Early diagnosis of low grade malignant lymphoma and chronic lymphocytic leukaemia. Verification of morphologically suspected malignancy in blood lymphocytes by flow cytometry.

According to international recommendations, the diagnosis of chronic lymphocytic leukaemia (CLL) is made on the grounds of persistent peripheral lymphocytosis or lymphocytic infiltration of the bone marrow. The appearance of morphologically atypical lymphocytes in low-grade malignant lymphoma (NHL) or CLL is easily overlooked, and is generally not regarded as a diagnostic criterion. We report 12 cases of CLL/NHL who were detected only by morphological screening of routine peripheral blood smears (83,400 blood smears). The diagnosis of CLL/NHL was not suggested by the patients' history, physical or other laboratory findings, and had not been contemplated by the physician in charge. Monoclonality of peripheral lymphocytes was confirmed by immunophenotyping and Southern blotting. The lymphoma was classified histologically according to the International Working Formulation (bone marrow biopsy). A monoclonal lymphatic population was not found by immunophenotyping in the blood of 11 patients whose lymphocytes were morphologically classified as activated-abnormal. However, 3 patients suspected to have NHL/CLL on morphological screening of blood smears had to be classified as benign after immunophenotyping. We conclude that morphological screening of routine blood smears is an inexpensive and easy additional screening method for CLL and low grade malignant NHL.

Monocyte rolling, arrest and spreading on IL-4-activated vascular endothelium under flow is mediated via sequential action of L-selectin, beta 1-integrins, and beta 2-integrins.

Leukocyte interactions with vascular endothelium at sites of inflammation can be dynamically regulated by activation-dependent adhesion molecules. Current models, primarily based on studies with polymorphonuclear leukocytes, suggest the involvement of multiple members of the selectin, integrin, and immunoglobulin gene families, sequentially, in the process of initial attachment (rolling), stable adhesion (arrest), spreading and ultimate diapedesis. In the current study, IL-4-activated human umbilical vein endothelium, which selectively expresses VCAM-1 and an L-selectin ligand but not E-selectin, and appropriate function blocking monoclonal antibodies, were used to study monocyte-endothelial interactions in an in vitro model that mimics microcirculatory flow conditions. In this system, L-selectin mediates monocyte rolling and also facilitates alpha 4 beta 1-integrin-dependent arrest, whereas beta 2-integrins are required for spreading of firmly attached monocytes on the endothelial cell surface but not their arrest. These findings provide the first in vitro evidence for human monocyte rolling on cytokine-activated endothelium, and suggest a sequential requirement for both beta 1- and beta 2-integrin-dependent adhesive mechanisms in monocyte-endothelial interactions.

Cytofluorometry as a diagnosis of protoporphyria.

Protoporphyria is a disorder that usually has cutaneous symptoms. Only in a few cases liver disease develops, invariably progressing to cirrhosis and liver failure. A case of a patient who suffered from photosensitivity as a result of protoporphyria since the age of 2 is described. At age 33, she first presented with cholestatic hepatitis. At age 40, liver failure developed requiring liver transplantation. Quantitative cytofluorometry proved to be a quick and simple method in the follow-up of her erythrocyte protoporphyrin levels before, during, and after transplantation. Fluorescence correlated well with the protoporphyrin levels obtained by high-performance liquid chromatography (r = 0.98), a comparably cumbersome and complicated method for the determination of protoporphyrin. In addition, single cell analysis enabled us to follow the effects of transfusion therapy on protoporphyrin levels of the patient's own erythrocytes, which has not been possible by previous methods. Thus, cytofluorometry might prove to be elegant and useful for screening and future studies on therapy and pathophysiology of protoporphyria.