Open AccessReference distributions for immunoglobulins A, G, and M: A practical, simple, and clinically relevant approach in a large cohort
Author(s) -
Ritchie Robert F.,
Palomaki Glenn E.,
Neveux Louis M.,
Navolotskaia Olga,
Ledue Thomas B.,
Craig Wendy Y.
Publication year - 1998
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/(sici)1098-2825(1998)12:6<363::aid-jcla6>3.0.co;2-x
Subject(s) - reference range , reference values , statistics , antibody , cohort , medicine , immunoassay , immunology , mathematics
Serum immunoglobulins are measured millions of times each year, yet clinical interpretations remain hampered by inadequate age‐ and gender‐specific reference limits. In order to provide more reliable and comprehensive reference distributions for IgA, IgG, and IgM measurements, we analyzed automated immunoassay values from 115,017 serum samples from northern New England patients (99% Caucasian) who were tested in our laboratory between 1986 and 1995. Measurements were standardized to reference material, CRM 470 (RPPHS). A simple, practical, and clinically relevant approach was used to determine reference distributions for the immunoglobulins over a wide range of ages for males and females. Levels of IgA and IgM varied considerably by age, and by gender for IgM. For each of the analytes, the observed 5th and 95th centiles were symmetric about the median and approximately constant over the entire age range. When immunoglobulin reference values are expressed as multiples of the age‐ and gender‐specific regressed medians, the resulting distributions fit a log‐Gaussian distribution well. This finding enables interpretation of serum immunoglobulin measurements using a common unit (multiples of the median) that is independent of age or gender. Insights gained from this study can help improve and simplify the interpretation of immunoglobulin measurements. J. Clin. Lab. Anal. 12:363–370, 1998. © 1998 Wiley‐Liss, Inc.