Intraoperative cell salvage: The impact on immune cell numbers

PLoS One. 2023 Aug 1;18(8):e0289177. doi: 10.1371/journal.pone.0289177. eCollection 2023.

Abstract

Background: Patient outcomes are influenced by many confounding factors peri-operatively, including the type of surgery, anaesthesia, transfusion, and immune competence. We have previously demonstrated (in-vitro) that compared to allogeneic blood transfusion (ABT), intraoperative cell salvage (ICS) improves immune competence. The peri-operative immune response is complex. Altered or impaired immune responses may predispose patients to develop adverse outcomes (i.e., post-operative wound infection, pneumonia, urinary tract infection etc.) Surgical patients may develop infection, even without the confirmed presence of a definite microbiological pathogen. With all these factors in mind it is important to consider changes in immune cell numbers (and sub-populations) and functional capacity during peri-operative transfusion.

Methods: In this TRIMICS-Cell (Transfusion Related Immune Modulation and Intraoperative Cell Salvage-Cell numbers) study (n = 17, October 2018-November 2019) we prioritized and analysed peri-operative changes in the number and proportions of immune cell populations and sub-populations (B cells (CD20+), NK (natural killer) cells (CD56+), monocytes (CD14+), T cells (total CD3+ and sub-populations: T helper cells (CD4+), cytotoxic T cells (CD8+), effector T cells (CD4+ CD127+), activated effector T cells (CD4+ CD25+ CD127+) and regulatory T cells (CD4+ CD25+ CD127-)), plasmacytoid dendritic cells (pDC; Lineage-, HLA-DR+, CD11c-, CD123+), classical dendritic cell (cDC) (Lineage-, HLA-DR+, CD11c+), and cDC activation (Lineage-, HLA-DR+, CD11c+), co-stimulatory/adhesion molecules and pDC (CD9+, CD38+, CD80+, CD83+, CD86+, CD123+). Firstly we analysed the whole cohort of study patients and secondly according to the relevant transfusion modality (i.e., three study groups: those who received no transfusion, received ICS only (ICS), or both ICS and allogeneic packed red blood cells (pRBC) (ICS&RBC)), during major orthopaedic surgery.

Results: For the whole study cohort (all patients), changes in immune cell populations were significant: leucocytes and specifically neutrophils increased post-operatively, returning towards pre-operative numbers by 48h post-operatively (48h), and lymphocytes reduced post-operatively returning to pre-operative numbers by 48h. When considering transfusion modalities, there were no significant peri-operative changes in the no transfusion group for all immune cell populations studied (cell numbers and proportions (%)). Significant changes in cell population numbers (i.e., leucocytes, neutrophils and lymphocytes) were identified in both transfused groups (ICS and ICS&RBC). Considering all patients, changes in immune cell sub-populations (NK cells, monocytes, B cells, T cells and DCs) and functional characteristics (e.g., co-stimulation markers, adhesion, activation, and regulation) were significant peri-operatively and when considering transfusion modalities. Interestingly DC numbers and functional capacity were specifically altered following ICS compared to ICS&RBC and pDCs were relatively preserved post-operatively following ICS.

Conclusion: A transient peri-operative alteration with recovery towards pre-operative numbers by 48h post-surgery was demonstrated for many immune cell populations and sub-populations throughout. Immune cell sub-populations and functional characteristics were similar peri-operatively in those who received no transfusion but changed significantly following ICS and ICS&RBC. Interesting changes that require future study are a post-operative monocyte increase in the ICS&RBC group, changes in cDC considering transfusion modalities, and possibly preserved pDC numbers post-operatively following ICS. Future studies to assess changes in immune cell sub-populations, especially during peri-operative transfusion, while considering post-operative adverse outcomes, is recommended.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Transfusion
  • Cell Count
  • Dendritic Cells
  • HLA-DR Antigens*
  • Humans
  • Interleukin-3 Receptor alpha Subunit*
  • T-Lymphocytes, Regulatory

Substances

  • Interleukin-3 Receptor alpha Subunit
  • HLA-DR Antigens

Grants and funding

This study was conducted within the Royal Brisbane and Women’s hospital (RBWH, Herston, Brisbane, Queensland, Australia). Patient recruitment and sample collection was supported by the intraoperative cell salvage group, the research nursing staff and staff specialist anaesthetists within the anaesthetic department at the RBWH through funding received from the grants mentioned below. Sample analysis occurred at the Australian Red Cross Lifeblood (Herston, Brisbane, Queensland, Australia), who supported the equipment, facilities, and staff, funded in part by the grant below and in part in kind. MR discloses receipt of the following financial support for the research: PhD scholarship grant support [grant number PSc01, $30,000] from the Australian National Blood Authority (NBA, Lyneham, Australian Capital Territory, Australia, online at https://www.blood.gov.au/), administered through the University of Queensland (St Lucia, Brisbane, Queensland, Australia); and from the Australian and New Zealand College of Anaesthetists (ANZCA, Melbourne, Victoria, Australia, online at https://www.anzca.edu.au/); project and scholarship grants ([grant number 18/023], $70,000 (2018), $20,000 (2019)), administered through the RBWH and RBWH foundation (Herston, Brisbane, Queensland, Australia). The other authors received no grant funding and the work on the study and manuscript was supported in kind. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.