PANDAS stands for “Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections”. PANDAS is typically diagnosed when a child has a strep infection and develops other disorders such as obsessive-compulsive disorder (OCD), a tic disorder, or both. If a child already has either one of these disorders, a strep infection that makes them worse could also be considered PANDAS.
When symptoms develop, they do so quite suddenly. For example, a child may be completely fine when they go to bed at night and wake up with dramatic symptoms such as vocal or motor tics, new compulsions, or obsessions. Other signs of PANDAS can include anxiety attacks, separation anxiety, and irritability. It can be hard to determine if a child has PANDAS because there is no single test available – it takes quite a lot of investigation to come to a positive diagnosis. So how does laboratory testing for identifying PANDAS work? Read on to learn more.
What causes PANDAS?
Strep bacteria are ancient organisms that have learned to evade detection by the immune system over time. They can do this by camouflaging against immune cells by using other molecules in the body.
For example, strep bacteria can cover their cell walls with molecules almost identical to organs within the body, such as the heart and brain. Other molecules it can use to stay hidden can appear similar to those found in the joints and skin. This molecular mimicry is why the bacteria can keep themselves hidden within the body.
The bacteria’s ability to hide doesn’t last forever, though. Eventually, the immune system will pick up on the imposter molecules and react to them by encouraging the production of antibodies. However, this is where issues develop. Because the molecules appear similar to those found in healthy tissues within the body, the immune system can get confused and begin attacking the healthy molecules in the process of attacking the strep bacteria.
OCD and other tic-like disorders develop because the antibodies that mistake healthy molecules for harmful strep bacteria often target the brain, creating neuropsychiatric symptoms.
How is PANDAS disease diagnosed?
No single test can diagnose PANDAS. Various methods are needed to ensure that a child is correctly diagnosed with the disorder and treated effectively.
There are several diagnostic criteria used for PANDAS. The first is the presence of an obsessive-compulsive disorder or a tic disorder at specific ages. Children aged between three and 12 are the most likely to have PANDAS. The second revolves around the symptoms, their severity, and how often they occur. For example, if a child has PANDAS, their symptoms will appear suddenly and be severe right away. Then, over several weeks or months, tics and symptoms will gradually improve.
Another diagnostic tool used for PANDAS is checking for a strep infection. Without the presence of a strep infection, a condition cannot be PANDAS. That is why ensuring that there is (or at least has been) a strep infection is an integral part of the diagnostic process for the disorder.
What tests are done to diagnose PANDAS?
Several tests are used alongside the aforementioned diagnostic tools to ensure that a child can be positively diagnosed with PANDAS. The first may be a throat culture. This test checks for the presence of strep bacteria within the body.
In many cases, blood tests are used as well. One such blood test is the anti-strep antibody titer test. This can determine whether a child has had a strep infection in the past. The results look for elevated levels of the anti-strep antibody titer. If the levels are higher than they should be, they indicate that a strep infection occurred within the past few months of symptom onset.
Other blood tests can include:
- Complete blood count (CBC)
- Iron level test
- B12 level test
- Vitamin D level test
- Antibody tests for IgA, IgM, and IgG antibodies
- Antinuclear antibodies (ANA)
Another test used to diagnose PANDAS is the Cunningham Panel. The Cunningham Panel is a series of complex blood tests that check for autoimmune antibodies, which are the antibodies that attack healthy tissues within the body. The tests look for levels of various biomarkers, including:
- Dopamine D1 receptor
- Dopamine D2L receptor
- Lysoganglioside GM1
- CaM kinase II
Elevated levels of these biomarkers show that an infection was present and caused autoimmunity. Each biomarker is related to different symptoms that appear in PANDAS. Thus, all five are done simultaneously to see how they measure up and whether or not they are contributing to the disease.
Until a singular test is created to determine if a child has PANDAS, various labs and other diagnostic tools are needed to help doctors find the correct diagnosis and put a child on the path to treatment.