Can PRLs Be Prevented or Reversed?
The data on PRLs have generated interest in whether they can be prevented or reversed once they appear. This might be dependent on first determining who is at risk. Another study presented at ACTRIMS suggested that it might not be complex. Lesion size might be critical.
In this study, 233 images were evaluated in 64 patients participating in an observational study at the UMass Memorial Medical Center, Worcester, Massachusetts.
In a univariable analysis, a long list of patient factors, disease characteristics, and imaging characteristics correlated with an increased risk of develop PRLs. These included patient age, disease duration, lesion volume, enhancement pattern (ring vs nodular), and use of disease modifying therapies.
When a regression analysis of these factors was performed, “none of the predictive factors on the univariable analyses were significant after including lesion size in the model,” reported Mustafa Al Gburi, MD, a fellow in neuroimaging at UMass.
While his data did show that exposure to steroids did not appear to reduce risk of developing PRLs, he is now running follow-up to see if specific disease-modifying therapies are more or less preventive for the development of PRL. Because of the limited number of patients and follow-up, it is now too early to tell.
Overall, the risk of PRLs appears to grow substantially at a lesion size of greater than 11 mm, Dr. Al Gburi reported. He believes that this might be “a simple bedside marker to determine patients at future risk of chronic active lesions.”
PRLs might not just be a diagnostic and prognostic tool. Dr. Gauthier said that PRLs are at least a theoretical treatment target. While their immediate promise is in monitoring disease, she thinks the evidence would predict a benefit if PRLs could be prevented or reversed.
Dr. Gauthier reports financial relationships with Genentech, Sanofi-Genzyme, and Mallinckrodt. Dr. Renner and Dr. Al Gburi report no potential conflicts of interest.