Reference Intervals of Serum Cartilage Oligomeric Matrix Protein in Nigerian Adults at Nnewi: A Pilot Study

Objective: To determine the reference intervals of serum Cartilage Oligomeric Matrix Protein in Nigerian adults at Nnewi, Nigeria. Methods: Eighty participants were partitioned into: group1; (29 years and younger); and group 2; (30 years and older), each group comprising twenty males and twenty females. Five milliliters of venous blood collected from each participant was measured for COMP with the COMP ELISA (Anamar Medical AB, Lund, Sweden). The statistical package for social sciences version 20.0 was used for data entry and analysis. Data was log transformed. Reference intervals for serum COMP for the various groups were obtained after back transformation of the calculated values obtained using the formula: reference interval = m - 2s to m + 2s for a variable that follows a normal distribution where m was the mean and s was the standard deviation. Results: In both groups, COMP showed good positive correlation with age: r=.546 in group 1and r=.624 in group 2 which was statistically significant; p=.001 in both groups. The reference intervals were 182.87 - 214.52ng/dl for the males and 170.67 - 208.66ng/dl for the females in group 1. For group 2, the reference intervals were; 174.54 – 608.22ng/dl for the males and 182.97 – 482.19ng/dl for the females. Conclusion: Serum COMP is a potential tool for making early diagnosis of KOA but multi-center studies using large sample sizes will be required to establish reference intervals for the Nigerian population.