recently published in Orphanet Journal of Rare Diseases
underscores how little is known about the symptom of fatigue in Gaucher disease. The paper’s first author is Yehudit Chen Zion, of Rambam Health Care Campus in Haifa, Israel.
(GD) is the most common lysosomal storage disorder in the world, occurring in about 1 in 50,000 people, but more commonly in people of Ashkenazi Jewish heritage. Mutations in the GBA gene lead to problems synthesizing the enzyme, β-glucocerebrosidase, which normally breaks down glucocerebroside. In people with GD, glucocerebroside builds up to toxic levels which lead to multiple symptoms that may include hepatosplenomegaly, anemia, thrombocytopenia, lung disease, bone pain, and serious neurological damage.
Extreme chronic fatigue is also a very common symptom of GD. For some patients, it is their most debilitating symptom, and it significantly reduces quality of life. The cause of this fatigue is unclear, and may result from a variety of factors, including anemia, immune abnormalities, pain, depression, and sleep disturbances.
There is no cure for GD, but enzyme replacement and supportive therapies can reduce some symptoms. Patients are regularly monitored with lab tests and radiological imaging. However, current guidelines do not include specific methods to assess fatigue, and fatigue management is not a standard part of these patients’ therapeutic goals.
Fatigue study findings
Zion and colleagues conducted Pubmed searches to identify reports studying fatigue in GD. The researchers found 6 studies which assessed fatigue in GD, only 2 of which used standard assessment tools for fatigue. Fatigue was not the primary endpoint in any of the reports.
To further explore the question of fatigue in GD, the researchers performed an exploratory survey of 14 patients and 19 physician specialists. The participants were asked to rate the importance of 6 parameters using a scale from 1 to 9. These parameters included fatigue, complete blood count (including hemoglobin and platelet count), liver and spleen volume, disease related biomarkers, bone density, and bone pain. Patients rated fatigue of higher importance than did physicians (7.6 to 5.8).
Improving assessment and treatment of fatigue in GD
The authors found that the information on fatigue in GD was quite limited, and they suggest that further research is needed. The authors also argue for a validated scale to measure fatigue, noting that the absence of practice guidelines for measuring fatigue may discourage providers from including it as an important treatment goal.
We also have much to learn about the optimal treatment of fatigue in GD. Enzyme replacement therapy appears to help somewhat, but more remains to be learned. Physicians do standardly treat certain potential causes of fatigue, such as anemia, but others remain to be defined. Clinicians will need to continue to identify the optimal ways to address the potential causes of this debilitating symptom.