Impact of High-Dose Acyclovir Cytomegalovirus Prophylaxis Failure in Abdominal Solid Organ Transplant Recipients

To evaluate the clinical course and long-term impact of high-dose acyclovir (HD-A, 800 mg 4 times/day) cytomegalovirus (CMV) prophylaxis failure in a CMV-seropositive abdominal solid organ transplant population.

Retrospective cohort study.

Tertiary academic medical center.

A total of 691 adults who received solid organ transplants between January 1, 2008, and June 30, 2013, without lymphocyte-depleting induction and were prescribed 3 months of HD-A prophylaxis at the time of hospital discharge. Of those patients, 54 experienced prophylaxis failure, defined as CMV detected via molecular diagnostics or on biopsy while receiving HD-A (prophylaxis failure group), and 637 did not (comparator group).

Mean ± SD time to failure was 64 ± 23 days; 98% (53/54 patients) was attributable to viremia diagnosed via positive polymerase chain reaction (PCR). Of these 53 patients, 34% (18 patients) were below the quantifiable range when detected. Median initial and peak CMV PCR for quantifiable readings were 1531 IU/ml (interquartile range [IQR] less than 250-2947) and 4442 IU/ml (IQR less than 250-32,500); 19 (36%) had a single detectable CMV PCR. Treatment was required in 56% (30/54 patients), with a median duration of 63 days; 40% (12 patients) were treated with valganciclovir alone, and the remainder received intravenous ganciclovir. CMV disease resulted in hospitalization in 28% (15 patients). Immunosuppression was modified in 52% (28 patients). The rate of CMV recurrence after 100 days was significantly higher in the prophylaxis failure group (59% vs 13%, p<0.0001). Higher rates of rejection; higher rates of 1-, 3-, and 5-year graft failure; and higher rates of 1-, 3-, and 5-year mortality were noted in the prophylaxis failure group on univariate analysis (43% vs 30%, p=0.045; 8%, 17%, and 34% vs 4%, 12%, and 17%, p=0.006; and 6%, 17%, and 26% vs 1%, 6%, and 10%, p=0.003, respectively). Multivariate analysis demonstrated an increased risk of graft failure in the prophylaxis failure group (hazard ratio [HR] 1.76, 95% confidence interval [CI] 1-3.1, p=0.0499) and a trend to increased mortality (HR 1.6, 95% CI 0.83-3.1, p=0.16).

Prophylaxis failure with HD-A was mostly limited to mild viremia; however, it was associated with significantly reduced long-term graft survival, likely reflecting the negative impact of CMV viremia.