K. Eappen1, P. Morrissey1, D.S. Heffernan1 1Brown University School Of Medicine, Department Of Surgery, Providence, RI, USA
Introduction: Early postoperative leukocyte responses are critical to long-term outcomes after renal transplant. Renal transplant outcomes are known to also vary by race and ethnicity. Differences exist between races with respect to both normal base-line leukocyte counts as well as differing responses to surgery and critical illness. However, there is a paucity of data relating to post-renal transplant leukocyte response between patients of different races.
Methods: A retrospective review of prospectively collected data of patients aged 18 years and older from a single center renal transplant database over the time period of July 2012 to July 2023. Chart review included demographics and race, Caucasian(Cauc), African American(AA), Hispanic(Hisp) or Asian(As), and all daily complete blood counts with differential (white cell count, neutrophil count and lymphocyte count) spanning from preop to posto day 7. Outcomes included long term (3 year) renal graft failure. All lab data is presented as raw number of cells x10^9/ml.
Results: Overall, there were 567 patients- 377 Cauc, 96 AA, 79 Hisp and 15 Asian. The average age was 53.1 years and 60.7% were male. At baseline, AA patients had the lowest preop baseline white cell counts (7.9+/-0.4 versus Cauc (9.0+/-0.2), As (9.0+/- 1.4) or Hisp (9.1+/-0,5); p=0.006. A leukocytosis was noted across all races by post-op day 1, however the absolute increase in white cell count was lowest in Cauc patients (2.7 +/0.2) compared with either AA (5.5+/-0.6;) or Hisp patients (5.1+/-0.6) (p<0.001). By postoperative day 5, all races had resolved their leukocytosis, however, the absolute change in white cell count from postop day 1 to postop day 5 was lowest in Cauc(3.4) and greatest in Hisp patients(6.3)(p<0.001). With respect to the lymphocyte profile, at baseline, Cauc patients had the lowest (1.00+/-0.04) and Hisp patients the highest (1.33+/-0.08) absolute lymphocyte count(p=0.0004). All patients developed a lymphopenia nadir by postoperative day 3. Whilst there was no significant difference in lymphocyte count between races at postop day3, this represented a significantly greater degree of absolute lymphocyte loss for Hisp patients. Recovery from this nadir was noted by day 5, and whilst all races exhibited a degree of ongoing lymphopenia, the absolute loss of lymphocyte count was greatest in AA patient (0.62+/-0.09) and least in Cauc patients (0.18+/-0.06)(p=0.009). Overall, with respect to long term outcome, logistic regression identified an association between higher rates of 3-year renal graft failure and either the relative change in lymphocyte count day0 to postop day5 (p=0.014), white cell count day0 to postop day1 (p=0.04).
Conclusion: A better understanding of factors that contribute to postop leukocyte/lymphocyte responses to renal transplantation will be critical to optimize individual patient-based care. The degree of changes in the early postop phase was associated with long term renal graft survival.