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Saliva diagnostic utility


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Saliva diagnostic utility

  1. 1. Dr.SATHEESH KUMAR.K Post Graduate Student
  2. 2. Salivary glands
  3. 3. INTRODUCTION:  The salivary glands in mammals are exo crine glands, glands with ducts, that produce Saliva  In general, healthy adults produce 500–1500 mL of saliva per day, at a rate of approximately 0.5 mL/min  There are 3 major salivary glands (namely parotid gland, submandibular and sublingual) and numerous minor salivary glands
  4. 4. PAROTID GLAND  The parotid glands are a pair of major salivary glands wrapped around the mandibular ramus in humans  The largest of the salivary glands, they secrete saliva to facilitate mastication and swallowing and to begin the digestion of starches
  5. 5.  It is the serous type of gland which secretes the ptyalin  It enters the oral cavity via the parotid duct or Stensen duct  The glands are located posterior to the mandibular ramus and anterior to the mastoid process of temporal bone  The parotid glands produce a thin, watery, and amylase-rich fluid on stimulation which accounts for up to 50% of the mouth volume of saliva under stimulated conditions, whereas it contributes much less (20%) to the unstimulated saliva secretion
  6. 6. SUBMANDIBULAR GLAND  The submandibular glands are a pair of major salivary glands located beneath the lower jaws, superior to the digastric muscles  The secretion produced is a mixture of both serous fluid and mucus, and enters the oral cavity via the submandibular duct or Wharton duct  Approximately 65-70% of saliva in the oral cavity is produced by the submandibular glands, even though they are much smaller than the parotid glands
  7. 7. SUBLINGUAL GLAND  The sublingual glands are a pair of major salivary glands located inferior to the tongue, anterior to the submandibular glands  The secretion produced is mainly mucous in nature, however it is categorized as a mixed gland  Unlike the other two major glands, the ductal system of the sublingual glands do not have intercalated ducts and usually do not have striated ducts either so they exit directly from 8-20 excretory ducts  Approximately 5% of saliva entering the oral cavity come from these glands
  8. 8. MINOR SALIVARY GLANDS  There are 800-1000 minor salivary glands located throughout the oral cavity within the submucosa of the oral mucosa in the tissue of the buccal, labial, and lingual mucosa, the soft palate, the lateral parts of the hard palate, and the floor of the mouth or between muscle fibers of the tongue  They are 1-2mm in diameter and unlike the major glands, they are not encapsulated by connective tissue, only surrounded by it  The gland has usually a number of acini connected in a tiny lobule  A minor salivary gland may have a common excretory duct with another gland, or may have its own excretory duct  Their secretion is mainly mucous in nature (except for Von Ebner glands- see next section) and have many functions such as coating the oral cavity with saliva
  9. 9. VON EBNER GLANDS (Ebner's glands or gustatory glands)  Von Ebner glands are glands found in a trough circling the circumvallate papillae on the dorsal surface of the tongue near the sulcus terminalis  They secrete a purely serous fluid that begins lipid hydrolysis  They also facilitate the perception of taste through secretion of digestive enzymes and proteins  The arrangement of these glands around the circumvallate papillae provides a continuous flow of fluid over great number of taste bud present along the sides of the papillae  It is important for dissolving the food particles to be tested
  10. 10. COMPONENTS AND MAJOR FUNCTIONS OF SALIVA Functions Components involved (1) Protective functions Lubrication Mucins, proline-rich glycoproteins, water Antimicrobial Amylase, complement, defensins, lysozyme, lactoferrin, lactoperoxidase, mucins, cystatins, histatins, proline-rich glycoproteins, secretory IgA, secretory leukocyte protease inhibitor, statherin, thrombospondin Growth factors Epidermal growth factor (EGF), transforming growth factor-alpha (TGF-a), transforming growth factor- beta (TGF-b), fibroblast growth factor (FGF), insulin-like growth factor (IGF-I & IGF-II), nerve growth factor (NGF)
  11. 11. COMPONENTS AND MAJOR FUNCTIONS OF SALIVA Mucosal integrity Mucins, electrolytes, water Lavage/cleansing Water Buffering Bicarbonate, phosphate ions, proteins Remineralization Calcium, phosphate, statherin, anionic proline-rich proteins (2) Food- and speech-related functions Food preparation Water, mucins Digestion Amylases, lipase, ribonuclease, proteases, water, mucins Taste Water, gustin Speech Water, mucins
  12. 12. ADVANTAGES OF SALIVA COLLECTION  The most commonly used laboratory diagnostic procedures involve the analyses of the cellular and chemical constituents of blood  Whole saliva can be collected non-invasively, and by individuals with limited training
  13. 13.  Diagnosis of disease via the analysis of saliva is potentially valuable for children and older adults, since collection of the fluid is associated with fewer compliance problems as compared with the collection of blood  Further, analysis of saliva may provide a cost-effective approach for the screening of large populations
  14. 14. TYPES OF SALIVA  Saliva can be considered as gland- specific saliva and whole saliva  Gland-specific saliva can be collected directly from individual salivary glands: parotid, submandibular, sublingual, and minor salivary glands  The collection and evaluation of the secretions from the individual salivary glands are primarily useful for the detection of gland- specific pathology, i.e., infection and obstruction
  15. 15. WHOLE SALIVA  However, whole saliva is most frequently studied when salivary analysis is used for the evaluation of systemic disorders  Whole saliva (mixed saliva) is a mixture of oral fluids and includes secretions from both the major and minor salivary glands, in addition to several constituents of non- salivary origin, such as gingival crevicular fluid (GCF), expectorated bronchial and nasal secretions, serum and blood derivatives from oral wounds, bacteria and bacterial products, viruses and fungi, desquamated epithelial cells, other cellular components, and food debris
  16. 16. SALIVA COLLECTION  Saliva can be collected with or without stimulation  Stimulated saliva is collected by masticatory action (i.e., from a subject chewing on paraffin) or by gustatory stimulation (i.e., application of citric acid on the subject's tongue)  Stimulation obviously affects the quantity of saliva; however, the concentrations of some constituents and the pH of the fluid are also affected
  17. 17.  Unstimulated saliva is collected without exogenous gustatory, masticatory, or mechanical stimulation  Unstimulated salivary flow rate is most affected by the degree of hydration, but also by olfactory stimulation, exposure to light, body positioning, and seasonal and diurnal factors  The best two ways to collect whole saliva are the draining method, in which saliva is allowed to drip off the lower lip, and the spitting method, in which the subject expectorates saliva into a test tube
  18. 18. SERUM COMPONENTS IN SALIVA  There are several ways by which serum constituents that are not part of the normal salivary constituents (i.e., drugs and hormones) can reach saliva  Within the salivary glands, transfer mechanisms include intracellular and extracellular routes  The most common intracellular route is passive diffusion, although active transport has also been reported  Ultrafiltration, which occurs through the tight junctions between the cells, is the most common extracellular route
  19. 19.  In contrast, a serum molecule reaching saliva by diffusion must cross five barriers: the capillary wall, interstitial space, basal cell membrane of the acinus cell or duct cell, cytoplasm of the acinus or duct cell, and the luminal cell membrane  Serum constituents are also found in whole saliva as a result of GCF outflow  Depending on the degree of inflammation in the gingiva, GCF is either a serum transudate or, more commonly, an inflammatory exudate that contains serum constituents
  20. 20. SYSTEMIC DISORDERS AFFECTING SALIVARY GLANDS AND SALIVA  Autoimmune disease - Sjögren's syndrome, rheumatoid diseases,myasthenia gravis, graft-vs.-host disease  Cancer  Cirrhosis  Cystic fibrosis  HIV infection  Hormonal disorders - adrenal-cortical disease, diabetes mellitus, thyroiditis, acromegaly  Hypertension  Metabolic disturbances - malnutrition, dehydration, vitamin deficiency  Neurological diseases - Parkinsonism, Bell's palsy, cerebral palsy, Alzheimer's disease  Renal disease  Sarcoidosis
  21. 21. HEREDITARY DISEASES Cystic fibrosis (CF) Submandibular saliva  Elevated levels of phosphate, neutral lipids, phospholipids, glycolipids, electrolytes (sodium, chloride, calcium, phosphorus), urea and uric acid, and total protein  Decrease in flow rate, Decreased protease activity  Epidermal growth factor (EGF) anomaly and elevated salivary levels of prostglandins E2 (PGE2)  The parotid saliva of CF patients does not demonstrate qualitative changes as compared with that of healthy individual
  22. 22. Coeliac disease  Measurement of salivary IgA-AGA has been reported to be a sensitive and specific method for the screening of coeliac disease, and for monitoring compliance with the required gluten-free diet(sensitivity of 60% and specificity of 93.3%)
  23. 23. 21-Hydroxylase deficiency  Early morning salivary levels of 17- hydroxyprogesterone (17-OHP) were reported to be an excellent screening test for the diagnosis of non-classic 21- hydroxylase deficiency, since the salivary levels accurately reflected serum levels of 17-OHP
  24. 24. AUTOIMMUNE DISEASES—SJÖGREN'S SYNDROME  A low resting flow rate and abnormally low stimulated flow rate of whole saliva  Increased concentrations of sodium, chloride, cystatin C, cystatin S, inflammatory mediators—i.e., eicosanoids, PGE2, thromboxane B2, and interleukin-6  Elevated levels of IgA, IgG, lactoferrin, lipids ,albumin  A decreased concentration of phosphate  SS anti-La antibodies(SS is characterized by autoantibodies to the La and Ro ribonucleoprotein antigens)  Analysis of unstimulated whole saliva was more sensitive than analysis of stimulated whole saliva for detection of these changes, since stimulation caused the elevated levels of sodium and IgA seen in SS patients to decline to the levels observed in healthy controls
  25. 25. MALIGNANCY  SCC - p53 antibody, Elevated levels of salivary defensin-1  BREAST CARCINOMA - tumor markers c-erbB-2 (erb) and cancer antigen 15-3 (CA15-3)  EPITHELIAL OVARIAN CANCER - Elevated salivary levels of CA 125(CA 125 is a tumor marker for epithelial ovarian cancer)
  26. 26. INFECTIOUS DISEASES  Helicobacter pylori - presence of H. pylori DNA in saliva by polymerase chain-reaction (PCR) assay(sensitivity of 84%) and salivary antibodies against H. Pylori  Shigellosis - higher titers of anti-lipopolysaccharide and anti-Shiga toxin antibody
  27. 27.  Pigeon breeder's disease (PBD) - salivary IgG against antigens derived from pigeons  Pneumococcal Pneumonia - pneumococcal C polysaccharide in saliva by ELISA  Lyme disease - detection of anti-tick antibody in saliva  Neurocysticercosis - Specific antibody to Taenia solium larvae
  28. 28. VIRAL DISEASES (EXCLUSIVE OF HIV)  Acute hepatitis A (HAV) and hepatitis B (HBV) - presence of IgM antibodies in saliva  viral hepatitis B and C  Screening for hepatitis B surface antigen (HbsAg) in epidemiological studies  Immunization and detecting infection with measles, mumps, and rubella  Rotavirus (RV) infection - For newborn infants, the salivary IgA response was found to be a better marker of rotavirus (RV) infection than the serum antibody response
  29. 29.  Herpesviruses (human herpesvirus –8, cytomegalovirus, and Epstein-Barr virus) – Shedding in saliva  Reactivation of herpes simplex virus type-1 (HSV-1) - PCR-based identification of virus in saliva  Dengue - Salivary levels of anti-dengue IgM and IgG  parvovirus B 19 - identification of the antibody
  30. 30. HIV  Specific antibody to HIV in saliva detected by ELISA and Western blot assay  Detection of IgA antibody to HIV in saliva  IgG antibody to the virus is the predominant type of anti-HIV immunoglobulin
  31. 31. DRUG MONITORING  Similar to other body fluids (i.e., serum, urine, and sweat), saliva has been proposed for the monitoring of systemic levels of drugs  A fundamental prerequisite for this diagnostic application of saliva is a definable relationship between the concentration of a therapeutic drug in blood (serum) and the concentration in saliva  For a drug to appear in saliva, drug molecules in serum must pass through the salivary glands and into the oral cavity
  32. 32. Drug Monitoring in Saliva 1) Therapeutic Drugs  Antipyrine  Caffeine  Carbamazepine  Cisplatin  Cyclosporine  Diazepam  Digoxin  Ethosuximide  Irinotecan  Lithium  Methadone
  33. 33.  Metoprolol  Oxprenolol  Paracetamol  Phenytoin  Primidone  Procainamide  Quinine  Sulfanilamide  Theophylline  Tolbutamide
  34. 34. 2) Drug Abuse/Recreational Drugs  Amphetamines  Barbiturates  Benzodiazepines  Cocaine  Ethanol  Marijuana  Nicotine  Opioids  Phencyclidine
  35. 35. THE MONITORING OF HORMONE LEVELS  Saliva can be analyzed as part of the evaluation of endocrine function  Cortisol, aldosterone, Testosterone, dehydroepiandrosterone , androstenedione, dihydrotestosterone, Estradiol, progesterone, estriol, Insulin
  36. 36. FORENSIC EVIDENCE  violent crimes- bite marks, cigarette butts, postage stamps, envelopes and other objects  amylase assay- Stains of dried saliva  Polymerase chain reaction (PCR)
  37. 37. DIAGNOSIS OF ORAL DISEASE WITH RELEVANCE FOR SYSTEMIC DISEASES  Evaluation of the quantity of whole saliva is simple and may provide information which has systemic relevance  Quantitative alterations in saliva may be a result of medications  At least 400 drugs may induce xerostomia. Diuretics, antihypertensives, antipsychotics, antihistamines, antidepressants, anticholinergics, antineoplastics, and recreational drugs such as opiates, amphetamines, barbiturates, hallucinogens, cannabis, and alcohol have been associated with a reduction in salivary flow
  38. 38.  Reduced salivary flow may lead to oral problems like progressive dental caries, fungal infection, oral pain, and dysphagia  Qualitative changes in salivary composition can also provide diagnostic information concerning oral problems  patients who received chemotherapy developing stomatitis - Increased levels of albumin in whole saliva and IgG
  39. 39.  Radiation therapy to the head and neck - a significant negative correlation was found between normalized EGF (concentration of salivary EGF relative to total salivary protein concentration) and severity of mucositis  Development of oral and gastric cancer – Increased levels of salivary nitrate, nitrite, and nitrosamine  Detection of oral candidiasis - salivary fungal counts  Monitoring of oral bacteria - increased numbers of  Streptococcus mutans and Lactobacilli in saliva were associated with increased caries prevalence and with the presence of root caries
  40. 40.  Saliva can serve as a vector for bacterial transmission, and also as a reservoir for bacterial colonization  Detection of certain bacterial species in saliva can reflect their presence in dental plaque and periodontal pockets
  41. 41. LIMITATION OF USING SALIVA  The transfer of serum constituents which are not part of the normal salivary constituents into saliva is related to the physicochemical characteristics of these molecules  Lipophilic molecules diffuse more readily into saliva than do lipophobic molecules  Furthermore, different substances reach saliva by different mechanisms  Although passive diffusion is considered to be the most common mechanism for drugs and hormones, ultra filtration and active transport have also been proposed for some substances.
  42. 42.  For accurate diagnosis, a defined relationship is required between the concentration of the biomarker in serum and the concentration in saliva  Normal salivary gland function is usually required for the detection of salivary molecules with diagnostic value  Salivary composition can be influenced by the method of collection and the degree of stimulation of salivary flow  Changes in salivary flow rate may affect the concentration of salivary markers and also their availability due to changes in salivary pH  Variability in salivary flow rate is expected between individuals and in the same individual under various conditions  In addition, many serum markers can reach whole saliva in an unpredictable way (i.e., GCF flow and through oral wounds).
  43. 43.  These parameters will affect the diagnostic usefulness of many salivary constituents  Furthermore, certain systemic disorders, numerous medications, and radiation may affect salivary gland function and consequently the quantity and composition of saliva  Whole saliva also contains proteolytic enzymes derived from the host and from oral micro-organisms  These enzymes can affect the stability of certain diagnostic markers  Some molecules are also degraded during intracellular diffusion into saliva  Any condition or medication that affects the availability or concentration of a diagnostic marker in saliva may adversely affect the diagnostic usefulness of that marker
  44. 44. POTENTIAL USE OF SALIVA  Saliva offers an alternative to serum as a biologic fluid that can be analyzed for diagnostic purposes  Whole saliva contains locally produced as well as serum-derived markers that have been found to be useful in the diagnosis of a variety of systemic disorders  Whole saliva can be collected in a non- invasive manner by individuals with modest training, including patients.  This facilitates the development and introduction of screening tests that can be performed by patients at home  Analysis of saliva can offer a cost- effective approach for the screening of large populations, and may represent an alternative for patients in whom blood drawing is difficult, or when compliance is a problem
  45. 45. Salivary Biomarkers with their possibility for use
  46. 46. THANK YOU