Inflammatory Markers -CRP, Plasma Viscosity
Recommendations for inflammatory marker testing in Cornwall from 1st January 2020
No guideline will adequately capture the minutiae of rationale for inflammatory marker testing. The Blood Sciences Department are happy to discuss or clarify individual issues as they arise; please direct queries to rch-tr.haematology-lab@nhs.net
CRP should be your first line inflammatory marker test of choice
There are not many situations where good clinical correlation with (or without) the CRP cannot guide patient management. If a second line inflammatory marker is required we will send plasma viscosity (PV) to University Hospital Plymouth. This test will carry an expected 2-4 day turnaround time.
PV should not be requested automatically for routine situations where the ESR was used previously. We will be consciously discouraging unnecessary PV requests. We will be monitoring our test volumes alongside any specific concerns that have been flagged by our users.
ICE will be set up to allow specification of PV request rationale:
- If temporal arteritis (TA)/giant cell arteritis (GCA) or hyperviscosity syndrome is suspected then PV, although not necessary, may be requested. Appropriate management of these indications should not be delayed while results are pending.
- If a systemic inflammatory illness such as rheumatoid arthritis or systemic lupus erythematosus is suspected and CRP is normal then PV may be appropriate to establish a baseline for monitoring.
- If CRP has been shown to inadequately reflect disease activity in a patient with established chronic inflammatory illness (such as rheumatoid arthritis or systemic lupus erythematosus) then monitoring with PV will be appropriate.
There is room to select ‘Other’ as the rationale for your PV request if it does not fall within these criteria. These will be vetted on a case-by-case basis. We aim not to be obstructive, but if clinical details are inadequate we will store the sample pending further information.
ESR redundancy and the consequent change in clinical practice are a work in progress. This document will be updated at intervals so that our guidance can adapt to reflect any consistent issues that arise.
Date Reviewed 23/01/2020
Date Next Review 23/01/2021
Author Dr Adam Forbes, Consultant Haematologist and Clinical Head of Department for Haematology
RMS Sifter Dr Michele Sharkey, RMS Haematology Lead
Version No. 1.0