G-CSF-induced decrease of the anti-granulocyte autoantibody levels in a patient with autoimmune granulocytopenia

Idiopathic, immune, infectious, and idiosyncratic neutropenias

In idiopathic and immune neutropenias the susceptibility to infectious agents is highly variable, but the reason why some patients exhibit no undue susceptibility whereas others contract life-threatening infections is poorly understood. An important factor is the efficacy of delivery of neutrophils to the tissues. Recent investigations of the mechanisms for mild to moderate chronic neutropenias have shown the significance of interactions between myelopoiesis and the immune system, as for example, in relation to immunoglobulin aberrations and the cytokine network. Antibody-mediated neutropenias (alloimmune, autoimmune) are now well-characterized diseases. If infections occur, apart from antibiotics, granulocyte colony-stimulating factor (G-CSF) is the treatment of choice, while intravenous or monoclonal immunoglobulins and cyclosporine are reserved for refractory cases.

The use of granulocyte colony-stimulating factor for treatment of autoimmune neutropenia

The advent of better diagnostic tools, molecular techniques, and cytokine therapies have come together at the end of the 20th century to provide an improved outlook for patients with autoimmune neutropenia. Severe chronic neutropenia is no longer idiopathic in most cases, and growth factor therapy can be safely offered to selected patient groups. Previously unsuccessful and even dangerous forms of treatment are no longer appropriate, and G-CSF treatment appears to be safe when administered long term. Fears about transformation of these disorders into acute myeloblastic leukemia probably relate to the underlying natural history of these disorders rather than to their treatment.

Inverse relation between plasma G-CSF levels and neutrophil counts in a patient with autoimmune neutropenia treated with G-CSF

The pharmacokinetic characteristics of granulocyte colony-stimulating factor (G-CSF) appears to be related to the neutrophil count. We report the case of an 81-year-old male with acquired antibody induced neutropenia treated with G-CSF. This produced a rapid increase in the neutrophil count which appeared to be associated with diminished trough plasma G-CSF levels. Our data appears to indicate that mature neutrophils may play a part in the clearance of G-CSF from plasma.