Serum G-CSF levels in primary myelofibrosis and chronic neutrophilic leukemia as estimated by the highly sensitive chemiluminescence enzyme immunoassay (CLEIA).

We previously reported that serum granulocyte colony stimulating factor levels of chronic myelogenous leukemia patients in chronic phase (CP) are significantly lower than those of healthy persons or other hematological malignancies as assessed by chemiluminescence enzyme immunoassay (CLEIA). In this study, we clarify the difference in serum G-CSF levels between patients with primary myelofibrosis (PMF, myelofibrosis with myeloid metaplasia; MMM) and those with secondary myelofibrosis caused by several hematological disorders, using the same highly sensitive CLEIA method. It is clearly demonstrated that serum G-CSF levels of the patients with PMF and chronic neutrophilic leukemia (CNL) are extremely low, similar to those in patients with CML in CP in this study. From these data, it is speculated that the abnormal proliferation of granulocytes in PMF and CNL may not be due to the stimulation by G-CSF, and that a negative feedback mechanism might exist between peripheral granulocytes and serum G-CSF.