T-cell chronic lymphocytic leukemia. T-cell function and lymphokine secretion.

The leukemic T-cells of the six patients with T-cell chronic lymphocytic leukemia (T-CLL), four with CD4 and CD45R-positive (CD4+ CD45R*) T-CLL and two with CD8 and CD45R-positive (CD8+ CD45R+) T-CLL phenotype were studied for detailed immunologic phenotypic and functional characteristics. The levels of soluble interleukin-2 receptors were elevated significantly in the serum of all four patients with CD4+ CD45R+ T-CLL. Moreover, the CD4+ CD45R+ T-CLL patients' T-cells, after in vitro stimulation with phytohemagglutinin and concanavalin A, expressed elevated percentages of interleukin-2 receptors on cells and secreted high interleukin-2 activity. The B-cell growth factor (BCGF) activity from three patients with CD4+ CD45R+ T-CLL was enhanced, but B-cell differentiation factor (BCDF) activity of the all T-CLL patients was decreased. Reduced BCGF and BCDF activity of the leukemic T-cells was one possible mechanism of hypogammaglobulinemia detected in two patients with T-CLL. All T-CLL patients' leukemic T-cells had diminished immunoregulatory functional activity in allogeneic mixed lymphocyte reactions. These observations suggest that leukemic T-cells from T-CLL patients have many immunologic functional defects that may be important in their proliferative potential.     

Phenotypic and functional characterization of HTLV positive neoplastic T cells cultured with interleukin-2--II. Inhibition of lymphoproliferative responses

T cells from the peripheral blood of a T-cell chronic lymphocytic leukemia (T-CLL) patients, were expanded by culture in the presence of interleukin-2 (IL-2). In contrast to the original leukemic T cells that showed a complete lack of suppressor activity, the proliferating T-CLL cells were extremely potent inhibitors of mitogen, antigen and alloantigen induced lymphoproliferative responses. Compared to the fresh T-CLL cells, the proliferating T-CLL cells showed an enhanced expression of the human T-cell leukemia/lymphoma virus (HTLV) p19 antigen and released type C virus particles into their culture supernatant. A direct involvement of the virus particles in the suppression was however unlikely, since the inhibition was found to be mediated by a soluble inhibitor in the culture supernatant of proliferating T-CLL cells. This inhibitor was very hydrophobic and was inactivated by treatment with trypsin, by heating to 56 degrees C for 2 h and by storage at -70 degrees C for more than 14 weeks. It could be excluded that the suppression of lymphoproliferation was due to competition for IL-2, to toxic effects, to nutrient depletion or to a shift in the kinetics of the target cell responses. Furthermore, it could not be attributed to suppressor inducer activity of the OKT4+ proliferating T-CLL cells, since normal T cells enriched for OKT4+ T cells and depleted for OKT8+ T cells were also inhibited in their proliferation. Since other hemopoietic cell lines, not of OKT4+ T lymphocyte origin, also were suppressed to proliferate, it is concluded that the proliferating T-CLL cells represent a neoplastic T-cell clone that had differentiated into suppressor effector T cells after prolonged culture in the presence of IL-2.     

Phenotypic and functional characterization of HTLV positive neoplastic T cells cultured with interleukin-2--I. Retention of morphology, phenotype and selective cytotoxic properties in long term culture

T cells from the peripheral blood of a T-cell chronic lymphocytic leukemia (T-CLL) patient, cultured in the presence of interleukin-2 (IL-2), were found to express the p19 structural core protein of the human T-cell leukemia/lymphoma virus (HTLV) and to release type C virus particles. Comparison of the T-CLL cell line with the original leukemic T cells revealed that both the fresh and the proliferating T-CLL cells were pleomorphic cells that showed a convoluted nucleus and formed rosettes with sheep erythrocytes (E-rosettes). They were reactive with the monoclonal antibodies OKT1, OKT4 and OKT11, but not with OKT3, OKT6 or OKT8, indicating that they were mature T cells but that they differed from normal T cells in their lack of reactivity with OKT3. In addition they did not bind peanut agglutinin or OKM-1, and were negative for Epstein-Barr nuclear antigen, surface immunoglobulin, non-specific esterase activity of Fc- or complement receptors. Part of the fresh T-CLL cells reacted with a monoclonal antibody recognizing HLA-DR antigens (p29, 34) (36%) and with anti-Tac (62%), a monoclonal antibody directed at the IL-2 receptor, indicating that the T-CLL cells were partially activated already in vivo. After culture in vitro all proliferating T-CLL cells expressed HLA-DR and Tac antigens. The fresh T-CLL cells were found to be defective in cell-mediated lympholysis (CML) generated in mixed lymphocyte culture (MLC), antibody-dependent cellular cytotoxicity (ADCC) and lectin-dependent cellular cytotoxicity (LDCC). In addition they failed to exhibit natural killer (NK) cell activity against targets that are usually very susceptible to lysis, such as K562, but were able to kill two tumor-derived cell lines, the melanoma NKI-4 and the neuroblastoma CHP-100. The same pattern of selective killing was observed using the proliferating T-CLL cells as effectors, or cloned T-CLL cultures obtained from them by limiting dilution procedures. Therefore, it was concluded that the T-CLL cells represented a clonal expansion of neoplastic T cells that retained their phenotype and cytotoxic properties after culture in vitro.     

Subtyping of chronic lymphocytic leukemia of T-type by dipeptidylaminopeptidase IV (DAP IV), monoclonal antibodies, and Fc-receptors

The authors have recently provided evidence for a restricted occurrence of the enzyme dipeptidylaminopeptidase IV (DAP IV) in normal human Tmu lymphocytes as far as blood and bone marrow cells are concerned. In this report, this issue has been extended to cases of chronic lymphocytic leukemia (CLL) along with T-monoclonal antibodies of OKT series (OKT4, OKT8) and Fc receptors for IgM (Tmu) and IgG (Tgamma). Seven of eight cases of T-CLL were DAP IV-positive, whereas all B-CLL cases like normal B-cells were invariably enzyme-negative. Parallel studies with OKT antibodies and Fc receptors showed that the cases positive to DAP IV also revealed OKT4 reactivity and, to some extent, Fc IgM receptor. In a single DAP IV-negative T-CLL with azurophilic granules, the leukemic cells were shown to be reactive for OKT8 and bore Fc IgG receptor. It was inferred that DAP IV represents a reliable marker for T-CLL derived from the OKT4 and Tmu positive subsets of T-lymphocytes, which encompasses the T-helper cell cohort.     

Cytotoxicity and clinical application of activated NK cells

We have shown that the patients with myelogenous leukemia display several defects in the NK cell lytic mechanism. However, this cytotoxic defect could be corrected after culture of effector cells from these patients with IL-2. The cytotoxic potential of IL-2-activated killer cells could be further augmented by treatment with OKT3 monoclonal antibody. Interleukin-2-activated lymphocytes were effective in killing not only a variety of tumor cell lines, but also autologous leukemic cells. Moreover, these cells were not stationary, but proliferated actively in culture with IL-2. Characterization studies, using the monoclonal antibodies against NK cell (CD16 and NKH1/Leu-19) or T-cell (CD3 and CD5) surface molecules showed that the antileukemia-directed cytotoxic cells were NK cells and not T-cells. In contrast, the T-cells (and not NK cells) exhibited an ability to down-regulate clonogenic activity of hematopoietic progenitors and to inhibit proliferation of bone marrow cells. Our data suggest that adoptive therapy with highly-enriched IL-2-activated NK cells may result in more powerful anti-leukemia effect. Alternatively, activated NK cells may be effective in eradication of leukemic cells from bone marrow for autologous bone marrow transplantation purposes.     

OKM1-positive T-cell leukemias. Relationships among morphologic features, phenotype, and functional activities

The morphologic features, phenotype, and functions of OKM1+ leukemic T-cells were studied. The leukemic T-cells in two patients with chronic lymphocytic leukemia (CLL) had specific features of large granular lymphocytes (LGL), and those in two patients with acute lymphocytic leukemia (ALL) had L2 morphologic characteristics. The phenotype of the leukemic cells from one patient with CLL was OKM1+, ER+, OKT3+, OKT4+, OKT8-, OKIa1-, IgGFc receptor (EA gamma)+, Leu-7+, Leu-11b+, and anti-Tac-. The cells had antibody-dependent cell-mediated cytotoxicity (ADCC), but no natural killer (NK) activity. They had a definitive helper effect on pokeweed mitogen-induced normal B-cell differentiation. The leukemic cells from the other patient with CLL were Leu-7-, and Leu-11b-, and lacked both ADCC and NK activity. The leukemic cells in the two patients with ALL were ER+, OKM1+, Leu-7-, and Leu-11-, and did not have any cytotoxicity. One was EA gamma +, and the other was EA gamma -. These findings suggest that OKM1+ leukemic T-cells consist of at least two subgroups: (1) T-cells with the morphologic features of LGL; and (2) those with a lymphoblastic morphologic type. In either case, the phenotype is novel and suggests the emergence of a small, distinct lymphocyte subset.     

Hemophagocytic syndrome associated with CD8 positive T-cell chronic lymphocytic leukemia

We describe a case of hemophagocytic syndrome (HPS) associated with CD8-positive T-cell chronic lymphocytic leukemia (CD8 + T-CLL). A 68-year-old man with CD8 + T-CLL presented with fever, progressive pancytopenia, and lymphadenopathy. Laboratory findings showed a hyper-ferritinemia, abnormalities of coagulation tests, and liver and renal dysfunction with hypoproteinemia. He did not respond to any treatments and died of respiratory failure 10 days after the admission and 14 months after the onset of CD8 + T-CLL. Pathological findings of the autopsy demonstrated infiltration of CD8 + T-CLL cells in multiple organs along with the increase of histiocytes with prominent hemophagocytosis. Serum concentration levels of IL-6, soluble IL-2 receptor and VEGF were all elevated at admission. These findings revealed that he had a secondary HPS. It was suggested that HPS should be considered in patients with an unexplained cytopenia and a fever during the clinical course of CD8 + T-CLL.     

Poorly expressed CD2 antigen on the leukemic cells of adult T-cell leukemia and chronic lymphocytic leukemia of T-cell lineage

Adult T-cell leukemia (ATL) and T-cell chronic lymphocytic leukemia (T-CLL) are hematologic neoplasms in differentiated stages of peripheral mature T cells. This is suggested by the presence of CD2 (E rosette receptor) and mature and/or pan-T cell membrane surface antigens on their leukemic cells. We recently encountered one patient with ATL and another with T-CLL; their leukemic cells poorly expressed CD2 antigens, but clinical presentation, morphology of the leukemic cells and other marker studies were characteristic of either ATL or CLL. The clinical significance of the poor expression of CD2 remains to be further studied. The two patients reported here died of severe complications 4 and 9 weeks after diagnosis. The poor expression of CD2 in the peripheral T cells in these neoplasms is likely to indicate an aggressive nature of the disease.     

Circulating cerebriform lymphoid cells (Sezary-type cells) in a B-cell malignant lymphoma

Circulating cerebriform lymphoid cells (Sezary cells) are considered to be highly predictive of cutaneous T-cell Lymphoma (CTCL). A leukemic peripheral blood (leukocyte count 24.5 x 10(9)/l) composed predominantly of cerebriform cells was found in a 75-year-old man presenting with weight loss and generalized lymphadenopathy but without skin lesions. Cell suspensions studies and immunohistochemistry of peripheral blood revealed that the cerebriform cells were B-cells (IgM+ Kappa+, HLA DR+, Leu 1+, CALLA-, B1+, and OKT 10+). A variety of T-cell markers (other than Leu1) was negative. Computer-assisted morphometry confirmed a nuclear profile typical of CTCL (mean nuclear contour index, 7.47). A lymph node that underwent subsequent biopsy revealed a follicular malignant lymphoma of small to intermediate cells with similar morphologic and immunologic characteristics to the circulating cerebriform cells. The findings of a leukemic presentation of a cerebriform B-cell lymphoma extends the recent observation of nodal B-cell lymphomas composed of cerebriform cells and indicates that circulating cerebriform cells should not be considered to be exclusively of T-cell origin.     

Reduced numbers of IL-7 receptor (CD127) expressing immune cells and IL-7-signaling defects in peripheral blood from patients with breast cancer

Interleukin-7-receptor-signaling plays a pivotal role in T-cell development and maintenance of T-cell memory. We studied IL-7Ralpha (CD127) expression in PBMCs obtained from patients with breast cancer and examined IL-7 receptor-mediated downstream effects defined by STAT5 phosphorylation (p-STAT5). Reduced numbers of IL-7Ralpha-positive cells were identified in CD4+ T-cells as well as in a CD8+ T-cell subset defined by CD8alpha/alpha homodimer expression in patients with breast cancer. PBMCs obtained from healthy donors (n = 19) and from patients with breast cancer (n = 19) exhibited constitutive p-STAT5 expression in the range of 0-6.4% in CD4+ T-cells and 0-4% in CD8+ T-cells. Stimulation with recombinant human IL-7 for 15 min increased p-STAT5 expression up to 36-97% in CD4+T-cells and to 26-90% in CD8+T-cells obtained from healthy control donors (n = 19). In contrast, PBMCs obtained from 13/19 patients with breast cancer did not respond to IL-7 as defined by STAT5 phosphorylation, despite expression of IL-7Ralpha on T-lymphocytes. T-cells were further characterized for IL- 2 and IFN-gamma production induced by PMA/Ionomycin. PBMCs from 9/19 patients with breast cancer showed decreased IL-2 and IFN-gamma production combined with IL-7-signaling defects; PBMCs from 4 patients with breast cancer exhibited deficient IL-7-signaling, yet intact cytokine production. Reduced numbers of IL-7Ralpha-positive cells and nonresponsiveness to IL-7, defined by lack of STAT5 phosphorylation, characterizes the immunological profile in T-cells from patients with breast cancer.     

Effect of anti-CD3 antibody on the generation of interleukin-2-activated lymphocytes from tumor tissues of gastrointestinal cancer.

BACKGROUND. The efficiency of anti-CD3 antibody (OKT3) for adoptive immunotherapy using lymphokine-activated killer (LAK) cells generated from tumor-infiltrating lymphocytes (TIL), regional lymph node lymphocytes (RLNL), and peripheral blood lymphocytes (PBL) was investigated. METHODS. TIL, RLNL, and PBL derived from 39 patients with gastrointestinal cancers (16 gastric cancers, 17 colorectal cancers, and 6 esophageal cancers) were cultured for 4 weeks with 200 U/ml of recombinant interleukin-2. To one group, solid-phase 10 micrograms/ml OKT3 was added during the initial culture period (day 2 or 4). Cytotoxicity against K562 cells (NK-like activity) and Daudi cells (LAK activity) and the phenotypes of effector cells generated after culturing for 2-3 weeks were studied. RESULTS. Proliferative responses were significantly increased by OKT3 in each type of effector cell (P less than 0.01); in particular, TIL expanded more by OKT3 than PBL and RLNL (P less than 0.01). The population of CD8+ CD11b- cytotoxic T-cells in OKT3-stimulated groups was significantly larger than that in unstimulated groups (P less than 0.01), whereas no differences were observed with CD4+ cells (helper/inducer T-cells) and CD8+ CD11b+ cells (suppressor T-cells). OKT3 enhanced the NK-like activity of TIL and PBL but did not affect their LAK activity. OKT3 suppressed the NK and LAK activity of RLNL. CONCLUSIONS. OKT3 stimulation did not significantly enhance the LAK activity, but the authors propose that OKT3 could be an effective addition to adoptive immunotherapy using TIL due to an increased proliferation and generation of a large cytotoxic T-cell population.     

Chronic T-cell leukaemias. III. T-colonies, PHA response and correlation with membrane phenotype

The functional capacity of T lymphocytes from 28 cases of chronic T-cell leukaemia — T-CLL, T-PLL, T-LCL and Sézary syndrome — was evaluated in a T-colony forming system and in a PHA response assay. Reduced or absent T-colony growth was observed in 23 cases (82%) while in five the growth was normal. Although a good correlation was generally observed between colony formation and PHA transformation, in a few cases a low PHA response was accompanied by moderate colony growth and vice versa. Characterization of the leukaemic T lymphocytes using monoclonal antibodies (OKT series) indicates that cases with a helper/inducer phenotype (OKT4+) showed moderately reduced or near-normal T-colony numbers, whilst cases with a suppressor/cytotoxic phenotype (OKT8+) — confined to T-CLL in this study — had a very low or absent colony growth. The functional abnormalities reported here suggest that neoplastic T-cells with a helper/inducer phenotype show a low proliferative response in the assay systems used, although expressing mature T-cell characteristics. The low growth observed in T-CLL confirms that cells with a suppressor/cytotoxic phenotype form few T-cell colonies.     

Functional T-cell anergy in a case of persistent polyclonal B-cell lymphocytosis

The T-cell population of a patient with persistent polyclonal B-cell lymphocytosis (PPBL) presenting with an intermittent Epstein-Barr virus (EBV)-associated disease was studied. Unstimulated T-cells did not express CD40 ligand (CD40L), whereas activation with IL-2 led to expression of this costimulatory molecule. CD40L expression was inhibited upon incubation with the supernatant of an EBV-positive B-cell line (SM) which had been grown spontaneously from the patient's peripheral blood cells. The supernatant of SM cells effectively inhibited cytotoxic T-cells. Elevated levels of IL-10, TNF-alpha and soluble CD40 were found in the supernatant of SM cells. Additionally, enhanced levels of LMP-1 protein were detected.     

Dysfunctional BLK in common variable immunodeficiency perturbs B-cell proliferation and ability to elicit antigen-specific CD4+ T-cell help

Common Variable Immunodeficiency (CVID) is the most prevalent primary antibody deficiency, and characterized by defective generation of high-affinity antibodies. Patients have therefore increased risk to recurrent infections of the respiratory and intestinal tract. Development of high-affinity antigen-specific antibodies involves two key actions of B-cell receptors (BCR): transmembrane signaling through BCR-complexes to induce B-cell differentiation and proliferation, and BCR-mediated antigen internalization for class-II MHC-mediated presentation to acquire antigen-specific CD4⁺ T-cell help.We identified a variant (L3P) in the B-lymphoid tyrosine kinase (BLK) gene of 2 related CVID-patients, which was absent in healthy relatives. BLK belongs to the Src-kinases family and involved in BCR-signaling. Here, we sought to clarify BLK function in healthy human B-cells and its association to CVID.BLK expression was comparable in patient and healthy B-cells. Functional analysis of L3P-BLK showed reduced BCR crosslinking-induced Syk phosphorylation and proliferation, in both primary B-cells and B-LCLs. B-cells expressing L3P-BLK showed accelerated destruction of BCR-internalized antigen and reduced ability to elicit CD40L-expression on antigen-specific CD4⁺ T-cells.In conclusion, we found a novel BLK gene variant in CVID-patients that causes suppressed B-cell proliferation and reduced ability of B-cells to elicit antigen-specific CD4⁺ T-cell responses. Both these mechanisms may contribute to hypogammaglobulinemia in CVID-patients.     

Characterization of two patients with lymphomas of large granular lymphocytes

Two patients with non cutaneous well-differentiated lymphocytic lymphoma with leukemic spread are reported. The large majority of their peripheral blood mononuclear cells (PBMC) formed rosettes with sheep erythrocytes, had receptors for the Fc portion of IgG, and an enzymatic profile of relatively mature T-cells. These cells were morphologically characterized as large granular lymphocytes. Studies with monoclonal antibodies in one of the cases showed an OKT3+, OKT10-, OKT4-, OKT8-, HNK-1-, OKM1+ phenotype, whereas PBMC from the other case were OKT3+, OKT10-, OKT4-, OKT8+, HNK-1+, OKM1-. PBMC from the first patient were able to suppress in vitro B-cell differentiation and were capable of a strong antibody dependent cellular cytotoxicity (ADCC) activity. Natural killer (NK) activity was reduced. Cells from the other patient who was hypogammaglobulinemic, exerted suppressor activity in immunoregulatory assays, and showed ADCC and NK activity. These data support the existence of LGL lymphomas consisting of the proliferation of mature appearing cells capable of functional activity.     

T-lymphocyte subpopulations in B-cell-derived non-Hodgkin's lymphomas and Hodgkin's disease

The authors used E-rosette formation and OKT3 reactivity to determine the percent of T-cells in lymph nodes involved by B-cell non-Hodgkin's lymphomas (B-NHL) and by Hodgkin's disease (HD). The percent of helper and suppressor/cytotoxic T-cells was determined by reactivity with OKT4 and OKT8, respectively. T-cells were also analyzed for two signs of activation: acquisition of Ia antigens and loss of acid a-naphthyl acetate esterase (ANAE) activity. The results were compared with those of lymph nodes exhibiting benign lymphoid hyperplasia (BLH). The percentage of T-cells ranged from 50% to 82%, mean 63 +/- 13%, in 25 cases of BLH, and from 6% to 62%, mean 23 +/- 11%, in 51 cases of B-NHL. The OKT4/T8 ratio was 1.0 to 6.2, mean 3.4 +/- 2.2, in the cases of BLH, and 0.5 to 5.1, mean 2.4 +/- 1.3, in the cases of B-NHL. There was no obvious or significant correlation between the percent of T-cells or the OKT4/T8 ratio and the surface immunoglobulin isotype expressed by the neoplastic B-cells, the morphologic category of B-NHL, or the clinical stage of disease. Activated T-cells were less than or equal to 3% in the cases of BLH and B-NHL. Fifteen lymph nodes involved by HD contained 44% to 96%, mean 74%, E+ (T) cells. Five of these 15 cases contained a significant number of E-OKT3+ cells suggesting that E-rosette formation is not always a reliable T-cell marker in HD. Three other cases contained a large number of E+OKT3- cells. The OKT4/T8 ratio ranged from 0.4 to 21.7, mean 6.7 +/- 5.3, in these cases, representing the most significant T-cell subset imbalances in this series. Large numbers of Ia+E+ and/or E+ANAE- cells, presumably activated T-cells, were present in 7 of these 15 cases of HD. These studies demonstrate the wide variation in the percent of T-cells and in the T-cell subset distribution in lymph nodes exhibiting benign lymphoid hyperplasia and in lymph nodes involved by B-cell-derived non-Hodgkin's lymphomas and Hodgkin's disease.     

Down-regulation of IL-18 receptor in cancer patients: its clinical significance

Interleukin-18 (IL-18) is a powerful inducer of interferon-gamma (IFN-gamma), a key immunoregulatory cytokine. Cellular immune responsiveness, as measured by IL-18-induced IFN-gamma production from peripheral blood mononuclear cells (PBMCs) in ELISA assay, was evaluated in 10 patients with advanced cancer and in 10 normal controls. Supernatant levels of IFN-gamma were detected at 2 hours after PBMCs culture and markedly increased thereafter in healthy volunteers. In contrast, IFN-gamma production in cancer patients was not detected during the culture period (0-72 hours). We also measured IL-18-stimulated IL-12 production in healthy volunteers and null response was observed in cancer-bearing patients. Next, we studied mRNA expressions of IL-18 receptor (IL-18R) and IFN-gamma in PBMCs in cancer patients and healthy volunteers by RT-PCR assay. Both mRNA levels of IL-18R and IFN-gamma were significantly decreased in cancer-bearing patients compared with normal controls. These results suggested that IL-18 responsiveness for IFN-gamma production in cancer-bearing patients was impaired. Using flow cytometric analysis, we studied T-cell subsets, CD3- CD56+ (NK cell), CD3+ CD45RO+ (memory T-cell), CD3+ CD95+ (Fas+ T-cell), CD3+ CD4+ (helper T-cell), CD3+ CD8+ (cytotoxic T-cell: CTL) and CD3+ V alpha24+ (NKT-cell), in cancer patients and normal controls. The NK and cytotoxic T-cells significantly decreased and NKT-cells had decreased tendency in cancer patients compared with normal controls. In contrast, memory T cells, Fas+ T-cells and helper T-cells were all significantly increased in cancer patients compared with normal controls. These results suggested that the underlying mechanism of impaired IL-18 responsiveness in PBMCs from cancer-bearing patients was, at least in part, ascribed to a drastic decrease of NK cells and CTL which constitutively and highly express IL-18R and also attributed to null production of IL-12 which up-regulates IL-18R.     

Immunoregulatory effects of PSK on the Th1/Th2 balance and regulatory T-cells in patients with colorectal cancer

It is very important for immunotherapy to release Th2-dominated and Treg-dominated immunological conditions in patients with malignant diseases. In the present study, we assessed the population of CD4+IL-10+T-cells and CD4+Foxp3+T-cells in peripheral blood in patients with colorectal cancer using a flow cytometric analysis, and we investigated whether Th2-dominated and Treg-dominated condition could be modulated by PSK. Peripheral blood samples were collected preoperatively from 40 patients with colorectal cancer before and after oral administration of PSK (3 g/day × 1 week). After PSK treatment, CD4+IL-10+T-cell percentages decreased in 63% of patients and CD4+Foxp3+T-cells percentages decreased in 63% of patients. However, no correlation was found between the ratio of CD4+IL-10+T-cell percentages and that of CD4+Foxp3+T-cell percentages after/before PSK treatment. These results suggest that PSK could release Th2-dominated and Treg-dominated immunological condition in patients with colorectal cancer. Further examinations are needed to investigate the after/before percentage ratio of CD4+Foxp3+T-cells can be useful predicting parameters for the selection of responders of PSK.