[Clinical characteristics and treatment outcomes of macrophage activation syndrome in adults: A case series of 67 patients].
OBJECTIVE
To described the clinical and laboratory features and outcome of 67 macrophage activation syndrome (MAS).


METHODS
A total of 67 MAS patients from three centers from January 2007 to December 2017 were enrolled. Clinical and laboratory features, and response to therapy were analyzed. Predictive factors for remission and survival were explored.


RESULTS
We identified a mean age of (36.1±16.3) years at diagnosis of MAS and a median connective tissue disease (CTD) duration of 8 months prior to MAS development. Among 67 MAS patients identified, underlying diseases included adult-onset Still's disease (AOSD) in 56.7% and systemic lupus erythematosus (SLE) in 30.0%. Fever and splenomegaly were found in 100.0% and 82.1% of the patients, respectively. Ferritinemia and elevation of serum soluble interleukin-2 receptor was seen in 100.0% and 93.2% of the patients. Serum levels of alanine aminotransferase, D-dimer, ferritin and C reactive protein were significantly higher in MAS associated with the AOSD patients than in MAS associated with the SLE patients. A significant decrease of erythrocyte sedimentation rate was found in MAS associated with AOSD, as compared with MAS associated with SLE. The most commonly used therapy was corticosteroids, which were initially administered in 100.0% of the patients. Intravenous immunoglobulin (IVIG) was administered in 91.0%, cyclosporine A in 64.2%, and etoposide in 46.3% of the patients, respectively. The induction therapy yielded a complete remission (CR) at the end of week 8 in 47.8% of the MAS patients. The overall mortality rate at the end of week 16 was 22.4%. The median serum levels of gamma-glutamyltransferase, alkaline phosphatase, total bilirubin and direct bilirubin were significantly lower in the patients who achieved complete remission at the end of week 8 than in those who did not, and splenomegaly was significantly less frequent (71.9% vs.91.4%, P=0.037). Both the mean age at diagnosis of MAS and the mean age at diagnosis of underlying CTD of the deceased patients were elder than those of the survived population (P=0.014 and P=0.017, respectively). The platelet count was significantly less in the deceased population as compared with the living population (P=0.018). No addition of cyclosporine A (P=0.004) was identified as risk factors associated with death in Logistic regression analysis.


CONCLUSION
MAS secondary to connective tissue disease is most common with AOSD and SLE. In terms of laboratory findings, there were considerable differences between the patients with underlying SLE and those with AOSD. Advanced age and low platelet counts are significant predictive factors for death, while treatment with cyclosporine may reduce the risk.