Reference intervals for immunoglobulins IgA, IgG and IgM in serum in adults and in children aged 6 months to 14 years.
Reference intervals were estimated for immunoglobulins IgA, IgG and IgM in serum in 313 healthy adults aged 17 to 64 years and in 399 children aged 6 months to 14 years. In adults a nonparametric method was chosen for estimating reference interval limits. In children the limits were estimated age-specifically using regression analysis. Immunoglobulin assays used in this study were standardized with a Finnish secondary standard which was calibrated against the World Health Organisation 67/99 immunoglobulin standard. Later, another international primary standard (US National protein standard preparation) was used, the immunoglobulin levels of which are calibrated against the WHO standard. The nominal immunoglobulin concentrations assigned by the manufacturers of several commercial immunoglobulin standard preparations were found to differ from the concentrations measured with the international calibrator used in this study. In conclusion, the reference intervals estimated in this study should be transferable to any laboratory using immunoglobulin assays calibrated against the WHO standard. The usefulness of commercial immunoglobulin standard preparations not calibrated against these primary standards is limited.
Irjala
K
K
Central Laboratory, University Central Hospital, Turku, Finland.
Koskinen
P
P
Icen
A
A
Palosuo
T
T
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000378:metabolism* / Q000592:standards; D007074:Immunoglobulin G / Q000378:metabolism* / Q000592:standards; D007075:Immunoglobulin M / Q000378:metabolism* / Q000592:standards; D007223:Infant; D008297:Male; D008875:Middle Aged; D012015:Reference Standards; D012016:Reference Values; D012044:Regression Analysis; D012737:Sex Factors
D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M