A single-center study of reference intervals for TAT, PIC, TM and t-PAIC in healthy older Chinese adults

To explore the distribution of thrombin–antithrombin complex (TAT), plasmin-α2-antiplasmin inhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) in healthy older Chinese adults, and establish the reference intervals (RIs). The Biotech Shine i2900 chemiluminescence immune assay was used to measure the plasma concentrations of TAT, PIC, TM, and t-PAIC in 1628 adults ≥ 60 years. The RIs were established using the 2.5th and 97.5th percentiles of the distribution. TAT levels were lower in males than females across all ages. Differences between the ages of 60–79 and ≥ 80 in both sex groups were statistically significant, with an upward trend with age. PIC levels showed no difference between the sexes but increased with age in both groups. TM levels did not differ between the sex groups, with slight fluctuation with age. The level in females aged 60–69 was slightly higher than that in the other groups; the difference was statistically significant. T-PAIC levels were not significantly different between the sex groups, with less fluctuation with sex and age. The level in males ≥ 80 years old was slightly lower than that in the other groups; the difference was statistically significant. The RIs for all markers in healthy older Chinese adults were determined and statistically reported by age and sex. For TAT, the RIs for males aged 60–79 and ≥ 80 are 0.51–2.30 ng/mL and 0.88–3.72 ng/mL, respectively, whereas for females aged 60–79 and ≥ 80, the RIs are 0.68–2.82 ng/mL and 1.02–3.67 ng/mL, respectively. For PIC, the RIs for the age groups 60–69, 70–79, and ≥ 80 are 0.10–0.89 µg/mL, 0.12–1.00 µg/mL, and 0.21–1.04 µg/mL, respectively. The RI of TM for females aged 60–69 is 3.32–13.22 TU/mL, whereas it is 2.96–13.26 TU/mL for the other groups. The RI of t-PAIC for males aged ≥ 80 is 1.63–10.68 ng/mL, whereas it is 2.33–11.34 ng/mL for the other groups. Discrepancies exist in thrombus markers among different sex and age groups. The RIs of TAT, PIC, TM and t-PAIC for healthy older Chinese adults were successfully established.