Am. J. Respir. Crit. Care Med.,
Volume 160, Number 4, October 1999, 1361-1365
Pulmonary Infiltrates after Cytokine Therapy for
Stem Cell Transplantation
Massive Deposition of Eosinophil Major Basic Protein Detected
by Immunohistochemistry
DANIEL J.
O'HEARN,
KRISTIN M.
LEIFERMAN,
FREDERICK
ASKIN,
and
STEVE N.
GEORAS
Division of Pulmonary and Critical Care, and Division of Surgical Pathology, The Johns Hopkins University School of Medicine,
Baltimore, Maryland; and Department of Dermatology, Mayo Clinic and Foundation, Rochester, Minnesota
Interleukin-2 (IL-2), a product of activated T-cells, is now being used in a number of protocols for
cancer immunotherapy. In one stem cell transplantation protocol for breast cancer, IL-2 is used together with interferon-
(IFN-) and cyclosporine to stimulate a graft-versus-tumor response and improve the likelihood of a prolonged remission. We present the case of a patient who developed peripheral eosinophilia, perihilar infiltrates, and hypoxemia after autologous stem cell transplantation
and the use of recombinant IL-2 and IFN-. Histologic analysis of transbronchial lung biopsies demonstrated a few eosinophils within the bronchial submucosa. Immunostaining using antibodies directed against eosinophil major basic protein (MBP), however, revealed massive extracellular deposition of this toxic granule protein throughout the lung parenchyma. IL-2 therapy is well known to
induce a peripheral eosinophilia and to be associated with the capillary leak syndrome characterized by weight gain, edema, and oliguria. The findings noted in this case report suggest that the eosinophil activation that accompanies immunologic therapy with IL-2 can result in direct toxicity to the
lung and a localized vascular leak syndrome. This syndrome should be considered in the differential
diagnosis of pulmonary infiltrates that occur acutely after bone marrow transplantation with cytokine augmentation.
