The current system of prioritizing children with liver disease who are waiting for transplantation may not be optimal because the Pediatric End-stage Liver Disease score (PELD) may underestimate risk of dying before a liver transplant in some children if kidney function is not taken into consideration. Adding the values from two additional blood tests, a kidney function test and serum sodium, improves the ability of the current system to identify those at most risk. This could help make the system of liver allocation work better for kids who are waiting. These are the findings of a study now published online, and in a future issue of Hepatology, the official publication of the American Association for the Study of Liver Diseases.
The PELD score is currently used to estimate the relative disease severity and likelihood of survival for children on the waiting list for a liver transplant. The variables used to calculate the PELD score include age, height, weight, albumin, bilirubin and international normalized ratio (INR).
"We hope our study will help pediatric transplant centers identify their patients at greatest risk, such that on a national level, organ prioritization can become more just, improving outcomes for all pediatric transplant candidates," says Leanne Thalji, B.M., M.S., a Mayo Clinic pediatric anesthesiologist and the lead researcher on the study.
Currently in the U.S. there are nearly 13,000 patients waiting for a liver transplant and more than 300 of these are pediatric patients. Allocation of livers nationally is based on severity of liver disease with the sickest patients prioritized for liver transplant.
Unlike the Model for End Stage Liver Disease, or MELD score, which was developed by Mayo researchers and is used to prioritize organ allocation in adults, the PELD score does not include variables reflecting kidney function. To improve the predictive accuracy of the PELD score, Dr. Thalji, and her collaborators from the Mayo Clinic studied the addition of laboratory variables reflecting kidney function to the PELD score to more accurately predict waitlist mortality. The study concluded that incorporating parameters of kidney function into the PELD score may identify patient subsets with underappreciated risk, while augmenting predictive accuracy of the score.
The study authors propose that consideration be given in future allocation policies to including variables of kidney function for organ allocation in children, thereby reducing morbidity and mortality on the waiting list for donor livers. This change alone will not be the solution to children dying on the waiting list while awaiting liver transplantation. The problem is that there are not enough donors, and efforts to increase awareness about the importance of organ donation are essential. Work also needs to be done to improve public awareness of the option of living liver donation.
Living donors can donate a kidney or a portion of their liver. Deceased donors can donate up to eight organs, corneas and other types of tissues. More than 112,000 people are on the waiting list for a lifesaving organ, according to the United Network for Organ Sharing. To register to become an organ donor, go to Donate Life America's website.
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