Korean J Transplant.  2022 Nov;36(Supple 1):S63. 10.4285/ATW2022.F-1802.

The predictive role of absolute lymphocyte counts for fatal infection in heart transplantation recipients who received induction therapy

• Kim SE
• Oh J
• Lee CJ
• Kang SM

• KMID: 2535481
• DOI: http://doi.org/10.4285/ATW2022.F-1802

Abstract

Background
The induction therapy for heart transplantation (HT) recipients could reduce the rejection risk. However, induction therapy also increases fatal infection risk by decreasing the absolute lymphocyte count (ALC). We investigated the relationship between ALC before and after induction therapy and fatal infection, and determined the cutoff value of ALC for selective induction therapy.
Methods
We retrospectively collected 181 HT recipients who received basiliximab or thymoglobulin induction therapy from Jan-uary 2011 to June 2021. Patients who maintained percutaneous cardiopulmonary support before and after HT were excluded. We collected ALC values at pre-induction (pre-ALC) and nadir after induction therapy (nadir-ALC). Infection within 1-month after HT and fatal infection were determined as clinical outcomes. Fatal infection was defined as mortality in a patient who developed an infection.
Results
Among a total of 107 patients (mean age, 49±13 years; female, 31.8%), 1-month infection after HT was confirmed in 24.3% (n=26) of patients and 9.3% (n=10) were fatal infection. ALC significantly decreased after induction (1440.0±629.4 to 275.4±165.7 cells/l, P<0.001). Pre-ALC (1492.9±626.5 vs. 927.0±395.7 cells/l, P=0.006) and nadir-ALC (287.1±164.0 vs. 162.0±144.0 cells/l, P=0.022) were significantly lower in patients with fatal infection than those without fatal infection, but there was no difference in the ratio of pre-ALC and nadir-ALC. The cutoff value of pre-ALC for fatal infection was 1,255 cells/l (AUC 0.782; 95% confidence interval, 0.64–0.92). When grouped into two groups by cutoff value of pre-ALC, the incidence of fatal infection was lower in a high pre-ALC group (1.8% vs. 18.0%, P=0.011).
Conclusions
Low ALC before induction therapy was associated with 1-month infection, especially fatal infection in HT recipients. A cut-off value of 1,255 cells/l in pre-ALC could identify the patients at high risk for infection-related death in HT recipients who had induction therapy.