[Macrophage activation syndrome in children with rheumatic disorders: a retrospective study on 6 patients]

To study the clinical manifestations of rheumatic disorders with macrophage activation syndrome (MAS) in children.

The authors characterized MAS by carrying out a retrospective study on patients who were identified during the past 12 years in Tianjin Children's Hospital.

Six cases (4 females, 2 males) were studied. Four had typical systemic onset juvenile idiopathic arthritis (SOJIA), two had systemic lupus erythematosus (SLE) with lupus nephritis. Clinical manifestations at diagnosis, which occurred in the lower activity state of these primary diseases, included high spiking fever (in 5 cases) or high fever (in 1), hepatosplenomegaly (in 6), lymphadenopathy (in 6), profound decrease of all 3 blood cell lines (in 6), significant injury of liver (in 6), diseminated intravascular coagulation (DIC)-like picture (in 2), and central nervous system dysfunction (in 3). Hypofibrinogenemia, elevated liver enzymes and hypertriglyceridemia were found consistently. The phagocytic histiocytes with plasmacytosis were found in 3 bone marrow smears (not done in others). MAS was presumed to have been precipitated by viral infections in 3 patients, two had evidences for herpes simplex virus infection and one for hepatitis A virus infection. The treatment regimen was tailored to each patient, as the clinical course was variable.

MAS may not only be most frequently seen in children with SOJIA, but also in those with other rheumatic diseases, and may be a syndrome that is more common than previously thought. Infection may be main trigger factor for MAS. The immunoapheresis combined with immunochemotherapy may be optimal for severe injury of the liver in patients with MAS.