Abstract: TH-PO1133

Recurrent SIADH: A Rare Complication of Intrathecal Interleukin-2 Treatment for Melanoma with Brain Metastases

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 704 Fluid, Electrolyte, Acid-Base Disorders

Authors

  • Ziaolhagh, Ali, Univ of Texas Medical School at Houston, Houston, Texas, United States
  • Ogbonnaya-Odor, Chinonye Chika, Univ of Texas Medical School at Houston, Houston, Texas, United States
  • Teakell, Jade M., Univ of Texas Medical School at Houston, Houston, Texas, United States
  • Lahoti, Amit, M D Anderson Cancer Center, Houston, Texas, United States
Background

The 10- year survival rate for patients with metastatic melanoma is less than 10%. Systemic therapy is the mainstay of treatment for most patients, and immunotherapeutic agents have been associated with durable response in some patients. High dose Interleukin-2 (IL-2), which activates T-cells and NK cells, was approved by FDA in 1998 for treatment of metastatic melanoma. Common adverse effects include fever, chills, hypotension, cardiac arrhythmias, oliguria, volume overload, delirium, and rash. Hyponatremia has not been commonly reported. We present an unusual case of recurrent SIADH with each cycle of intrathecal IL-2.

Methods

A 65 year old man with Stage IV melanoma with left parietotemporal hemorrhagic metastases, underwent stereotactic radiosurgery of a left temporal lesion. He was subsequently treated with intrathecal IL-2 every 3 months for 4 years. After every infusion, he developed symptomatic hyponatremia (gait instability and confusion). Elevated urine osmolality and urine sodium were consistent with SIADH (Table). The patient did not complain of pain or nausea with treatment. During each cycle of IL-2, hyponatremia improved with a single dose of oral tolvaptan 15 mg (Figure).

Conclusion

To our knowledge, this is the first reported case of recurrent SIADH with long-term intrathecal IL-2 administration. While this does not appear to be a common side effect, physicians should be aware of this potential complication. Hyponatremia in this situation appears to respond well to single dose of tolvaptan 15 mg orally.

Recurrent SIADH with Intrathecal IL-2 Administration
Aldesleukin (IL-2)Serum Na on AdmissionSerum Na NadirSerum OsMUrine OsMUrine Na
3/28/1614112526549687
5/23/16142127271682114
8/23/16135124 683110
11/15/16141129   
2/8/17141128268651178
5/10/17135129  40

Temporal Relationship of Hyponatremia with IL-2 and Improvement with Tolvaptan.