Introduction:
In a single-center cohort of pediatric renal transplant patients, we investigated BK virus-associated nephropathy (BKVN) incidence, management strategies, and clinical outcomes.
Methods:
We analyzed kidney transplant patients from Jan 2009 to Dec 2022. Ureteral stents placed during transplantation removed in 4-6 weeks.
Recipients had monthly urine and plasma PCR screening for BK virus for the first 12 months and during rejection treatment.
Results:
Among 101 patients, 17 (16.8%) had BK viruria, 15 (14.9%) had presumptive BKVN (DNAemia >10,000 copies/mL), and 15 (14.9%) had probable BKVN (DNAemia 1,000-10,000 copies/mL), with 4 showing blip DNAemia. Median time to BK viruria was 48 days post-transplant and 141 days for BK viremia. Of the 15 patients with presumptive BKVN, 11 (73.3%) were male; 10 (66.6%) were white, 4 (26.7%) African American, and 1 (6.7%) other. Mean age at transplantation was 11.6 years (range 2.4-18.4); 11 (73.3%) received kidneys from deceased donors.
10 patients had IVIg monthly at 500 mg/kg for 6 months. Before IVIg, mean urinary BKV DNA was 232 million ± 574 million copies/mL, and plasma load was 171,945 ± 428,810 copies/mL. At diagnosis, mean serum creatinine peaked at 1.3 mg/dL (baseline 0.85 mg/dL). Post-treatment, mean serum creatinine improved to 0.95 mg/dL, and plasma BKV DNA load decreased to 312 ± 788 copies/mL. 7/10 had non-quantifiable plasma loads. One IVIg-allergic patient received leflunomide alone, clearing BK viremia from 160,000 to non-quantifiable levels, with creatinine improving from 1.6 to 1 mg/dL.
4 patients received 10 monthly doses of IVIg but did not clear DNAemia and then received leflunomide. Two cleared BK virus (mean 27,900 copies/mL to undetected) with creatinine improving (2.02 to 1.14 mg/dL). Two non-responsive patients received low-dose IV cidofovir (0.5-0.75 mg/kg/dose) for six doses. Despite BK viral level improvements (28,000 to 15,000 copies/mL), viremia clearance was unsuccessful, with minimal creatinine improvement (1.45 to 1.2 mg/dL).
Conclusions:
At our center, IVIg seems to be an effective treatment for persistent BKVN after failed reduction in immunosuppression. IVIG was effective in 70% of cases, while leflunomide alone or following IVIG was effective in 60%. The addition of cidofovir for those resistant to IVIG and leflunomide was not successful.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.