A titer or titre is a value derived from a scientific method of testing called titration. Essentially, when something like blood is titrated, the substance looked for is diluted (watered down) repeatedly to see how long the substance remains. The amount of times dilution occurs with the element being evaluated remaining is its titer. This makes much more sense when it is considered in the context of medical testing, where there are many tests to determine different values of things that involve titrating samples.
Some common types of these tests include those to check antibodies to various infectious diseases like measles or mononucleosis. Titration of blood is also useful to evaluate abnormal antibody response that may occur in certain autoimmune diseases. In illnesses like lupus or Hashimoto’s thyroiditis, a blood or serum antibody test can be employed to evaluate the body’s immune response to itself. Higher titer or levels of antibody response may suggest the body is attacking itself and creating inflammatory response when it should not.
There are a few reasons why a titer test is ordered to evaluate exposure or antibodies to certain diseases. Doctors may want to know if patients have lost immunities that were conferred through having a disease or via vaccination years ago. Women who are thinking of getting pregnant might be asked by their doctors to wait until they take a rubella test, to make certain they are still immune to this illness that can seriously affect a fetus. If immunity is not shown, a doctor might want to immunize a woman first and have her wait a few months before trying to get pregnant so she is more protected.
In other situations, parents feel uncomfortable with the many booster shots kids receive and ask doctors to prove they are necessary by performing a antibody test first. When immunity hasn’t been lost, parents may decide to wait before repeating vaccinations. In some places they might even be able to use test results as a means of proving immunity to school districts that require immunization schedules be strictly followed.
Contraction of certain illnesses isn’t always noticed initially. With titration, doctors may be able to look for illnesses or exposure to them to diagnose some conditions. Presence of antibodies to mononucleosis often confirms diagnosis of this illness. Titer can also be checked for things like herpes simplex virus. Positive antibodies or higher dilution levels, suggest these diseases are present.
Some types of the titer test are useful diagnostics when autoimmune diseases are suspect. It can be very hard to positively confirm a lupus diagnosis in its early stages. Titer tests, though not always complete confirmation, may help make this easier.
People asked to undergo a titer test should know that in most cases, the average test is not that complicated. It typically involves having a small amount of blood drawn by a health care worker, often at a local lab. The actual titration takes place in a lab and the person waits at home for results, which are usually sent to the doctor first and then discussed by doctor and patient. Depending on type of test, the next step will vary tremendously and could involve doing nothing, getting an immunization, or initiating treatment for an illness or disease.