Millions of people around the globe experience a persistent itching condition without a known cause, referred to as chronic pruritus of unknown origin (CPUO). Unfortunately, there are currently no targeted treatments available for this condition. Many individuals endure this plight for years, often without any relief. However, a recent study from the University of Maryland School of Medicine may offer a glimmer of hope for future therapies. Researchers have detected unusually low levels of metabolite biomarkers in the blood plasma of these patients, which might help explain their severe symptoms.
Millions of people around the globe experience a persistent itching condition without a known cause, referred to as chronic pruritus of unknown origin (CPUO). Unfortunately, there are currently no targeted treatments available for this condition. Many individuals endure this plight for years, often without any relief. However, a recent study from the University of Maryland School of Medicine may offer a glimmer of hope for future therapies. Researchers have detected unusually low levels of metabolite biomarkers in the blood plasma of these patients, which might help explain their severe symptoms.
The study results were recently published in the journal Scientific Reports.
Lead researcher Shawn Kwatra, MD, who is the Joseph W. Burnett Endowed Professor and Chair of Dermatology at UMSOM and Chief of Service Dermatology at the University of Maryland Medical Center (UMMC), noted, “Our study identified a significant deficiency in certain metabolite biomarkers, such as several key amino acids and other substances involved in immune system regulation among patients with CPUO when compared to a healthy control group. This is an exciting discovery as it sheds light on the potential causes of this condition and reveals possible new therapeutic targets for the future.”
CPUO is most commonly found in older adults and results in intense itching that persists for more than six weeks. The typical treatments available to manage this condition are often used off-label and generally show limited effectiveness, leading to a notable decline in the quality of life for many patients.
In the recent study, Dr. Kwatra and his team analyzed blood plasma samples from individuals with CPUO alongside those from matched healthy patients. They discovered lower levels of nine amino acids in the blood of CPUO patients compared to the control group, and these lower levels were linked to the severity of itching experienced.
Earlier studies in animals have associated reduced amounts of these amino acids with itching symptoms in mice. These amino acids are essential for creating neurotransmitters—chemicals in the brain that influence the body’s itch response and various allergic skin reactions. When mice were given antidepressants to enhance neurotransmitters like serotonin, their itch symptoms decreased.
Dr. Kwatra stated, “Many of the biomarkers that we identified at reduced levels in CPUO patients, including tryptophan and glycine, could play a role in the development of this condition, but we definitely need larger studies to explore this further.”
The co-authors of this study also included faculty members from Johns Hopkins University School of Medicine and Duke University Medical Center.
In June, Dr. Kwatra published research in JAMA Dermatology showing that an anti-inflammatory drug (abrocitinib), which is approved for eczema treatment, significantly improved itching symptoms in individuals with CPUO as well as prurigo nodularis, another itching disorder. He also led a previous study demonstrating the effectiveness of the monoclonal antibody, nemolizumab, for treating prurigo nodularis. This drug was approved by the US Food and Drug Administration on August 13 and represents one of the first FDA-sanctioned treatments for this skin condition, which disproportionately impacts African-American patients.
Dr. Kwatra serves as a consultant and advisor to several pharmaceutical companies involved with abrocitinib and nemolizumab.
Since taking on his role at UMSOM earlier this year, Dr. Kwatra has established the Maryland Itch Center at the University of Maryland Medical Center.