Morphological variants of leukemic cells in B chronic lymphocytic leukemia are associated with different T cell and NK cell abnormalities

B chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease. The different morphological variants of leukemic B cells appear to define different clinical groups of patients. Several abnormalities have been found in T lymphocytes and natural killer (NK) cells from B-CLL patients. We have investigated the phenotypic and functional characteristics of purified CD2+ cells from B-CLL patients at Binet's stage A and classified according to the neoplastic B lymphocyte morphology criteria: 32 patients with typical B-CLL and 12 patients with atypical B-CLL. Forty-three age and sex matched healthy controls were also studied. In fresh purified CD2+ cells from typical B-CLL patients, percentages of CD4+, CD4+CD45RA+, CD8+CD45RA+ T lymphocytes and CD3−CD56+ (NK) cells were significantly higher than those found in atypical B-CLL patients. However, in DC2+ cells from typical B-CLL patients, percentages of CD3+, CD3+DR+, CD8+, CD4+CD45RO+, and CD3+CD56+ cells were significantly lower than those found in atypical B-CLL patients. Increased percentage of NK cells was only found in typical B-CLL patients. The proliferative response and the production of interleukin (IL)-2 and IL-4 by phytohemagglutinin (PHA) stimulated CD2+ cells were significantly higher in typical B-CLL patients than in atypical B-CLL patients. We concluded that different patterns of phenotypic and functional alterations in the T lymphocytes and NK cells of B-CLL patients are found in patients with typical or atypical B-CLL defined according to the morphology of the leukemic cells. Am. J. Hematol. 55:175–182, 1997. © 1997 Wiley-Liss, Inc.     

Recombinant alpha 2-interferon in the treatment of B chronic lymphocytic leukemia in early stages

Ten previously untreated patients with early B cell chronic lymphocytic leukemia (B-CLL) (seven in Rai's stage 0, three in stage I) were given recombinant alpha 2-interferon (alpha 2IF) (2 X 10(6) U/m2 intramuscularly three times a week for a minimum of 14 weeks) to assess its effectiveness. All patients were evaluable for response to therapy and toxicity. No complete response was achieved. In all cases a definite, although transient reduction in the absolute number of peripheral blood lymphocytes was observed. In eight patients an increase in the absolute number of granulocytes was detected. None of the patients experienced severe hematologic toxicity. Fatigue, malaise, and fever were the more common side effects, but all patients were able to finish their treatment as planned. The results of this pilot study suggest that low doses of recombinant alpha 2-IF have some activity in early and previously untreated B-CLL and that further studies of IF effectiveness in B-CLL seem warranted.     

Non-radioactive in situ hybridization for the detection and monitoring of trisomy 12 in B-cell chronic lymphocytic leukaemia

Non-radioactive in situ hybridization (NISH) with a chromosome 12-specific alpha satellite probe was performed on 20 patients with chronic lymphocytic leukaemia (CLL) with normal karyotype (15 cases) or with inadequate mitotic yield (5 cases) from mitogen-stimulated cultures. All patients had over 70% lymphocytes coexpressing the CD5/CD23 antigens. While less than 1% interphase nuclei showed three fluorescent spots in 16/20 patients, evidence of trisomy 12 in 15-25% interphase cells was detected in four patients. According to the FAB classification the diagnosis in these patients was typical B-CLL, stage III (Rai's staging system) in one case, CLL/PLL, stage II and III in two cases, PLL, stage III in one case. In order to confirm these results, NISH was repeated after 1 month in one patient and after 2 years in three patients. All patients had been treated with chemotherapy in the period between the two NISH experiments. In all cases a 1.8-3-fold increase of percentage of trisomic interphase cells was detected. These findings suggest that in B-CLL clones with trisomy 12 may have proliferative advantage over clonal B-lymphocyte without +12 and, possibly, that they may be more resistant to chemotherapy. We conclude that NISH is a sensitive technique allowing for the detection and monitoring of trisomy 12 in a fraction of B-CLL patients with normal karyotype or with no analysable mitoses despite employment of polyclonal B-cell mitogens.     

T-cell activation and subset patterns are altered in B-CLL and correlate with the stage of the disease

Two-color FACS analysis was used to study activated and "functional" T and natural killer (NK) cell subsets of circulating lymphocytes in 23 patients with B-type chronic lymphocytic leukemia (B-CLL) and in 30 healthy subjects. As compared with controls, B-CLL patients had increased absolute numbers of phenotypically activated, HLA-DR+ CD4+ and CD8+ cells and T suppressor/effector (CD11b+CD8+) cells. When patients in Rai stages II through IV (n = 11) were compared with cases in Rai stages O through I (n = 12), the former group of patients had higher numbers of activated CD4+ and CD8+ T cells and decreased levels of suppressor/effector T cells. The absolute numbers of T suppressor/inducer (CD45R+CD4+) cells were elevated in patients with stage O through I disease but within normal range in stage II through IV leukemia. We further showed that the absolute numbers of NK-like (CD16+) cells and their activated counterparts (DR+CD16+) are elevated in B-CLL patients as compared with healthy subjects. The comparison of relative T and NK subsets in the blood of patients and controls showed that the proportions of CD4+, CD8+, and CD16+ cells expressing the activation marker HLA-DR were increased in B-CLL. Furthermore, the percentage of T-suppressor/inducer (CD45R+) cells within the CD4+ population was decreased in the patients. The proportion of T- suppressor/effector (CD11b+) cells within the CD8+ subset was reduced in subjects with stage II-IV disease only. When stimulated in vitro with the T-cell-dependent inducer TPA, B-CLL cells from patients in Rai stages II through IV secreted larger amounts of IgM as compared with cells from stage O through I patients. A positive correlation was observed between the degree of phenotypic activation of CD4+ T-helper cells and their functional capacity to augment IgM secretion by autologous B-CLL cells. Our findings indicate a tumor cell-directed regulatory role of T cells (and possibly NK cells as well) in B-CLL. Furthermore, monitoring of phenotypically activated and functional T- cell subsets may be helpful in the prediction of disease progression and timing of therapy in B-CLL.     

T lymphocyte subpopulations in chronic lymphocytic leukemia of B cell type in relation to immunoglobulin isotype(s) on the leukemic clone and to clinical features

Total blood T lymphocytes and subpopulations (OKT4+ and OKT8+ cells) were studied in 59 patients with B cell chronic lymphocytic leukemia (B-CLL). In 48 previously untreated patients, total T lymphocytes were higher as compared to healthy controls (p less than 0.001). T-cells and OKT8+ cells were significantly increased in patients in advanced clinical stage and with progressive disease in comparison to patients with low stage and indolent disease. High numbers of OKT8+ lymphocytes were also seen in patients with a dominance of mu heavy chains on the leukemic clone. Moreover, in this patient group the OKT8+ subpopulation correlated with total B cells (r = 0.68, p less than 0.001) while in patients with a mu delta phenotype no such correlation was seen. After successful cytostatic therapy there was a reduction in total numbers of both OKT4+ and OKT8+ cells, in particular, with a concomitant increase in OKT4/OKT8 ratios.     

Expression of NK-lineage markers on peripheral blood lymphocytes with T- helper (Leu3+/T4+) phenotype in B cell chronic lymphocytic leukemia

Heterogeneity within lymphocyte subsets expressing T-helper (T4+/Leu3+) or T-suppressor (T8+/Leu2+) markers was analyzed in 38 patients with B cell chronic lymphocytic leukemia (B-CLL) and in 11 age-matched controls. Co-expression of NK-lineage markers (M1, Leu7) on Leu2+ or Leu3+ cells was investigated by two-color immunofluorescence, and the proportion of granular lymphocytes within each subset was determined by cytochemical staining for acid phosphatase. B-CLL patients and normal controls had similar absolute numbers of cells per microL with T- suppressor phenotype. However, the proportion of Leu2+ cells co- expressing the Leu7 antigen was higher in the B-CLL patients than in the control subjects (54 +/- 3% v 27 +/- 4%, P less than .0001). The absolute number per microL of cells with T-helper phenotype was somewhat decreased in B-CLL patients compared with normal subjects (649 +/- 104 v 799 +/- 33, P less than .02), with a consequent decrease of the helper/suppressor ratio. Furthermore, co-expression of the Leu7 and, more strikingly, of the M1 markers was increased significantly on Leu3+ cells from B-CLL patients compared with normal controls (11 +/- 2% v 2 +/- 0.7%, P less than .002 for Leu7 and 40 +/- 5% v 4 +/- 1%, P less than .00001 for M1). Cytochemical studies showed that a large proportion of Leu3+ cells from B-CLL patients were granular lymphocytes, as suggested by the co-expression of natural killer (NK) cell markers. The emergence of a population of Leu3+ granular lymphocytes with NK markers, which is barely detectable in normal subjects, may provide an explanation for the impairment of T cell functions repeatedly described in B-CLL.     

Natural killer, lymphokine-activated killer and interferon-gamma producing activities of peripheral blood- and regional lymph node-mononuclear cells in 23 cases of colorectal cancer

Natural killer (NK) activity, lymphokine-activated killer (LAK) activity and interferon-gamma (IFN-gamma) producing activity of peripheral blood mononuclear cells (PBMC) and regional lymph node mononuclear cells (LNMC) were studied in 23 previously untreated cases of colorectal cancer. NK and LAK activities were significantly lower in LNMC than in PBMC. Patients showed depressed NK and LAK activities in PBMC. In the Dukes C group, especially, both NK activity and LAK activity decreased compared to control patients. NK and LAK activities of PBMC decreased as the grade of invasion to lymphatic channels progressed. LAK activity positively correlated with NK activity in PBMC. Patients with high LAK activity showed high IFN-gamma production in both controls and Dukes A . B patients. However, in Dukes C patients, no relationship between LAK activity and IFN-gamma production was observed. We conclude that the depressed NK and LAK activities of PBMC reflect the local lymphatic invasion and that IFN-gamma involvement in LAK cell generation is impaired in advanced cancer patients. More fundamental studies should be carried out before clinical trials of adoptive immunotherapy using LAK cells, because LAK activity is not induced sufficiently in advanced cancer.     

Discrepancy between phenotypic and functional features of natural killer T-lymphocytes in B-cell chronic lymphocytic leukaemia

The phenotypic expression and functional capacity of natural killer (NK) T-lymphocytes (E+, OKT3+) were analysed in a series of untreated patients with B-cell chronic lymphocytic leukaemia (B-CLL). The mean value of NK activity of B-CLL T-lymphocytes, tested against the K562 cell line, was significantly depressed (P less than 0.01) in the 20 cases studied, compared with that of normal T-cells. Incubation with human leucocyte interferon produced an increase (P less than 0.05) in NK activity, although the mean value was still significantly lower (P less than 0.05) than that obtained with normal T-cells. Furthermore, the formation of effector-target conjugates was significantly lower (P less than 0.01) among B-CLL T-cells compared with normal T-lymphocytes. Despite the reduced NK functions observed in the majority of B-CLL patients, the capacity of T-cells to react with the monoclonal antibody (MoAb) Leu-7 (HNK-1 clone), assessed in 60 patients, was significantly higher (P less than 0.001) in B-CLL than in normal blood (mean 24% +/- 10.6 SD v 9% +/- 4.2), irrespective of the clinical stage of the disease. These findings suggest that the reduced cytotoxic ability of B-CLL T-lymphocytes may be due either to an expanded population of immature T-cells which already express a cytotoxic-like phenotype (E+, OKT3+, HNK-1+) but which lack adequate cytotoxic functions, or, alternatively, to an intrinsic defect of the natural effectors present within the T-cell population of B-CLL. The T-cell functional abnormalities documented in this study, together with other defective functions previously described, may be implicated in some of the complications frequently associated with B-CLL, particularly the high incidence of secondary neoplasms. There is growing evidence that natural cytotoxicity may play a major role in the immune surveillance system, both against tumour cells and virus-infected cells (Herberman & Ortaldo, 1981). Natural killer (NK) cells are a morphologically homogeneous population of large granular lymphocytes with azurophilic granules in the cytoplasm (Timonen et al, 1981), which are non-adherent and express receptors for the Fc portion of IgG. About 50% of these cells form rosettes with sheep red blood cells (E-rosettes) (West et al, 1977). A monoclonal antibody (MoAb) which appears to react with practically all human NK cells (HNK-1 clone, Leu-7; Becton Dickinson) has been recently produced (Abo & Balch, 1981).(ABSTRACT TRUNCATED AT 400 WORDS)     

Antilymphocyte globulin therapy enhances impaired function of natural killer cells and lymphokine activated killer cells in aplastic anaemia

MHC-unrestricted cytotoxic lymphocytes, namely natural killer (NK) and lymphokine activated killer (LAK) cells, have been implicated in the regulation of haemopoiesis. To investigate the possible role of these lymphocytes in the pathogenesis of aplastic anaemia (AA), we studied their functions in the peripheral blood mononuclear cells (PBMC) and bone marrow mononuclear cells (BMMC) of patients with AA treated with antilymphocyte globulin (ALG). Before treatment, both NK and LAK activities in the PBMC of 25 patients were low (NK = 1.9 +/- 2.1 x 10(3) LU/l) LAK = 4.7 +/- 3.6 x 10(3) LU/l) compared to normal (NK = 6.0 +/- 3.0 x 10(3) LU/l, LAK = 10.0 +/- 3.5 x 10(3) LU/l) or multiply transfused (NK = 7.8 +/- 6.6 x 10(3) LU/l, LAK = 25.2 +/- 13.6 x 10(3) LU/l) controls. The NK and LAK activities in the BMMC in AA patients were not significantly different from those in PBMC. In all patients with low LAK and NK activities pre ALG there was an increase in activity 2-24 weeks after therapy which eventually reached normal levels and which was maintained for up to 2 years. Analysis of lymphocyte phenotypes in AA patients before treatment showed both significantly low mean proportion and absolute numbers of CD16+ cells compared to normals, which increased after therapy. Changes in MHC-unrestricted cytotoxicity and lymphocyte phenotypes post therapy were not correlated with haemopoietic recovery. These data suggest that ALG treatment can enhance the functions of MHC-unrestricted lymphocytes independently from haemopoiesis. It is unlikely that these cells play a role in the pathogenesis of AA.     

Serum levels of CD8 antigen and soluble interleukin 2 receptors in patients with B cell chronic lymphocytic leukemia

We assayed the plasma levels of CD8 antigen (CD8Ag) and soluble interleukin 2 receptor (sIL-2R) in 34 subjects with B cell chronic lymphocytic leukemia (B-CLL) and in 15 controls using an immunoenzymatic method. The results showed higher average levels of soluble CD8 (sCD8) and sIL-2R in the leukemic patients compared to the controls (sCD8 = 860 vs. 306 U/ml; sIL-2R = 4,131 vs. 311 U/ml). The two antigen levels were significantly higher in patients with progressive disease than in those with indolent disease, and they also correlated with Rai's stage. sIL-2R levels correlated with lymphocyte count (p less than 0.001), while there was no correlation between sCD8 levels and total number of lymphocytes. These results seem to show that the measurement of serum levels of CD8Ag and sIL-2R may be a useful tool in the prognostic evaluation of patients with B-CLL.     

B-cell chronic lymphocytic leukaemia cells express and release transforming growth factor-beta.

Transforming growth factor-beta (TGF-beta) has been described as a potent inhibitor of various cell types, among others of primitive haematopoietic progenitors in vitro, and as a negative autocrine regulator of normal B lymphocyte growth and differentiation. In the present study we investigated TGF-beta gene expression in peripheral blood mononuclear cells (PBMC) and in B cells from patients with B-cell chronic lymphocytic leukaemia (B-CLL) and from normal controls. Monocyte depleted B-CLL cells expressed constitutively mRNA for TGF-beta 1 and secreted low amounts of TGF-beta activity into the culture medium. Stimulation of cells by phorbol ester noticeably enhanced mRNA levels as well as protein secretion in most cases. TGF-beta activity was of the same magnitude as in normal controls. We next analysed TGF-beta in highly enriched B lymphocytes from B-CLL (95-100% CD19+), and found that TGF-beta secretion was up to 3 times higher than in the original PBMC population. It is discussed that B-CLL cells might escape from negative regulation by TGF-beta and, on the other hand, inhibit normal haematopoietic cell proliferation and thereby achieve a growth advantage in the haematopoietic tissues.     

Impaired regulation of natural killer cells in immunoglobulin synthesis by peripheral blood mononuclear cells from patients with ulcerative colitis

Immunoglobulin (Ig) synthesis, natural killer (NK) cell activity, and lymphokine production by peripheral blood mononuclear cells (PBMC) were studied in 34 patients with ulcerative colitis (UC). Levels of Ig produced by PBMC were significantly higher in patients with active UC as compared to controls. However, there were no significant differences in Ig-synthesis between patients with inactive UC and controls. NK cell activity was significantly decreased in patients with active UC as compared to controls, and a significant negative correlation was observed between the level of IgA and NK cell activity in patients with UC. Reconstitution experiments demonstrated that CD56+ cells from controls suppressed the levels of IgA, when added to the culture containing a constant number of B cells and CD4+ cells. In contrast, CD56+ cells from patients with active UC completely lacked the capacity to suppress IgA production. In addition, the activities of interleukin-2 and interferon-gamma were significantly decreased in patients with active UC. The present study suggests that immunoregulatory abnormality of NK cells exists in patients with UC and impaired NK cell activity may be related to increased Ig-synthesis observed in these patients.     

A low blood lymphocyte count is associated with an expansion of activated cytotoxic lymphocytes in patients with B-cell chronic lymphocytic leukaemia

Abstract: In order to determine the relationships between CD2+ lymphocyte subpopulations and tumour mass, the immunophenotype of natural killer (NK) cells and T lymphocyte subsets was studied in 56 B-chronic lymphocytic leukaemia (B-CLL) patients and 38 healthy subjects. The patients were classified according to their blood lymphocyte count (BLC). Forty patients had BLC<30×10⁹/l (low BLC, less tumour mass) and 16 patients had BLC>30×10⁹/l (high BLC, larger tumour mass). The percentage of CD3^– CD56+ cells, as well as of CD8+, CD8+CD45RO+ and CD3+CD57+ T subsets in low BLC patients, were higher than those found in high BLC patients. Conversely, the percentages of CD3+HLA DR+, CD4+ and CD4+CD45RO+ lymphocytes were higher in high BLC patients than in low BLC patients. The CD4/CD8 ratio was decreased in low BLC patients while it was increased in high BLC patients and a significant positive correlation was found between their CD4/CD8 ratio and their BLC. We conclude that in low BLC B-CLL patients there is a decreased percentage of activated helper lymphocytes and an increased percentage of NK cells and activated cytotoxic T lymphocytes. These results suggest a role for NK cells, and helper and cytotoxic T lymphocytes in the control of tumour burden in B-CLL patients.     

Intracellular IFN-gamma expression by CD3+/CD8+ cell subset in B-CLL patients correlates with stage of the disease

Changes in the cytokine network may be responsible for malignant cell accumulation in B-cell chronic lymphocytic leukaemia (B-CLL). Among different cytokines of question interferon gamma (IFN-gamma) is indicated to prevent malignant cells from entering apoptosis. The aim of the study was to determine IFN-gamma production capacity of T-cell subsets and B lymphocytes in B-CLL patients in comparison with healthy individuals and during disease progression. Forty patients with newly diagnosed, untreated B-CLL and 20 healthy individuals were studied. The two- and three-colour flow cytometry techniques were used to detect intracellular cytokine expression. We detected statistically significantly higher percentage of both CD3+/CD4+/IFN-gamma+ and CD3+/CD8+/IFN-gamma+ in patients than in controls (P < 0.001 in both cases). Moreover the percentage of CD3+/CD8+/IFN-gamma+ cells correlated with stage of the disease (R = 0.39, P = 0.01) and parameters of disease progression like lymphocyte count and total tumour mass score (R = 0.33, P = 0.03 and R = 0.31, P = 0.04, respectively). By contrast, the percentage of CD19+/IFN-gamma+ cells in B-CLL group was lower than in controls (P < 0.01). These findings indicate that T-cell populations rather than malignant B cells are the source of IFN-gamma in B-CLL patients. The subset of CD3+/CD8+ cells expressing IFN-gamma seems to play a special role in the disease progression and more precise investigation should elucidate its role as a prognostic marker in B-CLL and a target for therapeutic strategies.     

B-cell chronic lymphocytic leukaemia cells express and release transforming growth factor-β

Summary Transforming growth factor-β (TGF-β) has been described as a potent inhibitor of various cell types, among others of primitive haematopoietic progenitors in vitro, and as a negative autocrine regulator of normal B lymphocyte growth and differentiation. In the present study we investigated TGF-β gene expression in peripheral blood mononuclear cells (PBMC) and in B cells from patients with B-cell chronic lymphocytic leukaemia (B-CLL) and from normal controls. Monocyte depleted B-CLL cells expressed constitutively mRNA for TGF-β1 and secreted low amounts of TGF-β activity into the culture medium. Stimulation of cells by phorbol ester noticeably enhanced mRNA levels as well as protein secretion in most cases. TGF-β activity was of the same magnitude as in normal controls. We next analysed TGF-β in highly enriched B lymphocytes from B-CLL (95100% CD19+), and found that TGF-β secretion was up to 3 times higher than in the original PBMC population. It is discussed that B-CLL cells might escape from negative regulation by TGF-β and, on the other hand, inhibit normal haematopoietic cell proliferation and thereby achieve a growth advantage in the haematopoietic tissues.     

Natural killer (NK) cell activity and reversal reaction in leprosy

Two studies were conducted to assess natural killer (NK) cell activity in leprosy patients and healthy Ethiopian controls. The first study tested 26 untreated leprosy patients across the spectrum of the disease. It was found that lepromatous leprosy and all untreated, nonreactional patients had lower NK activity than healthy controls. However, patients presenting with reversal reaction (RR) had NK activity within the normal range. Heterogeneity was particularly marked in the NK activity of borderline patients. In the second study, NK cell activity was assessed in treated borderline tuberculoid leprosy (BT) patients. There were 30 patients with a history of RR and 27 BT patients without such a history (NR). All patients had had at least 3 years of dapsone treatment and 6 months of multidrug therapy. There were 26 control subjects. NK activity was higher in controls than in patients only at one effector:target (E:T) ratio tested, but NK cells from the BT patient group appeared to be more "aggressive" in that there was significantly (p less than 0.001) less reduction of activity with dilution of effector cells. There were no significant differences in NK activity between RR and NR patients. The NK activity of NR patients was positively correlated with the size of induration of the lepromin response. We conclude that higher NK activity in acute RR would appear to be a consequence rather than a cause of reversal reactions.     

Altered pattern of cytokine production by peripheral blood CD2+ cells from B chronic lymphocytic leukemia patients

To determine if activation-induced cytokine production is altered in CD2+ lymphocytes from B-CLL patients, cytokine levels were determined by ELISA in supernatants of PHA-stimulated cultures of CD2+ cells from 33 B-CLL patients and 22 healthy controls. The production of Interferon γ (IFN-γ) and Tumor Necrosis Factor (TNF-α) by mitogen-activated CD2+ lymphocytes from B-CLL patients was higher than that found in healthy controls, while no differences were found in TNF-β production. IFN-γ and TNF-α levels determined at 72 h in PHA-stimulated CD2+ cell cultures from B-CLL patients statistically correlated with the percentages of CD3+CD45RO+ and CD3−CD56+ lymphocytes, respectively. Although there were differences in the production kinetics of interleukins (ILs) 2 and 4 between B-CLL patients and the healthy controls, no differences were found at the time when the levels of both interleukins peak. The production of both IFN-γ and IL-4 by PHA-stimulated CD2+ lymphocytes from non-smouldering B-CLL patients was significantly higher than that from smouldering B-CLL patients while no significant differences were found in the production of IL-2, TNF-α, and TNF-β between the two B-CLL patient groups. These data suggest that functional alterations in the production of cytokines by CD2+ cells from B-CLL patients could help to explain the expansion of leukemic cells in B-CLL patients. Am. J. Hematol. 57:93–100, 1998. © 1998 Wiley-Liss, Inc.     

HBV感染者自然杀伤细胞活性分析

目的 探讨不同临床病期的慢性HBV感染者外周血单个核细胞(PBMC)中T淋巴细胞亚群及NK细胞活性变化.方法 收集慢性乙型肝炎、慢性重型乙型肝炎、乙型肝炎肝硬化、肝癌四组患者及健康人群的外周血,应用流式细胞术检测CD8+T细胞、CD4+T细胞及NK细胞的表达量和分泌细胞因子的能力,并检测NK细胞的杀伤活性.结果 各组患...     

Effect of recombinant gamma interferon on natural killer cell activity in patients with gastric cancer

We investigated the effect of recombinant interferon-gamma (rIFN-gamma) in vitro on natural killer (NK) cell activity of peripheral blood lymphocytes (PBL) in patients with gastric cancer. Thirty untreated patients with gastric cancer and eleven healthy donors were studied. NK cell activity in healthy donors was 38.6 +/- 5.2%. In patients with gastric cancer, NK cell activity was 32.4 +/- 3.9% in stage I, 35.5 +/- 7.1% in stages II and III, and 22.4 +/- 3.9% in stage IV. NK cell activity in stage IV patients was significantly lower than in healthy controls or gastric cancer patients in stages I-III. After stimulation by rIFN-gamma, NK cell activity increased in all groups, and in stage IV patients NK cell activity recovered to normal levels. However, there was no significant increase in the proportion of Leu 7 positive or Leu 11 positive cells in PBL. In conclusion rIFN-gamma enhances the activity of NK cells, but does not increase the number of active NK cells.     

The effects of splenic irradiation on lymphocyte subpopulations in chronic B-lymphocytic leukemia

We describe the effect of splenic irradiation (SI) (0.5-1 Gy weekly) on lymphocyte subpopulations for 7 patients with progressive B chronic B-lymphocytic leukemia (B-CLL). Using specific cellular characteristics we could distinguish normal from abnormal cells. The irradiation resulted in a decrease of lymph node size, reduction in spleen volume and decrease in peripheral blood lymphocytes. The one exception was a patient with a prolymphocytoid transformation of B-CLL. For 3 patients SI had to be interrupted or stopped because of severe cytopenia. Quantitation of malignant B cells and normal T lymphocytes revealed that the total irradiation dose which resulted in a specific decrease of malignant lymphocytes varied from patient to patient. Normal T-cell subpopulations, which were increased before SI, decreased to normal or abnormally low values during SI. In previously untreated patients, natural killer (NK) cell numbers decreased more rapidly than T-cell subpopulations. For 2 patients refractory to chemotherapy an increase of NK cells was observed upon SI.