Clinical Information for Hevylite
Normal ranges for Hevylite*
The ranges below were obtained by measuring the IgA kappa and IgA lambda concentrations of 138 normal (blood donor) sera and the IgG kappa and IgG lambda concentrations of 130 normal (blood donor) sera . They are intended for guidance purposes only. Wherever possible it is strongly recommended that local ranges are generated.
| Normal Adult Serum | Mean | Median | 95 Percentile Range |
|---|---|---|---|
| IgA kappa (g/L) | 1.24 | 1.19 | 0.48 - 2.82 |
| IgA lambda (g/L) | 1.00 | 0.98 | 0.36 - 1.98 |
| IgA kappa / IgA lambda ratio | 1.28 | 1.27 | 0.80 - 2.04 |
| IgG kappa (g/L) | 6.90 | 6.85 | 4.03 - 9.78 |
| IgG lambda (g/L) | 3.84 | 3.81 | 1.97 - 5.71 |
| IgG kappa/IgG lambda ratio | 1.86 | 1.87 | 0.98 - 2.75 |
Ranges that include older individuals, hospital patients and patients with chronic infections and autoimmune diseases are required. Initial studies have indicated that Hevylite κ/λ ratios in diseases with raised polyclonal immunoglobulins are maintained within the narrow limits observed for blood donors in the same way as has been seen with Freelite serum free light chain κ/λ ratios.
Clinical data for Hevylite
Monitor with Hevylite to obtain rapid and reliable information
As can be seen in these case studies, Hevylite gives an earlier indication of relapse.
Case Study 1
At presentation this Multiple Myeloma patient had 66g/L IgA kappa. The patient initially responded well to treatment and received an autologous cell transplant. Both monoclonal IgA (quantified by densitometry) and heavy light chain (HLC) ratio clearly showed the reduction in paraprotein, although the ratio did not become normal until 194 days after the monoclonal protein became negative by IFE.
Residual disease was identified 596 days earlier using IgA kappa/IgA lambda ratios than detection by either SPE or IFE.
Hevylite ratios (IgAκ / IgAλ) (pink), SPE scanning densitometry of IgA (red) and total IgA by nephelometry (blue). NR:shows the upper limit of the Normal Range.
Case Study 2
One IgG lambda Multiple Myeloma patient was studied in detail during 2 remissions and relapses and illustrates the main features of HLC assays. The HLC ratio had a greater range of values than IgG quantitation by scanning densitometry or nephelometry and was more sensitive during remissions and indicated relapse earlier.
During the first course of chemotherapy (Cyclophosphamide) there was significant selective tumour cell kill, shown by the reductions of IgG (by either scanning densitometry or nephelometry) and Hevylite ratio. Following disease relapse the patient received a second course of therapy (C-VAMP), during which IgG measurements indicated a tumour response but the HLC κ/λ ratio remained unchanged, indicating no selective tumour cell kill was taking place. Unfortunately the patient subsequently died.
This indicates that the HLC ratio provided the correct interpretation of the lack of response to C-VAMP. The discrepancy between total IgG measurements and IgG HLC κ/λ ratios may, in part, be due to inhibition of the FcRn receptor by the chemotherapy. This would cause a fall in total IgG (because of faster turnover) but IgG HLC κ/λ ratio would be unaffected.
Hevylite ratios (IgGλ/ IgGκ) (pink), SPE scanning densitometry of IgG (red) and total Ig by nephelometry (blue). NR: shows the upper limit of the Normal Range.
Baseline Hevylite results may help in predicting progression free survival in Multiple Myeloma
"Increasingly abnormal HLC ratios were associated with shortened PFS in MM patients. The association of independent of serum markers such as B2M, albumin, SPE densitometry and genetic markers (Del 13, t(4;14) and Del 17p)"
Serum immunoglobulin heavy/light chain ratios are independent risk factors for predicting progression free survival in multiple myeloma.
Avet-Loiseau et al. Haematologica 2010; 95[suppl.2]:395, abs. 0953
- Separate nephelometric immunoassays for IgGκ and IgGλ for the assessment of patients with multiple myeloma (MM) - A.R. Bradwell et al.
- Separate nephelometric immunoassays for IgAκ and IgAλ for the assessment of patients with multiple myeloma (MM) - A.R. Bradwell et al.
- Serum immunoglobulin and free light chain abnormalities in non Hodgkin lymphoma - G. Mead et al.
- Serial sample analysis of 3 IgA multiple myeloma patients using a novel immunoassay measuring IgA kappa and IgA lambda - C. Margetts et al.
References
AR Bradwell
Serum Free Light Chain Analysis (Plus Hevylite) 5th Edition 2008, Chapter 32, p275-285
The book is available to order US $75.
Please contact your local office or distributor.
* Six Hevylite kits are available now. More kits in the range will become available late 2010.
