Risk of Dying from Infections Following Kidney Transplantation Drops by Half In Finland

Researchers in Finland say deaths from infection in kidney transplant recipients have dropped by half since the 1990s, showing a significant decline in the most common noncardiovascular cause of death following kidney transplantation.

Kidney transplants are one of the most common organ transplants, and kidneys can be donated from both living and non-living donors. While these procedures can save the lives of individuals experiencing organ failure from end-stage renal disease, kidney transplantation has its risks. Along with the potential for undetected donor-derived diseases, transplant recipients are also at risk because the body’s natural mechanism is to perceive transplanted organs as foreign and attack them. To prevent organ rejection, transplant recipients must take certain immunosuppressive medications to lower the immune system’s attack response, which, in turn, also increases susceptibility to infections from bacterial, viral, and fungal pathogens, a major cause of mortality and morbidity.

A 2009 study published in the journal Kidney International found that in kidney transplant recipients, the rate of first infections in the initial 3 years after transplantation was 45.0 per 100 patient-years of follow-up, more than half of which were bacterial. In Finland, the rate of kidney transplants has increased since a 2010 piece of legislation removed permission laws for organ harvesting unless the patient objected to it in advance. With the new presumed consent laws for organ donation, Finland reported an overall record number of organ transplants in 2015, including a record of 245 kidney transplants. Now, in a new study published in the Clinical Journal of the American Society of Nephrology, researchers from the University of Eastern Finland, Helsinki University Hospital, and the Finnish Registry for Kidney Diseases report that the country has halved its risk of dying via infection following kidney transplantation.

For their study, the authors looked at 3,249 adult recipients of a first kidney transplant from 1990 to 2012 and analyzed deaths from infectious causes. A total of 953 patients died during follow up, 204 of whom died from infections. The researchers then compared mortality rates between 2 eras, 1990 to 1999 and 2000 to 2012, and found that the mortality rate had declined, from 9.1 per 1000 person-years (the number of years of follow-up multiplied by the number of individuals in the analysis) in the earlier group to 4.6 per 1000 person-years. Bacterial infections accounted for most infectious deaths, while viral and fungal infections caused only 2% and 3% of infectious deaths, respectively.

"Our study shows that the risk of infectious mortality in patients with a kidney transplant is much lower than previously thought and that the risk has dropped by half in the 2000s in our cohort despite transplanting older and sicker patients and using more powerful immunosuppression," said the study’s lead author, Ilkka Helanterä, MD, PhD, in a recent press release. He noted that the discovery that the infections that cause death in transplant recipients are very similar to the infections that cause mortality in the general population is contrary to current thinking among experts. "In addition, surprisingly low number of infectious deaths were recorded during the first year after transplantation, and most of the infectious deaths occurred late, several years after transplantation."

The National Kidney Foundation says that kidney transplant recipients are at risk from common illnesses, such as flu or pneumonia. It recommends receiving vaccines, avoiding individuals with contagious illnesses, and frequent handwashing during cold and flu season to help avoid getting sick.