Interestingly, the researchers found a sex difference in ATX levels: Not only were ATX values in female patients significantly higher than those in female controls (median, 1.00 mg/L vs. 0.82 mg/L, respectively; P less than .001) but they also were higher than those of male patients (median, 0.78 mg/L; P = .005).
According to the authors, these findings highlighted a need for sex-specific benchmarks, as well as more research to clarify why the sex disparity existed.
A further longitudinal study conducted by the authors involving 29 patients seen at their clinic showed that ATX levels increased slowly but significantly over an 18-year period, with a median increase rate of 0.03 mg/L per year (P less than .00001).
Patients who died from their disease had a significantly higher autotaxin increase rate than did survivors (0.05 mg/L per year vs. 0.02 mg/L per year, respectively; P less than .01).