Hemophagocytic lymphohistiocytosis caused by primary Epstein-Barr virus in patient with Crohn’s disease

Table 1 Current diagnostic criteria for hemophagocytic lymphohistiocytosis[7]

The diagnosis of HLH may be established by1

A molecular diagnosis consistent with HLH (for example, pathologic mutations of PRF1, UNC13D or STX11 are identified) or

Fulfillment of five out of the eight criteria listed below:

Fever

Splenomegaly

Cytopenias (affecting at least two of three lineages in the peripheral blood):

Hemoglobin < 9 g/100 mL (in infants < 4 wk: hemoglobin < 10 g/100 mL)

Platelets < 100-103/mL

Neutrophils < 1-103/mL

Hypertriglyceridemia (fasting, 265 mg/100 mL) and/or hypofibrinogenemia (150 mg/100 mL)

Hemophagocytosis in BM, spleen or lymph nodes

Low or absent NK cell activity

Ferritin 500 ng/mL

Soluble CD25 (that is, soluble IL-2 receptor) > 2400 U/mL (or per local reference laboratory)

¹In addition, in the case of familial HLH, no evidence of malignancy should be apparent. HLH: Hemophagocytic lymphohistiocytosis; NK cell: Natural killer cell; CD: Crohn's disease; IL-2: Interleukin-2;PRF1: Pore Forming Proteingene;UNC13D:Unc-13 homolog Dgene;STX11:Syntaxin 11gene.