Increased macrophage colony-stimulating factor levels in immune thrombocytopenic purpura.
Thrombocytopenia is a dose-limiting toxicity of macrophage colony-stimulating factor (M-CSF) in preclinical and initial phase I trials. Modulation of macrophage-mediated platelet destruction in immune thrombocytopenic purpura (ITP) may be affected by M-CSF activity. In this study, plasma levels of M-CSF were determined by a sensitive radioimmunoassay in 23 patients with ITP. These were compared with control levels measured in 24 healthy subjects. M-CSF levels were significantly higher in the ITP patients than in the control subjects (218 v 179, P < .02); however, there was a great deal of overlap. The highest M-CSF levels (median = 299 U/mL) were observed in three patients with Evan's syndrome. Patients with severe ITP (platelets < 25,000/microL) had intermediate M-CSF levels (median = 231 U/mL) and those with mild thrombocytopenia (> 25,000/microL) had normal levels (median = 173 U/mL). Sixteen patients were treated with corticosteroids: 10 responded and 6 did not. Median M-CSF levels were higher in those who failed to respond compared with responders (272 v 202, P < .05). These findings suggest M-CSF may influence macrophage-mediated platelet destruction in ITP.
Zeigler
Z R
ZR
Western Pennsylvania Cancer Institute, Western Pennsylvania Hospital, Pittsburgh 15224.
Rosenfeld
C S
CS
Nemunaitis
J J
JJ
Besa
E C
EC
Shadduck
R K
RK
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D001792:Blood Platelets / Q000276:immunology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016173:Macrophage Colony-Stimulating Factor / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood* / Q000628:therapy; D013156:Splenectomy
D000305:Adrenal Cortex Hormones; D007074:Immunoglobulin G; D016173:Macrophage Colony-Stimulating Factor