Abstract: FR-PO1223
Can Sirolimus Cause Delayed Pericardial Effusion?
Session Information
- Transplantation: Clinical - Rejection, Biomarkers, and Pharmacology
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Singh, Devina, Wellstar MCG Health, Augusta, Georgia, United States
- Mulloy, Laura L., Wellstar MCG Health, Augusta, Georgia, United States
Introduction
Sirolimus (SRL) is a mammalian target of rapamycin (mTOR) pathway inhibitor used for immunosuppression in renal transplant recipients. Alongside benefits such as lower nephrotoxicity and fewer post-transplant malignancies than calcineurin inhibitors (CNIs), SRL also has adverse effects. Delayed-onset pericardial effusion (PE) is an uncommon adverse effect associated with SRL. We present a unique case of a kidney transplant recipient with delayed-onset PE potentially related to SRL use.
Case Description
A 61-year-old male with a history of renal transplant 20 years prior presented with shortness of breath for 3 months. CTA revealed massive PE with signs of early tamponade. Extensive laboratory testing including ESR, quantiferon, viral PCR, autoimmune panel, HIV, and hepatitis panel was negative. There was no history of malignancy or trauma. He underwent urgent pericardiocentesis with drainage of 3.1 L of straw-colored transudative fluid. Pericardial fluid cultures were negative for infection. Following this episode, the patient developed two additional episodes of PE. The first was managed conservatively, while the second required pericardial window formation. The etiology remained undetermined after extensive negative workup. By diagnosis of exclusion, SRL was considered the probable cause of this delayed-onset recurrent PE, an uncommon adverse effect of the medication. SRL was discontinued and replaced with tacrolimus, after which no recurrence of PE was observed.
Discussion
Lopez-Soler et al. reported symptomatic PE developing at a mean of 5 years after transplant in patients receiving SRL therapy. In contrast, our patient developed recurrent PE after 20 years of SRL use. This markedly delayed presentation highlights the absence of a defined temporal window for SRL-associated PE. The diagnosis was made after exclusion of other etiologies. Despite initial pericardiocentesis, recurrent PE occurred while the patient remained on SRL therapy. Definitive resolution occurred only after discontinuation of SRL.
The mechanism of SRL-associated PE remains incompletely understood. Inhibition of the mTOR pathway may impair lymphangiogenesis, decreasing lymphatic clearance and triggering late-onset PE. SRL has a prolonged half-life of 57–63 hours, which may contribute to delayed resolution and recurrent PE even after cessation