Kranzlin B, Gretz N, Kirschfink M, Mujais SK
Dialysis in rats with acute renal failure: evaluation of three
different dialyzer membranes
Artif Organs
(Nov) 20:1162-1168 1996

Whether cuprophan dialysis membranes increase morbidity/mortality in
the treatment of ARF is a topic of current debate. There are
presently two positive and one negative clinical paper in this area.
One of the theoretical underpinnings of this hypothesis was a study by
Schulman and Hakim (Kidney Int 40:1069-1074, 1991) where rats
with ischemic ARF injected with complement activated blood had
neutrophil infiltration of glomeruli and delayed recovery of function.
In this paper, which was presented at ASN in 1994, Kranzlin
et al. apparently tried and failed to replicate the results of
Schulman et al. In 48 rats, crossclamping of both renal arteries for
45 or 60 min was used as the ischemic insult. Rats were then
randomized to receive either no dialysis, or dialysis with cuprophan,
AN69, or hemophan mini-dialyzers. Dialysis was performed only twice,
for 60 min each time on days 4 and 8 after renal crossclamping. GFR
was measured on days 5 and 9 by inulin clearance. To make a long
story short, these investigators found no difference in the rate of
renal recovery in the dialyzed rats, and the membrane used made no
difference.
Comment: The difference between this and
the Schulman study was, that in the latter, complement-activated
plasma was injected during the induction phase of renal injury.
Kranzlin et al argue that this does not correspond to the clinical
situation. On the other hand, the total exposure to dialysis
membranes in the present study was short (two 1-hour sessions 4 days
apart). It would have been nice if the authors had replicated exactly
Schulman's design, and used this as a "positive control", and then
used graded amounts of exposure to complement activation to determine
if a critical amount and time course could be demonstrated. (John
T. Daugirdas, M.D., University of Illinois at Chicago)