What is indicated by dense wide bands in both the κ and λ lanes during immunofixation electrophoresis?

The presence of dense wide bands in both the κ and λ lanes during immunofixation electrophoresis suggests an increase in polyclonal immunoglobulins. This finding indicates that there is a stimulation of the immune system, often due to chronic inflammation, autoimmune diseases, or other conditions that result in an increased production of antibodies.

In a normal result, one would expect narrow bands, while in cases of light chain disease or multiple myeloma, typically there would be a predominance of bands from either κ or λ chains rather than both. Thus, dense bands in both lanes highlight that there’s a broad response from the immune system, consistent with increased polyclonal Fab fragments, rather than a monoclonal response typically seen in malignancies like multiple myeloma.