The multi-face expression of familial Mediterranean fever in the child.

Familial Mediterranean fever (FMF) is characterized by recurrent self-limiting flares of fever in the absence of pathogens, autoantibodies or antigen specific T cells and is inherited as an autosomal recessive trait probably deriving from common ancestors of Armenian, Jew, Turk and Arab origin. The underlying pathogenetic mechanisms of FMF have not been fully interpreted, but mutations in the gene MEFV encoding pyrin, a natural repressor of proinflammatory molecules, result in uncontrolled relapsing systemic inflammation, increased leukocyte migration to serosal membranes or joints and inappropriate response to inflammatory stimuli. FMF heterogeneous phenotypic expression could originate both from allelic heterogeneity or from the existence of modulating genes. Proper diagnosis of FMF is needed to begin both specific clinical management and treatment based on continuous prophylactic administration of colchicine, preventing flares or at least the onset of amyloidosis.

The pharmacologic basis of treatment with colchicine in children with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is the prototype of auto-inflammatory disorders and is ethnically restricted to people living in the Mediterranean basin and Middle-East. Pyrin, the protein product of the FMF gene, expressed in myeloid cells and fibroblasts, interacts with the cytoskeletal machinery and may modulate leukocyte effector functions. At present colchicine, an alkaloid with antimitotic activity interfering with microtubule formation, which has been used to alleviate acute gout, is the only available drug for patients with FMF to prevent both acute attacks and long-term complications such as amyloidosis. The anti-inflammatory effect of colchicine may be mediated not only through direct interaction with microtubules, but also through changes at the transcriptional level influencing cell cycle regulation and leukocyte migration. Gastrointestinal side effects may occur early and are the most frequent manifestations of colchicine toxicity in children, whilst multiple organ failure is very rarely reported as overdosage expression.

The clinical spectrum and treatment options of macrophage activation syndrome in the pediatric age.

Macrophage activation syndrome is a rare and potentially fatal complication of many childhood pathological settings, most frequently reported in systemic onset-juvenile idiopathic arthritis. The disruption of the macrophage-lymphocyte interaction leads to uncontrolled proliferation of highly activated macrophages and T lymphocytes. The syndrome comprises a heterogeneous group of disorders featuring sepsis-like characteristics typically combined with impaired function of natural killer cells and cytotoxic T-cells, haemophagocytosis and hypercytokinemia, often resulting in fatal multiple organ failure. The clinical picture shows high grade fever, hepatosplenomegaly, pancytopenia, lymphoadenopathy, central nervous system involvement and consumptive coagulopathy. Macrophage activation syndrome is associated with high mortality: even though diagnostic criteria have been proposed, definite diagnosis can be a challenge for clinicians, especially in early phases. There is no standardized therapeutic protocol for macrophage activation syndrome, but it is widely recognized that aggressive treatment strategies might strongly influence prognosis. First line-therapy is usually represented by parenteral administration of high dose-corticosteroids, whilst cyclosporine is added in the steroid-resistant cases. In this paper we provide clinical clues and summarize the most recent studies about pathophysiology and management suggestions for macrophage activation syndrome.