The expression of a human B-lymphocyte antigen on cells in different types of leukaemia

(3H)ouabain binding to leukaemic cells and intralymphocytic sodium content in chronic lymphocytic leukaemia; no evidence for alterations of the Na+/K+-pump

The number of specific (3H)ouabain binding sites and dissociation constants (Kd) were determined by Scatchard analysis of values for leucocytes from patients with B-cell chronic lymphocytic leukaemia (CLL), chronic myeloid leukaemia (CML), acute blastic leukaemia (AL) and healthy subjects. CLL lymphocytes and normal B-cells bound significantly less (3H)ouabain than did normal T-lymphocytes. CML granulocytes showed the same binding characteristics as normal granulocytes, while blast cells from AL patients bound significantly more (3H)ouabain than did normal granulocytes or B-cells. The increased binding capacity in blast cells might, at least partly, reflect their larger cell size. A decrease in Kd values was only found in CLL lymphocytes, as compared with normal B-cells. Intralymphocytic sodium content in CLL lymphocytes was significantly increased, as compared with that in T-cell-enriched normal lymphocytes. (3H)ouabain binding did not show any relationship to different prognostic variables in CLL. The present data mainly argue against altered Na+/K+-ATPase enzyme activity as an indicator of malignancy.

High expression of lymphocyte surface immunoglobulin in chronic lymphocytic leukaemia may be a bad prognostic sign

Lymphocytes from 27 patients with B-type chronic lymphocytic leukaemia (CLL) were tested with immunofluorescence for expression of surface membrane immunoglobulin (SmIg) and the B cell antigen 7420. When age at time of testing, sex, clinical stage according to Binet, disease progression according to Levin and percentage of SmIg and 7420 antigen-expressing cells were used as explanatory variables for survival in a linear logistic regression model, only the SmIg variable was significant (p less than 0.025). A high proportion of SmIg bearing cells (greater than 61%) was associated with short survival, large tumour mass and aggressive disease. The tentative conclusion is drawn that the differentiation stage of the tumour cells in CLL determines the clinical course of the disease and is inversely correlated to the SmIg expression.

Cellular expression of the non-HLA-DR B-cell antigen 7420: studies on non-lymphoid cells and on lymphocytes from different species

We recently reported on a heterologous antiserum (antiserum 7420), raised against chronic lymphocytic leukaemic lymphocytes, that reacts with B-lymphocyte antigen(s) different from known B-cell markers such as HLA-DR (Ia-like) antigens, surface immunoglobulin, and the Fc receptor. This antiserum is now shown to react also with a C3-receptor-positive population of lymphocytes from the dog, monkey, ox and sheep but not from rodents and avians. The antiserum does not react with the non-lymphoid human cells mature granulocytes, thrombocytes, erythrocytes, or spermatozoa, nor with the cultured cell lines tested, i.e. fibroblasts, melanoma cells, HeLa cells and green monkey kidney cells. This reactivity pattern differs somewhat from that reported for HLA-DR antiserum. The antigen(s) defined by the 7420 antiserum and the C3 receptor are different, since they redistribute independently on the lymphocyte surface.