Post transplant elevated tests

I am 7 1/2 years post transplant. Two years ago I had another baby (with the blessing of all:transplant doctors, gastr dr., high risk ob gyn) Until a year ago, my liver enzymes were all within normal. I had been also taking lipitor for many months.  My Alk phos and GGT increased. I was switched to zocor. They continued to go up. In November of 1999 they took me off of zocor. My Alk phos dropped to 158 and my GGT to 142 in January. In February my alk phos rocketed to 216 and my GGT to 171. My bilis are .3 direct and .6 total. Mt AST is 40 and my ALT is 63. I am under a transplant centers care but am at a loss as to what could cause these jumps in numbers after 71/2 of extreme stability. What could the alk phos and ggt indicate?