Wow! Is there any dried blood left anywhere on them?
I’m pretty sure that they did find blood on one of the thorns, (maybe the thorn in Paris), and I’m pretty sure that it is the same blood type (AB) that matches the Shroud of Turin, the Sudarium, and the Eucharistic miracle of Lanciano.
Sudarium - http://www.shroudstory.com/faq-sudarium.htm
Lanciano - http://www.therealpresence.org/eucharst/mir/lanciano.html
I don’t know about those articles, but it seems there is blood somewhere other than the Shroud of Turin. (Which has not been fully approved by the Church, as far as I am aware.)
I should have looked further. Nihil Obstat had your answer!