C47-33 BK Polyomavirus Infection in Lung Transplant Recipients With Renal Insufficiency: Does Underlying Lung Disease Influence Post-transplant Risk?

Abstract Background Lung transplant recipients (LTRs) with underlying restrictive lung disease (RLD) have a high prevalence of short telomere syndrome (STS) and are at increased risk of opportunistic viral infections, like cytomegalovirus and Epstein-Barr virus. This study aimed to characterize the frequency, management, and outcomes of another opportunistic virus, the BK polyoma virus (BKV) and to evaluate the association between underlying lung disease type and the occurrence of BKV DNAemia. Methods This is a retrospective, single center, cohort study of LTRs who underwent serum BKV PCR testing between January 2018 and 2025 as part of renal insufficiency workup. Chi-square and Fisher exact tests were performed to calculate p-values. A subgroup analysis compared the association of BKV DNAemia with underlying restrictive lung disease (RLD) or non-RLD. Results A total of 312 LTRs underwent BKV serum testing (207 66.3% with RLD, 105 33.7% with non-RLD) and 59 (18.9%) were diagnosed with BKV DNAemia. Among LTRs with BKV DNAemia, the median age at LT was 68 years (IQR 62-73), the median time from LT to BKV DNAemia was 20 months (IQR 8-36), and 43 (72.9%) LTRs were male. Maintenance immunosuppression included mycophenolate mofetil, a calcineurin inhibitor (CNI), and prednisone in 41 (69.5%) LTRs and a CNI and prednisone in 11 (18.6%); mTOR-inhibitors (2, 3.4%) and belatacept (5 8.5%) were used infrequently. Twelve (20.3%) LTRs had augmented immunosuppression within 3 months of BKV DNAemia and 5 (8.5%) were neutropenic (neutropenia=ANC 500/µl). BKV-directed treatment was initiated in 27 LTRs, with therapeutic regimens consisting of leflunomide (18 66.7%), reduced immunosuppression (19 70.4%), and intravenous immunoglobulin (14 51.9%). Among 51 patients retested for BKV, DNAemia resolved in 17 (33.3%), including 14/24 (58.3%) treated and 3/27 (11.1%) untreated LTRs (p 0.001). BKV DNAemia was more common among LTRs with RLD 45/207 (21.7%) than among those with non-RLD 14/105 (13.3%; p = 0.07). The incidence of BKV nephropathy was unknown as renal biopsies were rarely performed (4 LTRs biopsied, 3 75% had BKV nephropathy). Conclusions BKV DNAemia was common among LTRs with renal insufficiency, resolved in a third of cases, and appeared somewhat treatment responsive. There was a strong trend toward an association between post-LT BKV DNAemia and underlying RLD, suggesting that STS may be a risk factor for BKV DNAemia. This abstract is funded by: None