Gaucher biomarker changes may not mirror disease progression
Lyso-Gb1 levels can have different trajectories without treatment, study finds
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Levels of the Gaucher disease biomarker glucosylsphingosine (lyso-Gb1) can have different trajectories in people who aren’t actively receiving treatment, a study found.
While most untreated patients showed relatively little change in lyso-Gb1 over time, more than one-third experienced increases in the biomarker, which weren’t always associated with immediate disease progression, and a smaller group saw decreases.
The findings suggest that changes in lyso-Gb1 levels should be interpreted with caution and used alongside other clinical measures when making treatment decisions, the researchers said.
“These results support using lyso-Gb1 as a sensitive biomarker for monitoring untreated states but highlight that isolated changes should not automatically prompt treatment,” they wrote. “Instead, lyso-Gb1 trends should be evaluated alongside clinical assessments, [blood] parameters, and other disease signs.”
The study, “Glucosylsphingosine (Lyso-Gb1) Dynamics in Untreated States in Gaucher Disease,” was published in the International Journal of Molecular Sciences.
Levels tend to decline with treatment
Gaucher disease is an inherited condition in which the body cannot efficiently break down glucocerebroside (Gb1), a fatty molecule. As Gb1 accumulates inside cells, it can damage tissues and organs throughout the body.
Lyso-Gb1, a molecule derived from Gb1, has become one of the most widely used biomarkers for Gaucher disease. Its levels generally decline in response to treatment, making it useful for monitoring disease activity and treatment response. It has “increasingly become central to diagnostic and monitoring strategies,” the researchers wrote.
While lyso-Gb1 is routinely measured in clinical practice, little is known about how its levels change naturally over time in people who are not receiving therapy. Understanding those patterns could help clinicians better understand what to expect in untreated patients and distinguish treatment-related changes from the disease’s normal course.
The team, led by researchers in Israel, examined medical records from 701 people with Gaucher disease. Among them, 272 contributed data from periods when they were not receiving treatment, either because they had mild disease that did not require treatment or because the data were collected before or after treatment began or ended. Eligible patients had at least two available lyso-Gb1 measurements for those untreated periods.
Over the course of untreated periods, about half the patients showed no substantial changes in lyso-Gb1 levels. In turn, 36% had increases in the biomarker, and 12.9% experienced decreases.
When looking at factors associated with each trajectory, the researchers found that women were 3.5 times more likely than men to experience declining lyso-Gb1 levels while untreated. Higher lyso-Gb1 levels at the start of follow-up were also associated with subsequent decreases, which the researchers suggested could reflect temporary periods of increased disease activity that later subsided.
In contrast, lower levels of platelets and hemoglobin, which are indicative of more severe disease, at the first untreated visit were associated with later increases in lyso-Gb1.
The team conducted a separate analysis comparing 246 people who never received treatment with 297 who were on treatment throughout the study period. Consistent with the main findings, most never-treated patients (66.3%) showed stable lyso-Gb1 levels over time despite having higher biomarker levels overall.
“The stability observed in most patients who were never treated suggests that biochemical progression is not inevitable during untreated follow-up, particularly in individuals with milder disease [features],” the researchers wrote.
The researchers noted several limitations to consider when interpreting their study, including its retrospective design and differences in disease severity between treated and untreated patients that complicated direct comparisons. In addition, the chosen threshold for change in lyso-Gb1, 50 nanograms/ml, was conservative and may not always reflect meaningful differences in disease activity, they said.
“Even when lyso-Gb1 changes exceed this threshold, lyso-Gb1 trends should be interpreted in conjunction with clinical findings, including [blood] parameters, organ involvement, skeletal disease, and overall disease trajectory, rather than being used in isolation for treatment decisions,” the team concluded.
