Guide to blood tests in rheumatology

Inflammatory markers

  • Please perform, CRP (and consider PV if CRP normal) as discrepancy can be useful information.
  • Beware CRP rises with increasing BMI.
  • PV can be affected by age, exercise, smoking and pregnancy.
  • CRP typically normalises faster than PV on treating PMR/GCA
  • Normal inflammatory markers can be seen in inflammatory arthritis. If clinical suspicion remains high despite normal blood tests then refer ( this is especially true in psoriatic arthritis).

Rheumatoid Factor

  • Can be positive in 5-20% normal population, especially at low titres (11-30).
  • 70% of patients with RA will have positive RhF and 90% of patients with Sjorgens.
  • RhF can be negative in Rheumatoid arthritis so if strong clinical suspicion still refer.


Anti-CCP ( Anticycylic citrullinated peptide)

  • More specific for RA but can only be requested by secondary care

ANA ( Antinuclear antbodies)

  • Only check if Autoimmune disease is suspected, ie. Symptoms include inflammatory arthritis, myalgias, rashes, mouth ulcers, recurrent serositis (pericarditis and pleurisy), and sicca symptoms (dry eyes and mouth).
  • Prevalence of ANA in healthy people (3-30%), with higher levels in women and with increasing age.
  • Even at high titres (>1:160), a positive ANA result alone does not indicate Autoimmune disease.
  • Other conditions associated with positive ANA, include viral infections and cancers.

Uric acid

  • Raised levels associated with gout
  • Levels can be normal in gout especially at the time of acute attack 


Arthritis Research UK- Approach to polyarthralgia ,2012; Gout 2016

American college of Rheumatology, Patient information-2015


Guidelines reviewed                06/01/2020

Next review due                       06/01/2021

GP Sifter                                  Dr B Wesson ( RMS GP Lead for Rheumatology)


Version 1.4