Stem Cell

Test results after stem cell transplant for multiple myeloma can confuse patients and doctors about

Test results after stem cell transplant for multiple myeloma can confuse patients and doctors about
Dr. Gurmukh Singh, vice chair of clinical affairs for the Department of Pathology and Walter L. Shepeard Chair in Clinical Pathology at the Medical College of Georgia at Augusta University. Credit: Phil Jones

It’s a cancer of the plasma cells, which normally make an array of antibodies that protect us from infection.

With multiple myeloma, the cells start primarily producing instead a singular product, called a monoclonal antibody, or M spike, that leaves patients vulnerable for serious infections, like pneumonia, and can even eat away at their bones.

Sophisticated laboratory tests used to both diagnose the disease then follow treatment response, can send confusing messages to patients and their physicians, particularly after stem cell therapy to try to restore a healthy antibody mix, says Dr. Gurmukh Singh. Singh, vice chair of clinical affairs for the Department of Pathology and Walter L. Shepeard Chair in Clinical Pathology at the Medical College of Georgia at Augusta University, is corresponding author of the study highlighting reasons for potential confusion in the Journal of Clinical Medicine Research.

The tests, serum protein electrophoresis and serum immunofixation electrophoresis, or SPEP/SIFE, and serum free light chain assay, or SFLCA, separate proteins into groups according to their electrical charge.

The M spike stands out as a distinctive, dense band of color among the layers of protein groups, while typical antibody levels create bands of lighter smears.

But after stem cell therapy, which first destroys cancerous plasma cells then restores healthy ones, follow up profiles often yield a lineup of antibodies—called an…