According to the project proposal we had to evaluate our biomarker for Dry Eye syndrome (diadenosine tetraphosphate-Ap4A) in a clinical trial on 30 subjects. In order to achieve wide-ranging statistical results, we decided to raise the subjects to 52. The study was organized from June to September 2015 and it started in October 2015. After 4 months of intensive work on human subjects, the trial terminated in December 2015. The process of the results took two months, from January to February 2016.
Results
In the study participated 52 subjects, divided taking according to their respective score on the McMonnies tests. They were divided in two groups of symptomatic (25) and asymptomatic (27) subjects. Table 1 below, depicts the statistic results obtained for each of the tests.
We noticed, statistically significant differences between the two groups for the symptoms parameters (McMonnies and OSDI tests), and for the tear stability (TBUT) in the measurement of diadenosine tetraphosphate (Ap4A). On the other side, neither the existing diagnostic tests of TearLabTM osmolarity test nor the InflammaDryTM-concentration of MMP-9, showed significant differences when comparing symptomatic to asymptomatic patients.
In the case of TearLabTM-osmolarity test, the values obtained in both groups were above the cut-off values of dry eye, according to the parameter of 312 mOsm/l.
In the case of InflammaDryTM-concentration of MMP-9 test, the values found, were below the cut-off in both groups (considered at 40 ng / ml).
In the case of Ap4A, if we consider that the cut-off value to include a subject as dry eye patient, was 0.5 uM, it was found that:
24 of 25 subjects of the asymptomatic group (96%) had Ap4A concentrations below that cut-off value. This means we can consider that the Ap4A has a specificity of 96% on discarding the syndrome.
20 of 27 subjects in the symptomatic group (74%) had concentrations above that Ap4A cut-off value. This means we can consider that the Ap4A has a sensitivity of 74% to diagnose the syndrome.
Conclusions
There were statistically significant differences in the concentration of diadenosine tetraphosphate (Ap4A) between symptomatic and asymptomatic patients.
The sensitivity and specificity of the diadenosine tetraphosphate biomarker is high enough to suggest it as objective marker for the dry eye syndrome.