Haemostatic abnormalities and thrombotic disorders in malignant lymphoma

We examined haemostatic abnormalities and thrombotic disorders in 217 patients with malignant lymphoma. Plasma levels of fibrinogen and D-dimer were significantly higher in patients with malignant lymphoma than in healthy subjects. The incidence of severe complications, such as disseminated intravascular coagulation (DIC) and interstitial pneumonia (IP), differed with each clinical stage or histological type, but they occurred frequently in stage IV or natural killer (NK) cell lymphoma. Plasma levels of fibrinogen degradation products (FDP) and D-dimer, leukocyte tissue factor (TF) mRNA and plasma TF antigen were significantly higher in stage IV than in stage I, II or III. Plasma levels of FDP, D-dimer, and leukocyte TF mRNA in NK cell lymphoma were markedly higher than in other types of lymphoma. Immunohistochemical staining of NK cell lymphoma revealed that granulocyte macrophage colony-stimulating factor was positive in tumour cells, whereas von Willebrand factor and TF were positive in vascular endothelial cells of surrounding tissue. Our results suggested that patients with stage IV disease and NK cell lymphoma were in abnormal thrombotic and haemostatic state, and may frequently develop DIC and IP. One of the mechanisms of DIC and IP may involve elevated cytokine production by lymphoma cells, which can stimulate the expression of TF in blood cells or surrounding tissue.