Abstract: | One of the most common and problematic side effects of interleukin-2 therapy (IL-2) is vascular leak syndrome (VLS). VLS is characterized by an increase in vascular permeability accompanied by extravasation of fluids and proteins from the capillary vessels into the tissues resulting in interstitial edema, weight gain, pleural effusion, ascites in severe form, multiple organ failure. We, herein, report two cases of VLS, which occurred following IL-2 therapy against metastatic renal cell carcinoma. One of them died of multiple organ failure one month after the cessation of IL-2 therapy. |