Reference distributions for alpha2-macroglobulin: a comparison of a large cohort to the world's literature

The lack of satisfactory methods for quantifying serum levels and a credible reference material has limited bedside use of serum alpha(2)-macroglobulin (alpha2M) measurements. Great strides have been made in the last few years. The remaining barrier to more relevant and cost effective use of serum protein data for diagnosis and prognosis is the availability of reliable reference intervals from birth to old age for both males and females. A total of 40 publications reporting reference intervals have been identified that meet the criteria used in our prior five studies, and these have been analyzed statistically. On average, previous small studies of these individual proteins agree with our life-long reference ranges over their constrained age ranges. This meta-analysis provides support for our reference ranges and places them in the perspective of previous publications.