Finding Biomarkers in ALS: Creatinine Levels and Oxidative Stress
The lack of biomarkers, or clinical tests to determine an ALS diagnosis, are a deep frustration for patients and the scientific community alike. In a recent study, Columbia University reseachers set out to determine the importance of blood creatinine, uric acid and urine oxidative stress levels in a large, long-term ALS study of 365 patients.
Samples were taken at first diagnosis, mid-point of life and the final blood draw before death. The researchers then associated these markers with the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) which stratifies the severity of amyotrophic lateral sclerosis (ALS) and indicates how fast the disease is progressing.
Importantly, blood creatinine levels correlated with the ALSFRS-R scale. The baseline creatinine levels siignificantly predicted survival. Time to death from basline was shortest for those in the two lowest creatinine quartiles compared to the hightest two quartiles. The creatinine and ALSFRS-R were correllated at all three time points of life. Creatinine and uric acid levels declined over time and oxidative stress markers increased over time.
To date, the creatinine levels predicted survival in the most accurate way compared to the other two markers. Plasma (blood) creatinine represents the degree of muscle mass and could also represent complex changes in ALS. For now, it's one of the few markers to watch.