Blood tests

Blood tests in the context of DMARD monitoring

FBC

Please refer to the Shared Care Guidelines for specific medications for advice re cut offs for stopping medication and seeking advice, but some general advice is provided here.

Anaemic

Low Hb in isolation, with normal WCC and PLTS is unlikely to be as a consequence of DMARD treatment. We would advise checking B12, folate and iron status (beware of using ferritin, which will be elevated if there is active inflammation, even if iron deficient). Haematinic abnormalities, and particularly iron deficiency should be managed as for any other patients.

Low WCC

May be as a consequence of the patients disease (particularly in SLE / connective tissue disease, where there are often low lymphocytes) – please look at the trend in results and follow the Shared Care Guidelines.

Low PLT Count

Patients are usually safe from bleeding complications providing platelet count >50. Again, PLT count may be disease related, follow advice in Shared Care Guidelines.

LFT

In general, extended LFT, which include both ALT and AST should be checked as part of the DMARD monitoring protocol. Elevations of the ALP and GGT are not usually medication related, and suggest obstructive pathology – if persistent and progressive an ultrasound scan should be requested. An isolated elevation in the GGT is usually caused by either alcohol consumption or fatty infiltration of the liver, which again is usually demonstrated on USS.

Elevation of ALT / AST may relate to DMARD treatment. In general DMARDs can be continued with careful monitoring providing ALT and AST <100, but should be stopped and rheumatology contacted for advice if elevated beyond this. If the patient is receiving methotrexate, LFTs can be improved by increasing folic acid supplementation to 5mg daily, except for the Mtx day.

Other causes of raised ALT / AST include – recent flu jab, viral illness, hepatitis (if markedly elevated consider Hep E for which patients have a lifetime risk of around 15%).