Heparin tube specimen NOT suitable (fibrinogen band can be confused with a paraprotein band).
.
Uncertainty of Measurement:
For the gamma region: The uncertainty of measurement of paraproteins (if present) is 10% at a concentration of 20g/L and 20% at a concentration of 8 g/L.
For the non-gamma region: The uncertainty of the quantitation (if present) is 5% at the concentration of 24g/L.
Frequency: Daily (not performed on weekends and stat days)
TAT is 5 working days for the EPG, with up to 5 extra days if immunofixation are required.
Myeloma Screen, following tests will be performed
- Immunoglobulin G, A and M
- Serum protein electrophoresis
-
Serum free light chains and kappa/lambda ratio
Monoclonal Gammopathies
- Capillary zone electrophoresis (CZE) is performed to identify abnormal bands. Features like e.g. significant reduction in albumin, low alpha 1 (raises possibility of alpha 1- antitrypsin deficiency) and patterns suggestive of acute phase reaction, iron deficiency, nephrotic syndrome, immune suppression or interference from e.g. haemolysis or contrast will also be commented on if present.
- If an abnormal band is detected or suspected on CZE, immunofixation will be performed to identify the isotype of the band while band quantitation will be performed by CZE.
- Immunofixation will only be performed when a new, abnormal protein band is detected; when a patient's protein electrophoretic pattern changes significantly; when immunofixation is specifically requested or at pathologist discretion.
- Immunofixation is not routinely performed if the CZE pattern looks normal. However, in peripheral neuropathy for investigation (where chronic inflammatory demyelinating neuropathy is suspected) immunofixation can be useful as it has a higher sensitivity than CZE; in these cases, "NEUROPATHY - immunofixation required" should be written clearly on the request form under Clinical Details. Otherwise, immunofixation will not be test added.
- First tier immunofixation routinely identifies IgG, IgA, IgM, kappa and lambda isotypes. For newly identified unmatched kappa or lambda light chain bands, immunofixation against the rare IgD and IgE heavy chain will be tested.
- Multiple bands of the same isotype can arise from in vitro polymerisation of the IgA or IgM monoclonal protein. Treatment with depolymerising reagent (beta-mercaptoethanol) before immunofixation can help to identify polymerisation.
Band quantitation
- Band quantitation aids monitoring patients with a quantifiable monoclonal band. The uncertainty of measurement for band quantitation is 15%.
- Quantitation of bands in the non-gamma region: perpendicular drop method (or selected perpendicular drop method if the reader can confidently define shoulders of the band). This gating method includes both the monoclonal band and the co-migrating normal serum proteins. This caveat (over-estimating the band quantity) is routinely stated in all such reports.
- Quantitation of bands in the gamma region: tangent skimming method.
For information on urine protein electrophoresis, please refer to Testguide entry: urine protein electrophoresis.
References:
- Tate J, Caldwell G, Daly J, Gillis D, Jenkins M, Jovanovich S, Martin H, Steele R, Wienholt L and Mollee P on behalf of the Working Party on Standardised Reporting of Protein Electrophoresis. Recommendations for standardized reporting of protein electrophoresis in Australia and New Zealand. Ann Clin Biochem 2019; 49; 242-256
- Tate JRT,Smith JD, Wijeratne N, Mollee P. Proposed Addendum to 2012 Recommendations for Standardised Reporting of Protein Electrophoresis in Australia and New Zealand. Clinical Biochemists Review 2019; 40(1): 23-30
- Dispenzieri A et al. International Myeloma Working Group guidelines for serum-free light chain analysis in multiple myeloma and related disorders. Leukemia, 2009. 23(2): p. 215-24
For any further information contact the chemical pathologist via email chemicalpathologist@adhb.govt.nz or via Lablink (Auckland City Hospital) EXT 22000 or 09 3078995.
Dr Cam Kyle (Clinical Head): CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Samarina Musaad : SamarinaM@adhb.govt.nz ext. 22402
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427
Dr Sakunthala Jayasinghe : sakunthala@adhb.govt.nz ext. 23427
Dr Owen Yi (Registrar): wenyiyi@adhb.govt.nz ext. 22045