Paul T. Rose et alPediatric Dentistry: July/August 1994

Volume 16, Number 4http://www.aapd.org/upload/articles/

rose-16-04.pdf

IgA Antibodies to Streptococcus mutans in caries-resistant and -

susceptible children

What is sIgA?Principal immunoglobulinHumoral element in secretory

immune systemHas a neutralizing component to

prevent attachment and adherence of oral bacteria

SIgA adheres selectively to M cells in intestinal Peyer’s patches, thus mediating the transepithelial transport of the Ab molecule from the intestinal lumen to underlying gut-associated organized lymphoid tissue

Goal of StudyCompare levels of IgA1 and IgA2 antibodies

to saliva Quantify S.mutans in caries-resistant (CR)

and caries-susceptible (CS) childrenAnalyze sIgA and IgA1 and IgA2 subclass

levels in whole and parotid using ELISA.IgA1made by bone marrow B cellsIgA2 made by B cells in mucosa

MethodsRandom selectionFluoridated communitiesMin of 20 subjects per group 21 CR (DMFS less than or equal to 1)20 CS (DMFS greater than 5)

B/w 7-11 yrs of ageNegative PMHNo medsMixed dentition w/ 6’s, 1’s, 2’sConsent

Saliva samplingOne clinician collected samples to reduce variability

b/w 8am-noon for unstimulated parotid and whole saliva

Whole saliva samplesParotid saliva samplesUnstim saliva samples were diluted 1:10 and 1:100 in

sterile saline and spiral plated in duplicate on mitis salivarius (MSS) agar supplemented w/15% sucrose and bacitracin for enumeration of total oral streptococci and S.mutans.

S.mutans was quantified from whole saliva by colonial morphology and incubated for 3 days and the % of S. mutans per total oral streptococci was calculated

ELISA sandwich and direct techniques were used to determine concentrations of whole salivary total IgA, IgA1, IgA2 and parotid salivary total IgA.

The direct detection method originated in the 1940s when Coons and colleagues labeled antibodies with a fluorescent tag to mark tissue antigens. In this technique, a labeled primary antibody reacts directly with the antigen.

Results analyzed by student’s t-testP values greater than 0.05 were significant

Key PointsIndividual differences in flow rate and IgA

antibody content for each subject were considered, there was a significant difference b/w CR and CS individuals for IgA antibodies to S. mutans in whole saliva.

# of salivary S.mutans higher in CS than CR children

IgA antibodies levels to S.mutans in whole saliva was higher in CR than CS children.

Main Fxn of IgAIgA functions at three anatomical levels in

relation to mucosal epithelium: 1) luminal SIgA Ab prevents adhesion and entry of Ag into the epithelium; 2) IgA Ab in the lamina propria

binds and excretes Ag to the lumen; and 3) IgA Ab in transit through the epithelium can inhibit virus production or neutralize proinflammatory Ags . An additional property of IgA is its inability to trigger the release of inflammatory mediators through receptors specific for its Fc domain (http://www.jimmunol.org/cgi/content/full/178/1/27)

Lawrence A.Tabak, DDS, PhDPediatric Dentistry – 28:2 2006

http://www.aapd.org/upload/articles/tabak-28-2.pdf

In Defense of the Oral Cavity: The Protective Role of the Salivary

Secretions

The secret is in the wholeAnalyzed salivary proteins assigned them

to a protein familyEach individualized molecule plays a roleProtein roles:

AdhesinsAgglutininsAntimicrobialpH modulating

Current view of salivary function

Saliva in ChildrenAt Birth, IgA not detectable4-6 wks levels rapidly riseIgA1 dominates, by 20 wks IgA2 increases to

adult levels.Early childhood: lysozyme and salivary

peroxidase are at adult levelsMUC5B dominates over MUC7 from 1mo-1yr Antimicrobial peptides:

Beta-defensin-3Cathelicidin LL37Alpha-defensins 1,2,3HNP1-3 were greater in cavity free children

http://www.sciencedaily.com/releases/2005/02/

"The eyes may be the window to the soul, but many scientists would say the mouth is the

window to the body" –Science Daily

Saliva and other oral fluids contain many of the same proteins and molecules as blood and urine do.

Saliva can reveal disease, i.e. cancerDeveloping technology for identifying molecules

“biomarkers” for diseaseDetermines who vulnerable pt is to caries“-human’s sugar chain makeup (oligosaccharides)

is 100% genetically determined and cannot be changed. The USC researchers found that the sugar chain makeup in saliva can predict a child’s future cavity history to plus or minus one cavity with greater than 98% confidence”.

Gcamerica.com

Saliva testing: good practice, good sense!

Saliva-Check Buffer Kit

Patient Education

Patient EducationCarbs and acidic foods amplify S.mutans and S.sobrinus in dental plaque which are related to the initiation and progression of dental caries.

Patient EducationOnce the salivary problem is identified the practitioner can recommend a course of preventive care (i.e. fluoride, chlorhexidine), lifestyle changes, altering oral hygiene, increasing saliva production.

10 min of testing:Step 1:

Hydration

The rate of production of resting saliva as a surrogate measure of hydration.

2. ConsistencyThe viscosity of resting saliva as a surrogate for measuring its relative water and mucin content.

3. Resting saliva pHThe pH of resting saliva

4. Stimulated saliva flow (5 min)The rate of production of stimulated saliva

5. Stimulated saliva pHHigher concentration of bicarbonate ions in parotid saliva and should be a higher pH than the resting pH.

6. Buffering capacityBuffering capacity of stimulated saliva in an aqueous env w/ differing amts of lactic acid. A small pipette is used to withdraw a small quantity of saliva, which is placed on test pads. Low buffer capacity – bright red (0pts)

Normal buffer – green (4pts)

Intermediate buffer – blue (2pts)

12 pt scale is created to keep track of any changes in buffer capacity over time.

Score b/w 10-12 is normal capacity

The remaining sample can be used for immuno-assay for S. mutans levels.