Haemophagocytic syndrome in intensive care: The great pretender.

The haemophagocytic syndrome is a unique disease process in which the dysregulation of the patient's immune system leads to an inflammatory storm which rapidly ravages through multiple organ systems, generating life-threatening end-organ dysfunction. Since it usually mimics other conditions frequently encountered in the critical care population - most notably septic shock - its diagnosis is elusive and the condition remains under-recognized and under-reported. We present a concise review of the pathophysiology and clinical features of the heamophagocytic syndrome and discuss the main diagnostic and therapeutic issues relevant to the management of this condition in the critically ill patient.

[Rapidly progressive crescentic glomerulonephritis in the elderly].

Rapidly progressive glomerulonephritis (RPGN) is a syndrome characterized by glomerular lesions giving rise to acute renal injury that develops within a brief period of time, usually days or a few months. It is classified according to the underlying mechanism of injury and the immunofluorescence findings into four main disorders. In the last decade, nephrologists have witnessed a steady rise in the mean age of the patients diagnosed with RPGN.

[Tolerance and autoimmunity. Novel therapeutic approaches].

The main function of the immune system is to protect the individual against potentially dangerous pathogens. It comprises innate and adaptive cellular and soluble components, both with the capacity to discriminate between harmful and harmless. These processes are regulated by homeostatic mechanisms that constitute the so-called immunological tolerance, which aims to limit the prolonged action of immune mediators and to silence the generation of potentially autoaggressive components.