Effect of leukoreduction on transfusion-related immunomodulation in patients undergoing cardiac surgery

In this study, we aimed to determine the consequences of different amounts of leukocyte transfusion on the outcome of patients undergoing cardiac surgery.

This was a prospective, single-blinded cohort study conducted for 1 year from July 2018 to June 2019.

The study setting was the Department of Transfusion Medicine, along with Cardiac Anaesthesia, Cardiac Surgery and Cardiac biochemistry departments in a tertiary care cardiac centre.

A total of 150 patients undergoing cardiac surgery during the study period were divided into three groups (50 in each): Leukofiltered (LR), Buffy coat depleted (BCD) and Non-leukoreduced (NLR).

The intervention was intra- and postoperative transfusion of packed red blood cells (PRBCs) having different amounts of leukocytes.

Patient details about length of intensive care unit (ICU) and hospital stay, blood usage, inotropic drug duration, mechanical ventilation, urine output and infection were recorded from the patient data sheet, whereas patients were followed up for 30 days post-operation, and any mortality was noted. Haematological parameters and biochemical parameters for renal function test were analysed on pre- and post-surgical days 1, 3, 5 and 7, whereas on postoperative days 1 and 7, cytokine-like FAS ligands, Interleukin-10 (IL-10) and Interferon-γ (INF-γ) were tested. Patients in all three groups received an average of four, two and two units of packed red blood cells, platelets and fresh frozen plasma, respectively. There was a statistically significant (P < .05) rise in total leukocyte, neutrophil and lymphocyte count in all three groups from day 0 to day 3, but it reduced to preoperative level on day 5. There was shorter ICU and hospital stay in the LR group of patients (46 ± 19.9 hours and 7.5 ± 2.4 days) compared to NLR (52.1 ± 24.2 hours and 7.9 ± 4.1 days) and BCD (53.3 ± 26.7 hours and 8.8 ± 3.1 days) group of patients, but it was statistically non-significant. The duration of mechanical ventilation was significantly lesser in LR group patients (10.2 ± 6.2 hours) as compared to NLR group (14.7 ± 12.7 hours). On risk ratio calculation of developing postoperative kidney injury, the NLR group had 1.3 and 2.6 times more risk compared to the BCD and LR groups, respectively. On postoperative days 1 and 7, FAS-L levels significantly increased in all three group of patients, whereas IL-10 increased in the NLR and BCD groups and decreased in the LR group non-significantly. The INF-γ levels decreased on day 1 in the NLR and BCD groups but increased in the LR group, but it was inversed on day 7.

Depletion of leukocytes decreased Transfusion Related Immunomodulation (TRIM) effects in patients undergoing cardiac surgery, but this also depends on the degree of leukoreduction. As found in our study, leukofiltration is more effective compared to buffy-coat depletion only.