Left posterior fascicular block due to high-dose interleukin-2
Anand Singla1, Samuel R Denmeade
1Department of Internal Medicine, Johns Hopkins University, Sinai Hospital of Baltimore, Baltimore, MD, USA. asingla@lifebridge-health.org
The Annals of Pharmacotherapy
|July 31, 2008
Summary
High-dose interleukin-2 (IL-2) therapy can cause a reversible heart condition called left posterior fascicular block (LPFB). This rare side effect resolved after stopping IL-2 treatment, highlighting a new potential cardiac complication.
Area of Science:
- Cardiology
- Oncology
- Pharmacology
Background:
- Metastatic renal cell carcinoma and melanoma are treated with high-dose interleukin-2 (IL-2).
- IL-2 therapy is associated with toxicities, including capillary leak syndrome.
- Cardiac adverse events are known complications of IL-2 therapy.
Observation:
- A patient receiving high-dose IL-2 developed new-onset left posterior fascicular block (LPFB).
- LPFB was diagnosed via electrocardiogram, showing right axis deviation and specific wave patterns.
- The LPFB resolved within 18 hours of discontinuing IL-2 therapy.
Findings:
- Left posterior fascicular block (LPFB) is a newly identified reversible adverse reaction to high-dose IL-2.
- The Naranjo probability scale suggests a probable link between IL-2 and LPFB in this case.
- LPFB recurred with subsequent IL-2 cycles and resolved spontaneously each time.
Implications:
- Healthcare providers should monitor for LPFB in patients undergoing high-dose IL-2 therapy.
- Recognizing LPFB as a potential cardiac complication of IL-2 is crucial for patient management.
- This finding expands the known spectrum of IL-2-associated toxicities.
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