Distribution of alpha interferon in serum and cerebrospinal fluid after systemic administration

Treatment of schizophrenic disorder, paranoid type, with intramuscular recombinant alpha-2b interferon

Twenty patients meeting DSM-III criteria for Schizophrenic Disorder, Paranoid Type were studied. After a 30 day drug-free period the patients were randomized in two groups. During a year, patients in Group 1 received intramuscular injections of a placebo while Group 2 received recombinant IFN alpha-2b. Both groups took anti-psychotic medication (APM) as needed on an individual basis, depending on their psychiatric symptomatology. Double blind evaluations, were performed at the beginning and at the end of the trial, using the Brief Psychiatric Rating Scale (BPRS) and the Reyes Scale for Social Evolution (RSSE). Information about relapses was gathered such as months without relapse, number and duration of the relapses and maximum dosages of APM given for relapse control. The statistical analysis of the results was performed with a matched pairs sign or Student's t tests for comparisons of each group before and after treatment. Groups were compared between them using the Fisher's exact test for frequencies and Student's t test for continuous variables. In Group 1: only one patient improved on the BPRS score; two had improved ratings on the RSSE; 2 patients got worse; and there were no changes in the rest of the group; three patients had no relapses and one increased in relapse frequency. These changes were not significant. The rate of relapses per year and their duration were not significantly modified in Group 1. The maximum dose of APM required for their relapse control was larger than before treatment although not significantly. All these patients required continuous APM. In Group 2 (IFN treated): 6 patients had improved BPRS scores (N = 6, K = 6, p < 0.01) and 5 improved their RSSE scores (n = 5, K = 5, p < 0.05). In 5 patients there were no relapses on their frequency decreased. There was significant reduction in the duration of the relapses (37.8 +/- 14.6 to 20.7 +/- 12.5 days; t = 4.83; d.f. = 9; p = 0.0009) after treatment. Only 3 patients in Group 2 needed continuous APM after a relapse and the maximum dose required for control was significantly less (1281 +/- 527 to 687 +/- 552 chlorpromazine-equivalent mg. per day; t = 5.56, p < 0.001). Comparisons between groups showed advantage for the IFN treated group in the BPRS change, proportion of patients needing continuous APM and integral evaluation. These results indicate that alpha IFN may be useful in the treatment of Schizophrenic Disorder, Paranoid Type.

Clinical pharmacokinetics of interferons

Interferons are a family of proteins shown to be effective in the treatment of viral (condylomata, acuminata) and neoplastic (hairy cell leukaemia and AIDS-related Kaposi's sarcoma) diseases. To date, the clinical utility of the interferons has been hampered by an incomplete understanding of their mechanism of action. However, there is supporting evidence that the route of administration, i.e. the pharmacokinetic behaviour, is an important treatment variable. The pharmacokinetics of interferons have been fairly well described. The decline in serum concentrations of interferon is rapid after intravenous administration. The volume of distribution approximates 20 to 60% of bodyweight. Work in animals suggests that the catabolism of interferons falls within the natural handling of proteins. Clearance values vary (4.8 to 48 L/h) across the family of interferons and probably reflect the natural internal digestion and turnover of these proteins. Terminal elimination half-lives range from 4 to 16 hours, 1 to 2 hours and 25 to 35 minutes for alpha, beta and gamma, respectively. Intramuscular and subcutaneous administration of interferons alpha and beta results in protracted but fairly good absorption: greater than 80% for interferon-alpha and 30 to 70% for interferon-gamma. Interferon therapy is associated with adverse events which are usually mild and reversible. Temporal relationships exist between the degree and duration of adverse effects and the route of administration. Attempts to relate inducible biochemical markers, such as 2',5'-oligoadenylate synthetase activity, to dose or concentration have met with some success although alterations in these markers have not been shown to relate to clinical response.(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant interferon-gamma applied to the brain ventricular system protects rats against pseudorabies

We examined the prophylactic efficacy of recombinant rat interferon-gamma (IFN-gamma) administered directly into the brain ventricular system or via the intraperitoneal (i.p.) route against central and peripheral pseudorabies virus (PRV) infection. Intraperitoneally given IFN-gamma completely protected rats against a lethal i.p. PRV infection. The same regimen showed no protective effect against lethal intracerebroventricular (i.c.v.) PRV challenge even if IFN-gamma was given in high concentrations. When given via the i.c.v. route, IFN-gamma protected rats against lethal i.c.v. infection and also evoked partial protection with extended survival times of i.p. infected rats. Our results demonstrate an IFN-gamma-mediated antiviral effect in the central nervous system.

In vitro modulation of lymphocyte proliferation by prednisolone and interferon-alpha in patients with HTLV-I-associated myelopathy (HAM)

One of the hallmarks of human T-lymphotropic virus type I (HTLV-I) infection is the proliferation in vitro of peripheral blood lymphocytes (PBLs) in the absence of growth factors. This phenomenon, the autologous proliferative response (APR), involves spontaneous growth of HTLV-I-infected T-cells and proliferation of T-cells in response to the infected cells. We studied the modulating effect of prednisolone (PSL) and interferon-alpha (IFN) on APR of PBLs obtained from five patients with HTLV-I-associated myelopathy (HAM). APR was significantly inhibited by PSL and IFN suggesting that APR is important in the pathogenesis of HAM.

Cerebral interferon entry in mice after osmotic alteration of blood-brain barrier

Systemically administered interferon (IFN) is not readily detected in the central nervous system (CNS) due to the presence of the blood-brain barrier (BBB). A method of osmotic BBB alteration in a mouse model was established in this laboratory. IFN's entry into the normal and osmotically altered brain after its intracarotid injection was investigated. Significant IFN levels (100-1,000 units) in the brain can be achieved by this method. The highest IFN activity was found in the brain hemisphere ipsilateral to the injection site within 20 min to 1 h after injection. IFN activity in the brain was detectable up to 4 h. Animals injected in this manner with murine IFN-alpha/beta (MuIFN-alpha/beta) and observed for a 6-month time interval showed no signs of neurological dysfunctions and resumed their normal activities. The therapeutic value of this method will be tested in a murine model of malignant glioma.

Intrathecal interferon in subacute sclerosing panencephalitis

Three patients at Stage II of subacute sclerosing panencephalitis (SSPE) were treated with semipurified alpha-interferon (IFN) using different combinations of intrathecal and intravenous routes: 1 x 10(6) IU of alpha-IFN were given every other day up to a total of 15 x 10(6) IU. Transient improvement of neurological symptoms and electroencephalogram were noted in all 3, while cognitive function slightly improved in 2 of them. Clinical benefits gradually disappeared 2 to 6 months after cessation of IFN. Intrathecal antibody production did not change substantially, but CSF Leu 3a/Leu 2a ratio appeared to increase. No significant side effects were observed, except for a mild meningeal inflammatory reaction after each intrathecal administration of IFN.

Intraventricular interferon in a case of subacute sclerosing panencephalitis

A patient with subacute sclerosing panencephalitis (SSPE) was treated by direct administration of Interferon B into the cerebral ventricles. Immediately after the first dose intrathecal synthesis of IgG and the CNS antimeasles antibody titer fell significantly, only to rise again to the pretreatment levels 2 months after discontinuation of treatment. There was no improvement in the patient's clinical status.

Exacerbations of multiple sclerosis in patients treated with gamma interferon

In an open, randomised study, 18 patients with clinically definite, relapsing-remitting multiple sclerosis (MS) received 1 microgram, 30 micrograms, or 1000 micrograms doses of recombinant gamma interferon (IFN-gamma), given by intravenous infusion twice a week for four weeks. 7 patients had exacerbations during treatment. This exacerbation rate, compared retrospectively with the pretreatment rate and prospectively with the post-treatment rate, was significantly greater than expected. Exacerbations were not precipitated by fever or other dose-dependent side-effects. A concomitant increase in circulating monocytes bearing class II (HLA-DR) surface antigen suggested that the attacks induced during treatment were immunologically mediated. IFN-gamma is unsuitable for treatment of MS.

Pharmacokinetics of recombinant interferon-alpha 2 following intralesional administration in malignant glioma patients

Pharmacokinetics of recombinant interferon-alpha 2 (rIFN-alpha 2) following intralesional administration into patients with malignant gliomas was investigated. A dose of 5 X 10(6) IU of rIFN-alpha 2 was injected locally postoperatively for 2 weeks each day, and the same dose was then given once a week for 10 additional weeks. During the daily and weekly administration, the IFN was consistently present in the fluid of the postsurgical cavity. Not until 5 weeks after the end of the IFN administration was the IFN undetectable. The decay of IFN injected was minimal.

The treatment of subacute sclerosing panencephalitis with interferon: a case report

A child with subacute sclerosing panencephalitis (SSPE) received intraventricular alpha interferon (IFN) as experimental treatment. The course was monitored by colleagues in pediatric neurology, neuro-opthalmology and clinical psychology, also by monthly EEGS and brain CT scans. Two courses of IFN were administered. During the first course, improvement occurred nearly to the premorbid level of function. About 1 month after this trial was stopped, a severe recrudescence rapidly produced a thalamic state. A second trial of IFN resulted in less improvement. When the brain CT showed severe degeneration, the second trial was stopped. Intraventricular administration of alpha IFN was well tolerated in both courses of therapy. Alpha IFN has promise in the treatment of SSPE but the optimal dosage and duration of treatment are undetermined.

The new alpha interferons

Alpha interferons are biological response modifiers that regulate immune function, slow cell proliferation, and inhibit virus replication. Large supplies of purified preparations are now available for clinical trials. Common toxicity includes an influenza-like syndrome to which tolerance occurs after several doses, and chronic fatigue and anorexia that may be dose-limiting. Myelosuppression is mild. Alpha interferons have established clinical activity against several human cancers, including melanoma, Kaposi's sarcoma, multiple myeloma, non-Hodgkin's lymphoma, hairy cell leukemia, and renal cell carcinoma. These data and alpha interferon nomenclature are summarized in table form. Intranasal alpha interferon is effective in prophylaxis of common viral upper respiratory tract infections, although toxicity in long-term use is prohibitive. Short-term administration to high risk populations may be most useful. Optimal doses and schedules need to be determined for all indications.