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Blood lymphocytes from thirteen patients with CLL were studied for surface-bound Ig (SIg), Fc receptors (EA rosettes), receptors for sheep erythrocytes (E rosettes) and receptors for Helix pomatia A haemagglutinin (FTP), a carbohydrate-binding protein with specificity for N-acetyl-D- galactosamine and related sugars. Fluorescein-labelled HP binds to subpopulations of human peripheral blood lymphocytes (PBL) treated with neuraminidase. In normal peripheral blood, HP binds to the T-lymphocytes while the majority of the B cells bearing surface-bound immunoglobulin do not have receptors for HP. In untreated CLL, HP binds to 90-100% of the neur-aminidase-treated PBL. Almost all of the SIg-positive cells in CLL patients also have receptors for HP. Two groups of patients were found: in one the total fraction of SIg+ cells was ⩽50% and about 30% of these lost their Ig during incubation at 37° C. No such loss of Slig was revealed in the remaining patients where total SIg+fraction was ≈70%. These patients usually had higher blood lymphocyte counts, probably reflecting a more advanced disease. CLL patients in remission with low numbers of leukaemic cells also had low numbers of blood lymphocytes carrying both SIg and HP-receptors. It is concluded that leukaemic cells carry both HP receptors and SIg. Testing of this combination therefore provides a valuable new tool for monitoring patients with CLL. [ABSTRACT FROM AUTHOR]

Eight donors immune to hepatitis B(HB)after natural infection were studied for their cellmediated immune response to hepatitis B core (HBc) protein in vitro. Significant specific activation was observed in highly purified peripheral blood lymphocytes and T cells from these donors after 5-8 days of incubation with HBc protein. This in vitro response wits modulated by monocytic cells and maximal ³H-thymidine incorporation was elicited with low concentrations of the antigen (0.1-10 ng/ml). The cell-mediated immune reactivity towards HBc-protein was significantly (P<0.005) elevated compared to the envelope material of the virus (HBsAg) when analysed in the same donor population. In contrast, donors with plasma-derived hepatitis B vaccine induced immunity lo HB exhibited only specific lymphocyte activation to HBsAg, These data Indicate that the composition of immune responses conferring protection against HBV after natural infection is far more complex than after immunization with the hepatitis B vaccine. Further characterization of the cell-mediated immune response to HBc protein and its relation to protection against HBV seems warranted when strategies for new HB-vaccines are being designed. [ABSTRACT FROM AUTHOR]

Cell mediated and humoral immunity to hepatitis B surface antigen (HBsAg) was studied in nine asymptomatic HBsAg carriers, nine patients with natural acquired immunity to MB infection and nine HB-susceptible donors. Peripheral T and B lymphocytes from all asymptomatic HBsAg carriers and all HB-immune donors studied were specifically induced into proliferation and anti-HBs secretion when stimulated with low doses of HBsAg (2-30 ng antigen protein/ml) in vitro. This activation was achieved by mixing purified B and/or T cells with optimal concentrations of autologous monocytic cells. T and B cells from the HB-susceptible donors were non-responsive under identical culture conditions. These data do neither substantiate the existence of a qualitative defect in T cell function, nor the absence of circulatory B cells capable of synthesizing anti-HBs in vitro in asymptomatic HBsAg carriers. Thus, the inability to mount a satisfactory antibody response to HBsAg in vivo might be a consequence of altered immune responsiveness to this antigen, which may be a relevant factor in the pathogenesis of asymptomatic HBsAg carriership. [ABSTRACT FROM AUTHOR]