Human recombinant stem-cell factor induces melanocytic hyperplasia in susceptible patients.
BACKGROUND
Recombinant human stem-cell factor (SCF), a cytokine acting on hematopoietic progenitor cells, has potential for the treatment of several hematologic and oncologic disorders. In a hematology-oncology phase I trial of SCF, several patients had cutaneous hyperpigmentation at the SCF subcutaneous injection sites.


OBJECTIVE
Our purpose was to investigate the pathogenesis of this hyperpigmentation phenomenon.


METHODS
Skin biopsy specimens were obtained before, at the completion of, and after SCF therapy and were processed for histology, immunohistology, and electron microscopy.


RESULTS
Skin at the site of SCF injection had an increased number of melanocytes, increased melanocytic dendrite extension, and melanin as compared with noninjected tissue. Immunohistochemical stains revealed an increase in staining with melanocyte-specific monoclonal antibodies HMB-45 and NKI/beteb, and a monoclonal antibody to the receptor for SCF, c-kit.


CONCLUSIONS
Subcutaneous injection of SCF results in hyperplasia of melanocytes. SCF may be useful in the treatment of melanocytopenic disorders, but caution may be necessary in patients with disorders of melanocyte proliferation.
Grichnik
J M
JM
Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
Crawford
J
J
Jimenez
F
F
Kurtzberg
J
J
Buchanan
M
M
Blackwell
S
S
Clark
R E
RE
Hitchcock
M G
MG
D000911:Antibodies, Monoclonal; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D016190:Carboplatin / Q000008:administration & dosage; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy; D015815:Cell Adhesion Molecules / Q000008:administration & dosage / Q000009:adverse effects*; D003712:Dendrites / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D004198:Disease Susceptibility; D005047:Etoposide / Q000008:administration & dosage; D005500:Follow-Up Studies; D016298:Hematopoietic Cell Growth Factors / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D017495:Hyperpigmentation / Q000139:chemically induced* / Q000473:pathology; D006965:Hyperplasia; D007279:Injections, Subcutaneous; D008175:Lung Neoplasms / Q000188:drug therapy; D008543:Melanins / Q000032:analysis; D008544:Melanocytes / Q000187:drug effects / Q000473:pathology / Q000648:ultrastructure; D011994:Recombinant Proteins; D019089:Stem Cell Factor
D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D016298:Hematopoietic Cell Growth Factors; D008543:Melanins; D011994:Recombinant Proteins; D019089:Stem Cell Factor; D005047:Etoposide; D016190:Carboplatin