Reverse Engineering of Digital Measures: Inviting Patients to the Conversation

Background

Digital measures offer an unparalleled opportunity to create a more holistic picture of how people who are patients behave in their real-world environments, thereby establishing a better connection between patients, caregivers, and the clinical evidence used to drive drug development and disease management. Reaching this vision will require achieving a new level of co-creation between the stakeholders who design, develop, use, and make decisions using evidence from digital measures.

Summary

In September 2022, the second in a series of meetings hosted by the Swiss Federal Institute of Technology in Zürich, the Foundation for the National Institutes of Health Biomarkers Consortium, and sponsored by Wellcome Trust, entitled "Reverse Engineering of Digital Measures," was held in Zurich, Switzerland, with a broad range of stakeholders sharing their experience across four case studies to examine how patient centricity is essential in shaping development and validation of digital evidence generation tools.

Key Messages

In this paper, we discuss progress and the remaining barriers to widespread use of digital measures for evidence generation in clinical development and care delivery. We also present key discussion points and takeaways in order to continue discourse and provide a basis for dissemination and outreach to the wider community and other stakeholders. The work presented here shows us a blueprint for how and why the patient voice can be thoughtfully integrated into digital measure development and that continued multistakeholder engagement is critical for further progress.

Proteolipid protein is required for transport of sirtuin 2 into CNS myelin

Mice lacking the expression of proteolipid protein (PLP)/DM20 in oligodendrocytes provide a genuine model for spastic paraplegia (SPG-2). Their axons are well myelinated but exhibit impaired axonal transport and progressive degeneration, which is difficult to attribute to the absence of a single myelin protein. We hypothesized that secondary molecular changes in PLP(null) myelin contribute to the loss of PLP/DM20-dependent neuroprotection and provide more insight into glia-axonal interactions in this disease model. By gel-based proteome analysis, we identified >160 proteins in purified myelin membranes, which allowed us to systematically monitor the CNS myelin proteome of adult PLP(null) mice, before the onset of disease. We identified three proteins of the septin family to be reduced in abundance, but the nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase sirtuin 2 (SIRT2) was virtually absent. SIRT2 is expressed throughout the oligodendrocyte lineage, and immunoelectron microscopy revealed its association with myelin. Loss of SIRT2 in PLP(null) was posttranscriptional, suggesting that PLP/DM20 is required for its transport into the myelin compartment. Because normal SIRT2 activity is controlled by the NAD+/NADH ratio, its function may be coupled to the axo-glial metabolism and the long-term support of axons by oligodendrocytes.

Fungal antigens expressed during invasive aspergillosis

Rabbits that had been infected intravenously with conidiospores of Aspergillus fumigatus were used as sources of antibody for screening a lambda phage cDNA expression library. The cDNA was derived from A. fumigatus mRNA that had been extracted from newly formed, germling hyphae. Thirty-six antigens were identified using antisera from six rabbits. Though many of these antigens were expected to be intracellular proteins because their genes did not encode a signal sequence, the antisera showed consistently a stronger immunoblot reaction with a cell fraction enriched for the fungal cell wall than with a fraction of predominantly intracellular components. Antibodies to eight antigens, including the glycosylhydrolase Asp f 16, were produced by more than one rabbit. In current vaccine studies, Asp f 16 is the only single antigen which has been reported to be capable of inducing protection against invasive aspergillosis in mice. Enolase and Aspergillus HSP90 were detected also; their homologues in Candida albicans have been tested as vaccines and have been reported to provide a partially protective response against invasive candidiasis in mice. The Aspergillus antigens reported here may have value both in diagnostic tests for different forms of aspergillosis and as vaccine candidates for protection against invasive disease.