'Two for the price of one' tactic improves outcomes after organ transplantation

A new study of more than a million transplant recipients has found that rejection rates are lower in patients who receive two organs at once than in those who receive a single organ.

The study, published in Annals of Surgery, found that the rejection rates for organs cotransplanted with a donor-specific liver, heart or kidney were significantly lower than those for organs transplanted alone.

It has been known for some time that transplanting a liver with another organ such as a kidney or a section of intestine reduces the likelihood of rejection of the primary organ, leading to the suggestion that liver allografts protect other organs from rejection. Combined liver and kidney transplantation is used in patients with hepatorenal syndrome - in which acute kidney failure occurs as a result of liver cirrhosis or fulminant liver failure - or in patients with end-stage renal disease who also have liver damage as a result hepatitis B or C virus infection. Simultaneous intestine and liver transplantation is used in patients with intestinal failure following the removal of a large section of intestine (e.g. because of a tumor) and end-stage liver disease, which may be due to receiving their meals intravenously following intestine removal (total parenteral nutrition).

The recent study by Rana et al. has revealed that heart and kidney allografts are also immunoprotective and are themselves protected when transplanted with another organ.

The authors searched the United Network for Organ Sharing database – which contains data about every transplant that has taken place in the US since 1986 – and identified all thoracic, kidney, intestine and liver transplant recipients over 18 years old.

In patients who simultaneously received heart and kidney transplants from a single deceased donor, the incidences of renal allograft rejection and cardiac allograft rejection at one year were lower than in patients who received either a heart or a kidney allograft alone. In addition, the rate of rejection-free survival at one year was higher in the combined organ recipients. Likewise, compared with patients who received a single organ, rejection of either organ and rejection-free survival were lower and higher, respectively, in individuals who received combined liver and kidney transplants.

On the other hand, cotransplantation of intestine or pancreas in patients undergoing kidney or liver transplantation did not lower the risk of rejection or improve rejection-free survival.

The authors suggest that combined simultaneous organ transplantation could be used more widely to reduce rejection rates and lower the need for immunosuppression in transplant recipients.
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Rana A et al. (2008) The Combined Organ Effect: Protection Against Rejection? Annals of Surgery 248 (5): 871-879 DOI: 10.1097/SLA.0b013e31817fc2b8

Chronic kidney disease patients claim to know nothing about their condition

A study by Finkelstein and colleagues published recently in Kidney International has found that as many of a third of patients with chronic kidney disease (CKD) claim to know nothing about their disease or about their treatment options when their kidneys ultimately fail.

CKD encompasses many types of kidney damage and is characterized by the gradual loss of renal function, often with few symptoms bar raised blood pressure and nonspecific signs such as fatigue and reduced appetite. CKD is graded on a 5-point scale, with stage 1 being slightly diminished kidney function and stage 5 being established kidney failure. Despite treatment many cases progress, in some instances to the point of kidney failure, otherwise known as end-stage renal disease. Once a patient reaches end-stage renal disease, they have to regularly undergo life-saving treatment that mimics the roles performed by their now defunct kidneys. Some such treatments include dialysis and kidney transplantation.

In the study by Finkelstein et al., 676 patients with stage 3–5 CKD who had been receiving nephrology care for about 5 years completed a questionnaire to assess their knowledge of CKD and of renal replacement therapies. Only 23% of patients reported having a great deal or extensive knowledge about their CKD and 35% reported having very limited or no knowledge. When questioned about their knowledge of renal replacement therapy, 35% of patients reported knowing nothing about any end-stage renal disease treatment modality.

Various studies have shown that decent education about CKD can delay the onset renal failure, increase the likelihood of the patient choosing a less costly home-based therapy rather than elaborate hospital-based dialysis, and improve outcomes of patients after the start of dialysis.

The findings of the Finkelstein et al. study indicate that despite receiving specialized kidney care for several years, many patients with CKD feel they have little knowledge of their disease and are, therefore, ill equipped to make treatment decisions. In an editorial accompanying the research, Chester Fox and Linda Kohn of University at Buffalo, New York, suggest that, "A multidisciplinary team - including dieticians, social workers, nurse educators, and pharmacists - and access to transplant surgeons are necessary to improve patient knowledge and understanding about progression of CKD and treatment options."

Finkelstein FO et al. (2008). Perceived knowledge among patients cared for by nephrologists about chronic kidney disease and end-stage renal disease therapies Kidney International 74 (9): 1178-1184 DOI: 10.1038/ki.2008.376
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Another recent study, this time published in Archives of Internal Medicine, measured whether the introduction of early detection guidelines had improved the number of patients with CKD who were aware that they had the disease. The authors specifically asked 2,992 patients with stage 1-4 CKD whether or not they had been told that they had weak or failing kidneys. Between 1999 and 2004, awareness improved only in patients with stage 3 CKD. Patients with risk factors for CKD such as diabetes or hypertension were most likely to be aware of their disease.

Herbal remedies and acute kidney disease

Nature Clinical Practice Nephrology has recently published a review by Luyckx and Naicker highlighting the link between traditional medicines and kidney injury.

Traditional and herbal remedies are widely used worldwide, with as many as 80% of people in some populations using such treatments. The use of herbal remedies becoming increasing common in Western countries, as shown by a 2002 survey that found that 36% of people in the US use alternative or complementary medicines.

Herbal therapies all pass through the kidney on their way out of the body; consequently, many have been associated with acute kidney disease. Luyckx and Naicker report that "folk remedies account for up to 35% of cases of acute kidney injury and mortality rates for acute kidney injury range from 24% to 75%."

The herbal remedies most commonly used in the US include echinacea, which is used as an immunostimulant, and St John’s wort, which is used to treat depression among other things. Echinacea, however, has been associated with acute kidney injury and St John's Wort with kidney transplant rejection.

Various factors besides direct toxicity of the agent can contribute to kidney injury, such as contamination of the preparation or incorrect administration. In addition, the type of nephrotoxicity experienced by an individual taking a herbal remedy is dependent on which part of the kidney is affected, and the authors discuss these factors in more detail in their review.

Luyckx and Naicker do point out that the effects of herbal remedies are something of an unknown quantity; for example, some studies have shown that cranberry decreases the risk of kidney stones, whereas other studies find that cranberry increases this risk.

The review concludes by saying "The incidence and prevalence of acute kidney injury associated with the use of traditional remedies is unknown and probably varies greatly from place to place. Since the use of traditional remedies is common worldwide, it is probably safe to assume that the incidence of acute kidney injury is not high. Individual morbidity, however, can be considerable."