2079. The Relation between Panel Reactive Antibody Assay and Cytomegalovirus Reactivation in Seropositive Solid Organ Transplantation Recipients
Session: Poster Abstract Session: Diagnostics: Virology
Saturday, October 6, 2018
Room: S Poster Hall
Background: Cytomegalovirus (CMV) can lead to severe morbidities and mortalities including pneumonia in particular as well as graft dysfunction through indirect immunomodulation in solid organ transplantation recipients. High degree of HLA mismatch is a well-known risk factor of post-transplant (Tx) CMV reactivation. Recent laboratory advances for evaluating HLA mismatch can measure existence of donor-specific antibodies for single HLA allele, however, there was little evidence whether single panel reactive Ab (PRA) assay could predict CMV reactivation in SOT recipients.

Methods: We retrospectively analyzed pre-Tx HLA mismatch tests in total 300 of SOT recipients. All of them were CMV seropositive in donor and recipients and received regular blood CMV VL monitoring during ≥ 6 months after SOT. Lung (N=83) and heart (N=76) recipients received universal prophylaxis for 3 months, and kidney (N=63) and liver (N=78) received pre-emptive CMV therapy. The single PRA test for HLA class I/II was performed by bead-based immunoassay. The percentage of PRA was calculated by following formula: (No. of positive bead reaction/No. of beads in the assay) X 100. We categorized HLA-Ab specificity into two groups according to median fluorescent intensity (MFI) of bead; (1) strong with ≥ 10000 of MFI, (2) not strong with < 10000. The calculated PRA was obtained from the frequency of HLA alleles in normal Korean population according to formula from USA Organ Procurement and Transplantation Network.

Results: The reactivator with ever ≥ 500 IU/mL of CMV had significantly higher positive percentage of HLA class I screening test compared than non-reactivator (33.8% vs. 11.6%, P=0.004) but not class II (P=0.085). The PRA and cPRA values only for HLA class I were significantly lower in non-reactivator (PRA, 0 [0-0] % vs. 0 [0-15] %, P=0.005; cPRA, 0.5 [0-15.5] % vs. 4.5 [0-41.5] %, P=0.030), but not class II (PRA, P=0.393, cPRA, P=0.446). The percentage of strong MFI group for class I in non-reactivator was significantly lower than those in reactivator (7.1% vs. 28.8%, P=0.028), but not class II (11.6% vs. 15.8%, P=0.512). The maximal levels of CMV VL did not have any significant correlation to MFI values of class I nor II.

Conclusion: Seropositive SOT recipients with strong PRA or cPRA values for HLA class I in pre-Tx single PRA test had higher risk of CMV replication.

Da Eun Kwon, MD1, Kyoung Hwa Lee, MD1, Yeonju La, MD1, Seul Gi Yoo, MD1, Sang Hoon Han, MD, PhD1, Young Goo Song, MD, PhD1, Jae Geun Lee, MD2, Ku Ha Huh, MD, PhD2, Myoung Soo Kim, MD, PhD3, Jin Sub Choi, MD, PhD2, Soon Il Kim, MD, PhD2 and Yu Seun Kim, MD, PhD2, (1)Division of Infectious Diseases, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), (2)Department of Transplantation Surgery and Research Institute for Transplantation, Yonsei University College of Medicine, Seoul, Korea, Republic of (South), (3)Department of Surgery, Yonsei University College of Medicine, Seoul, Korea, Republic of (South)

Disclosures:

D. E. Kwon, None

K. H. Lee, None

Y. La, None

S. G. Yoo, None

S. H. Han, None

Y. G. Song, None

J. G. Lee, None

K. H. Huh, None

M. S. Kim, None

J. S. Choi, None

S. I. Kim, None

Y. S. Kim, None

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