Browsing by Author "Acker, Leah"

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    ItemOpen Access
    Cerebrospinal Fluid Proteome Changes in Older Non-Cardiac Surgical Patients with Postoperative Cognitive Dysfunction.
    (Journal of Alzheimer's disease : JAD, 2021-02-26) VanDusen, Keith W; Li, Yi-Ju; Cai, Victor; Hall, Ashley; Hiles, Sarah; Thompson, J Will; Moseley, M Arthur; Cooter, Mary; Acker, Leah; Levy, Jerrold H; Ghadimi, Kamrouz; Quiñones, Quintin J; Devinney, Michael J; Chung, Stacey; Terrando, Niccolò; Moretti, Eugene W; Browndyke, Jeffrey N; Mathew, Joseph P; Berger, Miles; MADCO-PC Investigators

    Background

    Postoperative cognitive dysfunction (POCD), a syndrome of cognitive deficits occurring 1-12 months after surgery primarily in older patients, is associated with poor postoperative outcomes. POCD is hypothesized to result from neuroinflammation; however, the pathways involved remain unclear. Unbiased proteomic analyses have been used to identify neuroinflammatory pathways in multiple neurologic diseases and syndromes but have not yet been applied to POCD.

    Objective

    To utilize unbiased mass spectrometry-based proteomics to identify potential neuroinflammatory pathways underlying POCD.

    Methods

    Unbiased LC-MS/MS proteomics was performed on immunodepleted cerebrospinal fluid (CSF) samples obtained before, 24 hours after, and 6 weeks after major non-cardiac surgery in older adults who did (n = 8) or did not develop POCD (n = 6). Linear mixed models were used to select peptides and proteins with intensity differences for pathway analysis.

    Results

    Mass spectrometry quantified 8,258 peptides from 1,222 proteins in >  50%of patient samples at all three time points. Twelve peptides from 11 proteins showed differences in expression over time between patients with versus withoutPOCD (q <  0.05), including proteins previously implicated in neurodegenerative disease pathophysiology. Additionally, 283 peptides from 182 proteins were identified with trend-level differences (q <  0.25) in expression over time between these groups. Among these, pathway analysis revealed that 50 were from 17 proteins mapping to complement and coagulation pathways (q = 2.44 *10-13).

    Conclusion

    These data demonstrate the feasibility of performing unbiased mass spectrometry on perioperative CSF samples to identify pathways associated with POCD. Additionally, they provide hypothesis-generating evidence for CSF complement and coagulation pathway changes in patients with POCD.
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    Postoperative changes in cognition and cerebrospinal fluid neurodegenerative disease biomarkers.
    (Annals of clinical and translational neurology, 2022-02) Berger, Miles; Browndyke, Jeffrey N; Cooter Wright, Mary; Nobuhara, Chloe; Reese, Melody; Acker, Leah; Bullock, W Michael; Colin, Brian J; Devinney, Michael J; Moretti, Eugene W; Moul, Judd W; Ohlendorf, Brian; Laskowitz, Daniel T; Waligorska, Teresa; Shaw, Leslie M; Whitson, Heather E; Cohen, Harvey J; Mathew, Joseph P; MADCO-PC Investigators

    Objective

    Numerous investigators have theorized that postoperative changes in Alzheimer's disease neuropathology may underlie postoperative neurocognitive disorders. Thus, we determined the relationship between postoperative changes in cognition and cerebrospinal (CSF) tau, p-tau-181p, or Aβ levels after non-cardiac, non-neurologic surgery in older adults.

    Methods

    Participants underwent cognitive testing before and 6 weeks after surgery, and lumbar punctures before, 24 h after, and 6 weeks after surgery. Cognitive scores were combined via factor analysis into an overall cognitive index. In total, 110 patients returned for 6-week postoperative testing and were included in the analysis.

    Results

    There was no significant change from before to 24 h or 6 weeks following surgery in CSF tau (median [median absolute deviation] change before to 24 h: 0.00 [4.36] pg/mL, p = 0.853; change before to 6 weeks: -1.21 [3.98] pg/mL, p = 0.827). There were also no significant changes in CSF p-tau-181p or Aβ over this period. There was no change in cognitive index (mean [95% CI] 0.040 [-0.018, 0.098], p = 0.175) from before to 6 weeks after surgery, although there were postoperative declines in verbal memory (-0.346 [-0.523, -0.170], p = 0.003) and improvements in executive function (0.394, [0.310, 0.479], p < 0.001). There were no significant correlations between preoperative to 6-week postoperative changes in cognition and CSF tau, p-tau-181p, or Aβ42 changes over this interval (p > 0.05 for each).

    Interpretation

    Neurocognitive changes after non-cardiac, non-neurologic surgery in the majority of cognitively healthy, community-dwelling older adults are unlikely to be related to postoperative changes in AD neuropathology (as assessed by CSF Aβ, tau or p-tau-181p levels or the p-tau-181p/Aβ or tau/Aβ ratios).

    Trial registration

    clinicaltrials.gov (NCT01993836).