Section 3.8
Immunology Problem Solving

On January 4, a serum protein electrophoresis on a specimen obtained at your hospital in North Dakota from a 58-year-old patient shows a band at the β-γ junction. The specimen was also positive for rheumatoid factor. You recommend that an immunofixation test be performed to determine if the band represents a monoclonal immunoglobulin. Another specimen is obtained 2 weeks later by the physician in his office 30 miles away, and the whole blood is submitted to you for the IFE. The courier placed the whole blood specimen in an ice chest for transport. In this specimen, no β-γ band is seen in the serum protein lane, and the IgM lane is very faint. The rheumatoid factor on this specimen was negative. The physician wants to know what’s wrong with your laboratory. Your response is:

Nothing’s wrong with our laboratory; the patient had an infection 2 weeks ago that has cleared up Something’s wrong with our laboratory—we likely mislabeled one of the specimens; please resubmit a new specimen and we will test it at no charge You will run a second specimen using a 2-mercaptoethanol treatment that will eliminate IgM aggregates and allow for more sensitive monoclonal IgM detection The physician should redraw another specimen from the patient and this time separate the serum from the clot in his office before sending the specimen in by courier