Prognostic Significance of Early Leukopenia in Heart Transplant Recipients

Abstract

<h3>Purpose</h3> Although leukopenia is a relatively frequent finding after heart transplantation, its effects on patient outcomes remain poorly defined. We evaluated the long-term prognostic impact of early leukopenia in this patient population. <h3>Methods</h3> We performed a retrospective single-center cohort study in 133 consecutive heart transplant recipients transplanted between January 2009 and September 2016. Recipients with intensified immunosuppression (IS) and patients who died within the first post-transplant year were excluded. All patients received immunoinduction with basiliximab and maintenence IS therapy with tacrolimus (TAC)/mycophenolate mofetil (MMF)/steroids. Infection prophylaxis consisted of posaconasole (6 months), TMP-SMX (life-long) and valgancyclovir (discontinued pending positive Quantiferon-CMV assay). Early leukopenia was defined as any episode of WBC count <4.0x10⁹/L within 12 months after transplantation. Late CMV reactivation was defined as PCR CMV >1000 IU/mL after discontinuation of virostatic therapy. All patients were followed for 5 years. <h3>Results</h3> Within the first post-transplant year, 47 (35%) patients had at least one episode of leukopenia (Group A) and in 86 (65%) no leukopenia was registered (Group B). The two groups did not differ in gender (male; 77% in Group A vs. 86% in Group B, P=0.12), age (57±10 years vs. 54±11 years, P=0.25), heart failure etiology (ischemic: 41% vs. 42%, P=0.97), the presence of hypertension (68% vs. 61%; P=0.34) and diabetes (32% vs. 24%; P=0.23). IS regimen was comparable in both groups and consisted of TAC (mean C0 level 7.4±1.7 μg/mL vs. 7.2±2.1 μg/mL, P=0.41), MMF (mean dose 1979±100 mg vs. 1994±53 mg, P=0.11) and steroids. However, the duration of valgancyclovir therapy was significantly longer in Group A than in Group B (73±143 days vs. 46±97 days, P=0.001). During follow-up, the patients in Group A were more likely to develop malignancy (21% vs. 6% in Group B, P=0.01). We found no differences in late CMV reactivation (12% in Group A vs. 13% in Group B, P=0.98) and 5-year survival (90% vs. 91%; P=0.88) between the two groups. <h3>Conclusion</h3> In heart transplant recipients early leukopenia episodes are likely related to the prolonged use of virostatic therapy and may be associated with increased rates of post-transplant malignancies.