The CCP is a newer blood test for rheumatoid arthritis; at moderate to high positive levels it indicates a higher chance of joint damage being possible from uncontrolled symptoms. Here's a nice summary on that blood test that's easy to read through:
Your other tests are measures of kidney function. They are inversely and pretty much directly related to each other, the key one to look at is the estimated GFR which in your case is 56. If you have a eGFR under 60, and have protein evidence in your urine, this can mean you have chronic kidney disease. If you only have a low GFR, but no protein loss in your urine then you would not be classified as having chronic kidney disease.
Definitely something to discuss with your doctors, and recheck. I have a GFR in the upper 50s for the last few years now and it hasn't deteriorated any further. I had to stop taking NSAID's as that probably contributed to my decline in kidney functioning. I leak more protein whenever I am on NSAID medications.