PB0258 - Plasma Lipoprotein(a) and Factor VIII levels after pediatric renal transplantation: a 10-year experience from a tertiary center in Brazil

Background: Renal transplantation is the treatment of choice for children with end-stage renal disease (ESRD). Graft thrombosis represents 2 to 18% of early allograft losses in pediatric patients. Several factors may be involved in the pathogenesis of graft thrombosis. Some transplant recipients may have acquired prothrombotic risk factors as factor VIII(FVIII) and lipoprotein A [Lp(a)] elevation, and the impact and pharmacological approaches of these conditions should be considered.

Aims: To evaluate serum levels of Lp(a) and FVIII before and after pediatric kidney transplantation.

Methods: Retrospective chart review of patients aged < 18 years, submitted to renal transplantation at a single center in Brazil, from 2011 to 2021. We evaluated FVIII and Lp(a) levels before the surgical procedure and after a median time of 12 months. Exclusion criteria: immediate postoperative graft thrombosis and/or plasmapheresis before Lp(a) and FVIII levels.

Results: Of 101 patients, six were excluded (immediate postoperative graft thrombosis). We analyzed 95 patients. The median age was 9.4 years (range: 2.7-17.4), 62% were males. (Table 1). The most prevalent thrombophilias were FVIII ≥150 IU/dL and Lp(a) >75nmol/L elevation. Prior to the transplantation Lp(a) and FVIII levels were elevated in 70,5%, and 50,5% of the subjects, respectively. Post-transplant, the proportion of elevated FVIII reduced to 26.3% (p < 0.001), and elevated Lp(a) was noted in 29.4% recipients, with a significant reduction in the median levels (p≤0.001) (Table 2). All patients received pharmacological prophylaxis with heparin, followed by aspirin for one year, according to institutional guideline for kidney transplant recipients, and no long-term graft thrombosis was observed.

Conclusion(s): Lp(a) and FVIII levels are raised in pediatric patients with ESRD, and it can be reversed by kidney transplantation. The risk of early allograft losses associated with these acquired abnormalities is unknown. Future prospective studies are needed to understand these conditions and the management of recipients.