Glossary

Why are blood tests used so regularly with autoinflammatory disease patients, what are they looking for and what do the results mean?

*Disclaimer: The following information has been approved by our Medical Advisory Board but please discuss your results with your GP or Consultant. This is an information guide about what each test is for, not a diagnostic tool.

Blood tests are often performed regularly on patients with diagnosed or suspected
autoinflammatory disease. The results can be used to:
· Aid diagnosis
· Look for signs of inflammation, for example spikes of inflammation during flares
· Determine if treatment being given is working effectively
· Check for ‘red flags’ requiring urgent treatment, such as excessive immunosuppression if on
treatment

Blood tests commonly performed for autoinflammatory disease patients include:
· Genetic testing
· C-Reactive Protein (CRP)
· Erythrocyte Sedimentation Rate (ESR)
· Serum Amyloid A (SAA)
· Full blood count
· Amongst others such as general tests of liver and kidney function

Genetic Testing
Autoinflammatory conditions often have many overlapping symptoms, which can make
diagnosis difficult. There are several gene panel tests which can be performed by a blood test.
The genetic tests will look to identify genetic mutations present in an individual’s DNA. Some
autoinflammatory diseases have specific genetic mutations associated with them, therefore the
results can help the doctors differentiate which disease a patient may have.

C-Reactive Protein (CRP)
CRP is a protein which is produced by the liver and found in blood plasma. The levels are
usually very low in a healthy individual, and often not detectable. CRP is used as a marker for
inflammation in the body. CRP is often raised in autoinflammatory patients experiencing a flare
of their symptoms and can be slightly raised outside of a flare. Other causes of raised CRP can
include infection or as a reaction to physical trauma.

Erythrocyte Sedimentation Rate (ESR)
ESR is a method used to monitor inflammation within the body. Like CRP, it does not give a
specific diagnosis or cause of symptoms but can evidence inflammation within the body. The
test involves measuring the time it takes for a red blood cells (erythrocytes) to fall to the bottom
of a tube of blood. In individuals with increased inflammation, the red blood cells will fall more
quickly, which will give a higher ESR result. Other causes of raised ESR include infection,
anaemia, pregnancy and old age.

Serum Amyloid A
SAA is another inflammatory biomarker which can be monitored in individuals with suspected
autoinflammatory disease. SAA is a protein which is released in response to inflammation in the
body. The levels of SAA are also monitored to assess the effectiveness of an individual’s
treatment, and to identify the risk of long-term complications such as amyloidosis. If SAA
remains high even whilst on treatment, it is an indication that higher dosage or alternative
treatment may be required. A high SAA does not equate to systemic amyloidosis, however.

Full Blood Count
The full blood count is common test that looks at a patient’s overall health. It looks at a patient’s
red blood cells, haemoglobin, white blood cells and platelets.
Red blood cell count shows the number of red blood cells present in a volume of blood. Low
red blood cell count and haemoglobin levels could indicate anaemia. Haemoglobin count looks
at the haemoglobin content of the blood. This is a protein which is found in red blood cells, it is
what carries oxygen in the blood and causes blood to be red in colour. Low levels indicate
anaemia.

MCV or Mean Corpuscular Volume is the average (i.e. mean) volume of red cells within a
blood specimen. This test’s value is low if red cells are small, i.e. microcytic, or high if the red
cells are large, i.e. macrocytic. The size of red cells helps doctors determine the possible cause
of anaemia, when considered together with other blood levels such as ‘Hb’ or Haemoglobin.

White blood cell count is the number of white blood cells present in a volume of blood. Low
white blood cell count can indicate immunosuppression (reduction in the effectiveness of the
body’s immune system), possibly due to various treatments used to treat autoinflammatory
disease. The most common cause of a high white blood cell count is usually infection
somewhere in the body, but for patients with autoinflammation can indicate active disease
without infection. With white blood cell count there is also a differential count performed. This
looks at the specific types of white blood cells, such as neutrophils and lymphocytes,
monocytes, eosinophils and basophils.

Neutrophils are a type of white blood cell responsible for immune system response to
infections or antigens (i.e. any kind of invader). Neutrophil levels may rise as a response to
infection or inflammation, such as from active autoinflammatory disease, injury, other types of
inflammatory processes, heart disease, or cancer. Neutrophil levels may be lower than average
as a side effect of medication, or as part of a disorder’s process.

Platelets are important in the blood clotting process, they are made up of fragments of a cell
type called a megakaryocyte, found in the bone marrow.
Low platelet count can be caused by several things including viral infection and due to the
presence of immunological disease.
High platelet count can indicate inflammation or infection.

Liver function
ALT or Alanine Transaminase is a test that measures the levels of an enzyme found mostly in
the liver. This enzyme, ALT, can also be found albeit in much lower amounts in a person’s
kidneys, heart and muscles. Elevated ALT levels may indicate liver damage or liver disease, but
ALT may also be elevated when a person has inflammation in the bile ducts, from fatty liver, or
a viral liver infection (hepatitis). It is important to note that some medication may also cause an
ALT elevation; your doctor will be able to determine whether this is the case and whether any
medication requires adjustment as a result. An ALT test is part of more wider liver function
tests, several different blood tests that measure the levels of different proteins and enzymes
that, when looked at together, can provide doctors with a comprehensive idea of how well the
liver is functioning.
ALP or Alkaline Phosphatase is a test that measures the levels of an enzyme found mostly in
the liver. This enzyme, ALP, is found in much lower amounts in the bones as well. Elevated
levels of ALP usually indicate liver disease, inflammation of the bile ducts or certain disease
processes of the bones. It is important to note that some medication may also cause an ALP
elevation; your doctor will be able to determine whether this is the case and whether any
medication requires adjustment as a result. An ALP test is part of more wider liver function tests,
several different blood tests that measure the levels of different proteins and enzymes that,
when looked at together, can provide doctors with a comprehensive idea of how well the liver is
functioning. Very high levels of ALP might indicate vitamin D deficiency. ALP levels tend to be
higher in healthy growing children than in adults.

Kidneys
Serum Creatinine is a waste product produced by the body and filtered through the kidneys.
Measuring a person’s serum creatinine level can show how well their kidneys are functioning.’

Blood Pressure
A Blood Pressure or BP Test, whilst strictly speaking not a blood test (i.e. no needle required)
may be done as an indicator of your cardiovascular health. The result will be interpreted in
conjunction with blood and urine test results, any relevant family history as well as diet. High
blood pressure is common in the population (“essential hypertension”), but sometimes can be
caused by medicines (e.g. steroids), or damage to the kidneys from diseases including some
autoinflammatory diseases