Macrophage activating syndrome is associated with lobular hepatitis and severe bile duct injury with cholestasis.

Macrophage activating syndrome (MAS) is a rare hematological disorder associated with uncontrolled systemic T-cell activation. Persistent fever, fatigue and hepatosplenomegaly are frequent clinical manifestations, whereas hyperferritinemia, elevated serum lactate dehydrogenase levels and cytopenia are key criteria for the diagnosis of MAS. The nature of liver pathology in MAS has been partially elucidated but destructive biliary lesions have been rarely described.

Haemophagocytic syndromes in adults: current concepts and challenges ahead.

Haemophagocytic syndrome (HS), also referred to as haemophagocytic lymphohistiocytosis or macrophage activation syndrome, comprises a heterogeneous group of disorders featuring sepsislike characteristics typically combined with haemophagocytosis, hyperferritinemia, hypercytokinemia and variable cytopenias, often resulting in fatal multiple organ failure. The availability of widely accepted diagnostic and therapeutic guidelines for the hereditary, paediatric forms of HS has improved outcome and lead to a better pathophysiological understanding. Although similar, reactive (secondary) HS in adults are distinct from childhood forms.

The stereochemistry of the amino acid side chain influences the inflammatory potential of muramyl dipeptide in experimental meningitis.

Intrathecal injections of 50 to 100 micro g of (N-acetylmuramyl-L-alanyl-D-isoglutamine) muramyl dipeptide (MDP)/rabbit dose-dependently triggered tumor necrosis factor alpha (TNF-alpha) secretion (12 to 40,000 pg/ml) preceding the influx of leukocytes in the subarachnoid space of rabbits. Intrathecal instillation of heat-killed unencapsulated R6 pneumococci produced a comparable leukocyte influx but only a minimal level of preceding TNF-alpha secretion. The stereochemistry of the first amino acid (L-alanine) of the MDP played a crucial role with regard to its inflammatory potential.