Reduced natural killer cell activity in patients with dementia of the Alzheimer type

We examined the natural killer (NK) cell activity in 50 patients with dementia of the Alzheimer type (DAT) and 37 age-matched normal controls. The NK cell activity in DAT was significantly lower than in the normal controls. The NK cell activity induced by either interferon-alpha (IFN-alpha) or interleukin-2 (IL-2) in DAT was also significantly lower than in the normal controls. There were no significant differences in the level of serum IL-2 and IFN-alpha between the two groups. As regards NK cell subsets, two-color flow cytometric analysis showed no significant differences between the percentages of Leu-11+ Leu-7- cells, Leu-11+ Leu-7+ cells and Leu-11- Leu-7+ cells in the two groups. Our results suggest that NK cells in DAT may have functional abnormalities and may provide important clues to fundamental cellular and molecular aberrations in DAT.

Determination of tumor necrosis factor alpha (TNF alpha) and interleukin 2 (IL 2) in women with idiopathic recurrent miscarriage

Some recurrent miscarriages may be due to a host versus graft reaction. Elevated Interleukin 2 (IL2) levels have been found during pregnancy and elevated TNF alpha levels during acute rejection crises of allotransplantats and so we determined IL2- and TNF alpha levels in women with recurrent miscarriages. Samples were taken for serum TNF alpha and IL2 radioimmunoassays (IRE Medgenix, Belgium) from 28 healthy non-pregnant women and in 49 women with at least 3 miscarriages between the 6th and 14th week of pregnancy, 38 women having their first or second miscarriage and 42 pregnant women with no complications. In women with recurrent miscarriage an increase in TNF alpha (P less than 0.05) and a decrease in IL2 serum levels (P less than 0.05) was found compared to women with normal pregnancies. These results support the concept that disturbances of immune tolerance of the fetus may account for some cases of recurrent miscarriage.

Circulating interferon-alpha in patients with Kyasanur forest disease

Endogenous interferon (IFN) levels were monitored in acute (51) and convalescent phase (19) sera collected from patients suffering from Kyasanur forest disease (KFD). Levels of circulating IFN in the acute samples (GM 216.3 +/- 8.7) collected between 4 to 7 post onset day (POD) were significantly higher (P less than 0.001) than the convalescent samples (GM 13.19 +/- 1.6) collected between 30th to 90th POD. Interferonemia was concomitant with the viraemic phase. Neutralization studies indicated that the endogenous (circulating) IFN was antigenically similar to acid stable form of IFN-alpha.

Determination of TNF alpha, interferon alpha, interleukin 2 and reactivity in the leucocyte migration inhibition test in breast cancer patients

To date, the results concerning the prognostic importance of parameters of cell-mediated immunity in breast cancer patients are very contradictory; moreover, in most of them the results are hardly comparable due to methodological differences and heterogeneous groups of patients. In 123 patients with nonmetastatic breast carcinoma TNF alpha, INF alpha, IL 2 and reactivity in the leucocyte migration inhibition test (LMI-Test) against autologous tumor tissue were determined and the results correlated with the clinical course of the disease up to a maximum of 108 months. In breast cancer patients TNF alpha-serum levels were significantly (p less than 0.05) elevated compared to healthy controls. We also found that patients with progressive disease had higher levels than patients without recurrences. There were no differences concerning the IL-2 and IFN alpha serum levels between cancer patients and controls, nor did we find a correlation with the clinical course of the disease. In 38% of all breast cancer patients examined, a MIF production against tumor tissue could be demonstrated in the LMI-test. There was no difference concerning the LMI-reactivity between the groups of lymph-node negative and positive patients, but the observation that those patients with an unfavourable clinical course respond more frequently with an enhanced macrophage migration and rarely with migration inhibition was considered of notable prognostic significance. According to these results, it is possible that determination of TNF alpha and delayed type hypersensitivity reaction against tumor tissue in the LMI-test is of clinical value for the determination of risk groups.

Regulation of tumor necrosis factor receptor expression by acid-labile interferon-alpha from AIDS sera

High levels of an unusual acid-labile interferon (IFN) alpha in sera of patients with human immunodeficiency virus (HIV) infection are associated with disease progression to acquired immunodeficiency syndrome (AIDS). Since IFNs have been shown to enhance the cytotoxic actions of tumor necrosis factor (TNF), a potent mediator of inflammation and cachexia, a study was undertaken to investigate whether the acid-labile IFN alpha produced in AIDS can regulate TNF receptor expression. The expression of TNF receptors was determined by studying the interaction of [125I]TNF with cellular receptors. The results show the acid-labile IFN alpha present in AIDS sera is capable of inducing the expression of cellular receptors for TNF. The extent of induction of TNF receptors depends on the concentration of the acid-labile IFN alpha in the AIDS sera. There is no significant induction of TNF receptors when the AIDS sera are preneutralized with polyclonal anti-IFN alpha antibodies. It is also shown that the synthesis of TNF by peripheral blood monocytes (PBM) from patients with HIV infection is enhanced during the progression of HIV infection in vivo. Thus, the TNF system is activated in patients with HIV infection. This activation may be a contributing factor to some of the physiological disturbances including the wasting syndrome observed in AIDS.

Distribution of human recombinant interferon-alpha 2 in rat plasma, liver, and experimental liver metastases

It has been ascertained that one of several possible reasons for negligible interferon activity in solid tumors, namely, hepatic metastases induced in rats after intraportal injection of Walker carcinoma 256 cells, is the significantly lower levels of interferon in the interstitial fluid of metastases in comparison to normal liver and plasma.

Interferon levels in human pulmonary tumors are lower than plasma levels

It is uncertain whether interferon levels in the interstitial fluid of tumors are equivalent to interferon plasma levels and we have investigated this problem in human pulmonary tumors by infusing human recombinant interferon alpha A and natural interferon Beta for about three hours before surgery. By determining the hematocrit and hemoglobin content it was possible to calculate interferon values (International Units/g wet tissue) present in the interstitial fluid of tumor and lung samples, simultaneously. In 14 patients (epidermoids, n = 9 and adenocarcinomas, n = 5) interferon levels in tumor and "normal" lung expressed as percentages of interferon plasma levels were: 9.5 +/- 3.9 and 29.8 +/- 6.9 for recombinant interferon alpha A and 3.1 +/- 0.4 and 10.1 +/- 2.4 for natural interferon Beta, respectively. Differences for both interferons are statistically significant (p less than 0.05). To our knowledge these are the first data indicating that interferon levels in pulmonary tumor interstitial fluid are markedly lower than those in normal lung although they do not clarify the main factor responsible for the decrease, they explain at least in part the negligible therapeutic activity of interferons in these tumors and emphasize the need for new approaches for improving the therapeutic index of interferons.

Effects of interferon-alpha in patients with AIDS-associated Kaposi's sarcoma are related to blood interferon levels and dose

Definition of improved therapeutic regimens of interferon-alpha (IFN-alpha) for the treatment of Kaposi's sarcoma (KS) would be useful since currently recommended doses are sometimes associated with unacceptable toxicity. IFN concentrations were measured in serum samples from men with AIDS-associated KS who were enrolled in a trial of IFN-alpha alone (16 patients) or a trial of IFN-alpha combined with zidovudine (25 patients). Analyses were done to examine the relationship between the dose of IFN-alpha, blood level of IFN, and the patient's clinical response to treatment. There was no correlation between dose of zidovudine given and response. As expected, there was a high correlation between dose of IFN-alpha and blood level in both studies (p less than 0.001). Furthermore, we found relationships between clinical response and both dose of IFN-alpha and blood level achieved. In the two studies combined, among men with greater than 200 CD4+ cells/mm3 of blood at baseline on average daily doses of greater than or equal to 10 million international units (MIU) of IFN-alpha, 13/19 (68%) responded compared to 6/17 (35%) on less than MIU (p = 0.05). Similarly, of men with IFN blood levels greater than or equal to 100 IU/mL 12/16 (75%) responded compared to 7/20 (35%) of those with blood levels less than 100 IU/mL (p = 0.02). The dose and blood levels of IFN achieved and maintained may be important factors in determining responses of KS. Additional clinical trials of IFN-alpha treatment of KS at doses about 10 MIU/day appear warranted.

Recombinant leukocyte interferon alpha-2a and medroxyprogesterone in advanced renal cell carcinoma. A randomized trial

In a randomized study of advanced renal cell carcinoma 60 patients were allocated to treatment with either recombinant interferon alpha-2a or medroxyprogesterone acetate. Correlation between the dose of interferon alpha-2a and plasma-concentration indicated linear kinetics. Survival was similar in the two treatment groups. Only one complete and one partial response were seen in the interferon group and only one complete response in the medroxyprogesterone group, indicating a low therapeutic potential of both interferon and medroxyprogesterone. Interferon influenced the serum liver enzyme levels; increased transaminases were seen in 17 patients treated with interferon but in only four patients in the medroxyprogesterone group. Two patients had very high serum liver-enzyme levels concomitant with intolerable tiredness, in both patients the symptoms disappeared and the enzymes normalized after discontinuation of the interferon treatment. Antibodies to interferon developed frequently in patients receiving high dose oligomeric interferon therapy but rarely in patients receiving low dose monomeric interferon treatment.

Recombinant human interferon alpha-2a: delivery to lymphoid tissue by selected modes of application

The effect of different parenteral administration routes (i.d., s.c., i.v.), infusion rates, and albumin contents of the drug vehicle on the cumulative recovery of recombinant human interferon alpha-2a (rIFN alpha-2a) in lymph and on its concentration in blood and lymph was determined in sheep. Blood samples were withdrawn from a jugular vein catheter and lymph was collected from a cannulated efferent popliteal lymphatic duct. The concentration of rIFN alpha-2a in lymph and blood plasma samples was measured by an enzyme immunoassay. Following i.v. infusion of 2 x 10(7) U of rIFN alpha-2a, the peak concentrations measured in blood plasma and lymph, respectively, were 8250 and 14 U/ml. The concentration measured in lymph after i.d. or s.c. administration of the same dose was about 10(5) times higher (peak concentration, 3.1 x 10(6) U/ml), while blood plasma levels remained low (peak concentration, 315 U/ml). The cumulative recovery of rIFN alpha-2a in lymph following i.d. or s.c. administration was 59.2 +/- 7% (mean +/- SD; N = 8) and was affected neither by the infusion rate nor by the coadministration of albumin. Our data indicate that following i.d. or s.c. administration, rIFN alpha-2a (MW 19,000) is absorbed mainly by the lymphatics. This results in high levels of rIFN alpha-2a in the lymph which drains from the application site to the regional lymph nodes. The knowledge gained in this investigation may help to improve the mode of administration and therapeutic efficacy of protein drugs whose targets are lymphoid cells.