Pathogenesis of hypofibrinogenemia in familial hemophagocytic lymphohistiocytosis.
In order to investigate the cause of hypofibrinogenemia in familial hemophagocytic lymphohistiocytosis (FHL), formalin-fixed and paraffin-embedded tissue sections of the spleen obtained at autopsy were examined by using immunohistochemical methods for the presence of fibrinogen antigens, and such antigens were detected in approximately 10% of the histiocytes in a diffuse staining pattern. This finding indicates uptake of fibrin and/or fibrinogen molecules by activated histiocytes and suggests that hypofibrinogenemia of FHL is caused by the direct action of activated histiocytes on factor X through Mac-1 receptors, subsequent activation of the common pathway of the coagulation protease cascade, and uptake of fibrin and/or fibrinogen molecules by such cells.
Ooe
K
K
Department of Pathology and Laboratory Medicine, Asahi General Hospital, Chiba, Japan.
D000347:Afibrinogenemia / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D005170:Factor X / Q000378:metabolism; D006644:Histiocytes / Q000378:metabolism / Q000473:pathology; D015616:Histiocytosis, Non-Langerhans-Cell / Q000097:blood* / Q000235:genetics / Q000473:pathology; D006801:Humans; D007223:Infant; D016177:Macrophage-1 Antigen / Q000378:metabolism; D013154:Spleen / Q000378:metabolism / Q000473:pathology
D016177:Macrophage-1 Antigen; D005170:Factor X