A validated liquid chromatography-tandem mass spectrometry assay for simultaneous quantitation of intact IGF-1 and IGF-2 in human serum

The simultaneous quantification of insulin-like growth factor (IGF) 1 and 2 has demonstrated significant potential for routine diagnostic applications in growth disorders. However, a simplified and rapid assay still remains to be developed. In this study, we established a simple, cost-effective and antibody-free serological assay based on tandem mass spectrometry to simultaneously quantify intact IGF-1 and IGF-2 in human serum. The lower limits of quantification were estimated to be 18.16 ng/mL for IGF-1 and 23.71 ng/mL for IGF-2. The linearity correlation coefficients exceeded 0.99 for both analytes. No significant matrix effects or carryover were observed. Intra- and inter-assay precisions were both less than 15 %. Recoveries from the standard addition assay fell within the range of 80 % to 120 %. We subsequently assessed the serum levels of IGF-1 and IGF-2 in a population residing in Wuhan, China, and found IGF-1 levels exhibited an age-related increase, peaking between 10 and 20 years of age, whereas IGF-2 levels remained consistently elevated across all age groups, although a relative decrease was noted between the ages of 20 and 30 years. This assay provides a simple, rapid, and immunoaffinity-free approach, rendering it more suitable for clinical applications aimed at assessing serum IGF-1 and IGF-2 levels.