Products
Search

Sign Up
To keep up to date with all our latest news, events and products,why not sign up to our newsletter.

Home> Products> Hevylite®
Hevylite®
   

Hevylite® immunoglobulin heavy chain/light chain analysis

Hevylite® (HLC), a new assay now available from Binding Site, promises to transform the way patients with B cell dyscrasias are managed, just as the Freelite® assay has done.

In summary Hevylite® assays offer:

  • Higher sensitivity than serum protein electrophoresis for quantifying monoclonal immunoglobulins
     
  • Numerical results for patients at a sensitivity as high as or better than immunofixation electrophoresis
     
  • Clinical value when monitoring patients with monoclonal gammopathies
     
  • HLC ratios which have a greater range of changes than monoclonal immunoglobulin measurements because the non-tumour immunoglobulin allows assessment of immunosuppression
     
  • HLC ratios which are not affected by changes in blood volume, haematocrit and variable metabolism (via FcRn receptors for IgG) that affect current assays for serum immunoglobulins
     
  • HLC ratios that provide information about the tumour selective killing rate versus non-tumour plasma cell kill rates. The assessment of selective tumour killing rates may help with decision making regarding effective chemotherapies

Ordering information for Hevylite® assays 
Target epitopes (in black) for Hevylite® antibodies are on the constant regions between the heavy and light chains of immunoglobulin molecules
Intact immunoglobulin molecules contain unique junctional epitopes between the heavy chain and light chain constant regions. These are the target of the Hevylite®* antibodies. They can identify separately the different light chain types of each immunoglobulin class ie IgGκ, IgGλ, IgAκ, IgAλ, IgMκ, IgMλ. The molecules are then measured in pairs e.g. IgGκ/IgGλ to produce ratios of involved monoclonal immunoglobulin/background uninvolved immunoglobulin concentrations, in the same manner as serum free light chain κ and λ ratios when using Freelite®.

As with Freelite® assays, the reagents used to make the Hevylite® tests are polyclonal antibodies produced in sheep. Immunisation and adsorption techniques are designed to ensure no cross-reactivity. So, for example, IgGκ reagents do not react with free κ or IgGλ, or any other immunoglobulins.
There are 4 Hevylite® epitope regions per immunoglobulin molecule - one on each side of the heavy chain / light chain contact regions and the same on the other arm of the molecule. Because there are 4 epitope regions per molecule, immune complexes readily form with immunoglobulins in the patient's serum. This is needed to produce good homogeneous immunoassays that are suitable for nephelometric and turbidimetric automated laboratory analysers.

Heavy chain/light chain pairs of IgG, IgA and IgM molecules showing the target epitopes for Hevylite® immunoassays in black.


 

Typical analytical tests for monoclonal gammopathies are serum protein electrophoresis (SPE or SPEP) with scanning densitometry and/or immunofixation electrophoresis (IFE) together with serum free light chain immunoassays. While SPE is a simple, low cost test, it is not very sensitive and quantification of proteins at low concentrations (1-3g/L) is inaccurate.
This is particularly apparent for monoclonal IgA since its anodal electrophoretic migration positions it over other bands such as transferrin. Improved sensitivity is achieved with IFE but IFE is a non-quantitative assay. Nephelometry is also used for immunoglobulin measurements and is analytically accurate down to low concentrations. However, patients' samples also contain non-tumour polyclonal immunoglobulins of both κ and λ types that are included in the analysis. This means results are clinically inaccurate at normal serum concentrations.
Furthermore, assessments of monoclonal IgG are unreliable because of variable catabolism as FcRn recycling receptors that bind albumin and IgG become saturated or reduced by chemotherapy.
  

Binding Site SPAplus Analyser

Description
Pack
Code
Binding Site SPAplus
NEW Hevylite® IgG Kappa kit**
 50 test NK621.S
Binding Site SPAplus
NEW Hevylite® IgG Lambda kit**
 50 test NK622.S
Binding Site SPAplus
Hevylite® IgA Kappa kit**
50 test
NK623.S
Binding Site SPAplus
Hevylite® IgA Lambda kit**
 50 test NK624.S
Binding Site SPAplus
NEW Hevylite® IgM Kappa kit**		 50 test NK625.S
Binding Site SPAplus
NEW Hevylite® IgM Lambda kit**		 50 test NK626.S

More kits in the range will become available late 2010.

Siemens Analysers/Platforms 

Description
Pack
Code
Siemens BN™II
Hevylite® IgG Kappa kit**
50 test
NK621.T
Siemens BN™II
Hevylite® IgG Lambda kit**
50 test
NK622.T
Siemens BN™II
Hevylite® IgA Kappa kit**
50 test
NK623.T
Siemens BN™II
Hevylite® IgA Lambda kit**
50 test
NK624.T
Siemens BN™II
Hevylite® IgM Kappa kit**
 50 test NK625.T
Siemens BN™II
Hevylite® IgM Lambda kit**
 50 test NK626.T

** Please enquire regarding FDA status