C3 and C4 are complement proteins, part of the immune system. They can rise when there is inflammation and fall in some immune conditions, such as lupus, so a doctor reads them alongside your other results.

Why is cystatin C included?

Cystatin C is a second measure of kidney function. Unlike creatinine, it does not depend on how much muscle you have, which can help when muscle mass is unusually high or low.

Muscle & Rheumatology Blood Test at Jace Medical

Muscle, bone & joints

Private blood test

Muscle & Rheumatology Blood Test

A broad panel covering muscle, inflammation, immune and organ markers relevant to rheumatology.

31 biomarkers
No fasting needed

£129Includes sample collection

Book this test Ask a question

We confirm your appointment and any preparation, such as fasting, before you attend.

What’s included

31 biomarkers in this test.

No fasting needed

Liver6

Enzymes and proteins that show how well your liver is working.

Alanine Aminotransferase (ALT)
Albumin
Alkaline Phosphatase (ALP)
Aspartate Aminotransferase (AST)
Gamma-Glutamyltransferase (GGT)
Total Bilirubin

Kidneys5

How well your kidneys filter waste from your blood.

Creatinine
Cystatin C
Estimated Glomerular Filtration Rate (eGFR)
Urea
Uric Acid

Body salts & minerals6

Electrolytes and minerals that help your nerves, muscles and heart work properly.

Calcium (adjusted)
Chloride
Magnesium
Phosphate
Potassium
Sodium

Iron & anaemia5

Your iron levels and stores, a common cause of tiredness when low.

Ferritin
Iron
Total Iron Binding Capacity (TIBC)
Transferrin
Transferrin Saturation

Vitamins1

Key vitamins for energy, nerves, bones and healthy blood.

Vitamin D

Inflammation & immunity7

Signs of inflammation in the body and how your immune system is working.

Complement Component 3 (C3)
Complement Component 4 (C4)
C-Reactive Protein (CRP)
Immunoglobulin A (IgA)
Immunoglobulin G (IgG)
Immunoglobulin M (IgM)
Rheumatoid Factor (RF)

Muscle & bone1

Markers of muscle damage and the hormone that controls calcium in your bones.

Creatine Kinase

About this test

Is the Muscle & Rheumatology Blood Test right for you?

Who it’s for

You have muscle aches, weakness or joint pain and want a broad set of results to take to your GP.
You take a statin and have muscle symptoms, and want your muscle, liver and kidney markers checked. Tell your prescriber about your symptoms as well.
You feel generally unwell with aches and tiredness and want to check for inflammation, low iron or low vitamin D.
You have had attacks of joint pain that may be gout.

What it can show

Creatine kinase (CK) is released when muscle is damaged or under strain. Uric acid helps confirm gout, and rheumatoid factor (RF) is an antibody found in many people with rheumatoid arthritis.
CRP shows inflammation in the body. Complement proteins C3 and C4 can rise with inflammation and fall in some immune conditions such as lupus. Immunoglobulins (IgG, IgA and IgM) are antibodies. Raised levels can be seen with long-term infections, autoimmune conditions and liver disease, and low levels can point to a weakened immune system.
Kidney markers (creatinine, eGFR, cystatin C, urea, sodium, potassium and chloride) and liver markers (ALT, AST, ALP, GGT, bilirubin and albumin) show how these organs are working. Cystatin C is a second kidney marker that, unlike creatinine, is not affected by muscle mass.
Iron, ferritin, transferrin, TIBC and transferrin saturation show your iron levels and stores. Calcium, phosphate, magnesium and vitamin D relate to bone and muscle health.

What it can’t tell you

This panel does not include anti-CCP antibodies, ANA or ESR, which are often used when looking into rheumatoid arthritis or lupus. Our Rheumatology test includes these.
CK can rise after strenuous exercise, injury or injections into a muscle. AST is found in muscle as well as the liver, so a raised result does not always mean a muscle or liver condition.
About 1 in 20 people without rheumatoid arthritis test positive for RF, and many people with it test negative. No blood test can prove or rule out rheumatoid arthritis on its own.
Results need to be interpreted alongside your symptoms. Diagnosis and treatment of muscle, joint and immune conditions are with your GP or specialist.

How it works

From booking to results in three steps.

Step 1
Request your test
Send a booking request online or call us. We confirm your clinic, appointment time and any preparation.
Step 2
Visit the clinic
A short appointment for professional sample collection at Greysteel or Letterkenny. No GP referral needed.
Step 3
Receive your results
Usually within a couple of working days, emailed to you once a doctor has reviewed them.

Common questions

Questions about this test.

This is a broad panel covering muscle, inflammation, immune proteins, kidney, liver, iron and vitamin D. The Rheumatology test is more focused and includes anti-CCP antibodies and ESR, with ANA in the Extended option.

Based on 12 sources, including NHS and NICE guidance