Biotherapy (Dordrecht, Netherlands)最新文献

Therapy for cancer patients with biologically active immune modulators is attractive but has met with limited clinical success. Interleukin-2 (IL2) stimulates T-cells and natural killer (NK) cells to kill tumor cells and levamisole (LMS) is an immunostimulant which has been shown to increase NK cells and activated T-cells in patients receiving this adjuvantly along with 5FU for Stage III colon cancer. This study was designed to evaluate whether treatment with LMS prior to IL2 would provide synergistic activity and improve response rates. Four patients with advanced malignancies were treated with LMS at 50 mg p.o. TID for 3 days followed on day 4 with 600,000 units/kg IL2 as a single i.v. bolus. This treatment was repeated weekly until progression. Serum soluble IL2 receptor (sIL2R) and interferon-gamma levels were monitored throughout the treatment course as markers of immune activation. All patients had eventual progression of disease. Toxicity was minimal with Grade II orthostatic hypotension the major consequence of therapy. The pattern of sIL2R levels in 3/4 patients revealed a steady increase over the several weeks of therapy, indicating ongoing immunostimulation (r=0.53 , p=0.001). Short-term treatment with LMS, however, resulted in a significant and consistent decreases in sIL2R levels (2198 U/ml vs. 1969 U/ml, p=0.001) in all patients. In conclusion, LMS/IL2 in the dose and schedule utilized here was not clinically effective. However, LMS reduced sIL2R levels immediately following a three-day course. This reduction in sIL2R by LMS may improve the possibility of response to IL2 by facilitating a decrease in inhibitory sIL2R. Combinations of these two agents should continue to be investigated as potential synergistic anti-tumor agents.

Thrombopoietin (TPO) or Mpl ligand is the primary physiological regulator of platelet production. This cytokine is the most potent stimulator of the proliferation and differentiation of MK progenitor and precursor cells in vitro. It also acts additively or synergistically with several cytokines on progenitor cells from various hematopoietic lineages, including the primitive stem cells. The factor is an extremely potent thrombocytopoietic agent when administrated to normal animals, and it accelerates platelet and erythropoietic recovery in several models of myelosuppression. Phase I/II clinical trials are ongoing with no detectable adverse effects. Mpl ligand does not induce platelet aggregation, but it lowers the platelet sensitivity to physiological dose of agonists. In experimental mouse models, high and chronic dose of Mpl ligand results in myelofibrosis. TPO is constantly produced by the liver and the kidney; its plasmatic clearance occurs by binding to its receptor expressed on megakaryocytes and platelets. However, the full spectrum of the biological effects of this new cytokine is not fully understood, in particular its the role in the terminal stage of platelet production. In the near future, it is likely that new insights will be obtained in the physiopathological mechanisms underlying abnormal platelet production in human.

We have been treating patients with advanced HIV disease using passive immunotherapy (PIT). Earlier studies of PIT which have been published concerned relatively short periods of treatment: our study is by far the longest and reports also on the long-term effects of plasmapheresis on healthy HIV-infected individuals. Fifty-nine patients with an average CD4+ T-cell count of 55 per cu.mm. at baseline were transfused at monthly intervals with 500 ml of hyperimmune plasma. No disease progression or death occurred among the 8 asymptomatic patients under the treatment, which lasted for 36.25 months on average. Seven of the 15 ARC patients progressed to AIDS but none died in an average period of 25.9 months. Seven of the 36 symptomatic AIDS patients with advanced disease died in an average period of 19.6 months. PIT appears to be nontoxic and to have beneficial effects lasting at least four years under continuous treatment. It probably delays disease progression in ARC and AIDS patients, and almost certainly does so in asymptomatic late HIV infection with a very low CD4+ T-cell count. None of the 51 donors suffered adverse effects, nor did any progress to ARC or AIDS in an average period of 30.1 months. Their laboratory parameters indicated a nearly stable condition: in particular, their average CD4+ T-cell count rose from 478 to 498. The study of our plasma donors indicated that repeated and frequent plasma donation by asymptomatic HIV-infected individuals could delay disease progression, although further studies are needed to investigate this.

Recombinant interferon (IFN) gamma was used in 10 patients, 6 to 15 years old, with juvenile chronic arthritis (JCA) for 5 to 11 years, resistant or with severe side effects to other treatments. Six patients had systemic JCA and 4 started as pauciarticular. Three of the latter became polyarticular. Treatment schedule was 50,000 IU-kg daily for 4 weeks, then 3 times per week for 3 months and twice a week up to 2 years. Eight cases had favourable clinical response. Prolonged steroid regime could be suspended in 7/8 cases who previously received it. Two patients with systemic JCA did not respond to IFN treatment. Side effects were fever (9), headache (8), chills (6), distal cyanosis, hypotension, leukopenia and myalgia (2), and vomiting (1). All were mild or moderate. IFN gamma was more tolerable than other drugs and seems to be beneficial for patients with JCA resistant to other treatments.

In order to analyse the effector population in an immunization model, we treated BALB/c mice with intraperitoneal (i.p.) active specific immunization (ASI), which consists of interleukin (IL)-1-beta and sonicated tumor supernatant (SS) of a plasmacytoma MOPC-104E followed by i.p. injection of cyclophosphamide (CY). This ASI-CY treatment provoked a protective immunity against i.p. tumor inoculation more strongly than that of ASI alone. The main effector cells in tumor neutralizing assay were CD4+ T cells at this pont. The number of spleen cells of the ASI-CY treated mice were significantly lower than that of ASI alone treated mice but it increased significantly 6 days thereafter while this increase was not observed on the mice treated with ASI alone. The spleen cells of the ASI-CY treated mice responded to SS in vitro in the presence of IL-2, more profoundly in CD4 enriched population which produced high amount of TNF-alpha. In vivo tumor-neutralizing activity at a later stage was dependent on CD8+ T cells in addition to CD4+ T cells. These results suggest that antitumor activity by ASI and CY is transduced by sequential population shift from CD4 alone to both of CD4 and CD8.

Administration of hot water extracts of six herbs to four patients with recurrent herpes labialis led to prompt crusting over and complete recovery within a few days. Similar treatment for one female patient who had been suffering from recurrent genital herpes resolved the associated pain dramatically. In all cases mentioned, symptoms disappeared much more quickly than with previous outbreaks when herb extracts were not administered.

We investigated possible mechanisms leading to the inhibition of the immune system in people with chronic disorders. Tumor cell produce protein released into the circulation, such as tumor associated antigens, may play an important role in processes preceding paralysis of the immune system. To test this hypothesis the following tumor associated antigens were used: AFP, OFP, CA-125, CA-50 and CA-19-9. Their role was assessed by modulating cytokine production in cord blood lymphocytes and peripheral white blood cells obtained from grown population of patients treated with colostrinin, an cytokine inducer. PHA, LPS and colostrinin were used as positive control in those essays. Each antigen tested individually induced IFN, TNF alpha and IL-6 in dose dependent fashion. None of the tested cytokines were spontaneously released by the cells. Data generated from these experiments indicated that tumor associated antigens are inducing type 1 cytokines in similar fashion as LPS or colostrinin. However, lymphocytes taken from patients undergoing therapy with colostrinin revealed progressive loss capability to produce type 1 cytokines as they did in case of colostrinin. The loss of the capability to respond to antigen may represent phenomenon leading to immune tolerance.