Research into treatments for kidney disease is ongoing.
Some studies are geared specifically towards cats (please see
Feline Research), but findings
from studies into humans or other species such as mice may eventually have
applications for cats.
It must be emphasised
that much of the research discussed below is in its very early stages, and
may turn out to be either unsuitable generally or for cats (who have
unique physiological needs) in particular; and any treatments that turn
out to be feasible may not be available for many years, if at all.
Therefore this page is
provided primarily for informational purposes: please do not pin your
hopes on any research described herein. In particular,
if your cat is critically ill, don't bother with this page but instead
please focus on the proven treatments outlined on the
Key Issues page.
Bone
morphogenetic protein 7 (BMP-7) is a protein used to repair bone in
humans. Research in mice and
human recombinant BMP-7
indicates that BMP-7 may be able to repair
damaged kidneys and even reverse kidney disease. No research on cats has
taken place that I know of.
BMP-7 is
already approved by the FDA for the treatment of broken bones in humans in
the USA, so these findings may eventually lead to further research into the kidney
angle, though very little has happened since I first reported on BMP-7.
I sometimes
hear from people desperate to try BMP-7 on their cats. Unfortunately, this
is not currently an option unless you are a millionaire. When used in
orthopaedic surgery, BMP-7 is distributed in sponge form. However, for
kidney treatment, this form is not usable; instead the pure protein form
of BMP-7, suspended in a carrier liquid, is required, and this is
infinitely more expensive. A couple of people I know looked into obtaining
this form of BMP-7, only to discover that even in 2005 it would have cost
in excess of US$142,000 a month to purchase the amount required for a 10
lb (4.5 kg) cat. The price may fall if BMP-7 starts to be used for humans with kidney disease, but
unfortunately this has not happened yet. Since BMP-7 is a human
product, it is also possible that a cat might develop antibodies to it.
Eurekalert has a report on BMP-7 in
layman's language.
KCP seems to work by enhancing signals from
bone morphogenic proteins such as BMP-7 which are essential to the normal functioning of healthy
kidneys. The study indicates that KCP activity is also important in
slowing the progression of kidney disease: mice who could not secrete this
protein were more likely to develop renal problems and had more scarring
on their kidneys than healthy mice who were able to secrete KCP. Eurekalert
has a report on this study.
Research is to
be undertaken into what role KCP could play in helping humans with kidney
disease.
Renalase
It has long been known that the kidneys regulate blood
pressure by producing a hormone called renin. Recent research,
Renalase is a novel, soluble monoamine oxidase that
regulates cardian function and blood pressure
(2005) Xu J, Li
G, Wang P, Velazquez H, Yao X, Li Y, Wu Y, Peixoto A, Crowley S, Desir GV
The Journal of Clinical Investigation115(5) pp1275-80,
discovered renalase, a monoamine oxidase that breaks down catecholamines,
such as adrenaline and dopamine, and which therefore appears to have a
role in regulating heart contraction and blood pressure.
Renalase is
secreted by the kidneys and circulates in the blood. Patients with kidney
disease have been found to have very low levels of renalase, presumably
because the kidneys can no longer produce it efficiently. In human
patients with end stage renal
disease (ESRD), this probably plays a role in the build up of
adrenaline, which in turn may then lead to heart disease, a common cause
of death in humans with ESRD.
It is therefore hypothesised that injecting renalase
might help those with kidney disease by replacing the missing renalase.
Researchers compared this to giving
erythropoiesis stimulating
agents such as Epogen
to severely anaemic patients whose kidneys can no longer produce
erythropoietin. It is possible that
Renalase might also be of use in treating heart disease.
Role of renalase in the regulation of blood pressure
and the renal dopamine system
(2011) Desir GV Current Opinion in Nephrology and Hypertension
20(1) pp31-6 found that renalase deficiency is linked to raised blood
pressure. The study states that recombinant renalase is a powerful
treatment for high blood pressure in rats with CKD.
Implantable
Artificial Kidney
The Kidney
Projectat the
University of California San Francisco is
developing an artificial implantable kidney for humans. It is apparently
undergoing clinical trials, with a view to the trials being complete and
the device commercially available by late 2021. I have not heard of any
similar plans for a cat-sized artificial kidney.
Acute Kidney Injury Research
Neutrophil Gelatinase-Associated
Lipocalin (Ngal) or Siderocalin
Research on mice indicates that a protein called
neutrophil gelatinase-associated lipocalin (Ngal) may be of use against
acute kidney
injury (AKI). Large amounts of Ngal are found in blood, urine and
kidney tissue at the onset of AKI, which means it could be
helpful for diagnosing AKI at an early stage.
It is thought that Ngal is produced by the body during
AKI in an attempt to protect the kidneys, but in many cases it is produced
too late to prevent damage. If Ngal were to be injected earlier, it
might also be able to prevent damage from occurring. It is expected that human
trials of Ngal will begin shortly.
Biomarkers of kidney disease: potential utilities
(2018) Segev G International Renal Interest Society says
"NGAL's specificity is questionable, as it originates from multiple
tissues as well as from neutrophils and therefore may increase during
inflammation and other disease processes accompanied by recruitment of
neutrophil."
Overview of biomarkers in acute kidney injury
(2012) Segev G Presentation to the Advanced Renal Therapies
Symposium, NYC pp12-16 reports on using Ngal and other markers to detect
AKI more quickly (go to page 12).
TREATING YOUR CAT WITHOUT VETERINARY ADVICE CAN BE
EXTREMELY DANGEROUS.
I have
tried very hard to ensure that the information provided in this website is
accurate, but I am NOT a vet, just an ordinary person who has lived
through CKD with three cats. This website is for educational purposes
only, and is not intended to be used to diagnose or treat any cat. Before
trying any of the treatments described herein, you MUST consult a
qualified veterinarian and obtain professional advice on the correct
regimen for your cat and his or her particular requirements; and you
should only use any treatments described here with the full knowledge and
approval of your vet. No responsibility can be accepted.
If your cat
appears to be in pain or distress, do not waste time on the internet,
contact your vet immediately.
This site was
created using Microsoft software, and therefore it is best viewed in
Internet Explorer. I know it doesn't always display too well in other
browsers, but I'm not an IT expert so I'm afraid I don't know how to
change that. I would love it to display perfectly everywhere, but my focus
is on making the information available. When I get time, I'll try to
improve how it displays in other browsers.
This site is a labour of love. Please do not steal from me by taking credit for my work.
If you wish to
link to this site, please feel free to do so. Please make it clear that
this is a link and not your own work. I would appreciate being informed of
your link.