Cytomegalovirus (CMV) IgG quantification and risk of CMV disease in seropositive renal transplant recipients with seropositive donors

Background: The benefit of antiviral prophylaxis in high-risk, cytomegalovirus (CMV) IgG donor-positive, recipient-negative (D+/R–) renal transplants is well established.  Yet, guidelines recommending prophylaxis in moderate-risk, recipient-positive (R+) transplants are based on expert opinion.  Our center further stratifies risk based on CMV IgG recipient quantification.

Purpose: To determine if incidence of CMV disease differs based on recipient IgG quantification.

Methods: A single-center, retrospective review was performed on all renal transplants between 7/2006 and 6/2010 with one year follow-up.  Patients were included if they were 18–75 years old with a D+/R low+ or D+/R+ seromatch; and were excluded if they received a multi-organ transplant or had HIV, HCV, or HBV co-infection.  The primary outcome was incidence of documented CMV disease.  Secondary outcomes included time to CMV disease, patient and graft survival, acute rejection, and infections.

Results: Of 250 renal transplants performed, 107 met inclusion criteria.  Demographics between groups were similar.  The patient population had a median age of 55 (IQR 44–61) years.  The majority of patients were D+/R low+ (n=78, 73%) and the remainder were D+/R+ (n=29, 27%).  Rabbit antithymocyte globulin was used for induction in 24% and rejection in 7% of recipients.  Most patients received valganciclovir 450 mg daily for prophylaxis (n=98, 92%); nine received acyclovir.  Median duration of prophylaxis was 6 months.  CMV disease rates were similar between D+/R low+ and D+/R+ groups (2.5% vs. 0%, p = 1).  No significant difference was identified between serogroups regarding acute rejection, patient survival, or graft survival.  D+/R low+ transplants had significantly greater infections than D+/R+ (22% vs. 4%, p = 0.02).

Conclusion: Incidence of CMV disease wasn’t significantly different between serogroups.  Quantification of recipient CMV IgG didn’t significantly affect the incidence of acute rejection or patient and graft survival.  However, D+/R low+ transplants had an increased rate of infections.