Did you mean protein in the urine? Your husband would be in trouble if he didn't have protein in his blood. If protein in the urine is what you meant, the answer is probably that he is drinking a lot of carbonated beverages and that is causing swelling in his kidneys and letting the protein leak from his blood into the urine.
This is why I recommend that all people do not drink them and especially not let their kids drink them. While doing ambulatory care I ran across 4 children running from trace to 4+ proteinuria (protein in the urine). Trace is the least amount measured and at 4+ you look for big time kidney problems. Changing nothing but leaving off carbonated beverages on all 4 of them, 1 week later 3 of them were negative for protein in the urine and the 4th one who had the 4+ was down to trace. Her mother had let her drink one on the way to the clinic. None of these children had a UTI at the time of testing, but as I told their mothers, "If you want your children to keep the kidneys they were born with, keep them away from carbonated beverages". Even if you are lucky enough to get a match for a transplant, you will be needing about $l0,000 in medicine to keep from rejecting that transplant, and that medicine affects your immune system making your more susceptible to everything including cancer.