[Quality of life in patients with remitting-relapsing multiple sclerosis in Germany]

The concept of health-related quality of life (QoL) includes physical, psychological,and social aspects. This pertains to consequences of chronic diseases and their therapies beyond biological or pharmacological relations. A considerable amount of literature concerning QoL has been published with regard to neurological and non-neurological entities. This study summarizes data from a study in 717 persons with remitting-relapsing multiple sclerosis (MS). Of them,576 could be reevaluated longitudinally after 1 year of treatment with interferon-beta 1a (44 microg subcutaneous Rebif once weekly). Compared to populations of healthy controls or other patients, considerable reductions in the eight subscales and both physical and emotional sum scales of the German version of the short form of the Rand Health Questionnaire (SF-36) questionnaire were assessed. These reductions were even more pronounced in persons with gait impairments. Most SF-36 scales only modestly correlated to physical disability. This indicates that QoL as reported by patients does not depend solely on the physical symptoms of MS. Most findings remained stable for the study population as a whole during 1 year of therapy, while statistically significant improvements were found in clinical responders as defined in this study (relapse-free, physically stable, stable or improved in physician's judgement). Side effects of therapy were not reflected in lower QoL scale values. Implications of findings for future concepts in MS therapy are discussed.

Mx proteins in blood leukocytes for monitoring interferon beta-1b therapy in patients with MS

OBJECTIVE

To correlate Mx protein (Mx) levels in lysed blood leukocytes with the clinical response to interferon (IFN) beta-1b (IFNbeta-1b) in relapsing-remitting MS (RR-MS) patients for monitoring treatment.

BACKGROUND

Intracellular Mx expression is exclusively induced by the type I IFNs (IFN-alpha, -beta, and -omega) or by viruses and is strongly increased under IFN treatment. Quantitative determination of Mx allows objective assessment of biological effects of IFN.

METHODS

Mx protein levels were measured in blood leukocyte lysates from IFNbeta-1b-treated RR-MS patients by ELISA and correlated to clinical parameters, including relapse rate and clinical deterioration.

RESULTS

In stable IFNbeta-1b-treated MS patients, Mx levels were significantly increased compared to patients with or without immunosuppressive treatment. In IFN-1b-treated MS patients during relapse, Mx levels were significantly lower than during stable phases of the disease. Mean values of Mx (MVMx) over time of treatment in patients with a reduction of relapse rate were significantly higher than in patients without response.

CONCLUSION

Mx levels in lysed blood cells may represent a useful surrogate marker for IFNbeta-1b activity corresponding to the clinical response during treatment of MS.

Expression of interferon-inducible Mx-proteins in patients with IgA nephropathy or Henoch-Schönlein purpura

Both viral infections and dysregulated cytokine synthesis have been implicated in the pathogenesis of immunoglobulin A nephropathy (IgAN) and Henoch-Schönlein purpura (HSP). Mx proteins are specifically induced by type I interferons (IFN-alpha, -beta, -omega) and are very sensitive in detecting, for example, virus-induced, in vivo production of IFN-alpha/-beta, because the biological half-life of Mx (approximately 3 days) markedly exceeds that of IFN-alpha/-beta (20 to 90 minutes). Mx concentrations in leukocytes were measured by enzyme-linked immunosorbent assay (ELISA) in 79 blood samples of 35 patients with IgAN and five with HSP. No patient showed symptoms of infections at the time of the examination. Compared with normal leukocyte Mx concentrations (<2 mU/1,000 leukocytes), only 3 of 79 samples of IgAN/HSP patients showed mildly elevated Mx concentrations (range, 2.2 to 3 mU/1,000 leukocytes). By contrast, patients with increased endogenous IFN production (lupus erythematosus) or patients treated with IFN-alpha2 showed leukocyte Mx concentrations of up to 35 mU/1,000 leukocytes. In patients with IgAN and HSP, leukocyte Mx concentrations were not correlated with various clinical parameters. Immunohistochemically, no renal Mx expression could be detected in eight renal biopsy specimens of patients with various stages of IgAN, whereas control specimens (skin of patients treated with IFN-alpha2) showed abundant cellular Mx expression. Furthermore, human mesangial cells in vitro showed marked Mx production after exposure to IFN-alpha or IFN-beta. We conclude that, in patients with IgAN/HSP, no evidence of an activation or dysregulation of the type I interferon system can be detected.

Progress in developing animal models for biliary atresia

Animal models for extrahepatic biliary atresia (EHBA) have failed to simulate the course of the disease. Until now only a few aspects of the entity could be investigated and no model was helpful in discovering the etiology of EHBA. Following the suspicion of a viral and hepatotropic infection, investigations in an infectious mouse model were continued. The results of previous and topical studies are summarized here. Infection of newborn Balb/c-mice with rhesus rotavirus (RRV) leads to cholestasis in 85% of the animals followed by a lethality of 90%. Preparation and histomorphological investigation of liver and ligamentum duodenale reveal EHBA of varying extent. Clinical course and morphological findings in mice are very similar to EHBA in newborn children and the results are presented in a chronological table. Hepatobiliary morbidity and lethality after RRV infection is higher in Balb/c-mice than in other mouse strains. This observation supports the suspicion that immunocompetence might be a determining factor in the etiology of EHBA. Initial therapeutic trials were made using this model by treating infected newborn mice with interferon-alpha (IFN). The prophylactic application of IFN protects the infected mice from cholestatic symptoms and appears to induce partial immunity. Their descendants are protected against the hepatotropic effect of RRV infection. Infected animals presenting with clinical signs of cholestasis can be treated successfully by IFN-therapy for one week. In the presented animal model. EHBA can be better induced and simulated than by any other method. As a first trial, a non-surgical and more etiologically orientated therapeutic method is tested in this model.

Treatment of extrahepatic biliary atresia with interferon-alpha in a murine infectious model

The etiology of extrahepatic biliary atresia (EHBA) in newborns remains unknown, although a first infectious animal model with complete obstruction of the common bile duct could be established. Intraperitoneal inoculation of newborn Balb/c mice with rhesus rotavirus induced cholestasis, leading, in most cases, to biliary atresia with lethal outcome, similar to EHBA in human newborns. The influence of interferon-alpha (IFN-alpha) on the hepatotropism of rotavirus infection was investigated in this animal model. Single-dose therapy with 10000 IU of IFN-alpha protected all rhesus rotavirus-infected pups from cholestatic disease. The same dose, injected 5 d after infection, had no protective effect. Starting with onset of cholestatic symptoms, the treatment with 10000 IU of IFN-alpha daily showed good results in 29 mice. Seventy-six percent of the mice recovered after 1 wk of therapy. Histologic investigation revealed normal findings in the hepatobiliary tract of clinically normal mice. Twenty-one percent of the descendants of infected and prophylactic IFN-alpha-treated mice showed cholestatic symptoms after infection with rhesus rotavirus (79% in an untreated control group) and a milder form of the illness. In conclusion, we found that prophylactic treatment with IFN-alpha prevented the hepatobiliary system of newborn Balb/c mice from severe damage by rhesus rotavirus in this artificially designed infectious model for EHBA. Infected and icteric mice, treated for 1 wk with IFN-alpha, had good prospects for recovery and prevention of complete and irreversible occlusion of the extrahepatic bile ducts. Infected and prophylactic IFN-alpha-treated dams gave good protection to their descendants. This means that EHBA in this model could probably be averted by maternal antibodies against rotavirus.

Adjuvant immunotherapy in malignant melanoma: impact of antibody formation against interferon-alpha on immunoparameters in vivo

In an adjuvant clinical trial for high-risk patients with malignant melanoma by using recombinant interleukin-2 (rIL-2) and recombinant interferon-alpha 2b (rIFN-alpha 2b), we monitored the development of antibodies against rIFN-alpha and various immunoparameters as biologic markers for IFN activity in vivo. Thirty-one patients (22 men, nine women) with high-risk malignant melanoma received eight 6-week cycles of rIL-2 and rIFN-alpha. Serum samples of all patients were screened for the presence of antibodies against IFN-alpha by a solid enzyme immunoassay (EIA). Specimens testing positive in the EIA were assessed for their ability to neutralize the antiviral effects of IFN-alpha in vitro in an antibody-neutralizing bioassay (ANB). Furthermore, serum levels of neopterin, beta 2-microglobulin, soluble IL-2 receptor (sIL-2R), anticardiolipin and antithyroglobulin were evaluated. Of 31 patients, 11 (36%) developed binding antibodies; three (27%) of them had antibodies with neutralizing capacities (range, 350-28,000 INU/ml). Of male patients, 8 (36%) of 22 versus 1 (11%) of nine female patients developed antibodies. Statistical analysis (unpaired t test) revealed that all patients with antibody titers showed significant (p < 0.04) lower serum levels of beta 2-microglobulin and reproducible decreases in sIL-2R levels, whereby those with neutralizing antibodies showed significantly (p < 0.0001) lower values than did those with binding antibodies. Elevations of anticardiolipin (17 of 31) and antithyroglobulin (one of 31) were not correlated to the presence of IFN antibodies. Our results show the in vivo significance of antibodies against rIFN-alpha, especially of those with neutralizing capacities. Monitoring of antibody formation as well as immunoparameters like beta 2-microglobulin in clinical trials can contribute to identifying patients who, if necessary, might benefit from alternative IFN treatment, for instance, by using natural IFNs.

Intracellular staining of Mx proteins in cells from peripheral blood, bone marrow and skin

AIM/BACKGROUND

The Mx proteins are known to be specifically and dose dependently induced in mononuclear cells (MNC) by type I interferons (IFN). The aim of this study was to establish a staining method for the human intracellular Mx proteins, MxA and MxB, in leucocytes and bone marrow and skin cells.

METHODS

Several monoclonal antibodies directed against the MxA and MxB proteins were generated. These antibodies were used to stain Mx proteins in both frozen and paraffin wax sections using the standard alkaline phosphatase anti-alkaline phosphatase (APAAP) method.

RESULTS

Granulocytes, monocytes and lymphocytes extracted from freshly collected blood from 21 healthy subjects did not stain. After incubating MNC from these subjects with IFN alpha 2b for 48 hours, Mx proteins were detected in monocytes and lymphocytes. Within two days of starting treatment with subcutaneous IFN alpha 2b, granulocytes, monocytes and lymphocytes of 16 patients with cancer stained strongly for Mx proteins. The intensity of staining was correlated with the Mx content of whole blood measured using a specific ELISA. Prior to IFN treatment, cells from bone marrow and skin tissue specimens were negative for Mx proteins with the exception of endothelial cells. During treatment with IFN alpha 2b, nearly all cells from bone marrow and skin stained intensely.

CONCLUSIONS

These new monoclonal antibodies facilitate the detection of Mx positive cells in peripheral blood and in frozen or paraffin wax specimens. The advantage of this staining method is that individual cells which have responded to viruses or biologically active IFN alpha, beta or omega can be identified.

Factors inhibiting IFN activity

Several factors may inhibit the activity of IFNs. Some of these occur naturally, others are therapy-induced or artificial. Naturally occurring antibodies appear to have a much broader reactivity than therapy-induced antibodies. Naturally induced antibodies are reported in patients suffering from chronic graft-versus-host disease after bone marrow transplantation. Differences in the reported immunogenicity between interferons may not be due to the minor variation in amino acid sequence. The clinical significance of therapy-induced antibodies has been unclear. In patients treated for chronic hepatitis C, antibody formation is closely related to relapse. In animal studies the efficacy of treatments targeting the IFN receptor interaction has been shown. Soluble IFN-gamma receptor inhibits the development of autoimmune diseases in mice. Monoclonal antibodies to the IFN-alpha receptor protects against allograft rejections in monkeys. Two naturally occurring inhibitors of IFN action were reported. The clinical significance and structure of these inhibitors remain elusive.

Epitopes recognized by neutralizing therapy-induced human anti-interferon-alpha antibodies are localized within the N-terminal functional domain of recombinant interferon-alpha 2

During prolonged recombinant interferon (rIFN)-alpha 2 therapy, a minority of patients develop high-titer neutralizing IFN-alpha antibodies. Sera from nine IFN-alpha antibody-positive patients were studied to characterize the specificity of anti-IFN-alpha neutralizing antibodies by their ability to inhibit the antiviral and antiproliferative activity of different rIFN-alpha subtypes and rIFN-alpha 1/alpha 2 hybrids. These therapy-induced antibodies (Tab) were compared with IFN-alpha-specific autoantibodies (Aab) from two patients with systemic lupus erythematosus who had never received any exogenous IFN-alpha. Although IFN-alpha subtypes are closely related in structure, Tab inhibited the antiviral activity of only recombinant (r)IFN-alpha 2 and rIFN-alpha 6, but not or slightly that of rIFN-alpha 1, -alpha 7, -alpha 8 and -alpha 14. Furthermore, of four different rIFN-alpha 1/alpha 2 hybrids tested, Tab inhibited only those which contained the N-terminal residues 17-64 of rIFN-alpha 2. Comparison of the primary sequences of neutralized and not neutralized subtypes suggests an epitope involving the residues 22-31 of IFN-alpha 2 is recognized. Thus, Tab block rIFN-alpha 2 by reacting with only one of two functional domains. In contrast, Aab possessed a broad specificity and neutralized both the antiviral and antiproliferative activity of rIFN-alpha 2, -alpha 6, -alpha 7, -alpha 8, and -alpha 14. They also neutralized all four rIFN-alpha 1/alpha 2 hybrids tested. These data demonstrate that Tab are highly specific for the therapeutic IFN-alpha subtype and specifically neutralize rIFN-alpha 2 by binding to its N-terminal functional domain.

[Therapy of chronic myeloid leukemia with interferon-alpha. A decade of experiences]

PATIENTS AND RESULTS

One hundred and fifty-nine patients with chronic myelogenous leukemia have been treated in six studies during 10 years at Hannover Medical School University Center. The prognosis of 111 patients without pretreatment has been improved compared to conventional therapy with a median survival of 5.7 years. Cytogenetic remissions have been induced in all studies followed for a longer time. The most pronounced improvement of prognosis has been observed in these patients.

CONCLUSIONS

Several conclusions can be drawn on the basis of the results on the different treatment concepts: 1. Patients with pretreatment have an unfavourable response to interferon. 2. There is a likely effect of the dose of Interferon alpha on the frequency of cytogenetic remissions. 3. The combination of Interferon alpha and interferon gamma has been toxic and ineffective in a pilot study. 4. The combination of interferon and cytosine arabinoside has a positive impact on the frequency of cytogenetic remissions. A continuous parallel application of both drugs seems to be most effective in this respect. An ongoing trial has been initiated to compare a fixed combination of Interferon alpha and cytosine arabinoside and with hydroxyurea respectively. Additionally the feasibility of autologous peripheral blood stem cell transplantation will be studied in patients with insufficient response to the interferon treatment.

No synergistic activity of epirubicin and interferon-alpha 2b in the treatment of hepatocellular carcinoma

Single-agent activity for anthracyclines reflected by response rates of 10%-30% has been reported in patients with advanced hepatocellular carcinoma (HCC). Preclinical data indicate that alpha-interferon could enhance the cytotoxic activity of the anthracycline Adriamycin or its analog epirubicin. In a phase I/II study, 31 patients with biopsy-proven inoperable HCC were treated with interferon-alpha 2b given s.c. at a dose of 3 x 10(6) units/m2 per day for 5 days per week plus weekly epirubicin given at 25 mg/m2 as an i.v. bolus. The protocol called for 4 consecutive weeks of treatment followed by 1 week off treatment. In all, 15 patients had been previously treated; 6 patients had failed hormonal therapy (tamoxifen), 5 patients had failed prior anthracycline treatment, and 4 patients had received chemoembolization of the tumor and had subsequently progressed. A total of 30 patients were evaluable for response. In all, 1 patient (3%) achieved a partial response for 8+ months and 11 patients (35%) achieved stabilization of disease. Six patients had a fall in alphafetoprotein (AFP) values of > 50% during therapy. The median survival for all patients was 9.5 months (range, 3-34+ months). The main side effects were hematological toxicity and fever, both of which were considered tolerable. As an indicator of the immunostimulatory effects of interferon, an elevation in serum markers of inflammation [C-reactive protein (CRP), beta 2-microglobulin] was found in 15%-20% of patients. All patients had measurable Mx protein production during therapy, but these effects were not correlated to the clinical response. The clinical response rate achieved in this trial indicates that the combination of interferon and epirubicin, at least when used on the schedule reported herein, is not superior to treatment with either agent alone for patients with advanced HCC. However, single patients achieved a prolonged progression-free interval (8-10+ months) on this therapy, and it may therefore be an option for patients who have failed prior hormonal or single-agent anthracycline therapy.

Common variable immunodeficiency (CVID) and MxA-protein expression in blood leucocytes

The underlying immunopathogenic mechanism of CVID has been suspected to involve a chronic viral infection or an autoimmune condition. However, formal proof of viral infection is lacking. Measurement of MxA-protein in leucocyte lysates is a sensitive test for evaluating the activation of the host's interferon system. Both viral infections and autoimmune diseases such as systemic lupus erythematosus (SLE) strongly induce MxA-protein in peripheral leucocytes. We therefore examined 15 patients with longlasting hypogammaglobulinaemia for MxA-protein induction in vivo: 13 patients suffered from CVID, one from hyper-IgM syndrome, and one patient had chronic B lymphocytic leukaemia associated with immunoglobulin deficiency and chronic papilloma virus infection (condylomata accuminata). Only the latter patient exhibited a strong MxA-protein expression; two CVID patients were borderline positive, and the remaining 12 patients including the hyper-IgM syndrome were MxA-protein-negative. There was no relationship between MxA expression and low CD4/CD8 ratios or increased CD8/CD57+ T cell counts, although both conditions are often observed in CVID as well as in chronic viral infections. When exposed in vitro to interferon-alpha (IFN-alpha), peripheral blood leucocytes of four MxA-negative patients were capable of producing normal amounts of MxA-protein. Taken together, these results argue against a viral or autoimmune pathogenesis of CVID.

Quantitation of interferon-induced Mx protein in whole blood lysates by an immunochemiluminescent assay: elimination of protease activity of cell lysates in toto

Due to the rapidly expanding usage of interferons and its costliness of therapy, it is important to evaluate the clinical efficacy of the various interferons. Directly assaying circulating interferon is technically quite difficult. Here, we present an alternate method to evaluate interferon therapy by assaying a unique protein, called Mx protein, which is a 78 kDa cytoplasmic protein selectively induced by type-1 interferon in human leukocytes. The current assay is a two-site chemiluminescent immunoassay, designed to detect Mx protein in whole blood lysates. Since the Mx protein once solubilized, is highly susceptible to proteolysis in whole blood lysates, we have devised a new procedure both to maximize its solubility and virtually eliminate its proteolytic degradation. A mouse monoclonal antibody conjugated to the derivatized-paramagnetic particles and an acridinium ester-labeled antibody serve as the solid phase capture and detector antibodies, respectively. This assay is applicable to both manual and automated modes with a detection limit of Mx protein at 20 ng/ml whole blood. Availability of a reliable assay for Mx protein should facilitate the clinical evaluation of many of the newly constructed type-1 interferons.

Low dose alpha interferon treatment in chronic hepatitis B virus infection

Fifty eight patients with chronic viral hepatitis B (HBV) were randomised in a prospectively controlled trial. Thirty patients were treated with 3 million units (MU) of interferon alfa-2b subcutaneously thrice weekly for four months. Twenty eight controls received no treatment. The follow up period after treatment was six months. Twenty eight treated patients and 27 controls completed the protocol. One woman in the treatment group showed a complete response, and eight other treated patients (32%) showed a partial response. Three patients in the control group (11%) lost hepatitis B e antigen and HBV-DNA spontaneously. This finding is statistically significant (p < 0.05). The elimination of HBV markers from the serum was associated with a return to normal of serum aminotransferase activities. Reactivation of hepatitis was not observed after seroconversion.

Effective natural interferon-alpha therapy in recombinant interferon-alpha-resistant patients with hairy cell leukemia

To explore the relationship between anti-interferon-alpha (anti-IFN-alpha) antibodies and loss of clinical responsiveness to IFN-alpha treatment, we examined sera from 59 patients with hairy cell leukemia who responded to therapy with recombinant IFN-alpha-2a (rIFN-alpha-2a). During the first 2 years of therapy, 10 patients developed rIFN-alpha-2a-neutralizing and 15 rIFN-alpha-2a-binding antibodies. Nine of the 59 initially responding patients became resistant to rIFN-alpha-2a and suffered a relapse of the disease at 7 to 24 months of treatment. All nine relapsing patients tested positive for both neutralizing and binding antibodies with titers above 400 INU/mL, while none of the antibody-negative patients relapsed. Six patients with detectable binding antibody titers below 400 INU/mL continued to respond to treatment. By measuring the IFN kinetics and the levels of the IFN-induced Mx-homologous protein in mononuclear cells after a single injection each of rIFN-alpha-2a and nIFN-alpha the IFN antibodies of eight of the nine resistant rIFN-alpha patients were found to be highly specific for rIFN-alpha-2a. Therefore, these eight patients were switched to natural IFN-alpha (nIFN-alpha) therapy at doses of 3 million IU, three times a week. All eight patients responded to treatment with nIFN-alpha, achieving durable objective responses similar to those obtained previously with rIFN-alpha-2a. These data clearly demonstrate that rIFN-alpha antibody-positive patients can effectively be treated with nIFN-alpha.

Treatment of anti-recombinant interferon-alpha 2 antibody positive CML patients with natural interferon-alpha

Of 38 patients with a Philadelphia-chromosome positive chronic myeloid leukaemia treated with recombinant interferon alpha (rIFN-alpha) 2a or 2b and monitored for emergence of IFN-antibodies in their sera 11 patients developed rIFN-alpha 2 binding and 10 rIFN-alpha 2 neutralizing antibodies. rIFN-alpha neutralizing antibody positive patients experienced significantly (P less than 0.025) more clinical relapses (6/10) than IFN-antibody negative patients (6/28) during continuous IFN-therapy. Furthermore, IFN-antibody-positive patients with titre above 400 INU/ml were more likely to relapse under rIFN-alpha-therapy than IFN-antibody-negative patients with titre below 400 INU/ml (P less than 0.05). Seven rIFN-antibody-positive patients experiencing a clinical relapse or a primary non-responsiveness were treated with two- to three-fold increased doses of rIFN-alpha 2. Only one of these seven patients developed a partial haematological remission upon intensification of the rIFN-alpha 2 therapy. Consecutively, the six patients failing high dose rIFN-alpha treatment were switched to a natural IFN-alpha preparation (3 x 9 x 10(6) I.U. weekly s.c.). Under such treatment two of the six patients achieved a long-lasting complete, one a partial haematological remission. In high-titred IFN-antibody positive patients significantly altered serum-IFN-titre and minimal IFN-inducible Mx-homologue concentrations were measured; in contrast, nIFN-alpha induced normal IFN-titre and dose-equivalent Mx-homologue amounts in these patients. The data prove that high-titred rIFN-alpha neutralizing antibodies abrogate the biological action of rIFN-alpha, but not of nIFN-alpha in vivo and explains why nIFN-alpha can be effective in the anti rIFN-alpha 2 positive patients.

[Multicenter prospective controlled study of therapy of chronic myeloid leukemia. Comparison of busulfan, hydroxyurea and interferon alpha (April 1990 status)]

In a multicenter study it is being determined, whether the use of hydroxyurea or of interferon alpha instead of busulfan prolongs the chronic phase of Philadelphia-positive CML. Additional goals are the examination, whether the types of disease evolution and the terminal phases differ between the treatment groups, and the prospective recognition of prognostic criteria for the duration of the chronic phase of CML. By September 5, 1990, 593 CML-patients had been randomized, 221 for busulfan, 228 for hydroxyurea and 144 for interferon alpha. The average age is about 51 years. By April 30, 1990, 106 patients had reached the end of the chronic phase, 126 had died. The median survival of Philadelphia-positive patients was 3.95 years, that of all patients 3.75 years. The median observation time of all patients was 1.34 years (mean 1.60 years). At present, no significant difference in survival is recognizable between the three treatment arms, although fewer adverse effects have been observed in the hydroxyurea arm.

Correlation of the antiproliferative effect and the Mx-homologous protein induction by IFN in patients with malignant melanoma

The human interferon-induced intracellular protein homologous to the murine Mx-protein has recently been identified by means of a specific monoclonal antibody. Three of six melanoma cell lines elicited this intracellular human Mx-homolog upon incubation with IFN-alpha or IFN-gamma, yet all six melanoma cell lines tested were susceptible to the antiproliferative effect of IFN-alpha and IFN-gamma. Compared per antiviral unit, IFN-gamma had weaker Mx-inducing but stronger antiproliferative activity than IFN-alpha. These data suggest that the IFN-induced Mx-homologous protein is not involved in the antiproliferative action of IFN on malignant melanoma cell lines. Furthermore, 51 patients with advanced malignant melanoma were treated thrice weekly with 10 x 10(6) IU rIFN-alpha-2b and 6 x 10(6) nIFN-alpha, respectively. Nine of the 51 patients experienced systemic objective tumor responses (3 complete response, 6 partial response), but had Mx concentrations in their mononuclear cells equal to the Mx levels of non-responders during IFN-alpha therapy. Therefore, the level of Mx-homologous protein induced during IFN therapy is not a predictive marker for an antitumor response in malignant melanoma.

The human intracellular Mx-homologous protein is specifically induced by type I interferons

The murine Mx-1 protein is one of the best biochemically and functionally characterized interferon (IFN)-induced proteins that is necessary, and sufficient, for providing resistance to murine cells against viral influenza infection. Recently an intracellular human protein homologous to the murine Mx-1 protein has been identified by means of a specific monoclonal antibody. The restricted induction of this intracellular protein in human mononuclear cells (MNC) by various cytokines was investigated. MNC from 26 of 28 healthy people and 35 of 36 cancer patients before IFN-alpha therapy had no detectable Mx-homologous protein. Incubation of human MNC with IFN-alpha and IFN-beta for 24 h at different concentrations led to a dose-dependent induction of the Mx-homologous protein. All IFN-alpha or IFN-beta preparations tested were equally effective in eliciting this intracellular protein. IFN-gamma induced only 1% of the Mx amount elicited by type-1 IFN compared on a weight basis. Neither interleukin (IL) 1 nor IL3, IL4, IL5, IL6, tumor necrosis factor-alpha/beta, granulocyte colony-stimulating factor (CSF) or granulocyte macrophage-CSF at any of the concentrations tested were capable of eliciting any detectable amount of the Mx homolog, while IL2 was a poor Mx-homologous protein inducer. In the presence of high-titered IFN-alpha antisera both IL2 and IFN-gamma were unable to stimulate this protein, proving that IFN-gamma and IL2 indirectly induce the Mx homolog via IFN-alpha. Therefore, the human Mx-homologous protein is a strictly by type I IFN-regulated protein in human peripheral blood lymphocytes.

Emergence and decay of the human Mx homolog in cancer patients during and after interferon-alpha therapy

The human Mx, an interferon (IFN)-alpha- and IFN-beta-induced 76-kd protein, is a homolog (Mx-homolog) to the murine Mx protein, which is necessary and sufficient to provide adequate resistance against influenza virus in murine cells and in mice. Leukocytes from 36 patients with tumors (chronic myelogenic leukemia, hairy cell leukemia, and malignant melanoma) were monitored for their Mx-homolog content before, during, and after rIFN-alpha-2b therapy. Before therapy, only one patient was slightly positive for Mx-homolog. All 36 patients showed a significant increase of Mx-homolog in their mononuclear cells within the first day of IFN therapy. During therapy, the Mx-homolog levels remained elevated. After cessation of treatment, the Mx-homolog content in the mononuclear cells decreased slowly; within 2 weeks, it was about 20-30% of its value during therapy. However, even after 3 weeks, the Mx-homolog was still detectable. The maximally induced Mx-homolog concentration showed a significant correlation to the IFN dose given in vivo. These data indicate that the Mx-homolog is an excellent marker for monitoring the activity of IFN during IFN therapy. In addition, the in vivo endogenous activation of the IFN system might be detectable by the determination of the Mx-homolog despite the lack of circulating IFN.

[Treatment of chronic hepatitis B with interferon alpha-2b]

In a prospective randomized trial 58 patients (46 men, 12 women; mean age 41 [18-65] years) with histologically proven chronic hepatitis B and demonstration of HBs antigen and hepatitis B virus DNA in serum were randomly divided into two groups: 30 patients were treated with recombinant alpha 2b interferon. The interferon was administered subcutaneously, 3 x 10(6) IU, three times weekly for four months. 28 patients served as untreated controls. There was a six-month post-treatment follow-up. Two patients in the treatment group and one in the control group had to be excluded later. In the treatment group one patient responded completely (HBs antigen, HBe antigen and HBV-DNA negative) and eight partially (HBe antigen and HBV-DNA negative). In three patients of the control group, HBe antigen and HBV DNA were no longer demonstrated (P less than 0.05). The loss of HBV features was associated with normalization of serum transaminases activity. Reactivation of liver inflammation after seroconversion was not observed.

The interferon-induced Mx-homologous protein in people with symptomatic HIV-1 infection

Twenty-six people with symptomatic HIV-1 infection were screened for the presence of interferon (IFN) alpha and IFN alpha antibodies in their sera and the presence of the IFN-induced intracellular Mx-homologous protein in their peripheral blood leukocytes. Eleven people had measurable IFN alpha levels ranging from 1 to 40 IU/ml. None of the sera tested was positive for IFN alpha binding or IFN alpha neutralizing antibodies in the assays employed. Twenty-five of the 26 people had significant levels of the Mx-homologous protein in their peripheral mononuclear cells. The Mx concentrations varied from 0.3 to 6 U/ml in the people studied. IFN alpha-positive people had significantly higher levels of the Mx homolog than IFN alpha-negative people (P less than 0.03). Furthermore, the Mx homolog content in Walter-Reed class 2 people was significantly lower than in Walter-Reed class 5/6 people (P less than 0.01). Our results suggest that the IFN system is activated in more than 90% of the people with lymphadenopathy-associated syndrome, AIDS-related complex and AIDS. Since acid-labile IFN alpha can induce the Mx homolog in vitro endogenously produced IFN alpha seems likely to be responsible for the high Mx homolog levels detected.

Humoral response to recombinant interferon-alpha 2b in patients receiving recombinant interferon-alpha 2b therapy

Twenty-seven patients in the chronic phase of a Philadelphia chromosome-positive chronic myelogenic leukemia (CML) underwent a monotherapy with recombinant interferon-alpha 2b (rIFN-alpha 2b), receiving a mean dose of 3 x 5 Mio. IU per week. Eight of the 27 patients developed both rIFN-alpha 2b-binding and -neutralizing antibodies during therapy. Sera of these patients abrogated both antiviral and antiproliferative activities of rIFN-alpha 2b, but not of nIFN-beta or rIFN gamma. Only one serum neutralized nIFN-alpha. The IFN binding and neutralizing titers rose during therapy, while a decrease occurred over months after cessation of therapy. The IgG fraction obtained by DEAE chromatography contained more than 90% of the IFN-neutralizing capacity of the purified sera. This result strongly suggested that IgG antibodies are responsible for the IFN-alpha-neutralizing activity.

MX homologous protein in mononuclear cells from patients with systemic lupus erythematosus

The 76-kd human interferon (IFN)-induced MX protein is the homolog to the murine protein, which is necessary and sufficient to provide adequate resistance to influenza virus infection in murine cells and in mice. Fifty-one patients with systemic lupus erythematosus (SLE) were screened for the presence of the MX homolog in mononuclear cells and for IFN and anti-IFN antibodies in serum. In 47 of 51 patients, significant levels of the MX homolog were found, while only 15 of 51 patients had measurable alpha-IFN in their serum. The IFN activity found in these sera was characterized as a partially acid-labile alpha-IFN, by means of acid-stability cross-reactivity on heterologous cells, trypsin sensitivity, and neutralization by homologous or heterologous antisera. Four of the patients had no detectable MX homolog in their leukocytes; 3 of these 4 possessed an anti-alpha-IFN antibody that was able to neutralize both a natural alpha-IFN preparation and the acid-labile IFN in SLE sera. Also, acid-labile alpha-IFN-containing SLE sera induced the MX homolog in vitro in mononuclear cells from healthy donors. These observations suggest that endogenously produced alpha-IFN is responsible for the observed induction of the MX homolog in SLE and that the IFN system is activated in more than 90% of SLE patients.

Recombinant human interferon (IFN) alpha-2b in chronic myelogenous leukaemia: dose dependency of response and frequency of neutralizing anti-interferon antibodies

Twenty-seven patients with Philadelphia chromosome positive chronic myelogenous leukaemia in the chronic phase were treated with low doses of recombinant interferon (IFN) alpha-2b. Ten patients entered a complete and six a partial haematologic remission with a median duration of 5.8 and 9.1 months respectively. Five minor cytogenetic responses were observed. These results are inferior compared to other studies with higher interferon-doses. Fever was an acute side effect after injection of IFN, limb pains and fatigue occurred protractedly. Haematologic side effects, nonspecific EEG changes, weight loss, and development of pulmonary infiltrates were observed in later periods of the treatment. Eight patients developed neutralizing anti-IFN antibodies after 4.2-20.4 months (median 12.8 months). Anti-IFN antibodies were associated with relapse or refractoriness to IFN treatment: five out of nine patients with rising WBC after initial fall had antibodies, while four did not. Two out of four patients with primary non-response had IFN-antibodies. These results may indicate a serious problem in the long-term treatment of CML with recombinant interferon.

[Exacerbation of psoriasis during alpha-interferon therapy]

In three female patients with metastasising malignant melanoma psoriasis exacerbated during the third week of treatment with recombinant interferon-alpha-2b, at a weekly dosage of three times 10 million IU. The psoriatic lesions vanished almost completely after discontinuing the drug and systemic administration of corticosteroids. It appears that induction of psoriasis exacerbation is yet another important side effect of interferon, at least at elevated doses, whereas low alpha-interferon dosage levels may improve psoriasis in nononcological patients.

Presence of interferon and anti-interferon in patients with systemic lupus erythematosus

Sera from 61 patients with systemic lupus erythematosus (SLE) were serially screened over a period of at least 2 years for IFN and anti-IFN antibodies. IFN concentrations were measured both with a cytopathic effect assay and a more sensitive radioimmunoassay. Of the patients 15% (9/61) had IFN in their serum at one or more occasions as measured in the bioassay (greater than or equal to 6 IU/ml); employing a RIA (greater than or equal to 1 IU/ml) 28% (17/61) of the patients studied were positive for IFN-alpha. Fifteen patients had a measurable interferonemia over 2-16 months; only two patients had detectable IFN in their serum at only one occasion. In five patients, hourly and daily variations of the IFN titer as measured by RIA were found to amount to less than 80%. The IFN activity found in these sera was characterized as IFN-alpha by means of acid stability, cross-reactivity on heterologous cells, trypsin sensitivity, and neutralization by homologous and heterologous antisera. IFN antibodies were quantified with a neutralization bioassay, an ELISA, and a radioimmunoassay. Of the 61 patients 5% (3) possessed high titers of anti-IFN antibodies which persisted over 2 years. The IFN-alpha antibody positive patients had an inactive form of the disease over years without visceral involvement but decreased serum complement levels (C4, C3, CH50) and repeated episodes of Quincke-like edema.

Treatment with natural human interferon alpha of a CML-patient with antibodies to recombinant interferon alpha-2b

A patient with Philadelphia-chromosome positive chronic myelogenous leukemia developed interferon antibodies on treatment with recombinant interferon alpha-2b. Clinically this event corresponded with progressive disease. No cross-reactivity of antibodies with human leukocyte interferon was found by Western blot. Treatment was switched to human leukocyte interferon with an obvious clinical effect: WBC was reduced and platelet count stabilized, but the effect was transient and no hematologic remission was achieved. Human leukocyte interferon may be an alternative in CML-patients with neutralizing antibodies to recombinant interferon alpha.

Intralesional interferon-alpha therapy in advanced malignant melanoma

Fifty-one evaluable patients with histologically proven metastatic melanoma and at least one skin metastasis were treated intralesionally with interferon-alpha (IFN-alpha). Twenty-six of the patients were given highly purified natural IFN-alpha 6 Mio. IU three times per week. Twenty-five patients were given 10 Mio. IU three times per week of a recombinant IFN-alpha 2b (rIFN-alpha 2b). All patients were examined for systemic and local responses to this treatment. The systemic responses consisted of nine objective remissions, each of which lasted from 2 to 18 or more months. There were 24 complete or partial local responses. Forty-two of the 51 patients had at least two skin metastases so that IFN-injected and noninjected tumor sites could be compared. The difference between systemic and local efficacy was highly significant statistically (P = 0.0004). The results show that IFN-alpha has clinically observable antitumor activity in malignant melanoma.

[Low-dose alpha-interferon treatment of hairy cell leukemia]

Fifteen patients (36-71 years old) with histologically proven hairy-cell leukemia were treated with a low dose of IFN-alpha. The treatment consisted of 1 million I.U. given daily subcutaneously. After 1 month the dose was reduced in all patients 1 million I.U. thrice weekly. Four of the 15 patients have been splenectomized, with two patients receiving chemotherapy prior to the IFN treatment. All patients exhibited at least one cytopenia. The IFN treatment was well tolerated. Only two of the 15 patients experienced mild fever after the first injection, one patient had apathia and mild somnolence after 2 months of therapy. At present 15 patients can be evaluated: 6-18 months after start of therapy two patients showed a complete response with normalization of both peripheral blood and bone marrow, 10 patients experienced a partial response, while one patient showed a slight response with improvement of the thrombocyte count only. Two patients showed no improvement after 3 months of therapy; these patients are presently being treated with 5 million I.U. IFN-alpha thrice weekly. In spite of the low number of patients these data strongly indicate that IFN-alpha-2 is effective in hairy-cell leukemia at this low dose.

[Beta interferon therapy in hairy cell leukemia]

Eleven patients with histologically proven hairy-cell leukemia were treated for 2 to 6 months with a natural beta-interferon (beta-IFN) preparation (3 X 4 million units week i.v.). Three of the eight evaluable patients experienced a partial response, two a minor response, and three no improvement. A reduction of the hairy-cell infiltration of the bone marrow was observed in one patient. Typical IFN side-effects with flu-like symptoms were noted. These results demonstrate that IFN-beta has some clinical efficacy in hairy-cell leukemia.

Characterization of interleukin 2-dependent cytotoxic T-cell clones. IV. Production of alpha, beta and gamma interferons and interleukin 2 by Lyt-2+ T cells

The production of alpha, beta and gamma interferons (IFN) and interleukin 2 (IL-2) by Lyt-2+-dependent cytotoxic T-cell lines/clones was investigated. Cloned and uncloned T-cell lines specific for H-2Dd or the unique RL male 1 leukemia antigen were studied. After infection with Sendai virus (SV) or Newcastle disease virus (NDV) all cell lines produced IFN-alpha and -beta. Induction of IFN-gamma was attempted with the mitogens Con A, PHA, PWM, SEA, and SEB, with poly(I:C), with antibodies Lyt-1.2, -2.2, and Thy-1.2, or with the target cells Meth A (H-2Dd+) and RL male 1. All mitogens were effective inducers. However, the antibodies and poly(I:C) were not. One uncloned RL male 1-specific cell line CTLL-RP, produced IFN-gamma after induction with RL male 1. Production of IFN-alpha, beta depended on IL-2, whereas production of IFN-gamma did not, although addition of highly purified IL-2 increased IFN-gamma production even in the absence of other inducers. Crude IL-2 inhibited the production of IFN-gamma but not IFN-alpha, beta. In response to mitogens, some T-cell clones also produced IL-2. The results demonstrate that Lyt-2+ cells can produce a broad spectrum of lymphokine activities after appropriate stimulation. Their availability now affords us the opportunity to study the regulation of lymphokine production at the clonal level.

Ia dependent lymphokine production in the syngeneic mixed lymphocyte response

We have shown that Interleukin 2 (IL-2) is produced in the murine syngeneic mixed lymphocyte response (SMLR) by T cells from both young thymus and adult spleen responder populations. We extend these findings in this report by showing that: 1) IL-2 production is the function of an Lyt 1+, Lyt-2-, Qa-2,3+, Qa-5- and Ia- T cell; 2) Similar to IL-2 elicited following alloantigen or mitogen stimulation, it peaks at day 2-3 of culture in both thymic and splenic SMLR; 3) The presence of the SMLR/IL-2-producing cell in thymus is a transient event, disappearing by 4 weeks of age; 4) The production of cytotoxic T lymphocyte (CTL) helper factor activity in primary SMLR is under the same Ia control as is IL-2 production and 5) That significant levels of interferon (IFN) are produced in the splenic SMLR. These findings support our contention that the SMLR represents an in vitro model of an in vivo mechanism for the production of IL-2, and that such a mechanism may play a role in T cell differentiation.

Role of interferon in natural kill of HSV-1-infected fibroblasts

The production of interferon during natural killer (NK) assays against HSV-1-infected fibroblasts (NK(HSV-1)) was studied to determine whether this interferon was responsible for inducing the preferential lysis of herpes-virus-infected target cells over uninfected target cells. The interferon produced during NK(HSV-1) assays was analyzed and found to have the properties of HU-IFN-alpha. Little or no IFN was produced during NK assays against uninfected fibroblasts (NK(FS)) or K562 (NK(K562)) cells. Although the appearance of interferon in the culture supernatants seemed to parallel the development of cytotoxicity during NK(HSV-1) assays, the levels of cytotoxicity and IFN generated did not correlate, arguing against a strict quantitative dependence of cytotoxicity upon IFN production. NK(K562) and NK(FS) cytotoxicity developed with little or no production of IFN. When IFN-pretreated effector cells were used, there was still a preferential lysis of infected over uninfected target cells. This preferential lysis by IFN-treated effector cells of infected over uninfected targets was seen as early as 2 hr into the assay. Anti-IFN antibodies added to the NK assays, although neutralizing all the IFN produced during the assays, had no effect on NK(FS) or NK(K562) cytotoxic activity and caused a slightly reduction of NK(HSV-1) activity only in one of three experiments. We conclude that although IFN is generated during NK(HSV-1) assays, this IFN cannot solely account for the increased lysis of infected over uninfected cells and that NK(HSV-1) activity is in some other way dependent on the virus infection.

Role of interferon in natural kill of HSV-1-infected fibroblasts

The production of interferon during natural killer (NK) assays against HSV-1-infected fibroblasts (NK(HSV-1)) was studied to determine whether this interferon was responsible for inducing the preferential lysis of herpes-virus-infected target cells over uninfected target cells. The interferon produced during NK(HSV-1) assays was analyzed and found to have the properties of HU-IFN-alpha. Little or no IFN was produced during NK assays against uninfected fibroblasts (NK(FS)) or K562 (NK(K562)) cells. Although the appearance of interferon in the culture supernatants seemed to parallel the development of cytotoxicity during NK(HSV-1) assays, the levels of cytotoxicity and IFN generated did not correlate, arguing against a strict quantitative dependence of cytotoxicity upon IFN production. NK(K562) and NK(FS) cytotoxicity developed with little or no production of IFN. When IFN-pretreated effector cells were used, there was still a preferential lysis of infected over uninfected target cells. This preferential lysis by IFN-treated effector cells of infected over uninfected targets was seen as early as 2 hr into the assay. Anti-IFN antibodies added to the NK assays, although neutralizing all the IFN produced during the assays, had no effect on NK(FS) or NK(K562) cytotoxic activity and caused a slightly reduction of NK(HSV-1) activity only in one of three experiments. We conclude that although IFN is generated during NK(HSV-1) assays, this IFN cannot solely account for the increased lysis of infected over uninfected cells and that NK(HSV-1) activity is in some other way dependent on the virus infection.

Induction of human gamma-interferon in lymphoid cells by Staphylococcus enterotoxin B; partial purification

Human white blood cells produced interferon (IFN) in response to Staphylococcus enterotoxin B (SEB) in vitro. The majority of this IFN was classified as IFN-gamma by virtue of its acid instability, non-neutralization by antisera recognizing alpha or beta IFNs and species-specificity for human cells. The IFN activity appeared after 3-6 hr and reached maximum levels between day 2 and 3. The SEB-induced IFN was partially purified to about 10(5.5) units/mg protein by chromatography on controlled pore glass beads (CPG) and Sephadex G-100 columns. While the CPG column purification step increased the specific activity 50 to 100-fold, two peaks of IFN activity were eluted from the Sephadex G-100 column. The first activity peak containing the majority of the loaded IFN appeared to be active only on human cells and was not neutralized by anti-HuIFN-alpha and had an apparent molecular weight of about 44,000 daltons, the second peak (about 5% of the loaded IFN) showed antiviral activity on both human and bovine cells, was at least partially neutralizing by anti-HuIFN-alpha and had an estimated molecular weight of 21,000 daltons. The specific activity in the first IFN peak was about 30-fold increased by the gel filtration chromatography with a recovery of approximately 60-80%.

Human gamma interferon production by leukocytes induced with monoclonal antibodies recognizing T cells

The murine monoclonal antibody OKT3 (IgG2), which recognizes the majority of human E-rosette-forming cells, was found to induce interferon (IFN) production in human peripheral lymphocytes in vitro. This IFN was classified as IFN-gamma by virtue of its acid stability, nonneutralization by antisera recognizing human IFN-alpha and beta, and non-cross-reactivity on bovine kidney cells. OKT3 elicited considerable IFN-gamma yields at a concentration of 1 ng/ml, at which only very low mitogenesis of the lymphocytes measured by 3H-thymidine incorporation was seen. The IFN-gamma activity appeared beginning 3 to 6 hr after stimulation and reached its maximum after 36 hr. Anti-human Lyt3, anti-human Lyt2, or anti-human Lyt1 monoclonal antibodies, recognizing all or the majority of the E-rosette-forming cells, did not elicit IFN-gamma production. The OKT4 monoclonal antibody, which defines a subpopulation of T cells containing cells with helper activity, induced marginal levels of IFN-gamma. In contrast, OKT8 monoclonal antibody (defining cytotoxic/suppressor cells) as well as monoclonal or heterologous antibodies recognizing histocompatibility antigens or surface immunoglobulin failed to induce IFN-gamma production. Heterologous anti-thymocyte globulin or anti-lymphocytic serum were effective IFN-gamma inducers. Cell separation studies of the leukocytes demonstrated that E-rosette-forming cells are responsible for production of IFN-gamma induced by OKT3. Treatment of the leukocyte suspension with OKt3 monoclonal antibody plus complement abolished IFN-gamma production induced by this antibody. These results demonstrate that the OKT3 antibody recognizing an antigen present on the majority of the E-rosette-forming cells alone is sufficient to induce IFN-gamma production. OKT3-positive cells are apparently the producers of this IFN-gamma.

Human gamma interferon production by leukocytes induced with monoclonal antibodies recognizing T cells

The murine monoclonal antibody OKT3 (IgG2), which recognizes the majority of human E-rosette-forming cells, was found to induce interferon (IFN) production in human peripheral lymphocytes in vitro. This IFN was classified as IFN-gamma by virtue of its acid stability, nonneutralization by antisera recognizing human IFN-alpha and beta, and non-cross-reactivity on bovine kidney cells. OKT3 elicited considerable IFN-gamma yields at a concentration of 1 ng/ml, at which only very low mitogenesis of the lymphocytes measured by 3H-thymidine incorporation was seen. The IFN-gamma activity appeared beginning 3 to 6 hr after stimulation and reached its maximum after 36 hr. Anti-human Lyt3, anti-human Lyt2, or anti-human Lyt1 monoclonal antibodies, recognizing all or the majority of the E-rosette-forming cells, did not elicit IFN-gamma production. The OKT4 monoclonal antibody, which defines a subpopulation of T cells containing cells with helper activity, induced marginal levels of IFN-gamma. In contrast, OKT8 monoclonal antibody (defining cytotoxic/suppressor cells) as well as monoclonal or heterologous antibodies recognizing histocompatibility antigens or surface immunoglobulin failed to induce IFN-gamma production. Heterologous anti-thymocyte globulin or anti-lymphocytic serum were effective IFN-gamma inducers. Cell separation studies of the leukocytes demonstrated that E-rosette-forming cells are responsible for production of IFN-gamma induced by OKT3. Treatment of the leukocyte suspension with OKt3 monoclonal antibody plus complement abolished IFN-gamma production induced by this antibody. These results demonstrate that the OKT3 antibody recognizing an antigen present on the majority of the E-rosette-forming cells alone is sufficient to induce IFN-gamma production. OKT3-positive cells are apparently the producers of this IFN-gamma.

Production of interferon in the murine mixed lymphocyte culture. II. Interferon production is a T cell-dependent function, independent of proliferation

Interferon production occurs after two days of culture in murine mixed lymphocyte cultures (MLC). This was demonstrated in various combinations of mouse spleen cells differing at the major histocompatibility (H-2) locus. Interferon production could be demonstrated in one-way MLC when F1/parent combinations were used and in reactions in which one partner was treated by puromycin. After treatment of both cell populations with mitomycin C, interferon production occurred in the absence of lymphoproliferation. Interferon production in response to alloantigen did not occur in spleen cell cultures of nude mice and in cultures treated by anti-theta antiserum plus complement indicating that interferon production is a T cell-dependent function.