Association between lymphocyte count and neurological outcomes in post‐cardiac arrest patients treated with mild therapeutic hypothermia

Abstract

AimTo examine lymphocyte counts as a predictive prognostic marker in patients with coma after cardiac arrest.MethodsWe retrospectively evaluated patients with coma after cardiac arrest admitted to the intensive care unit of Shiga University of Medical Science (Otsu, Japan). Lymphocyte counts were measured for 6 days from admission. Neurological outcome was assessed as favorable or unfavorable using cerebral performance categories. Associations between lymphocyte count and prognosis were investigated using multivariate logistic regression analysis and receiver operating characteristic curves.ResultsForty‐six patients were assessed from February 2012 to December 2016. Survivors had significantly higher lymphocyte counts than non‐survivors on days 2 and 5. Multivariate analysis showed that lymphocyte count was not associated with 90‐day mortality. Patients with favorable neurological outcome at discharge had significantly higher lymphocyte counts on days 2–6 than patients with unfavorable outcomes. Multivariate logistic regression analysis, including possible confounders, showed that lymphocyte counts on days 2–4 and 6 were associated with neurological outcome (day 2: odds ratio [OR] = 0.75, 95% confidence interval [CI] = 0.58–0.97, P = 0.029; day 3: OR = 0.68, 95% CI = 0.47–0.98, P = 0.04; day 4: OR = 0.4, 95% CI = 0.16–1.00, P = 0.05; day 6: OR = 0.69, 95% CI = 0.48–0.99, P = 0.046). Receiver operating characteristic curve analysis indicated high accuracy for predicting neurological outcome for each lymphocyte count on days 2–6 using the area under the curve, day 4 values being most accurate (day 2: 0.776, day 3: 0.787, day 4: 0.909, day 5: 0.774, day 6: 0.839).ConclusionLymphocyte counts on days 2–4 and 6 after cardiac arrest are associated with neurological outcome; counts on day 4 most accurately predict neurological outcome.

Single-cell transcriptomics reveal hyperacute cytokine and immune checkpoint axis in patients with poor neurological outcomes after cardiac arrest

“…Our study corroborated some findings from the limited immunophenotyping of prior studies in clinical CA (Asmussen et al, 2021; Kim et al, 2018; Miyatake et al, 2019; Ryzhov et al, 2019; Villois et al, 2017; Wei ser et al, 2017). For example, a prior study (Asmussen et al, 2021) associated reduced expression of HLA-DR on monocytes with poor outcomes after CA.…”

“…The global ischemia-reperfusion injury (IRI) of CA leads to a profound systemic inflammatory response characterized by high levels of circulating cytokines, endotoxemia, and dysregulated immune responses (Adrie et al, 2002). Increases in proinflammatory cytokines (e.g., interleukin [IL]-6, tumor necrosis factor [TNF]-α), reduced lymphocyte counts, and high neutrophil- to-lymphocyte ratios are associated poor neurological outcome and mortality after CA (Adrie et al, 2002; Fries et al, 2009); (Miyatake et al, 2019; Weiser et al, 2017); (Villois et al, 2017)(Kim et al, 2018; Weiser et al, 2017). Transcriptomic analysis of whole blood by microarray corroborated the increased expression of proinflammatory genes is associated with worse outcomes after CA (Tissier et al, 2019).…”

Systemic immune derangements are shared across various CNS pathologies and reflect novel mechanisms of immune privilege

“…Just as the local ischemia and reperfusion within the CNS induced by stroke can cause systemic immune derangements, occlusion of CNS blood supply from other causes may have similar effects. 107–109 As a pathology that indirectly impacts the CNS, decreased circulating lymphocytes have been identified in patients within the first days following CA/CPR. 110 , 111 Consistent with findings in the single-insult pathologies described above, peripheral lymphocytes in CA/CPR patients hit their nadir approximately 90 minutes following the reperfusion event then begin to return to baseline.…”