Death risk from infections halves since 1990s

At present, the risk of death from infections after kidney transplantation has dropped to a level half of that prevailed during the 1990s, found a recent analysis.

The analysis also found that common bacterial infections remain the most frequent causes of infection-related deaths among kidney transplant recipients, said a University of Helsinki press release.

The study was carried out by researchers from the University of Eastern Finland, the University of Helsinki, Kuopio University Hospital, and Helsinki University Hospital and its findings were run by the Clinical Journal of the American Society of Nephrology (CJASN).

The risk of infection is something that all nephrologists think of when a patient is considered for kidney transplantation.

Indeed, infections are the most common non-cardiovascular causes of death after kidney transplantation, likely due to the patients’ need for immunosuppressive medications to prevent rejection. No recent data about the infectious causes of death after kidney transplantation exist, however.

To provide an estimate on infection-related mortality among the kidney transplant recipients in a modern developed country, a team led by doctor Ilkka Helanterä, (Helsinki University Hospital) and doctor Susanna Kinnunen (University of Eastern Finland and Kuopio University Hospital) examined data on all adult recipients of a first kidney transplantation between 1990 and 2012 in Finland. Infectious causes of death were analyzed and the mortality rates for infections were compared between two eras (1990-1999 and 2000-2012). The data was obtained from the Finnish Registry for Kidney Diseases.

Among the 3,249 adult recipients of a first kidney transplant in the analysis, 953 patients (29%) died during follow-up, with 204 infection-related deaths. The mortality rate due to infections was lower in patients in the more recent era than in patients in the 1990s (4.6 vs. 9.1 per 1,000 person-years. A person-year is the number of years of follow-up multiplied by the number of people in the analysis).

Common bacterial infections were the most frequent causes of infection-related mortality, whereas opportunistic viral, fungal or unconventional bacterial infections rarely caused deaths after kidney transplantation. Older recipient age, higher plasma creatinine concentration at the end of the first post-transplant year, diabetes as a cause of kidney failure, longer pre-transplant dialysis duration, acute rejection, low albumin level, and earlier era of transplantation were found to be associated with higher risks of infectious death.

“The 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 immune suppression,” said the press release.

The release said 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, a 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 the transplantation,” the press release added.