Reactive haemophagocytic syndrome (RHPS), also called macrophage activation syndrome (MAS), is a serious complication of viral, rheumatic and malignant diseases, thought to be caused by the excessive activation of T lymphocytes and macrophages. MAS is characterized by polyorgan involvement with typical features: non-remitting fever, hepatic enlargement, considerable lowering of blood cell count and erythrocyte sedimentation rate (ESR), elevation of serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), lactate dehydrogenase (LDH) and serum ferritin level, with hypofibrinogenemia. The most characteristic feature is the presence of well differentiated macrophages, revealing an active haemophagocytosis in the bone marrow aspirate. Because of rapid progression and fatal prognosis of the disease, prompt and immediate therapeutic intervention is very important. Although there is no standardized treatment, commonly applied glucocorticoids (GCS), and cyclosporine A (CsA) are used. The study was aimed to a general characteristics of pathogenic factors, clinical picture, laboratory features and results of treatment in 8 children with RHPS /MAS.
Material and methods : The study included 8 children (5 girls and 3 boys) aged 3 to 16 years (mean age was 10 years and 3 months) hospitalized in the Clinic of Pediatrics at IPCZD and in the Department of Pediatric Rheumatology at the Institute of Rheumatology in Warsaw. The analysis covered potential etiological factors, considering the basic disease, clinical symptoms (Table II), results of laboratory tests (Table III), including immunological tests, applied therapy. In 4 patients, systemic-onset juvenile idiopathic arthritis was accompanied by MAS, and in 2 patients it was the first manifestation of sJIA. In one patient, EBV infection was confirmed by the polymerase chain reaction (case 1). In patient 3, PCR evaluation revealed Cytomegalovirus (CMV) infection. Cytomegalovirus infection was also confirmed in case 4, however, simultaneously genetic as well as serological evaluation for Parvovirus B19 infection revealed positive results in this patient. In patient 5 CMV infection and/or Toxocara canis infection could be a triggering factor for RHPS (Table I). In seven patients, haemophagocytosis was confirmed in bone marrow biopsy. No response to GCS treatment, including pulse therapy, or IVIG therapy was observed. Remission was induced by treatment with CsA (Table IV). The diagnostic criteria for haemo­phagocytic lymphohistiocytosis are presented in Table V.