Hi Jaded, I haven`t come across any references to Harvoni causing a reduction in Est GFR levels although you say you had noticed a drop before treatment.  Yes, there is a connection between Hep C and kidney problems but your current levels are only showing a moderate reduction. Lab results can jump about while on treatment and I think your doctor will be the best person to speak to about this. 

Let us know what you find out after your doctor has got back to you. Try not to worry. 

I just got my week 16 blood test back and noticed a drop in my Est GFR from 83-86 over the last few months to 64 with normal being above 60. It was once at 66 I noticed about a year and 1/2 ago. I'm wondering if this is to close to the lower limits and if I am beginning to have kidney problems as I have read HCV can cause this. My Urea and Creatinine levels are right in the middle of normal. I am wondering if Harvoni might be a cause for the recent drop in Est GFR and if anyone else on Harvoni has noticed this? I am waiting to hear back from my Dr.