Detection of impaired mitogen responses in autologous whole blood of cancer patients using an optimized method of lymphocyte stimulation

Assessment of cellular response to mitogens in long-term allogeneic hematopoietic stem cell transplantation survivors

Infection is one of the major causes of death in hematopoietic stem cell transplantation (HSCT) survivors. Precise assessments of immune function after HSCT will be critical in establishing appropriate treatment and prophylaxis, such as re-vaccination. Although several surrogate markers for prediction of clinical outcomes after HSCT have been proposed, definitive markers of immune reconstitution and data on those markers in long-term survivors are lacking. In this study, cellular response to mitogens was assessed and clinical features associated with a poor response to mitogens were investigated in long-term allogeneic HSCT survivors. Age at transplantation and age at the time of mitogen stimulation test were each identified as significant risk factors for poor response to phytohemagglutinin and concanavalin A, respectively (P < 0.001 each). However, time elapsed since transplantation was not found to be correlated with responsiveness to mitogens in this study. Prospective, in-depth studies on immune reconstitution are needed to establish appropriate prophylaxis against infections after HSCT and a schedule for re-vaccination.

Functional Evaluation of Proliferative T Cell Responses in Patients with Severe T Lymphopenia: Characterization of Optimal Culture Conditions and Standardized Activation Signals for a Simple Whole Blood Assay

In this methodological study, we describe an assay for analysis of proliferative T cell responses in patients with severe leukopenia. Severe treatment-induced cytopenia is observed in patients with malignant disorders who receive conventional intensive chemotherapy or autologous stem cell transplantation. The quantitative T cell defect can then be characterized by flow cytometric analysis of membrane molecule expression, whereas the functional status of the remaining T cell population is more difficult to evaluate. In the present study, we describe a standardized whole blood assay that requires small sample volumes and can be used for repeated analysis even in severely ill patients. The assay is based on the following strategy: (i) blood samples are diluted with the serum-free medium X-vivo 10, (ii) T cells are activated either with monoclonal immunoglobulin E (IgE) anti-CD3 or anti-CD3 plus anti-CD28; (iii) T cell proliferation is assayed by [(3)H]thymidine incorporation after 4 days of in vitro culture. These proliferative responses are not affected by the plasma levels of interleukin-2 (IL-2), sIL-2-R alpha, IL-7 and IL-15, and the kinetics of the response are not altered by the presence of exogenous cytokines. Detectable proliferation is observed for most patients with treatment-induced cytopenia. We conclude that the assay can be used for functional characterization of remaining T lymphocytes in patients with severe T lymphopenia.

Detection of intracellular interleukin-2 production in peripheral T lymphocytes by flow cytometry in patients with pancreatobiliary malignancies

BACKGROUND AND AIMS

To date, it has been reported that cellular immunity is decreased in patients with cancer and investigations into cytokine production has been insufficient. Therefore, we examined intracellular cytokine production by using flow cytometry in patients with cancer and discussed the reasons for the impairment of their immune system.

METHODS

Eleven patients with hepatobiliary malignancies (68.5+/-11.8 years of age), eight age-matched controls (70.0+/-12.0 years of age) and 10 young volunteers (31.9+/-3.1 years of age) were used in the present study. Stimulated peripheral blood mononuclear cells from these patients were stained with fluorescence-labeled anticytokine monoclonal antibodies and analyzed with a Fluorescence activated cell sorter (FAC)Scan.

RESULTS

The percentage of positively stained T cells was calculated and compared with controls. Repeated measured ANOVA was used for statistical analysis. Interleukin (IL)-2 production was significantly decreased in patients with cancer compared to controls (P=0.0122), and it may suggest decreased cellular immune activity of the patients. Simultaneously, spontaneous intracellular IL-4 production was observed in patients and age-matched controls, but levels were significantly increased when compared with the young volunteers (P=0.0052, P=0.031, respectively).

CONCLUSIONS

It was of interest that spontaneous intracellular IL-4 production was detected in elderly subjects.

Immunosuppressive activity of sera from patients with colorectal and gynecological carcinomas as evaluated by impaired IFN-gamma, IL-1 alpha and TNF-alpha production of human peripheral mononuclear cells

The sera from patients with preoperative colorectal and gynecological carcinomas (ovarian and breast cancer) were investigated for their putative immunosuppressive activity (ISA). ISA was measured by determining the changes in the production of IFN-gamma, IL-1 alpha and TNF-alpha by human peripheral mononuclear cells (PBMC) from six normal donors. Phytohemagglutinin-stimulated PBMC were incubated with sera from patients with colorectal and gynecological carcinomas and healthy controls and in the 4-day post-inductional supernatants the cytokines were measured by an enzymoimmunological assay (ELISA). Sera from patients with carcinomas significantly decreased the IFN-gamma production as compared to the controls. In the cultures containing sera from patients with colorectal and ovarian but not breast carcinoma, significantly lower levels of IL-1 alpha and TNF-alpha were measured compared to the cultures with sera from healthy controls.

Whole blood culture for measuring mitogen induced T cell proliferation provides superior correlations with disease state and T cell phenotype in asymptomatic HIV-infected subjects

Proliferative responses to a panel of mitogens were compared in parallel for two sources of cells, whole blood (WB) and conventionally prepared peripheral blood mononuclear cells (PBMC), obtained from asymptomatic HIV seropositive and control subjects. Weak but statistically significant correlations of the proliferative responses were observed. Use of either lymphocyte source produced significant differences in the proliferative responses between the HIV seropositive and control subjects, but the use of WB was more powerful, with a smaller sample size being required to discriminate between the proliferative responses of the two study groups. Furthermore, proliferative responses using WB gave strong and highly significant correlations with a number of important changes in the surface marker phenotype of the lymphocyte populations in the HIV seropositive subjects including CD4, CD8, CD4:CD8 ratio and certain CD8 subsets, whereas strong correlations were not observed with the PBMC. The response of WB lymphocytes to staphylococcal enterotoxin B (SEB) was highly reproducible and provided the best discrimination between HIV-infected and control subjects. We conclude that the use of WB for measuring lymphoproliferation is easy, rapid, accurate, and discriminative for assessing and following the changes in immune function which occur in HIV seropositive subjects, applicable in the clinical as well as in the research setting.

Impaired cytokine production in whole blood cell cultures of patients with gynaecological carcinomas in different clinical stages

The production of the cytokines IFN-gamma, IL-1-alpha, IL-2 and TNF-alpha was investigated in mitogen-stimulated, whole blood cell culture from 239 untreated patients with primary gynaecological carcinomas (breast, cervix, ovary, endometrium), and 191 healthy female controls. The cytokines were measured in the 4-day post-induction supernatants by a sensitive enzymoimmunological assay. In the blood cell cultures of all four groups of cancer patients, significantly lower values of IFN-gamma (P < or = 0.001), IL-2 (P < or = 0.01) and IL-1 alpha (P < or = 0.01) were found as compared to the controls, although lymphocyte and monocyte counts were almost identical. Grouping the tumour patients into different clinical stages we could show in the four groups of carcinomas a gradual depression of the cytokine production according to growing tumour burden.

Impaired cytokine production in whole blood cell cultures of patients with urological carcinomas

The production of the cytokines interferon gamma (IFN gamma), interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha) was investigated in the mitogen-stimulated whole blood cell culture media from 51 patients with urinary bladder carcinomas, 52 patients with renal carcinomas, 31 patients with prostatic carcinomas and 360 healthy controls. The cytokines were measured 4 days after induction by a sensitive enzymo-immunological assay. In the blood cell culture supernatants of the patients with urinary bladder carcinomas significant lower levels of IFN gamma (P < or = 0.001), IL-2 (P < or = 0.01) and TNF alpha (P < or = 0.05) were found as compared to the controls. Blood cells of patients with renal carcinomas had lower production of IFN gamma (P < or = 0.01), IL-2 (P < or = 0.001) and IL-1 alpha (P < or = 0.01), whereas the values of the total group of patients with prostatic carcinomas were not significantly different from those of the controls. Lymphocyte and monocyte counts were almost identical in the control and all tumor patient groups. When the patients with renal carcinomas and prostatic carcinomas were analyzed according to their different clinical stages we could show a gradual depression of the IFN-gamma levels, which was related to tumor burden.

Impaired cytokine production in whole blood cell cultures from patients with colorectal carcinomas as compared to benign colorectal tumors and controls

Cytokine production was investigated in whole blood cell cultures from 74 patients with colorectal carcinomas, 20 patients with benign colorectal tumors, and 314 healthy controls. In the 4 day post induction supernatants the levels of IFN-gamma, IL-1-alpha, IL-2, and TNF-alpha were measured by a sensitive immunoassay. In the blood cell cultures of the patients with colorectal carcinomas significantly lower values of IFN-gamma (P less than or equal to .001), IL-1-alpha (P less than or equal to .001), and IL-2 (P less than or equal to .01) were found as compared to the patients with benign tumors and the controls, although total and differential leukocyte counts were similar in all three groups. A linear correlation between the levels of IFN-gamma and IL-1-alpha and the tumor stages could be shown. Our results suggest that a growing tumor burden may induce increasing immunological deficiencies as reflected by a decreasing cytokine production of the immune cells.

Evaluation of a test system for measuring cytokine production in human whole blood cell cultures

A simple and reproducible method is described for the measurement of mitogen-induced cytokine production in cultures of both human peripheral blood mononuclear cells (PBMC) and whole blood. In the culture supernatants the cytokines interleukin-1 alpha (IL-1 alpha), interleukin-2 (IL-2), interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) were determined by a rapid and sensitive immunoassay using various monoclonal and polyclonal antibodies. Comparing the PBMC cultures with the whole blood system a good correlation was obtained if the cell number was taken into account. In the post-induction supernatants the cytokine values were found to follow typical kinetic curves. The protocol was evaluated by screening 60 cancer patients with primary disease and 60 healthy controls. A markedly reduced secretion of IFN-gamma and IL-1 alpha was found in the cancer patients compared to controls, although leukocyte and lymphocyte counts were almost identical in both groups.

Whole-blood lymphocyte cultures

A simple and reproducible method is described for the measurement of proliferative responses of peripheral blood lymphocytes in whole blood upon stimulation with horse anti-human lymphocyte serum (ALS), phytohaemagglutinin (PHA) or a monoclonal antibody (mAb) directed against CD3. Only small aliquots of blood are needed and separation procedures are not necessary. Since the method proved to be very reproducible and showed little variation, reference values of proliferation, expressed in cpm per 15 microliters blood and cpm per 10(3) CD3+ lymphocytes, were determined based upon the 5th and the 2.5th percentile of the distribution of the values in our reference population. In addition, the use of whole blood lymphocyte cultures in longitudinal studies of immunocompromised individuals is demonstrated.