I've been considering this conversation, since watching the movie "Hellbound?" -- After reading the scripture and many commentaries, I've come to the conclusion that Pilate was referring to what Jesus answered about Truth... that Truth was "true" for those who were "from" the Truth. What does it mean to be "from" the Truth? THAT is what I think Pilate was referring to... the idea that Truth in fact, in his own experience, depended upon what a person did or did not accept as the Truth, period.
Therefore, in Pilate's view, in this life, Truth is what you think is True, and there is not a reliable way to know what is Truly True - which "Truth" corresponds to reality.
Truth may be an objective thing - there can only be one Truth, ultimately. (I think...LOL) But in the context of spiritual matters, such as what Jesus taught, versus the Jews, versus Pagans, there is no way to objectively conclude what is Truth. It is a subjective decision... we all decide to be "from" one Truth or another.