I developed a toxic contraindication after about 5 years of taking it, and its affected my lungs (fibrosis), as well as caused some other very strange symptons thats affected my eyes, and some other organs. The docs have confirmed that I am allergic to it - but are less sure about the other ailments which all miraculously stabilsed within 3 months of my stopping MTX.
I am obviously an outlier where the allergies are concerned - so I would be vigilant if I were you.