Pattern of Circulating Mesenchymal Stromal Cells and Hematopoietic Progenitor and Stem Cells in the Peripheral Blood of Trauma Patients with and without Hemorrhagic Shock

Circulating stem and progenitor cells (SPCs), including mesenchymal stromal cells (MSCs) and hematopoietic stem/progenitor cells (HSPCs), are mobilised after tissue injury but their temporal behaviour after hemorrhagic shock (HS) and relationship to cytokine milieus and outcome remain unclear. In a prospective observational cohort at JPN Apex Trauma Centre, AIIMS, New Delhi we studied 100 participants: 50 trauma patients with hemorrhagic shock and traumatic brain injury (HS index group), 25 trauma patients without HS, and 25 minor-injury controls. Peripheral blood was collected at admission (day 0) for all groups and additionally at days 3, 7 and 14 for the HS group. PBMCs were phenotyped by flow cytometry (HSPC markers: CD45, CD123, CD38, CD34; MSC markers: CD105, CD73, CD90) and serum SDF-1, VEGF-A, EGF, GRO- and GRO-{beta}, GM-CSF and G-CSF were measured by ELISA; group and time effects were evaluated with mixed-effects models and correlations by Spearman tests (two-tailed p<0.05). At admission, trauma patients without HS had significantly higher MSC and HSPC-like populations versus controls (p<0.0001). In the HS cohort SPC percentages rose modestly at day 0-3 then declined sharply by days 7-14 (time effect p<0.0001); non-survivors exhibited significantly higher early SPC and cytokine levels that persisted until death while survivors showed an early rise followed by decline (outcome and time interaction p<0.0001). All cytokines were up-regulated in trauma groups, peaked at day 0-3 in HS patients, and correlated positively with SPC counts (notably SDF-1, VEGF-A, G-CSF, Gro- and GM-CSF; Spearman p<0.05); higher early SPC and cytokine signatures associated with greater organ dysfunction (higher SOFA) and with timing of sepsis. These findings indicate that trauma provokes an early SPC and cytokine response that in HS is followed by later decline, and that persistent early elevation predicts worse outcomes, suggesting serial SPC and cytokine profiling may have prognostic value and identify an early therapeutic window for regenerative or immunomodulatory interventions.