Changes in T-lymphocyte subsets and natural killer cells of patients after out-of-hospital cardiac arrest and resuscitation: a retrospective study.

PURPOSE

Immune dysregulation in patients resuscitated from out-of-hospital cardiac arrest (OHCA) represents a major clinical issue. This study aimed to analyze the changes in T-lymphocyte subsets and natural killer (NK) cells after the return of spontaneous circulation.

METHODS

A total of 183 OHCA patients were enrolled in this study. The counts and percentages of T-lymphocyte subsets and NK cells were retrospectively collected. These patients were stratified into four groups based on the time interval from OHCA to sample collection: ≤12 h, 12-24 h, 24-48 h, and >48 h. The outcome measures were survivors and neurological function as defined by the Cerebral Performance Category (CPC) scale at discharge.

RESULTS

After ROSC, the counts of CD3+ T cells, CD4+ T cells, CD8+ T cells, and NK cells were all lower. The percentage of CD4+ T cells increased over time (≤12 h vs 12-24 h vs 24-48 h vs >48 h: 28.6 ± 11.5 % vs. 37.9 ± 15.0 % vs. 39.0 ± 11.6 % vs. 40.9 ± 15.0 %,  = 0.008). Both the count and percentage of NK cells declined over time (count: 101.5[55.8-181]/μL vs. 68[31.5-149.8]/μL vs. 72.5[31.5-175]/μL vs. 34[19-61]/μL,  < 0.001; percentage: 18.6[11.7-22.2] % vs. 9.7[6.2-21.8] % vs. 10.6[7.6-16.9] % vs. 7.2[3.5-9.9] %,  < 0.001). The percentages of CD3+ T cells and CD4+ T cells increased over time in survivors (CD3+:  = 0.38,  < 0.001; CD4+:  = 0.40,  < 0.001) and CPC 1-2 (CD3+:  = 0.39,  = 0.02, CD4+:  = 0.51,  = 0.002), but not in patients with non-survivors and CPC 3-5 (all  > 0.05). In death, the percentage and count of CD8+ cells decreased over time (percentage:  = -0.32,  = 0.006, count:  = -0.26,  = 0.03).

CONCLUSIONS

After OHCA, T-lymphocyte subsets and NK cells were present at low levels, and the temporal variation trends of different lymphocyte subsets differed.