Dynamic Changes, Cut-Off Points, Sensitivity, and Specificity of Laboratory Data to Differentiate Macrophage Activation Syndrome from Active Disease.

The dynamic changes in some laboratory data, especially PLT, can differentiate between MAS and active disease. The changes in WBC, PMN, and ESR and the levels of the liver enzymes may also be helpful in the early differentiation. Very high levels of ferritin may also help the diagnosis along with other clinical and laboratory signs.