Effective control of infection-associated hemophagocytic syndrome with chloroquine

Effects of pristane alone or combined with chloroquine on macrophage activation, oxidative stress, and TH1/TH2 skewness

We investigated the protective role of chloroquine against pristane-induced macrophage activation, oxidative stress, and Th1/Th2 skewness in C57BL/6J mice. Those mice were treated with pristane alone or combined with chloroquine. Hematological and biochemical parameters, macrophage phagocytic function, the oxidant/antioxidant index, cytokine for IFN-γ, TNF-α, IL-4, and IL-6, and the isotypes of IgG2a and IgG1 were determined. And the expression of T-bet/GATA-3 and IL-12/IL-10 mRNA in spleen were analyzed by real-time PCR. We found that pristane treatment for a period of 12 or 24 weeks triggered macrophage activation syndrome, characterized by hemophagocytosis in spleen and peripheral blood, enhanced lipid phagocytosis by peritoneal macrophages in vitro, erythropenia and leucopenia, increased anti-Smith, lactic dehydrogenase, triglyceride, and ferritin, as well as hypercytokinemia of IFN-γ, TNF-α, IL-4, and IL-6. In parallel, a significant increase in lipid peroxidation and a decrease in superoxide dismutase, glutathione, and catalase activity, as well as a skewed Th1/Th2 balance in spleen, were observed. However, chloroquine supplementation showed a remarkable amelioration of these abnormalities. Our data indicate that pristane administration induces macrophage activation, oxidative stress, and Th1/Th2 skewness, which can be attenuated by chloroquine.

Syndrome d’activation macrophagique (syndrome d’hémophagocytose)

Macrophage activation syndrome MAS describes the clinical, biological and histological symptoms related to a probably T lymphocytes/NK cell driven stimulation of macrophages with the consequence of a hemophagocytosis involving numerous organs, preferentially bone marrow, explaining the other term of "hemophagocytic syndrome". Clinical symptoms include cytopenia, multiple organ dysfunction, fever unresponsive to antibiotics, fatigue and rash. Infections (bacteria, virus or parasites), lymphoproliferative disorders, cancers, systemic diseases are the most prevalent triggers or etiologies of M.A.S. Evidence of haemaphagocytosis is obtained in the majority of cases with bone marrow specimens. In some cases haemophagocytosis can spare the bone marrow with involvement confined to other tissues such as liver and spleen. Very high levels of ferritine seem to correlate well with the presence of haemophagocytosis and is a possible marker for an early diagnosis. Early treatment initiation is mandatory. Corticosteroids, cytostatic drugs such as etoposide, cyclosporine A, plasmapherese, intravenous immunoglobulins and anti TNFalpha are proposed but no randomized trials were published.