Comparison of serum biomarkers for the diagnosis of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis.

Our study aimed to compare the accuracy of serum biomarkers for the diagnosis of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (s-JIA). Serum cytokine levels (neopterin, IL-18, and CXCL9 and soluble tumor necrosis factor receptor type I (sTNFR-I) and II) were determined by enzyme-linked immunosorbent assay in 78 patients with s-JIA, including 21 with MAS. Receiver operating characteristic curve analysis revealed area under the curve values and cut off values of neopterin, IL-18, CXCL9, sTNFR-II/I ratio and ferritin were 0.9465/19.5 nmol/l, 0.8895/69250 ng/ml, 0.9333/3130 pg/ml, 0.9395/3.796 and 0.8671/2560 ng/ml, respectively. Serum neopterin levels were significantly elevated in patients with MAS and those were correlated positively with disease activity. In conclusion, serum neopterin levels may be used as a promising indicator of disease activity in s-JIA and MAS and for evaluating it. It may also be a useful marker to diagnose the transition to MAS from active-phase s-JIA.

Successful treatment of rituximab- and steroid-resistant nephrotic syndrome with leukocytapheresis.

Although rituximab (RTX) is a promising therapeutic agent for treating steroid-resistant nephrotic syndrome (SRNS) resistant to various immunosuppressive agents, some patients have shown resistance to RTX. We report the case of a patient with RTX-resistant nephrotic syndrome and SRNS who was successfully treated with leukocytapheresis (LCAP). After LCAP, there was a significant reduction in proteinuria and in the total number of lymphocytes, T cells, and HLA-DR+- activated T cells. Moreover, the patient became sensitive to steroids and RTX. LCAP reduced circulating immune cells including activated T cells and could be effective in treating rituximab-resistant nephrotic syndrome and SRNS and in achieving remission of proteinuria.

FDG-PET in macrophage activation syndrome associated with systemic juvenile idiopathic arthritis.

We herein describe a case of systemic juvenile idiopathic arthritis (s-JIA)-associated macrophage activation syndrome (MAS) in which the 18F fluorodeoxyglucose positron emission tomography (18F FDG-PET) findings were characteristic. The pattern of greater 18F FDG accumulation into the spleen compared with the liver was more remarkable in this patient compared with s-JIA. This pattern, however, was also observed in cases of acute leukemia. In the present patient, serum interleukin (IL)-18 was extremely elevated (255 000 pg/mL), whereas in leukemia patients it is mildly elevated (360-1480 pg/mL). 18F FDG-PET might be a useful indicator of s-JIA and MAS in patients with fever of unknown origin. The pattern of 18F FDG accumulation, however, can also be observed in acute leukemia. The combination of 18F FDG-PET and serum IL-18 might be useful for the diagnosis of s-JIA and MAS.

Serum ferritin as an indicator of the development of encephalopathy in enterohemorrhagic Escherichia coli-induced hemolytic uremic syndrome.

OBJECTIVES: To investigate the diagnostic value of serum ferritin levels as a marker of disease activity and the development of encephalopathy in hemolytic uremic syndrome (HUS) induced by enterohemorrhagic Escherichia coli. METHODS: Twenty patients with HUS were studied. Serum ferritin levels were compared with clinical features and serum soluble tumor necrosis factor receptor (sTNFR) I and sTNFRII levels. Serum sTNFRI and sTNFRII levels were quantified by enzyme-linked immunosorbent assays. RESULTS: Serum ferritin levels were significantly elevated at the time of the diagnosis of HUS. Serum ferritin levels were significantly elevated in patients with encephalopathy compared to patients without encephalopathy. HUS patients with serum ferritin levels of >687.5 ng/ml were at high risk of encephalopathy. Serum ferritin levels were significantly positively correlated with serum sTNFRI and sTNFRII levels. CONCLUSIONS: Serum ferritin levels are a promising indicator of the development of encephalopathy in HUS.