Myeloma can be classified by according to the type of defective immunoglobin (paraprotein) produced by the myeloma cell. However, it is easier to classify it by it’s genetic subtype.
There are several different types of immunoglobin (aka antibodies). Each is ‘Y’ shaped and made of two identical Heavy Chains and two identical Light Chains
There are 5 types of heavy chain (G, A, D, E and M)
There are two types of light chain (κ) and (λ)
The immunoglobins are known respectively as IgG, IgA, IgD, IgE or IgM
These are further designated IgGκ, IgGλ, IgAκ, IgAλ etc
If you are healthy then you produce a good mix of these immunoglobins with a good mix of heavy and light chains, but in Myeloma a large amount of a single abnormal type is produced known as paraprotein.
Most people with myeloma have one of the IgG types, some have IgA types but the other types are rare.
In 20% of patients the myeloma only produce Light Chains – called Bence Jones proteins – and no whole immunoglobins at all.
These will either be exclusively κ light or λ light and of all the types of myeloma are most likely to cause kidney damage, by blocking the kidney tubules and inflaming the tissue.
When I arrived the measures amount of light chains was 40,000 in my blood stream – today they were measured at just 2000.
My kidney function has improved and my Glomerula Filtration rate (GMR) has risen to 11 which whilst well below the desired 60 has shown steady improvement over my time here.