Optimization of the Transwell® assay for the analysis of neutrophil chemotaxis using flow cytometry to refine the clinical investigation of immunodeficient patients.

Chemotaxis is the directed movement of neutrophils towards an infected site. This physiological process can be reproduced using a modified Boyden chamber, such as the Transwell® support. Different techniques can be used to count neutrophils after migration to the lower chamber of the holder.

Ferritin-associated iron induces neutrophil dysfunction in hemosiderosis.

Neutrophils (PMNs) from patients with secondary iron overload have an increased iron and ferritin content as well as a phagocytosis defect. Several serum components might be incriminated in the cellular iron accumulation. We therefore compared the effects on the PMN phagocytosis of total serum as well as the ferritin and transferrin fractions of serum derived from patients with thalassemia major and healthy control subjects.

Neutrophils from patients with secondary haemosiderosis contain excessive amounts of autotoxic iron.

Secondary haemosiderosis may be accompanied by a decrease in the phagocytic function of neutrophils (PMNs). This dysfunction has been attributed to an exaggerated generation of oxidants induced by intracellular iron. However, an accumulation of iron has so far not been reliably demonstrated in neutrophils harvested from iron-overloaded patients.

Mucormycosis during deferoxamine therapy is a siderophore-mediated infection. In vitro and in vivo animal studies.

This study investigates the pathophysiology of mucormycosis caused by Rhizopus, which has been reported in 46 dialysis patients, while treated with deferoxamine (DFO). This drug aggravates mucormycosis, which we experimentally induced in guinea pigs and which lead to a shortened animal survival (P < or = 0.01).