IgG class anti-DGP antibodies may be useful in people with IgA deficiency. In children younger than two years, anti-DGP antibodies perform better than anti-endomysial and anti-transglutaminase antibodies tests.Because of the major implications of a diagnosis of coeliac disease, professional guidelines recommend that a positive blood test is still followed by an endoscopy/gastroscopy and biopsy. A negative serology test may still be followed by a recommendation for endoscopy and duodenal biopsy if clinical suspicion remains high.Historically three other antibodies were measured: anti-reticulin (ARA), anti-gliadin (AGA) and anti-endomysial (EMA) antibodies. ARA testing, however, is not accurate enough for routine diagnostic use. Serology may be unreliable in young children, with anti-gliadin performing somewhat better than other tests in children under five. Serology tests are based on indirect immunofluorescence (reticulin, gliadin and endomysium) or ELISA (gliadin or tissue transglutaminase, tTG).Other antibodies such as anti–Saccharomyces cerevisiae antibodies occur in some people with coeliac disease but also occur in other autoimmune disorders and about 5% of those who donate blood.Antibody testing may be combined with HLA testing if the diagnosis is unclear. TGA and EMA testing are the most sensitive serum antibody tests, but as a negative HLA-DQ type excludes the diagnosis of coeliac disease, testing also for HLA-DQ2 or DQ8 maximises sensitivity and negative predictive values.
Antisialagogues are drugs or substances that decrease the flow rate of saliva and their effect is opposite to that of sialagogues. Their origin may be both natural and synthetic. Anticholinergics generally have antisialagogue effects, and most produce some level of sedation, both being advantageous in surgical procedures. Classic antisialagogues include:

atropine,
opium,
alkalies,
belladonna,
hyoscyamus,
stramonium,
tobacco in excess,
all nauseous or insipid substances. == References ==