Search

Objective: To evaluate the impact of menopause and estradiol substitution on natural killer cell activity., Methods: Natural killer cell activity and antibody-dependent cellular cytotoxicity were measured in peripheral blood of 53 postmenopausal and 20 premenopausal women in an interval of 3 weeks. Postmenopausal patients were randomly assigned to receive either estradiol valerate (2 mg daily) orally (n = 18), estradiol (50 micrograms/24 h) transcutaneously (n = 18) or no substitution (n = 17), and the testing was repeated 3 weeks later., Results: Natural killer cell activity but not antibody-dependent cellular cytotoxicity was significantly (P < 0.01) higher in unsubstituted postmenopausal compared to premenopausal subjects. Natural killer cell activity decreased both in orally and transcutaneously estradiol-treated patients (mean [S.D.] before vs. after 3 weeks; oral: 60.8 [9.2]% vs. 52.8 [8.2]% P < 0.01; transcutaneous: 61.5 [10.6]% vs. 54.3 [9.1]% P < 0.01; no substitution: 60.6 [10.6]% vs. 59.3 [8.9]% P > 0.1), whereas antibody-dependent cellular cytotoxicity showed no changes. The addition of 0.1 to 10 ng/ml estradiol to peripheral blood mononuclear cells of untreated postmenopausal women in vitro had no influence upon natural killer cell activity., Conclusion: Postmenopausal women receiving no estrogen replacement exhibited an increased natural killer cell activity which decreased during estrogen substitution.

The study examined lymphokine-activated killer cell (LAK) and natural killer (NK) cell activity in breast cancer patients prior to surgery as compared to effector cell lysis in patients with non-malignant breast tumors, further in connection with lifetime diagnosis of major depression, severity of current depression, anxiety and coping styles. Follow up studies covered a period of 6 and 12 months. Prior to surgery, life time diagnosis of major depressive disorder, trait anxiety and coping styles did not discriminate patients as far as effector cell lysis is concerned. LAK activity but not NK activity was reduced in patients with actual depressive symptoms (P < 0.01) and high state anxiety (P < 0.05). These findings support the hypothesis that LAK activity is a state marker of actually existing depression and anxiety prior to surgery. Affective rather than coping measures showed significant differences in LAK activity. For LAK activity, 1 year after surgery the only predicting factors were Tamoxifen therapy and chemotherapy.

Background: Patients with testicular cancer can be cured by cisplatin-based chemotherapy in many cases. Thus, concern about possible late toxicities of treatment is warranted., Methods: In this investigation, the absolute number of natural killer (NK) cells according to their CD56+ phenotype, NK cell activity, and antibody dependent cellular cytotoxicity (ADCC) were investigated in 29 patients with seminomas or nonseminomatous germ cell tumors (NSGCT) a median of 31 months (range, 5-73 months) after termination of chemotherapeutic treatment., Results: No difference in the absolute number of NK cells, NK cell activity, and ADCC was found between patients with testicular cancer after either standard polychemotherapy consisting of bleomycin, etoposide, and cisplatin (BEP) or monotherapy with carboplatin and healthy control subjects. When patients were analyzed further using multivariate analysis, a significant (P < 0.05) detrimental influence of BEP polychemotherapy versus carboplatin monotherapy on NK cell activity was found. Moreover, NK cell activity also depended significantly (P < 0.05) on the time elapsed after chemotherapy was administered, but normalized with time. Because the absolute number of NK cells was not affected, is was assumed that polychemotherapy induced a functional defect. In a subanalysis of patients with NSGCTs, metastases at diagnosis resulted in a significant (p < 0.05) and persistent stimulation of NK cell activity but not of ADCC., Conclusion: Cytostatic chemotherapy in patients with testicular cancer did not lead to compromised lytic effector cell function as assessed by NK cell activity and ADCC. However, a short, time-dependent reduction was found that also depended on the intensity of chemotherapeutic treatment. This finding related to the observation of a long-lasting stimulus of NK cell activity by initial metastases in patients with NSGCTs.

In vitro and in vivo studies in rodents and human suggested an immunostimulatory effect of prolactin. The aim of the present study was to determine the impact of chronically elevated serum prolactin concentrations on the immune system in patients with prolactinomas. For this purpose parameters of the humoral and cellular immune system were studied in seven patients with prolactinomas on two occasions (1) when their serum prolactin concentration had been normalized through treatment with dopamine agonists and (2) when their serum prolactin concentration was high. Serum concentrations of immunoglobulines, interleukin 1, 3 and 6, TNF-alpha, interferon-gamma and the soluble interleukin 2 receptor, leukocyte subsets and the natural killer cell activity were found to be within the normal range on both occasions, i.e. at normal and at high serum prolactin concentrations. The assumption could be made that long-lasting elevation of serum prolactin concentration induces adaptive changes when the acute stimulatory effects of prolactin on several parameters of the immune system have subsided.

We investigated spontaneous and gamma-interferon stimulated natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) in patients with chronic liver disease: A significantly reduced NK activity was found in alcoholic liver cirrhosis (LZ) and in chronic active hepatitis (CAH), as compared to healthy control individuals (p less than 0.001 and p less than 0.005, respectively). Patients with primary biliary cirrhosis (PBC) or with alcoholic non-cirrhotic liver disease had normal NK activities. Furthermore, ADCC was found to be significantly reduced in patients with CAH (p less than 0.05). The addition of gamma-interferon to peripheral blood mononuclear cells in vitro induced a similar increase in NK cell activity in all studied groups of patients. The reduced NK cell activity found in patients with LZ and CAH could constitute an important mechanism in the pathogenesis and contribute to the high incidence of virus-associated hepatic malignancies in these disorders.

According to the immunosurveillance theory, the immune system plays an important role in the control of tumor development. Besides of specific cytotoxic T-cells, natural killer (NK) cells have gained recently in attention as effectors of the aforementioned function. They are lymphoid cells, and lyse tumor cells after having recognized them through a variety of membrane properties. Lymphokines can increase NK cell activity and enlarge their spectrum to previously NK-insensitive targets. Several clinical trials are being conducted at present in order to test the potential of lymphokine activated killer cells to function within this new biologic set-up.

Natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) were tested in patients with schizophrenia or depression. It was found that NK activity as well as ADCC were significantly lower in both groups, as compared to healthy control individuals (P less than 0.001). Psychopharmacologic treatment with neuroleptics and antidepressives resulted in a significant increase in NK activity and ADCC (P less than 0.005) in patients with schizophrenia but not in treated patients with depression. In patients with schizophrenia, no correlation could be established between the dose of neuroleptic given and the increase in NK activity. Lithium also did not produce an increase in NK activity and ADCC. The addition of serum, derived from untreated patients with schizophrenia, to cell cultures in concentrations of 10 and 20% had an inhibitory effect upon the ADCC and, to a lesser degree, upon NK activity (20% serum concentration only); sera from treatment schizophrenics produced no inhibition of NK activity, but did affect ADCC. No serum-derived inhibitory effect upon either NK activity or ADCC was found to be present in sera from patients with depression. We conclude that lytic effector mechanisms are impaired in patients with schizophrenia or depression and that this defect is reversed in schizophrenic patients on treatment, but not in depressives on therapy. Patients with schizophrenia also tend to have a reversible serum-mediated inhibition of NK activity which is absent in patients with depression.

Natural killer cell (NK) activity and antibody-dependent cellular cytotoxicity (ADCC) exerted by peripheral blood mononuclear cells (PMNC) were investigated in 53 patients with Crohn's disease (CD). NK activity and ADCC were found to be significantly reduced in patients with CD (p less than 0.0005) as compared to healthy controls. Both effector cell functions increased after in vitro treatment of PMNC with gamma-interferon, but did not reach the levels found in controls (p less than 0.0005). Neither NK activity nor ADCC was significantly influenced by therapy with corticosteroids. Moreover, the reduced serum zinc levels in patients with CD, which have been shown to be associated with impaired immune function, did not influence the lytic effector cell mechanism assayed either. Finally, no association could be found between NK cell activity or ADCC and CD activity index, the extent of the disease and several laboratory parameters of inflammation. We conclude that patients with CD have a reduced lytic effector cell function which remains uninfluenced by corticosteroid treatment and seems to be present independently of disease activity.

The present study aimed at elucidating lytic effector cell function in 32 schizophrenic patients and comparing the results with data obtained in 27 normal probands. Natural killer cell (NK) activity and antibody dependent cellular cytotoxicity (ADCC) were tested. Schizophrenics did not differ from normal controls in either test system. Within the schizophrenic group, higher NK activity was detected in patients with neuroleptic monotherapy (p less than 0.05). Patients given a combination of neuroleptics, antidepressants and/or lithium did not differ from drug-free patients in either test system. There was no influence of psychopathological variables on lytic effector cell function.

The influence of T cells on the production of prostaglandins (PGE2) and on PGE2-mediated regulation of natural killer (NK) activity was studied. Supernatants from peripheral blood mononuclear cells (PBMC) and from PBMC depleted of T cells ((PBMC)-T), both of which had been incubated in plastic petri dishes overnight, contained similar amounts of PGE2, as detected by radioimmunoassay and by their potential to inhibit NK activity of peripheral blood mononuclear cells in a 51Cr release assay with K 562 cells as the target population. However, the NK activity of PBMC was inhibited significantly more strongly (P less than 0.005) by PGE2-containing supernatants than was the NK activity of (PBMC)-T. In further assays, in which synthetic PGE2 in concentrations of 10(-4) and 10(-5)M was added, a significant inhibition of NK activity was observed in PBMC populations (P less than 0.05), but not in (PBMC)-T. Thus, T cells did not seem to be involved in the control of PGE2 production, but their presence was necessary for PGE2-mediated inhibition of NK activity.

The influence of various modes of immunosuppression using cyclosporin A (CyA), corticosteroids (Cort), azathioprine (AZA), and antithymocyte globulin (ATG) alone or in combination with each other upon natural killer (NK) cell activity and antibody-dependent cellular cytotoxicity (ADCC) was assessed. CyA given alone did not influence either NK or ADCC activity; in contrast, the administration of Cort resulted in a significant decline (P less than 0.01) of ADCC but not of NK activity (P greater than 0.1). The combination of the two drugs led to a significant impairment of NK activity (P less than 0.01). The combination of AZA and Cort was found to produce an even more pronounced reduction in NK activity compared to both healthy controls (P less than 0.001) as well as patients from the CyA + Cort group (P less than 0.001). A similar decrease was found also after the addition of ATG to CyA + Cort (P less than 0.001, compared both with patients on CyA + Cort and with controls). In these instances, ADCC showed an overall similar pattern. We conclude that the administration of either CyA or Cort does not influence NK activity, while the combination of CyA with Cort and of AZA with Cort leads to a decrease in both NK and ADCC activities. The monotherapy with Cort only leads to a reduction of ADCC. These findings may explain the higher incidence of malignancies in patients undergoing combined immunosuppressive treatment.

Unstimulated and interferon (IFN)-stimulated natural killer cell (NK) activity was investigated in patients with malignant melanoma prior to the removal of the primary melanoma (stage I disease) or in patients with melanoma metastases. Unstimulated as well as IFN-stimulated NK activities, directed against the primarily NK-sensitive K562 cell line, were found not to differ significantly from the NK activity of healthy control subjects. In contrast, IFN-stimulated NK activity directed against the primarily NK-insensitive Chang hepatoma and JY cell lines was significantly lower in patients with metastatic melanoma than in patients with non-metastatic disease (Chang hepatoma cell line: P less than 0.02; JY cell line: P less than 0.0017) and - in experiments using the JY cell line - than in healthy controls (P less than 0.01). Stage I melanoma patients did not differ in their IFN-induced NK activity from healthy control subjects using Chang hepatoma and JY cell lines. Finally, the IFN-induced increase in NK activity directed against primarily NK-insensitive target cell lines was significant in stage I melanoma patients and in healthy controls (P less than 0.01, respectively), but not in patients with metastatic melanoma (P greater than 0.5). We thus conclude that patients with metastatic malignant melanoma exhibited a defect in IFN-augmented NK activity directed against primarily NK-insensitive targets.

Tumor-bearing patients with breast cancer were assayed for their natural killer (NK) cell activity and for the function of activated cytotoxic T-cells, as assessed by lectin-dependent cellular cytotoxicity (LDCC). Tumor-bearing patients with breast cancer had a significant increase in NK activity and in LDCC, as compared with healthy control individuals. Although the enhanced NK cell activity and LDCC were closely associated with high levels (greater than 31 fmol/mg) of estrogen receptor (ER) content in the primary tumor, no other clinical or histologic correlation between the increase in either parameter of cytotoxic effector cell function could be found. Thus, ER levels greater than 31 fmol/mg might be associated with increased cytotoxic effector cell function in tumor-bearing patients with breast cancer.

Unstimulated IFN- and IL2-stimulated (NK) cell activities were investigated in patients with breast cancer who had received either local radiotherapy alone or adjuvant chemotherapeutic treatment with CMF combined with radiotherapy 12 to 18 months previously. When tested against the primarily NK-sensitive K562 cell line, patients who had received adjuvant chemotherapeutic treatment with CMF were shown to have a significantly decreased unstimulated and IFN-stimulated NK cell activity, as compared to both patients after radiotherapy only (P less than 0.002) and P less than 0.005, respectively) and healthy control persons (P less than 0.05). The former group of patients also had a significantly decreased IFN-stimulated NK cell activity, when tested against the primarily NK-insensitive Chang hepatoma cell line, as compared to patients after radiotherapy only (P less than 0.005) and healthy controls (P less than 0.05). Moreover, patients after radiotherapy only proved to have a significantly increased unstimulated (P less than 0.01) and IFN-stimulated NK cell activity (K562: P less than 0.05; Chang hepatoma cell line: P less than 0.05), as compared to healthy control individuals. In contrast, no difference in IL2-stimulated NK cell activity was detected. The investigation for the expression of CD3 and/or Leu 19 antigens as phenotypic markers of cells with non-MHC restricted cytotoxicity showed a significantly lower percentage of cells with the CD3+ phenotype in patients with breast cancer, irrespective of the chosen post-operative treatment, as compared to healthy controls (P less than 0.01). Finally, patients with breast cancer who had received radiotherapy only had a significant trend towards an increased percentage of CD3+/Leu 19+ PMNC, as compared to both patients after CMF treatment (P less than 0.05) and healthy controls (P less than 0.025). We conclude that patients with breast cancer vary on a long-term basis in their NK activity and in the phenotype of their PMNC depending on their post-operative adjuvant management.