COMPLICATIONS - INFECTIONS

J.K. Preiksaitis¹, K. Toogood², J. Fenton^2
1Department Of Medicine, University of Alberta, Edmonton/CANADA, ²Virology, Provincial Public Health Laboratory, Edmonton/CANADA

Body: Introduction: Because, seronegativity to Epstein-Barr virus (EBV) is a significant risk factor for the development of post-transplant lymphoproliferative disorder, pre-transplant EBV serostatus determination is recommended. Age specific EBV seroprevlance, optimal screening methods and result interpretation in solid organ transplant (SOT) recipients has not been described. Methods: We analyzed pre-transplant EBV serology in 2,935 adult and pediatric SOT recipients (kidney or kidney/pancreas [1223], pancreas [4], heart [446], lung [339], liver or liver/kidney [919], small bowel/multivisceral [4]) transplanted between Jan 1994 and Oct 2007 at our center. EBV serostatus was determined by enzyme immunoassay screening for either anti-VCA IgG or anti-EBNA-1 IgG using Gull Laboratories, Salt Lake City, Utah USA (1994-2001) or Captia ^TM Trinity Biotech, Bray, Ireland (2002-2007) assays. Pre-transfusion samples or samples collected remote from blood transfusion were used whenever possible. True positives were positive for either anti-VCA or anti-EBNA-1 on initial screen with no follow up testing. Samples negative on initial screening were tested for the alternate marker; true negatives were negative for both markers (anti-VCA IgG and anti-EBNA-1 IgG). Samples with discordant anti-VCA IgG and anti-EBNA-1 IgG results were considered unresolved. Seroprevalence relative to age, and transplant type was examined. Results: EBV seroprevalence and cumulative seroprevalence as a function of age are summarized in figure 1. After the age of 39 only 2.4% of recipients were seronegative; 2.5% had unresolved serology. Age-specific seroprevalence did not differ across organ types. The use of anti-VCA IgG ( n= 749) resulted in significantly fewer unresolved results compared to using anti-EBNA-1 IgG ( n= 2186) as the initial screen (3.2% vs 1.5%, p=0.01). Children ( n= 91) 0-18 months demonstrated decreasing “ seropositivity” with age (figure2). Cytomegalovirus seronegativity was observed in 70.1%, 50.6% and 35.4% of EBV seronegatives, unresolved and seropositives, respectively. Conclusions: EBV seroprevalence rises rapidly through childhood and early adult years in SOT recipients; true seronegativity in adults over the age of 40 is uncommon. EBV seronegative patients are often (70.1%) CMV seronegative. Anti-VCA is preferred as a screening test relative to anti-EBNA-1. Interpretation of EBV serology is difficult in children <18 months because of passive maternal antibody.

Disclosure: All authors have declared no conflicts of interest.