofilm (by DNA concentration), total streptococci (by quantitative PCR), and streptococcal diversity (by Streptococcus-specific denaturing gradient gel electrophoresis)., Results: Total biofilm DNA and total streptococci were correlated. Both were highest on buccal molar surfaces and lowest on lingual lower central incisors, and both were significantly lower in the High Aggregation-Adherence groups (particularly at the buccal molar site). Fifty distinct bands were observed in denaturing gradient gels. There was great diversity within and between sites. Three major bands were present in almost every person at every site. Densities for two of those bands were significantly lower in both High Aggregation-Adherence groups. Other less-prevalent bands also showed the same pattern., Conclusion: These findings are consistent with our caries results in suggesting that differences in salivary function can influence the quantity and composition of streptococci in oral biofilms.

Current views, mainly clinical, concerning allergic inflammation in the upper respiratory tract are presented.

Bilateral transection of the glossopharyngeal nerves (GLOx) disrupts the immune-to-brain communication from the posterior oral cavity. The current report tested whether this effect is due to the afferent (sensory) or efferent (parasympathetic motor) components of the nerve. Injection of lipopolysaccharide (LPS) into the soft palate (ISP) of GLOx or sham-operated (SHAM) rats increased the circulating levels of interleukin-1beta (IL-1beta), interleukin-1 receptor antagonist (IL-1ra) and corticosterone (CORT), as well the hypothalamic content of IL-1beta; no difference in circulating levels and hypothalamic content was found between GLOx and SHAM at 2 and 4.5 h after LPS injection. These results indicate that glossopharyngeal neural efferents do not mediate the effects of GLOx on the immune-to-brain communication.

The planarian Dugesia japonica has two genes encoding myosin heavy chain, DjMHC-A and B (Kobayashi et al., 1998). We produced antibodies specifically recognizing each myosin heavy chain protein using their carboxyl terminal regions expressed in E. coli as antigens. Immunohistochemical analyses of sections and whole-mount specimens revealed the detailed structure and distribution of each type of muscle fiber in the planarian. In general, the MHC-A muscle fibers were distributed beneath the epithelial layers, namely, they were observable in the pharynx, the mouth, the intestine, the eyes and the body wall. In the pharynx, only MHC-A muscle fibers were present. In contrast, the MHC-B muscle fibers were distributed in the mesenchyme as dorso-ventral and transverse muscles, and in the body wall. The body-wall muscles were composed of an outer layer of circular MHC-A muscles and inner longitudinal and intermediate diagonal MHC-B muscle layers. Thus, two types of muscle fibers were distinguished by their distribution in the planarian.

Objective: To establish the prevalence of antibodies to HIV (anti-HIV) and associated risk factors among injecting drug users (IDU) in Togliatti City, Samara Oblast, Russian Federation., Design: An unlinked anonymous cross-sectional community recruited survey with oral fluid sample collection., Methods: Between September and October 2001, 426 IDU were recruited by trained fieldworkers. Participants completed an interviewer administered questionnaire, and oral fluid samples were tested for anti-HIV. Univariate and multivariate analyses compared potential risk factors for anti-HIV., Results: Anti-HIV prevalence was 56% (234/418). Three-quarters of anti-HIV-positive IDU (74%) were unaware of their positive status. In an adjusted model, the odds of HIV infection were higher among IDU who had ever injected home-produced drugs, who reported injecting with used needles and syringes in the past 4 weeks, and who were living in one particular district of the city (Komsomolksii)., Conclusion: The high prevalence of HIV, and a recent increase in HIV detected through routine screening tests since 2000, suggests that an explosive epidemic has occurred among IDU in Togliatti City. In the face of currently inadequate HIV prevention coverage among IDU, this has urgent implications for maximizing the distribution of sterile injecting equipment as well as for enhancing sexual risk reduction. Recognizing that it is likely that similar explosive epidemics are taking place in other Russian cities, we recommend community-wide HIV prevention coverage supported by city and state policies oriented to harm reduction., (Copyright 2002 Lippincott Williams & Wilkins)

Anaerobes of oral origin are common in chronic upper respiratory tract and other head and neck infections. Anaerobes are the predominant components of the normal human oropharyngeal flora, and are therefore a common cause of bacterial infections of the upper respiratory tract that are of endogenous origin. These bacteria can be isolated in chronic otitis media, sinusitis, and tonsillitis, and their complications. Anaerobes also predominate in deep oral and neck infections and abscesses. Their isolation requires appropriate methods of collection, transportation, and cultivation of specimens. In addition to their active pathogenic role in these infections, many anaerobes express an indirect effect through their ability to produce the enzyme beta-lactamase. This enables these organisms to shield non-beta-lactamase-producing bacteria (BLPB) from penicillins. Inadequate therapy against BLPB may lead to clinical failures. Treatment of anaerobic infection is complicated by their slow growth, their polymicrobial nature, and the growing resistance of anaerobic bacteria to antimicrobials. Antimicrobial therapy is often the only form of therapy needed, whereas in other instances it is an important adjunct to a surgical approach. Because anaerobes generally are isolated mixed with aerobic organisms, therapy should provide for adequate coverage of both types of pathogens., (Copyright 2002, Elsevier Science (USA). All rights reserved.)

Objective: To document HIV prevalence/incidence trends from 1995-2000 and associated risk factors among injection drug users (IDUs) in Eastern Central Canada as an indication of harm reduction strategy effectiveness., Methods: Nonnominal cross-sectional data (one-time participants) and longitudinal data (repeat participants) were collected using convenience sampling. Participants provided informed consent for face-to-face interviews focused on injection drug use and sexual practices during the previous 6 months; oral fluid samples were taken for HIV testing by enzyme immunoassay. Unique encrypted codes for initially HIV-negative repeat participants permitted incidence rate calculations., Results: In all, 6387 IDUs (median age, 31 years; range, 13-67; males, 73.5%) participated on 9724 occasions. HIV prevalence ranged from 4.7% (95% confidence interval [CI], 2.9-6.5) in semiurban areas to 20.1% (95% CI, 17.6-22.7) in Ottawa, Ontario. HIV incidence was 6.0 (95%CI, 4.5-7.6) per 100 person-years (py) in Montréal, Québec, 3.2 (95% CI, 2.2-4.2) per 100 py in Québec City and 7.0 (95% CI, 4.1-9.8) per 100 py in Ottawa/Hull. Reusing other IDUs' needles was reported by 38.4%. In multivariate logistic regression, IDUs injecting for 6 or more years were more likely to be HIV positive, particularly if cocaine was the predominant drug injected. Multivariate Cox regression revealed higher HIV incidence among those who predominantly injected cocaine, reused others' needles, had injected 6 years or more, injected with strangers, or were men reporting commercial sex work., Conclusions: These results reveal a volatile situation of continuing HIV transmission among IDUs in Eastern Central Canada.

Oral fluid (saliva) samples are increasingly used as a minimally invasive alternative to serum to detect antibody for viral diagnostics and population-based surveys of immunity to common infections. Postal collection of these samples is convenient, but it is uncertain how oral fluid antibody levels may deteriorate during transit. In this study multiple oral fluid samples, from a group of individuals, were collected and kept at two different temperatures (10 and 20 degrees C, simulating winter and summer conditions ) for periods of up to 7 days. They were then tested for total immunoglobulin G (IgG) and for rubella-specific IgG. Total IgG concentrations ranged from 2.0 to 48.6 mg/l but showed no significant decrease over the 7-day period. There was also no significant change in rubella-specific IgG measured using an antibody capture ELISA, but testing with an indirect rubella IgG ELISA revealed a significant decrease in absorbance values between day 1 and day 7 at 20 degrees C. The difference in the rubella assay results may reflect the different assay formats with the signal in the indirect procedure related to the concentration of rubella IgG in the oral fluid sample, rather than the proportion of virus-specific IgG measured with the antibody capture format. The study demonstrated that total and rubella specific IgG in oral fluid samples were stable for up to 7 days at differing temperatures and that an antibody capture assay format should be used for virus-specific testing to minimise inaccurate results due to low IgG concentrations in oral fluid samples.