Page 187 - Registrar Orientation Manual 2016

Reference:
Effective date:
2015
Expiry date:
2018
Page:
13 of 28
Title: Laboratory Testing Guidelines (DRAFT)
Type:
Clinical Guideline
Version:
01
Authorising initials:
Immunology
ANA ($25) ENA Screen ($30)
The Choosing Wisely recommendations include the following:
Don’t test for ANA sub-serologies unless ANA +ve and clinical suspicion or evidence of rheumatic disease.
Don’t repeat ANA if established JIA or SLE.
We recommend:
Do not request ANA unless there are features suggestive of a connective tissue disease.
Do not repeat ANA within 12 months of previous tests unless the result does not fit the clinical picture or there has been evolution in the clinical picture.
Do not repeat ENA testing unless there has been a change in the clinical picture.
ANA testing has limited specificity and, if performed unselectively, gives many false positives.
ENA results do not usually change significantly with treatment and repeat testing is therefore not useful unless there has been a change in the clinical picture suggesting evolving disease. The laboratory will not process repeat specimens without being contacted on (07) 8398726 x98461.
The laboratory will not repeat ANA or ENA tests within 12 months without SMO discussion.
ANCA ($24)
The DHB Shared Services Laboratory Test Referral Guidelines recommend the following are indications for an ANCA:
1. Glomerulonephritis (especially RPGN),
2. Pulmonary haemorrhage (especially pulmonary renal syndrome),
3. Cutaneous vasculitis with systemic features, multiple lung nodules,
4. Chronic destructive disease of the upper airways,
5. Longstanding sinusitis or otitis,
6. Subglottic tracheal stenosis,
7. Mononeuritis multiplex or other peripheral neuropathy,
8. Retro-orbitalmasses,
9. Monitoring response to treatment (more controversial).
We recommend:
Do not do an ANCA unless a patient has one of these indications. Anti-CCP ($55)
We recommend:
Do not do anti-CCP unless there is a clinical suspicion of an inflammatory polyarthritis that might be rheumatoid arthritis.
Do not do anti-CCP in the work-up of a monoarthropathy.
Coeliac Abs ($33)
Gliadin or deaminated gliadin peptide (DGP) is the preferred test for coeliac disease. Testing costs the DHB over $60,000 a year. We recommend the following:
Do not test for coeliac disease unless there are good clinical reasons (for example unexplained iron deficiency or symptoms of malabsorption).