Immunoassay For Quantifying Type â…  Collagen Degradation In Urine Established And Evaluated

Objective:We developed a assessment with a marker of collagen degradation, C-terminal telopeptide of type I collagen (CTX).CTX in urine reflect the situation of bone type I collagen degradation. The ELISA quantitatively determined degradation products of type I collagen.Method:The antibodies are raised against synthetic peptide with an amino acid sequence specific for a part of the C-telopeptide of the al chain of type I collagen. It is a competitive-inhibition enzyme-linked immunosorbent assay. The measuring range was 0.1-10mg/L with a detection limit of 200ug/L. Within-run and total CVs were 10%and 15%,respectively. Creatinine (Cr) were measured and used to correct CTX parameters in urine.Result:We have used this ELISA to measured a sample of 168 women,aged 1-82 yr. The result show that CTX in urine correlated with age. In children (2-4 yr),the level of CTX/Cr in urine is highand then,it begin to decrease. Among 20-40, the CTX in urine isn't significantly increase. In menopausal women's CTX in urine showed an increase compared to values in premenopausal woman. After menopause, the level of CTX was significantly different from premenopausal women.CTX measured by ELISA and NTX (N-terminal telopeptide of type I collagen) measured by NTX kit (NTX,OSTCOMARK) are highly correlated.(r=0.6-0.7)Conclusion:These results indicate that CTX ELISA is useful for monitoring bone loss in menopausual women.CTX and NTX concentration in urine are highly correlated.