Evaluating Urinary p75ECD as a Biomarker for Adrenoleukodystrophy
Adrenoleukodystrophy (ALD) is a peroxisomal, X-linked disorder that mutates the ABCD1 gene, which encodes for adrenoleukodystrophy protein (ALDP). Without the functioning of this protein, very long chain fatty acids build up in tissues and body, primarily on top of adrenal glands and in the central nervous system. ALD has no current cure and bone marrow transplantation is currently the main treatment method for ALD. Therefore, looking at ALD’s biomarkers could give indication about its prognosis and disease progression. The extracellular domain of neurotrophin receptor p75 (p75ECD) has been shown to be a biomarker in other neurodegenerative conditions, primarily amyotrophic lateral sclerosis, or ALS. Similarly, examining levels of p75ECD in ALD could help determine its significance in this disease, and if it can serve as a marker for prognosis. To check for urinary p75ECD among ALD patients, baseline urine samples were processed and gathered from Dr. Lund’s biorepository that would be compared with control urine samples. An enzyme-linked immunosorbent assay was performed to check for p75ECD levels, followed by a creatinine assay to normalize all samples. After normalization, p75ECD levels were found to be statistically different between ALD patients and control samples. Although p75ECD levels were increased in ALD patients, many confounding variables still exist. Reducing these differences would help depict a better picture of how p75ECD levels differ in ALD patients.