In vivo modulation of leukocyte trafficking receptor following therapeutic purging of myeloid cells: implications for treatment of HIV infection and other immune disorders

Therapeutic purging of myeloid cells (monocytes and granulocytes) (MYP) has been proposed as a treatment of severe inflammatory conditions like ulcerative colitis and rheumatoid arthritis. Although direct purging of inflammatory cells contributes to its efficacy, the precise mechanism of action is still unclear. We have tested MYP in a pilot study on 12 patients with chronic HIV infection, of whom 6 underwent MYP. Three/6 MYP patients and none of the controls displayed a strong and long-lasting decrease of cells expressing CXCR3, a major chemokine receptor responsible for trafficking of inflammatory cells. In these three patients, the number of circulating CD4 T cells increased during treatment. The data provide a rational for the use of MYP as a therapeutic tool acting via the modulation of immune cell trafficking.