Is it time to say goodbye to protein fractions?

I recently responded to a post on the Artery about how to establish reference intervals for serum protein fractions using electrophoresis. I questioned the usefulness of even reporting these, stating that the only reason to request a “serum protein electrophoresis” was to look for a monoclonal immunoglobulin. (An implied additional reason would, of course, be following a patient with a known monoclonal immunoglobulin.) Many protested that the interpretation of serum protein patterns still provides valuable information. Methinks they protest too much!

I know that there is a long history of providing these interpretations. Old textbooks contain examples of patterns consistent with “acute infectious or inflammatory disorder”, “chronic inflammatory disorder”, “liver disease”, etc. Happily newer editions seems to corroborate my opinion. (The examples in the chapter on electrophoresis in the new Tietz show only monoclonal immunoglobulin.)

A forthcoming  special issue of Clinical Biochemistry will focus on the diagnosis and management of plasma cell dyscrasias (1). It will include a report from a working group proposing guidelines for reporting results of protein electrophoresis (2). Although their focus is monoclonal gammopathy, they do recommend reporting protein fraction quantitation. At least they are honest in describing the rationale for this recommendation as “primarily based on historical practice”. This is always a bad reason for any recommendation! Before they begin discussing in great detail how many decimal places to use, they mention that abnormally elevated levels of a particular protein fraction may be a tip-off that a monoclonal immunoglobulin is lurking within it. So I think most of the members of this group were really focused on identification of monoclonal immunoglobulin, not clinical utility of interpretation for what they describe as “a limited number of scenarios”

Let’s move protein fraction reporting where it belongs: in Jurassic Lab, the place for laboratory tests whose time has come and gone.

1. Keren DF. Editorial on laboratory diagnosis and management of plasma cell dyscrasias special issue. Clinical Biochem, in press.
2. Booth RA et al. Candidate recommendations for protein electrophoresis reporting from the Canadian Society of Clinical Chemists Monoclonal Gammopathy Working Group. Clinical Biochem, in press.