NEW YORK (360Dx) – Screening blood donors could help identify people with familial hypercholesterolemia, a new study has found.
Familial hypercholesterolemia (FH) is a common autosomal dominant genetic condition that affects about 20 million people worldwide. Although FH leads to a 100-fold increase in risk of a coronary artery disease event, as compared to people without the condition, many adults are not aware they have it.
The University of Texas Southwestern Medical Center's Amit Khera and his colleagues examined data from blood donors to determine whether screening people who give blood could identify individuals with FH. As they reported in JAMA Cardiology today, the researchers found that the prevalence of FH, as gauged by serum cholesterol levels, was similar among donors as it is in the general population. They noted, though, that it was slightly more prevalent among younger individuals — the population that may most benefit from early diagnosis.
"[B]lood donation represents a novel and potentially cost-effective approach to identifying FH, particularly in younger individuals who are not engaged in the medical system," Amit Khera and his colleagues wrote in their paper.
He and his colleagues gathered data on 1.18 million donors over the age of 16 who gave blood through Carter BloodCare, an independent, Texas-based blood program, between January 2002 and December 2016. The program, the researchers noted, routinely measures total non-fasting serum cholesterol levels among donors. Between 2002 and 2009, those non-fasting total cholesterol levels were measured using the Abbott Aeroset System, and from 2010 through 2016 it was measured using Beckman Coulter's AU680 Chemistry Analyzer.
Using the Make Early Diagnosis to Prevent Early Death (MEDPED) criteria, the researchers determined FH status for each donor based on their serum cholesterol levels.
Based on those criteria, they reported that 3,473 donors — or 1 in 339 donors — met MEDPED criteria for FH, which is broadly similar to the reported prevalence in the general population.
That prevalence, though, varied by donor age and was slightly higher for younger donors — 1 in 257 — the researchers reported. They noted that that was possibly because of the lower MEDPED threshold for determining FH at younger age, survival bias as older individuals with FH may die prematurely of coronary artery disease, and cholesterol levels in older individuals being influenced by lipid-lowering treatments.
Still, this suggested to Khera and his colleagues that screening blood donors for FH could help identify those at risk of the disease. In particular, they noted that as blood donors must be free of certain medical conditions like cancer and infectious, pulmonary, and cardiovascular disease and are often young, such screening could capture a segment of the population that doesn't regularly visit medical professionals.
"Identifying possible cases of FH has important implications for early treatment as well as cascade screening of family members," the researchers wrote.
They further noted that adding total cholesterol testing to screening would have a negligible cost in comparison to other tests run on donated blood.
In a related commentary in JAMA Cardiology, the University of Colorado School of Medicine's Stephen Daniels wrote that the situation is actually more complicated. A number of individuals gave blood more than once in the timeframe the UT-Southwestern researchers studied, some of whom met MEDPED criteria for FH. However, only 29 percent of those repeat donations also met MEDPED criteria, suggesting there could be variability in measurements or that some individuals received treatment.
Daniels also noted that for a screening program to be effective, it has to be connected to the healthcare system, and he suggested that rather than measuring cholesterol levels, moving from having that data to getting patients treatment might be the bigger hurdle to clear.