Poster Presentation 29th Annual Lorne Proteomics Symposium 2024

Exploratory proteomic investigation to improve diagnostic management of transient ischaemic attacks (TIAs).  (#135)

Deeksha Sharma 1 , Rachael Protzman 2 , Marten Snel 2 , Paul Trim 2 , Austin Milton 3 , Joshua Mahadevan 3 , Craig Kurunawai 3 , Timothy Kleinig 3 , Jim Jannes 3 , Simon Koblar 1 , Monica Anne Hamilton-Bruce 3
  1. The University of Adelaide, Adelaide, SA, Australia
  2. South Australian Health & Medical Research Institute, Adelaide, SA, Australia
  3. Central Adelaide Local Health Network, Adelaide, SA, Australia

Background 

Stroke is a leading cause of death and disability worldwide1, with a stroke occurring every 19 minutes in Australia2. Approximately 71% of strokes are caused by an interruption to the blood supply to the brain (ischaemia)1, resulting in depleted oxygen and significant neuronal death3. A transient ischaemic attack (TIA) is a key predictor for ischaemic stroke4, and timely, accurate diagnosis and treatment of a TIA has the potential to significantly reduce the risk of subsequent ischaemic stroke5. However, TIA diagnosis is complex and there are a number of neurological conditions with symptomatic overlap (TIA mimics, minor ischaemic strokes), resulting in a high rate of misdiagnosis6. A plasma biomarker would be an ideal biomarker to improve diagnostic management and reduce the risk of ischaemic stroke. 

Aim

To identify potential proteomic biomarkers for diagnostic management of transient ischaemic attacks. 

Methodology

A ≤10mL plasma sample was collected from patients presenting with TIA-like symptoms at the Royal Adelaide Hospital within 48 hours of symptom onset. Samples were processed and stored at SAHMRI in line with HUPO guidelines. Proteomic investigation was conducted using LC-MS; tryptic peptides were loaded onto a Dionex UltiMate 3000 nano-LC with a 58-minute active gradient and ran on a Bruker TimsTOF Pro 2 Mass Spectrometer using DIA-PASEF. Proteins were identified using Spectronaut v.18.4. All samples were clinically categorised independently as either TIA mimic, TIA, or minor ischaemic stroke by two vascular neurologists, with any disagreement resolved by a third, senior vascular neurologist. 

Results

The first subset of proteomics investigation was conducted with 50 patient plasma samples (29 Females, 21 Males) aged 39-94 (Median:72) at time of sample collection. All patients were classified based on clinical data, with 56% established as a TIA mimic. A total of 863 proteins and 786 protein groups were identified, with an average of 691 proteins from 625 protein groups from each sample. The average number of missed cleavages was 0.4. Differential expression in the clinical groups was observed in comparison to the control group, with pathway analysis and additional statistical analysis currently underway. 

Conclusion

Exploratory proteomic investigation has elucidated potential for differential proteomic involvement in TIAs, TIA mimics, and minor strokes. Further analysis is ongoing will be expanded to n=100 for additional examination. 

 

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