"Bioartificial" Kidney Tested in Dogs"



NEW YORK, Apr 27 (Reuters Health) -- Researchers at the University of Michigan, Ann Arbor, have developed an artificial kidney that uses living kidney cells to help filter blood, according to a report in the May issue of the journal Nature Biotechnology.

The "bioartificial" kidney -- part machine, part living tissue -- provided nearly 50% of the functional capacity of a natural kidney in dogs whose kidneys had been removed, report the research team.

Like hemodialysis machines, which cleanse the blood of people with kidney failure, the bioartificial kidney developed by Dr. H. David Humes and colleagues works outside of the body, filtering blood to remove excess water and waste products. However, because the new device incorporates living kidney cells into its design, it can also produce important hormones, process metabolites, and provide immune functions that dialysis cannot. Humes and his team developed a cartridge lined with cultured kidney tubule cells, through which the patient's blood is pumped. In a natural kidney, these tubule cells not only maintain fluid and electrolyte balance but also perform metabolic and endocrine functions.

The next step will be to test the bioartificial kidney on humans. The researchers have applied to the Food and Drug Administration to begin testing in humans. Ultimately, the team hopes to develop a bioartificial kidney that can be implanted.

Hemodialysis, which became available in 1956, can sustain life for patients suffering from acute and chronic renal failure for long periods. But the treatments are frequent and uncomfortable and affect the patient's quality of life.

In an editorial, Clark K. Colton, a professor at the Massachusetts Institute of Technology, writes that the new bioartificial kidney "is a beautiful example of sophisticated targeted research."

The bioartificial kidney "appears ready for human testing, and Humes (and colleagues) suggest that their first target will be ischemic or nephrotoxic acute renal failure, a logical choice because mortality rates are very high with current artificial kidney treatments," Colton writes. "The system is also ready for testing in end-stage renal disease in order to examine the incremental benefit provided by the metabolic, endocrinological, and immunological functions of the...device," Colton concludes.

SOURCE: Nature Biotechnology 1999;17:451-455, 421-422.

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