Personally, I'd be interested to know why he went into renal failure. If it was something he could have avoided (i.e. drugs), then I think he should be responsible for the rent, on time. It was his poor choices that got him where he is.
If on the other hand, it's due to an underlying medical problem (Rheumatic fever, renal artery stenosis etc), I'd give the guy a break as best i could. If he had no control over what happened, he deserves a helping hand. That of course doesn't mean charity, but I'd give him some leeway.
Renal failure is basically a death sentence, unless he can get a transplant. Even then, he'll die much sooner than someone who didn't have renal failure.
Good luck
Erik
