Study sees potential for byproduct of muscle function to be sensitive biomarker. Blood levels of creatinine, a byproduct of normal muscle function, may be a potential biomarker of disease severity and treatment response in adults and adolescents with spinal muscular atrophy SMA , a study in China shows. The loss of this protein particularly affects motor neurons β the nerve cells that control voluntary movements β leads to hallmark disease symptoms like muscle weakness and wasting.
Current SMA biomarkers, which can range from SMN and neurofilament protein levels to imaging markers like MRI and muscle ultrasound, can lack the needed sensitivity and accuracy, the researchers noted. The researchers conducted an observational study in 28 SMA patients, mainly males As a control group, they included 28 sex- and age-matched healthy individuals. Among the patients, 15 could walk independently ambulant , while 13 could not; eight of them were unable to sit alone, and five were unable to sit independently.
Compared with controls, SMA patients had significantly lower blood creatinine levels Over up to two years of follow-up, ambulant SMA patients had more than double the creatinine levels of those who could not walk 32 vs. People with four or more copies of the SMN2 gene showed near twice the levels of creatinine than patients with fewer than four gene copies Likewise, higher creatinine levels associated with an increase in ulnar muscle upper limb response to nerve stimulation, a measure called compound muscle action potential, or CMAP.
And these levels linked with better lung function, according to measures of forced vital capacity FVC , the maximum amount of air one can forcibly exhale after a deep breath. After six months of treatment, half of 22 evaluable patients had stable or higher creatinine levels, as did 11 of 16 patients Creatinine levels also were able to predict up to This was significantly higher than that of other biomarkers, including SMN2 gene copy number, nerve conductance, and FVC.
News Blood creatinine levels may best mark progression, therapy response Blood creatinine levels may best mark progression, therapy response Study sees potential for byproduct of muscle function to be sensitive biomarker by Andrea Lobo January 15, Share this article: Share article via email Copy article link. Recommended Reading. Print This Page. She was a postdoctoral and senior researcher at the Institute for Research and Innovation in Health in Porto, in drug addiction, studying neuronal plasticity induced by amphetamines.
