The use and performance of lyso-Gb3 for the diagnosis and monitoring of Fabry disease: A systematic literature review.

BACKGROUND

Fabry disease (FD) is a rare, X-linked lysosomal storage disorder in which a lack of alpha-galactosidase (α-Gal A) enzyme activity leads to intracellular accumulation of deacylated globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3), and their analogs. Lyso-Gb3, present in the blood and urine of affected patients, has been extensively investigated as a biomarker for FD. This systematic literature review (SLR) aimed to comprehensively assess the use of lyso-Gb3 as a biomarker for screening, monitoring, and diagnosis of FD in both real-world and clinical trial settings.

METHODS

An SLR was performed to identify the following outcomes in adult and pediatric patients with FD: lyso-Gb3 testing patterns, lyso-Gb3 levels in subpopulations, performance and accuracy of lyso-Gb3 testing for diagnosis, and lyso-Gb3 testing for monitoring of disease progression or treatment efficacy/effectiveness. Interventional and non-interventional studies published between 1 January 2017 and 3 November 2022 were included. Searches were primarily conducted in MEDLINE and Embase; pragmatic or hand searches were also performed. The methodological quality of included full-text studies was assessed using validated appraisal tools. Extracted data were synthesized qualitatively.

RESULTS

The SLR included 83 eligible publications, comprising 71 observational studies and 12 clinical trials. Differences in lyso-Gb3 levels were identified across subpopulations, with several studies reporting higher levels in males versus females. Lyso-Gb3 demonstrated good diagnostic performance in newborns and high-risk patients when used in combination with other markers (α-Gal A activity or GLA variants) but failed to diagnose females with late-onset FD. Reliability and stability across different methods used to measure lyso-Gb3 was high, with a coefficient of variation <10 % for inter- and intra-assay measurements. Several studies identified moderate to strong correlation between plasma lyso-Gb3 levels and cardiac measures, but association with renal measures needs further investigation.

CONCLUSIONS

Lyso-Gb3 testing demonstrated accuracy in screening, diagnosis, and monitoring of FD in certain subpopulations, particularly males, but considering its lower sensitivity in late-onset female patients, it should be used in conjunction with other tools. Given the reliability of the test, it can be considered a feasible method for monitoring disease progression in FD in individual patients. Several gaps in the literature were identified, warranting further investigation.

REGISTRATION: PROSPERO (CRD42022375141).