Differential response of malignant human B-cells to anti-IgM immunoglobulin (anti-mu) and B-cell growth factor: unique direct cytotoxicity of anti-mu on prolymphocytic leukemia cells.

We examined in vitro tritiated thymidine uptake by B cells from seven prolymphocytic leukemia (PLL), seven chronic lymphocytic leukemia (CLL), and four plasma cell leukemia (PCL) patients in response to culture with anti-human IgM antibody (anti-mu) and B-cell growth factor (BCGF). In contrast to the stimulatory effect observed in normal B-cell cultures, the divalent F(ab')2 anti-mu antibody uniquely inhibited the autonomous proliferation and induced marked cytotoxicity in six of seven PLL cell cultures independent of complement or Fc-receptor-mediated mechanisms. There was neither stimulation or inhibition of the slgM+ CLL or the slgM- PCL cells. The inhibitory effect on the PLL cells was observed at an anti-mu concentration below the stimulatory threshold for normal B cells. Significant impairment of trypan blue exclusion was delayed until 48 hours, with morphological cellular changes suggestive of a programmed cell death mechanism or apoptosis. The cytotoxicity was independent of the slgM-staining intensity or the autonomous and BCGF-augmented DNA synthetic activity of the PLL cells and was similar in patients with de novo PLL or with prolymphocytic transformation of CLL. Cells from a PLL patient were separated by elutriation into two fractions, a BCGF-unresponsive large "transformed" cell fraction with marked autonomous DNA synthesis and a smaller lymphoid cell subset with low 3H-thymidine uptake that could be augmented by BCGF. Both fractions were equally susceptible to the cytotoxic effect of anti-mu. These data suggest that certain slgM-bearing malignant B cells are susceptible to anti-mu-triggered cytotoxicity. They may represent the malignant counterpart of a "tolerogenic" normal B-cell subset, and the unique direct cytotoxicity of anti-mu may provide a therapeutic strategy specifically for PLL.

Evaluation of circulating malignant cells provides prognostic information in cutaneous T cell lymphoma.

Peripheral blood lymphocyte morphology was evaluated prospectively by light microscopy of blood smears and E rosette preparations in 160 patients with cutaneous T cell lymphoma (CTCL). Blood involvement was related to the type of cutaneous T-stage, being present in 90% of patients with erythroderma (T4), 27% of those with cutaneous tumors (T3), 9% of those with generalized (T2), and 0% of those with limited skin plaques (T1). Untreated patients with blood involvement (38 of 105) had a higher frequency of CTCL in lymph nodes and viscera and survival inferior to that of patients with normal or nondiagnostic lymphocyte morphology (P less than .001). Multivariate analysis showed skin stage and age to be the most important pretreatment risk factors for survival. Although blood involvement was not an independent risk factor for the entire group, it appeared to have some adverse influence in the T2/T3 subsets (P = .051). Both lymphocytosis and size distribution of the circulating CTCL cells at initial diagnosis influenced survival. Patients with "mixed cell" cytology (greater than 20% large [greater than 11 microns] CTCL cells), had a worse survival than those with predominantly small circulating CTCL cells (P = .009). The former were more likely to have aggressive features, including lymph node effacement by tumor (P less than .001) and visceral disease (P = .074), than were "small cell" patients. Our data indicate that detailed review of the blood lymphocyte morphology in patients with diagnosed or suspected CTCL is helpful in predicting extent of disease and prognosis.

Expression of glucagon receptors on T- and B- lymphoblasts: comparison with insulin receptors.

Activation of T- and B-lymphocytes by a variety of immunological stimuli has been reported to induce specific insulin receptors. The purpose of the present work was to determine whether glucagon receptors are also induced in activated cells. Studies of glucagon and insulin receptors were carried out using normal human mononuclear cells activated by phytohemagglutinin or T-cell growth factor (TCGF), as well as established B- and T-lymphoblastoid cell lines. With phytohemagglutinin, glucagon and insulin binding increased 15- and 36-fold, respectively, and peaked after 5 days in parallel with the rise in thymidine incorporation. Increased binding was associated with an increase in the number of receptors, most marked for insulin, though affinity for the insulin receptor was decreased. Normal human mononuclear cells cultured with TCGF showed an early modest rise in insulin binding due to increased receptor number, without a change in affinity, and a striking and progressive rise up to 50-fold in glucagon binding due to both increased receptor number and affinity. The differences in receptor response to these T-cell mitogens suggest that TCGF selects out a T-lymphoblast subset with very high glucagon receptors. B- and T-lymphoblastoid cells showed patterns of glucagon and insulin receptors that appear to be characteristic for each cell type. Glucagon binding was 7-fold higher (P less than 0.01), while inulin binding was 7-fold lower (P less than 0.01) in T- vs. B-lymphoblastoid cells. T-Cell lines had twice the number of glucagon receptors, whereas B-lines had 4-fold the number of insulin receptors, with much greater affinity for insulin compared with T-line insulin receptors. Induction of both insulin and glucagon receptors on activated lymphoblasts suggests that these receptors may play a significant role in cell function.

Blood and lymph node T lymphocytes in cutaneous T cell lymphoma: evaluation by light microscopy.

Cytology of peripheral blood and lymph node lymphocytes from a group of unselected patients with cutaneous T cell lymphoma (CTCL) was studied by light microscopy. Twenty of 45 patients had circulating lymphocytes with convoluted nuclei recognized in routine Wright-Giemsa-stained peripheral blood smears. Cytocentrifuge preparations of E-rosetted lymphocytes showed that greater than 10% of the T cells had convoluted nuclei in each of 16 patients with positive blood smears and in six of 17 whose blood smears were negative or inconclusive. Peripheral blood involvement with greater than 10% convoluted T cells was most frequent in patients with erythroderma (100%) including those with normal of decreased lymphocyte counts, and was not uncommon in patients with mycosis fungoides in the plaque or tumor phase (42%). The light-microscopic morphology of the abnormal cells found in the patients with the plaque or tumor phase of mycosis fungoides was not distinguishable from that of the erythrodermic patients. Increased percentages (less than 15%) of T cells having convoluted nuclei were also found in the lymph node cell suspensions from CTCL patients with adenopathy (18 of 25 patients). These results suggest that a high frequency of extracutaneous involvement occurs in patient with CTCL, the clinical significance of which remains to be determined.

Monocyte-mediated inhibition of lymphocyte blastogenesis in Hodgkin disease.

Mononuclear leukocytes isloated from the blood of previously treated patients with advanced active Hodgkin disease contained high concentrations of monocytes and showed poor lymphocyte blastogenesis to mitogens. In five of eight patients with disseminated disease, blastogenesis became normal or improved markedly when the leukocyte suspensions were depleted of monocytes before culture. Addition of autologous macrophages to the monocyte-depleted lymphocytes resulted in a reappearance of the inhibition of blastogenesis. Monocyte inhibition was associated with the presence of active disease, lymphocytopenia, and low lymphocyte/monocyte ratios in the peripheral blood. The role of previous treatment is uncertain, since inhibition tended to disappear when the patients were retreated. Inhibitory monocyte-lymphocyte interactions may be one of the causes of impaired cell-mediated immunity in Hodgkin disease.