The glycosylated ferritin has been included in the diagnostic criteria for Still's disease in adults. A cut-off of less than 20 % has a sensitivity and specificity of 72 and 69 % respectively , and 35 and 94 % when combined with a total ferritin level greater than 5 times normal value. This parameter was also suggested to be a more specific marker to confirm a diagnosis of HLH than a high ferritin level ( > 500μg / L). However, several limitations of this parameter were highlighted, some conditions making its interpretation difficult : particularly in cases of major hepatic cytolysis and severe sepsis (miliary tuberculosis, lymphoma and disease Adult Still).