NEW YORK (GenomeWeb) – A new study published in the journal Biomarkers shows that saliva's antibody levels are linked to those in blood serum, making saliva suitable for assessing how protected a given patient is against bacterial infections.
Taking saliva test samples is non-invasive, requires no special training, and may be more cost-effective than using blood serum, according to researchers at the University of Birmingham. The method may be particularly important for children and patients in developing countries because taking blood samples is not always feasible.
The researchers took blood and saliva samples from 72 healthy adults and analyzed them for concentrations of IgG-, IgM-, and IgA-antibodies against 12 pneumococcal antigens. They found that higher antibody concentrations in serum were generally associated with higher concentrations in saliva — they observed the strongest relationships for IgA antibodies.
"Protection against bacterial infection is usually inferred by measuring antibody levels in blood serum," lead author Jennifer Heaney, from the School of Immunity and Infection at Birmingham, said in a statement. "The suggestion that antibody levels in saliva may be indicative of those in serum has important implications for markers of immunity and vaccination in many parts of the world."
Previous Birmingham research showed that lower levels of antibodies in saliva are associated with an elevated risk of mortality, and that saliva sampling to determine IgA secretion rate has the potential to be used as an indicator of overall health during a general check-up. Measuring antibodies in saliva may have promise when clinicians are conducting future epidemiological studies that involve vaccinating people to prevent bacterial infections, the researchers said.
Heaney noted that the research community would need to conduct larger studies to investigate the potential of saliva testing as a clinical tool to assess immunity.