Macrophage activation syndrome in a newborn: report of a case associated with neonatal lupus erythematosus and a summary of the literature.

BACKGROUND: Macrophage activation syndrome (MAS) is a life-threatening hyperinflammatory syndrome and is caused by a severely dysregulated immune response. It has rarely been associated with neonatal lupus. CASE PRESENTATION: We present a female neonate with MAS born to a mother who had cutaneous lupus erythematosus with circulating anti-nuclear antibodies (ANA), anti-SSA, anti-SSB and anti-extractable nuclear antigen (anti-ENA) antibodies. Because of neonatal lupus (NLE) with a total atrioventricular block, epicardial pacemaker implantation was required on the sixth day of life. Following surgery she developed non-remitting fever and disseminated erythematous skin lesions. A diagnosis of MAS was made based on these symptoms, with hyperferritinemia, elevated transaminases, hypertriglyceridemia, and a skin biopsy that showed hemophagocytosis. Our patient was treated with steroids for 3 months with good effect. No relapse has occurred. CONCLUSIONS: MAS is a rare complication of neonatal lupus that may be difficult to diagnose, but needs to be treated promptly. In this article, pathogenesis and overlap of MAS and hemophagocytic lymphohistiocytosis (HLH) has been described. Diagnosis of MAS can be difficult. Different diagnostic criteria are used in both diagnosing MAS and HLH. Validated criteria for diagnosis of MAS in other disease than systemic onset JIA have not been validated yet. In NLE, diagnosing MAS is even more difficult, since skin lesions are already common in NLE. We show the potential additional value of skin biopsy in diagnosing MAS.

Encapsulating peritoneal sclerosis is associated with T-cell activation.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is an excessive fibrotic response of the peritoneum that may occur after long-term peritoneal dialysis (PD). The underlying pathophysiology is poorly understood, but involvement of peritoneal inflammatory T helper 1 cells may be pivotal. METHODS: Soluble interleukin-2 receptor alpha (sCD25) concentration was measured as a marker for T-cell activation in serum and ascites from EPS patients and various control patient groups. Peritoneal biopsies were stained for the presence of T cells, and T cells isolated from ascites of EPS patients were characterized in detail for differentiation status and cytokine expression. RESULTS: Serum sCD25 concentrations are significantly and specifically increased in EPS patients compared with haemodialysis, PD and predialysis patients. Peritoneal effluent of stable PD patients contains very low levels of sCD25, while sCD25 levels in ascites of EPS patients are high and indicative of local production. In the years preceding the diagnosis of EPS, the serum sCD25 concentrations increased while remaining at stable levels in control PD patients. The peritoneum and ascites of EPS patients showed a significant influx of T cells with relatively increased numbers of CD4(+) T cells. These T cells were fully differentiated and displayed a T helper 1 cell type with a pro-inflammatory cytokine profile. CONCLUSIONS: Increased serum sCD25 concentrations and peritoneal lymphocytosis in EPS patients indicate the involvement of activated T cells in the pathophysiology of excessive fibrosis.