IgA Antibodies In Saliva Research Articles

Serum and salivary IgA antibody responses to Saccharomyces cerevisiae, Candida albicans and Streptococcus mutans in orofacial granulomatosis and Crohn's disease.

Orofacial granulomatosis (OFG) is a condition of unknown aetiology with histological and, in some cases, clinical association with Crohn's disease (CD). However, the exact relationship between OFG and CD remains uncertain. The aim of this study was to determine whether OFG could be distinguished immunologically from CD by comparing non-specific and specific aspects of humoral immunity in serum, whole saliva and parotid saliva in three groups of patients: (a) OFG only (n = 14), (b) those with both oral and gut CD (OFG + CD) (n = 12) and (c) CD without oral involvement (n = 22) and in healthy controls (n = 29). Non-specific immunoglobulin (IgA, SigA, IgA subclasses and IgG) levels and antibodies to whole cells of Saccharomyces cerevisiae, Candida albicans and Streptococcus mutans were assayed by enzyme-linked immunosorbent assay (ELISA) in serum, whole saliva and parotid saliva. Serum IgA and IgA1 and IgA2 subclasses were raised in all patient groups (P < 0.01). Salivary IgA (and IgG) levels were raised in OFG and OFG + CD (P < 0.01) but not in the CD group. Parotid IgA was also raised in OFG and OFG + CD but not in CD. The findings suggest that serum IgA changes reflect mucosal inflammation anywhere in the GI tract but that salivary IgA changes reflect involvement of the oral cavity. Furthermore, the elevated levels of IgA in parotid saliva suggest involvement of the salivary glands in OFG. Serum IgA antibodies to S. cerevisiae were raised markedly in the two groups with gut disease while serum IgA (or IgG) antibodies to C. albicans were elevated significantly in all three patient groups (P < 0.02). No differences were found with antibodies to S. mutans. Whole saliva IgA antibodies to S. cerevisiae (and C. albicans) were raised in the groups with oral involvement. These findings suggest that raised serum IgA antibodies to S. cerevisiae may reflect gut inflammation while raised SIgA antibodies to S. cerevisiae or raised IgA or IgA2 levels in saliva reflect oral but not gut disease. Analysis of salivary IgA and IgA antibodies to S. cerevisiae as well as serum antibodies in patients presenting with OFG may allow prediction of gut involvement.

Saliva Secretory IgA Antibodies Against Molds and Mycotoxins in Patients Exposed to Toxigenic Fungi

Upper respiratory exposure to different environmental antigens results first in the activation of mucosal immunity and production of IgA antibodies in different secretions including saliva. Despite this there is no study, which addresses secretory antibodies against molds and mycotoxins. The purpose of this study was to evaluate mold‐specific salivary IgA in individuals exposed to molds and mycotoxins in a water‐damaged building environment. Saliva IgA antibody levels against seven different molds and two mycotoxins were studied in 40 patients exposed to molds and in 40 control subjects. Mold‐exposed patients showed significantly higher levels of salivary IgA antibodies against one or more mold species. A majority of patients with high IgA antibodies against molds exhibited elevation in salivary IgA against mycotoxins, as well. These IgA antibodies against molds and mycotoxins are specific, since using molds and mycotoxins in immune absorption could reduce antibody levels, significantly. Detection of high counts of molds in water‐damaged buildings, strongly suggests the existence of a reservoir of mold spores in the environment. This viable microbial activity with specific mold and mycotoxin IgA in saliva may assist in the diagnosis of mold exposure. Whether mold and mycotoxin specific IgA antibodies detected in saliva are indicative of the role of IgA antibodies in the late phase of type‐1 hypersensitivity reaction or in type‐2 and type‐3 delayed sensitivities is a matter that warrants further investigation.

Total and allergen-specific immunoglobulin A levels in saliva in relation to the development of allergy in infants up to 2 years of age.

The association between salivary IgA levels and development of allergy is controversial and the employed methodology has been questioned. The aim of the study was to relate the levels of total IgA, SIgA and allergen-specific IgA antibodies in saliva to the development of allergy in infants during the first 2 years of life. Saliva samples from 80 infants participating in a prospective study regarding the development of allergy were collected at 3 or 6, and 12 and 24 months of age. Total IgA, SIgA and Fel d 1 and beta-lactoglobulin specific IgA levels were analysed with ELISA. The levels of total IgA and SIgA increased with age. The number of samples with detectable IgA to Fel d 1 tended to increase with age, whereas the opposite was observed for IgA to beta-lactoglobulin. Infants who developed allergy tended to have higher levels of total IgA, and allergen-specific IgA was more commonly detected than in non-allergic children. In contrast, non-allergic children tended to have higher levels of SIgA. Furthermore, the levels of SIgA were higher in sensitized infants with no allergic symptoms than in sensitized children with symptoms. Infants with allergic parents had lower SIgA levels than infants without. Direct exposure to cat and cow's milk did not influence the levels of allergen-specific IgA levels, nor was there any association between breast-feeding and IgA production. The kinetics of food and inhalant allergen-specific IgA in saliva during the first 2 years of life is similar to what has earlier been shown for IgG in serum. Development of allergy tended to be associated with high levels of total and allergen-specific IgA antibodies, but low levels of SIgA. Furthermore, high levels of SIgA seemed to protect sensitized children from developing allergic symptoms during the first 2 years of life, supporting a possible protective role of SIgA against development of allergy.

Responses of varicella zoster virus (VZV)-specific immunity in seropositive adults after inhalation of inactivated or live attenuated varicella vaccine

To examine boostering of varicella zoster virus (VZV)-specific immunity in seropositive adults after nasal inhalation of heat-inactivated or live attenuated varicella vaccine, we determined specific cellular immunity, IgG antibody in sera and secretory IgA antibody in saliva before and after the inhalation. The mean titers in specific IgG antibody and skin test findings significantly increased following inhalation of both vaccines. However, the ratio of a two-fold or more increase in the levels of IgG antibody or skin test did not show significant difference after inhalation of the inactivated vaccine in comparison with those in the control. After inhalation of the live vaccine, the ratio showed significant difference but transmission of the live vaccine virus to others was suspected. No significant increase in VZV-secretory IgA antibody levels in saliva was noted following inhalation. The results of this study suggested that nasal inhalation of the live vaccine could increase specific immunity in adults. This method would be similar to the natural infection and simpler than subcutaneous injection.

Plasma and salivary IgA subclasses and IgM in HIV-1-infected individuals.

We examined IgA and IgM responses in parotid saliva from human immunodeficiency virus-1 (HIV-1)-infected individuals. Compared to the uninfected controls, levels of salivary secretory IgA2 were significantly increased in HIV-1-infected subjects, with higher levels in those who displayed oral manifestations of HIV- I infection. Assessed by enzyme immunoassay, about two thirds of the HIV-1-infected individuals tested positive for salivary HIV-1-specific IgA antibodies but not for salivary IgM. No clear correlations between the amount of HIV-1-specific IgA and CD4 counts or plasma viral loads were found. The proportions of HIV-1-specific IgA did not correlate with the levels of total IgA. Determined by Western blot, IgA1 accounted for the majority of anti-HIV-1 IgA antibodies in saliva. Comparisons between the specificities of plasma and salivary IgA directed to HIV-1 proteins revealed the absence of salivary anti-gp41 IgA antibodies, and lower HIV-1-specific reactivity of IgA and IgM were determined in saliva than in plasma.

Meningococcal outer membrane vesicle vaccine given intranasally can induce immunological memory and booster responses without evidence of tolerance.

We have studied the ability of outer membrane vesicle (OMV) vaccines from Neisseria meningitidis serogroup B to induce vaccine-specific antibody and spleen cell proliferative responses in mice after being administered intranasally (i.n.) and/or subcutaneously (s.c.). A series of four weekly i.n. doses (25 microg) without adjuvant or a single s.c. dose (2.5 microg) with aluminum hydroxide was followed 2 months later by secondary i.n. or s.c. immunizations. After i.n. priming, both immunoglobulin G (IgG) antibody responses in serum, measured by enzyme-linked immunosorbent assay, and IgA antibodies in saliva and extracts of feces were significantly boosted by later i.n. immunizations. The IgG antibody responses in serum were also significantly augmented by secondary s.c. immunization after i.n. as well as s.c. priming. Sera from mice immunized i.n. reached the same level of bactericidal activity as after s.c. immunizations. The s.c. immunizations alone, however, had no effect on mucosal IgA antibody responses, but could prime for booster antibody responses in secretions to later i.n. immunizations. The i.n. immunizations also led to marked OMV-specific spleen cell proliferation in vitro. Both serum antibody responses and spleen cell proliferation were higher after i.n. priming and later s.c. immunizations than after s.c. immunizations alone. There was thus no evidence that i.n. priming had induced immunological tolerance within the B- or T-cell system. Our results indicate that a nonproliferating meningococcal OMV vaccine given i.n. can induce immunological memory and that it may be favorably combined with similar vaccines for injections.

Oligonucleotide containing CpG motifs enhances immune response to mucosally or systemically administered tetanus toxoid

Oligodeoxynucleotides (ODN) containing unmethylated CpG dinucleotides induce proliferation of B cells and activation of macrophages and thus stimulation of the immune system. We tested an oligonucleotide containing an unmethylated CpG dinucleotide flanked by two 5′ purines and two 3′ pyrimidines (GAGAA CG CTCGACCTTCGAT) for the ability to affect antibody levels to tetanus toxoid (Tt). Groups of male Rowett rats ( n=5–6/group) received colloidal aluminium hydroxide (Al(OH) 3) either alone, or with Tt bound to the Al(OH) 3, or with Tt bound to Al(OH) 3 with the addition of the CpG oligonucleotide. Antigens were administered subcutaneously in the salivary gland vicinity once, or by gastric intubation on 3 consecutive days. On day 124 all animals were given a boost with the same material by the same route. Serum IgG and saliva IgA antibody to Tt was determined by ELISA. Serum antibody levels were significantly higher in ODN+Tt treated rats than in Tt-alone rats immunized by either route after primary or booster immunizations. Thus, administration of an ODN containing unmethylated CpG motifs along with an immunogen bound to Al(OH) 3 can result in enhanced specific antibody when administered by intragastric as well as subcutaneous routes.

ウサギ口蓋へん桃を介した唾液中常在菌に対する自然抗体の誘導

We isolated the predominant indigenous bacteria from the saliva of non-immune rabbits. The presence of naturally occurring antibodies to the isolated bacteria and the induction of these antibodies were then studied. The bacteria in the saliva was identified as Staphylococcus lentus using a commercial identification kit, and found to have 1.5 (±2.2) × 106 cells/ml and to account for 16.1 (±5.6)% of the bacteria grown under aerobic condition. The concentration of anti-S. lentus antibodies in the saliva of non-immune rabbits was higher than that of the other kinds of staphylococci in ELISA. In non-immune rabbits, the anti-S. lentus IgA antibodies in the saliva was higher than that in the nasal wash and the intestinal fluid, while the anti-S. lentus IgA antibodies in the saliva, the nasal wash and the intestinal fluid were similar in level. When the suspension of fluorescence-labeled isolated Sta. lentus cells in saliva was applied to palatine tonsil of rabbits, many spots of the fluorescence were found in the cortex of the tonsil. Weekly tonsillar application of 1010 isolated Sta. lentus cells in one ml PBS caused an increase in the concentration of anti-S. lentus IgA antibodies in saliva the and the IgG antibodies and IgM antibodies in the blood plasma. Even one week following the first application of isolated Sta. lentus, the antibodies in the saliva were found to have increased. The anti-S. lentus antibodies was induced by the application of 108 cells or 106 cells. The antibody level after six weeks of these applications was similar in level to that applied 1010 cells. The above results show that naturally occurring antibodies to the predominant indigenous oral bacteria were induced in the saliva of rabbits through the stimulation of the palatine tonsil.

Intranasal immunization with heat-inactivated Streptococcus pneumoniae protects mice against systemic pneumococcal infection.

In order to study the mucosal and serum antibody response to polysaccharide-encapsulated bacteria in mice, a preparation of heat-inactivated Streptococcus pneumoniae type 4 was administered, with and without cholera toxin, at various mucosal sites. It appeared that intranasal immunization of nonanesthesized animals was superior to either oral, gastric, or colonic-rectal antigen delivery with regard to the induction of serum immunoglobulin G (IgG) and IgA, as well as saliva IgA antibodies specific for pneumococci. The marked IgA antibody response in feces after intranasal, but not after oral or gastric, immunization is suggestive of a cellular link between the nasal induction site and the distant mucosal effector sites. Intranasal immunization also induced antibodies in serum and in mucosal secretions against type-specific capsular polysaccharide. IgA and IgG antibody levels in pulmonary lavage fluids correlated well with saliva IgA and serum IgG antibodies, respectively. Antibody determinations in pulmonary secretions may therefore be redundant in some cases, and the number of experimental animals may be reduced accordingly. After intraperitoneal challenge with type 4 pneumococci, mice immunized intranasally were protected against both systemic infection and death, even without the use of cholera toxin as a mucosal adjuvant. Thus, an efficient intranasal vaccine against invasive pneumococcal disease may be based on a very simple formulation with whole killed pneumococci.

Decreased Helicobacter pylori- Specific Gastric Secretory IgA Antibodies in Infected Patients

Despite an increase in local Helicobacter pylori-specific IgA production in H. pylori infection, the bacterium is able to persist over decades. We focused on IgA and secretory IgA (sIgA) in gastric juice because sIgA is more relevant in local protection and more resistant to degradation than nonsecretory IgA. H. pylori-specific IgA and sIgA in gastric juice, saliva, and serum of H. pylori-infected patients were compared. Samples from 28 H. pylori-positive and 16 negative patients were tested by means of immunoblotting for the presence of H. pylori-specific IgA and sIgA. In gastric juice the majority of H. pylori-specific IgA was not of the secretory type, whereas total IgA was bound mainly to the secretory component as shown by immunoblot and slot blot. In contrast H. pylori-specific IgA antibodies in saliva of infected patients were of the secretory type as shown by immunoblot. The presence of specific, nonsecretory IgA may be a consequence of the damaged mucosal epithelium at the site of H. pylori infection allowing IgA to bypass the secretory transport system. Considering the resistance of secretory IgA against hydrolysis and proteolysis, these data suggest that the predominantly nonsecretory IgA specific for H. pylori may lead to a decreased protection against H. pylori.

Protection against measles virus-induced encephalitis by antibodies from mice immunized intranasally with a synthetic peptide immunogen

Balb c mice were immunized intranasally (i.n.) with a chimeric synthetic peptide containing two copies of a T- and one copy of a B-cell epitope (TTB) from measles virus (MV) fusion protein, plus cholera toxin B (CTB) adjuvant. The antibodies induced cross-reacted with, and neutralized MV and on passive transfer, protected mice against encephlitis induced by neuroadapated MV. Immunization with TTB alone induced antibodies which increased survival but not significantly compared to controls. Furthermore, i.n. immunization with TTB plus CTB induced TTB-specific IgA antibodies in saliva and nasal washes. Co-administration of CTB increased the affinity of antibodies to the B-cell epitope of TTB and caused a relative increase in the level of anti-peptide antibodies of the IgG2a subclass and the overall titre of IgG antibodies. These results indicate the potential of the i.n. route for immunization with synthetic peptide immunogens for induction of both local and systemic anti-peptide antibody responses.

Circulating antibody secreting cell response to parenteral pneumococcal vaccines as an indicator of a salivary IgA antibody response

This study assessed the mucosal immune response in healthy adult volunteers immunized parenterally with either pneumococcal polysaccharide ( N = 8) or pneumococcal polysaccharide-protein conjugate ( N = 10) vaccine with an aim to evaluate the relevance of antibody secreting cell (ASC) response after parenteral vaccination. An ASC response to the four types of capsular polysaccharide tested was observed in all vaccinees 7–9 days after immunization. IgA was the predominant class in the ASC response, and IgG the next common, with very few IgM ASCs. The IgA IgG ratio in the ASC response was higher after immunization with the polysaccharide than the conjugate vaccine. Antibodies of the IgA class were frequently seen in the saliva already before immunization; especially to serotypes 14 and 19F. A twofold increase of the type specific secretory IgA antibodies in saliva was found in eight of the 16 instances in which the specific IgA ASC response was > 100 ASC per 10 6 cells and in only one of the 52 instances with fewer ASCs. We conclude that the ASC response in the peripheral blood is a useful parameter of the antibody response to pneumococcal vaccines and a good indicator of a secretory IgA response in the saliva.

Local and systemic antibody levels against protein D of Haemophilus influenzae following immunization and infection in rats

Outer membrane proteins of Haemophilus influenzae are considered as possible vaccine candidates against non-typable H. influenzae (NTHi), a major cause of respiratory infections. Here, we study local and systemic antibody responses to protein D, a well-conserved 42-kDa membrane protein, following local and systemic immunization, and experimental acute otitis media (AOM) with NTHi and H. influenzae type b (Hib) in rats. Animals that were challenged and rechallenged in the middle ear with Hib strain Minn A or NTHi strain 1161 developed IgG and IgA antibodies in serum but not in middle ear lavage (MEL) material or saliva. In contrast, following per oral immunization with NTHi strain 772 and Escherichia coli JM83 (pHIC348) (containing protein D gene) and, to a lesser degree after intranasal inoculation of NTHi strain 772, high saliva IgA antibodies to protein D developed, but there was no rise in antibodies to protein D in the MEL material or the sera of these animals. These results show that protein D can elicit different systemic and local antibody responses depending on the site of delivery and the form of administration. Furthermore, experimental AOM with NTHi and Hib induces systemic IgG and IgA antibodies to protein D but fails to induce a mucosal immune response.

Specific antibodies against Actinobacillus actinomycetemcomitans in serum and saliva of patients with advanced periodontitis

The aim of the present study was to discover any possible correlation between specific antibodies against Actinobacillus actinomycetemcomitans (A.a.) in serum and saliva. The test group consisted of 38 patients aged 31-68 yr (mean 49) with advanced periodontitis. Twenty-nine subjects aged 23-67 yr, without periodontal destruction, formed a control group with a reference level of specific salivary antibodies against A.a. A subgingival plaque sample for culturing A.a., a specimen of stimulated whole saliva, and a sample of venous blood were taken from each subject of the test group. Specific IgG and IgA antibodies against A.a. were determined from serum and stimulated whole saliva by means of the ELISA test. Fifteen of the patients (39%) had cultivable A.a. Six of the 15 A.a. culture-positive patients and one of the 29 reference subjects exhibited very high antibody titers against A.a. in saliva. Specific IgG and IgA antibodies in saliva correlated highly significantly with the corresponding antibody values in serum among the patients in the test group. It was concluded that among patients with severe adult periodontitis, the less invasive saliva sample has a diagnostic value equal to that of the serum sample concerning specific antibodies against A.a.

Murine model for evaluation of protective immunity to influenza virus

We have characterized a murine model as an inexpensive, readily available and sensitive animal model for the evaluation of protective immune responses induced by various routes of administration of influenza A vaccine preparations. Using a non-mouse-adapted human influenza virus to infect unanaesthetized animals intranasally, we established that the optimum dose for infection of Balb/c mice was 10 4 plaque forming units of virus and that the optimum sampling time for measurement of virus yields in the organs of the respiratory tract was 72 h after challenge. We found that the infection was initiated in the nose and progressed by descending into the trachea and lungs over a period of days. Evaluation of protection against infection clearly showed that the tissues of the mouse respiratory tract were completely protected after administration of whole killed virus intranasally and partly protected when virus was administered subcutaneously. The protection correlated with the level of virus-specific IgA antibodies in saliva.

Salivary IgA responses to Porphyromonas gingivalis in the cynomolgus monkey. 1. Total IgA and IgA antibody levels to P. gingivalis.

Porphyromonas gingivalis has been associated with the subgingival plaque of advancing disease lesions in various types of periodontitis. Additionally, this species of oral microorganism has been found to increase dramatically in ligature-induced periodontitis in nonhuman primates (Macaca fascicularis) and has recently been shown to induce progressing disease when implanted into the subgingival plaque in this animal model. Although systemic antibody responses have been demonstrated to P. gingivalis in both human and nonhuman primate with periodontitis, no information is available on the oral secretory IgA antibody response to this bacteria. This report describes the methods for reproducible collection of salivary secretions from cynomolgus monkeys and the development of methods for analyzing salivary IgA levels and specific IgA antibody in the saliva reactive with P. gingivalis. Purification of monkey salivary IgA allowed quantification of IgA using an enzyme-linked immunosorbent assay (ELISA). Estimation of total IgA levels in saliva showed approximately a 20% greater level of IgA in whole versus parotid saliva from a group of 13 monkeys, with a 2-3 fold variation in levels among this group of animals. Naturally occurring salivary IgA antibody to P. gingivalis, as measured by ELISA, were routinely detectable but low in whole saliva; however, many of the parotid saliva specimens collected exhibited negligible levels of antibody to this microorganism. The IgA antibody in whole saliva showed nearly an 18-fold variation among the samples from the monkeys. Correlational analyses indicated that, although there was a positive relationship between antibody levels in whole and parotid saliva, the majority of natural IgA antibody in whole saliva appears to be derived from other sources.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of Intestinal Amebiasis Using Salivary IgA Antibody Detection

This investigation sought to determine whether detection of salivary IgA antibodies to Entamoeba histolytica could identify intestinal amebic infections among 223 school children. Four groups of children were identified through coproparasitoscopic examination: E. histolytica as other parasites only (20%); and parasite-free (25%). The diagnostic accuracy of salivary IgA antibodies to an E. histolytica membrane extract was 91.5% (sensitivity, 85%; specificity, 98%), maintaining high predictive value at different prevalences. Also, a positive correlation (r = .753, P less than .001) was observed between fecal E. histolytica membrane antigen levels and salivary IgA antibody activity. Measurement of IgA antibodies in saliva may be useful in diagnosing intestinal infections with E. histolytica within a wide range of prevalences. Moreover, sampling of saliva may be a useful non invasive test for immunoepidemiologic surveys.

Effect of local deposition of antigen on salivary immune responses and reaccumulation of mutans streptococci

In this study glucosyltransferase (GTF) from Streptococcus sobrinus was topically administered onto the lower lips of young adults. The effect of this route of antigenic exposure on labial and parotid gland and serum antibody levels to GTF and on the reaccumulation of indigenous mutans streptococci after a dental prophylaxis was then measured. Young adults between 18 and 42 years of age were screened for levels of antibody activity to GTF in parotid and labial gland salivas and levels of mutans streptococci in their whole saliva. Prior to antigen administration, two groups were formed which had similar distributions of mutans streptococci in their whole saliva. Antigen (GTF) or placebo, each combined with aluminum phosphate (AP), was then administered to the lower lip daily for 5 days. Immediately prior to topical application of GTF or placebo to the labial salivary glands, all subjects were given a dental prophylaxis. Statistically significant differences in anti-GTF IgA antibody activity in parotid or labial salivas were not observed between the GTF-administered and the placebo groups during the 6 weeks following topical application. However, the proportions of indigenous mutans streptococci/total streptococcal flora, or total cultivable flora, were always lower in the whole salivas of the GTF, compared with the placebo group. These differences were statistically significant on days 13, 20, 34, and 41 after initial topical application. Delays in reaccumulation were significantly associated (P less than 0.025) with elevations in parotid saliva IgA antibody levels of all subjects. Seven of 10 of the subjects demonstrating this association were in the group to which GTF was topically administered.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective secretory immunoglobulin A antibodies in humans following oral immunization with Streptococcus mutans.

Ingestion of a vaccine containing killed Streptococcus mutans, originally isolated from each volunteer, daily for 10 consecutive days induced increased levels of specific secretory immunoglobulin A (sIgA) antibodies to S. mutans cells and two cell surface proteins, glucosyltransferase and surface antigen I/II, in parotid saliva and tears of four healthy males and in parotid saliva, tears, colostrum, and milk of a pregnant woman. In addition, these antibodies inhibited glucosyltransferase activity. Both IgA1 and IgA2 antibodies were induced. The levels of IgA antibodies in all secretions remained significantly above preimmunization levels for more than 50 days after oral administration of antigen. A second series of immunizations for 7 consecutive days resulted in even higher levels of sIgA antibodies, which peaked earlier and persisted longer than those observed after the primary immunizations. No increase in levels of antibodies in serum were detected in any subject. Antibodies reactive with human heart and kidney antigens could not be detected in saliva, tears, colostrum, milk, or serum samples collected at any time during the immunization regimen. The numbers of viable S. mutans organisms in dental plaque and whole saliva decreased after each series of immunizations, which correlated with increased levels of IgA antibodies in saliva, suggesting that IgA antibodies in saliva were responsible for the reduced adherence of this bacterium. These results indicate that ingested S. mutans antigen induces secretion of specific IgA1 and IgA2 antibodies in saliva, tears, colostrum, and milk, providing further evidence for the existence of a common mucosal immune system.

The relationship between IgA antibodies to Streptococcus mutans antigens in human saliva and breast milk and the numbers of indigenous oral Streptococcus mutans

The influence of indigenous Streptococcus mutans on naturally-occurring levels of IgA antibodies was studied in 42 lactating females. Breast milk, parotid and whole-saliva samples were collected and analysed by the ELISA method for IgA antibodies, reacting with antigens from Strep. mutans. All salivas and breast milk showed IgA antibody activity to five antigenic preparations from Strep. mutans and to a pool of Escherichia coli antigens. No correlation was observed between the IgA antibody level in breast milk and that in saliva. The total IgA in breast milk was, however, considerably higher than in the salivas. In subjects with active caries and subjects with high DMFS scores, there was a tendency toward lower levels of IgA antibodies in whole saliva than in subjects with low caries experience. The levels of specific IgA antibodies in saliva did not reflect the amount of indigenous Strep. mutans present in the mouth at the time of sampling.