I would recommend blood and urine testing for kidney disease at least every three months to monitor kidney function. This should include a serum creatinine and an estimated glomerular filtration rate (eGFR). Urine testing should be for blood, protein and infection. It is true that intravenous immune gamma globulin (IVIG) treatments may rarely be associated with kidney damage. This does not occur with the newer formulations of IVIG, but still is a risk.
I suggest that you discuss this with your pediatrician and ask for monitoring and testing.
Tests to measure kidney function click here: