A data-driven approach to choosing privacy parameters for clinical trial data sharing under differential privacy.

OBJECTIVES: Clinical trial data sharing is crucial for promoting transparency and collaborative efforts in medical research. Differential privacy (DP) is a formal statistical technique for anonymizing shared data that balances privacy of individual records and accuracy of replicated results through a "privacy budget" parameter, ε. DP is considered the state of the art in privacy-protected data publication and is underutilized in clinical trial data sharing. This study is focused on identifying ε values for the sharing of clinical trial data. MATERIALS AND METHODS: We analyzed 2 clinical trial datasets with privacy budget ε ranging from 0.01 to 10. Smaller values of ε entail adding greater amounts of random noise, with better privacy as a result. Comparison of rates, odds ratios, means, and mean differences between the original clinical trial datasets and the empirical distribution of the DP estimator was performed. RESULTS: The DP rate closely approximated the original rate of 6.5% when ε > 1. The DP odds ratio closely aligned with the original odds ratio of 0.689 when ε ≥ 3. The DP mean closely approximated the original mean of 164.64 when ε ≥ 1. As ε increased to 5, both the minimum and maximum DP means converged toward the original mean. DISCUSSION: There is no consensus on how to choose the privacy budget ε. The definition of DP does not specify the required level of privacy, and there is no established formula for determining ε. CONCLUSION: Our findings suggest that the application of DP holds promise in the context of sharing clinical trial data.

Elevated cerebrospinal fluid ubiquitin C-terminal hydrolase-L1 levels correlate with phenotypic severity and therapeutic response in Niemann-Pick disease, type C1.

BACKGROUND: Niemann-Pick disease, type C1 (NPC1) is an ultrarare, recessive disorder due to pathological variants of NPC1. The NPC1 phenotype is characterized by progressive cerebellar ataxia and cognitive impairment. Although classically a childhood/adolescent disease, NPC1 is heterogeneous with respect to the age of onset of neurological signs and symptoms. While miglustat has shown to be clinically effective, there are currently no FDA approved drugs to treat NPC1. Identification and characterization of biomarkers may provide tools to facilitate therapeutic trials. Ubiquitin C-terminal hydrolase-L1 (UCHL1) is a protein which is highly expressed by neurons and is a biomarker of neuronal damage. We thus measured cerebrospinal fluid (CSF) levels of UCHL1 in individuals with NPC1. METHODS: CSF levels of UCHL1 were measured using a Quanterix Neuroplex 4 assay in 94 individuals with NPC1 and 35 age-appropriate comparison samples. Cross-sectional and longitudinal CSF UCHL1 levels were then evaluated for correlation with phenotypic measures and treatment status. RESULTS: CSF UCHL1 levels were markedly elevated (3.3-fold) in individuals with NPC1 relative to comparison samples. The CSF UCHL1 levels showed statistically significant (adj p < 0.0001), moderate, positive correlations with both the 17- and 5-domain NPC Neurological Severity Scores and the Annual Severity Increment Scores. Miglustat treatment significantly decreased (adj p < 0.0001) CSF UCHL1 levels by 30% (95% CI 17-40%). CONCLUSIONS: CSF UCHL1 levels are elevated in NPC1, increase with increasing clinical severity and decrease in response to therapy with miglustat. Based on these data, UCHL1 may be a useful biomarker to monitor disease progression and therapeutic response in individuals with NPC1.