Effect of human leukocyte interferon on hepatitis B virus infection in patients with chronic active hepatitis

Lymphoblastoid interferon therapy of chronic HBV infection. A comparison of 12 vs. 24 weeks of thrice weekly treatment

This study set out to examine the relative effectiveness and tolerability of 12- versus 24-week courses of thrice weekly intramuscular lymphoblastoid interferon in the treatment of hepatitis B 'e' antigen (HBeAg)-positive chronic hepatitis B virus (HBV) infection, and to identify pretreatment factors predicting the outcome of therapy. Twenty patients were randomised to each treatment group. Treatment was associated with clearance of HBeAg and HBV-DNA in 59% of the 32 male patients, whereas none of the eight women responded (48% overall response rate). This response rate in males is at least three times the recorded spontaneous seroconversion rates in this population. Most of the women (5/8) were of Oriental origin and had minimal disease, factors that may have influenced response. The longer course was poorly tolerated and was therefore no more effective: eight of 20 patients withdrew because of side-effects. Variables associated with response included high AST (aspartate transaminase), short duration of disease and previous history of acute hepatitis. A response to antiviral therapy was accompanied by clinical and biochemical evidence of improvement in liver disease.

The effect of recombinant alpha-interferon treatment on serum levels of hepatitis B virus-encoded proteins in man

The effect of alpha-interferon treatment on serum levels of hepatitis B virus-encoded proteins was analyzed in eight patients with chronic type B hepatitis who participated in a pilot study of interferon therapy. Three individuals became HBsAg-negative, 4 lost HBeAg but remained HBsAg-positive and 1 remained positive for both HBsAg and HBeAg. Initiation of interferon treatment was rapidly followed by reduction or loss of hepatitis B virus DNA in the serum but by little immediate change in hepatitis B virus antigen levels. Changes in hepatitis B virus antigens were usually delayed. Loss of HBsAg from the serum was preceded by the sequential disappearance of pre-S-encoded proteins (pre-S1 and polymerized human serum albumin) and HBeAg. In patients who lost HBeAg but remained HBsAg-positive, serum levels of pre-S1 and polymerized human serum albumin usually, but did not always, decrease. The individual who remained HBsAg- and HBeAg-positive had unchanged serum levels of pre-S1, polymerized human serum albumin and HBsAg. These results suggest that alpha-interferon inhibits hepatitis B virus DNA replication but has little direct effect on synthesis of hepatitis B virus gene products.

2',5'-Oligoadenylate synthetase activity in peripheral blood lymphocytes as a clinical marker in interferon therapy for chronic hepatitis B

Treatment of chronic hepatitis B (CHB) with human leukocyte interferon (IFN-alpha) was studied in terms of increase of 2',5'-oligoadenylate (2-5A) synthetase activity in peripheral blood lymphocytes (PBL) after IFN-alpha administration. The 2-5A synthetase activity in PBL increased to a maximum 16-24 h after IFN-alpha injection and then gradually decreased, while serum HB virus DNA polymerase (HBV-DNAP) activity, which corresponds to the amount of HBV virions in the serum, decreased to a minimum after about 48 h. Increase in 2-5A synthetase activity was followed about 1 day later by decrease in DNAP activity. Furthermore, of 9 patients treated with IFN for at least 22 weeks and observed for over 1 year after IFN treatment, the effective 5 cases in which HBeAg disappeared during IFN therapy and did not reappear showed rather high increases in 2-5A synthetase activity, whereas the ineffective 4 cases in which HBeAg remained positive at the end of IFN therapy showed little increases in enzyme activity. The present study suggests that prescreening by 2-5A synthetase assay before IFN therapy should be useful for obtaining better results in IFN treatment of CHB patients.

Changes of hepatitis B virus (HBV) markers during prolonged recombinant interferon alpha-2A treatment of chronic HBV infection

Eleven HBsAg chronic carriers were treated with recombinant-interferon (rIFN)-alpha-2A with either 20 X 10(6) (n = 6) or 10 X 10(6) IU/m2 body surface (n = 5), i.m. twice weekly for 6 months. HBV-markers were tested monthly for 15 months. Throughout the follow-up, 6 patients (54%) became HBeAg, HBV-DNAp and HBV-DNA negative (responders). In addition, 8 were HBcAg-negative, 10 anti-HBc-IgM-negative and 2 HBsAg/IgM complexes negative. All patients gave polymerized human serum albumin receptors and HBsAg-positive results. The low rIFN dose seems to be more efficient for clearing HBV-markers than the high dose. Responder patients already showed lower (P less than 0.05) HBsAg concentration and HBsAg/IgM complexes levels in their basal samples as compared to non-responders, and exhibited under rIFN treatment significant decreases (P less than 0.05) in all HBV-markers studied. In conclusion, the most reliable HBV-markers to be assayed in the evaluation of antiviral therapy are HBV-DNA, HBV-DNAp or HBcAg. The testing of pHSA-R, HBsAg/IgM complexes and anti-HBc-IgM does not seem to be very useful.

A review of the efficacy of adenine arabinoside and lymphoblastoid interferon in the Royal Free Hospital studies of hepatitis B virus carrier treatment: identification of factors influencing response rates

We have reviewed the results of treating over 100 HBV carriers with adenine arabinoside, adenine arabinoside monophosphate and lymphoblastoid interferon. In the homosexual group of carriers, adenine arabinoside and its monophosphate have no value. However in this group, lymphoblastoid interferon will produce a response in over 50% of cases. This lack of effectiveness of adenine arabinoside monophosphate in this group may stem from its immunosuppressant properties. In heterosexual carriers both adenine arabinoside monophosphate and lymphoblastoid interferons are effective in approximately 50% to 60% of cases. However, the response rate is different in the various racial groups. Northern European and Mediterranean people appear to respond whereas those from the Far East do not. This may reflect the fact that there are at least two mechanisms by which the chronic carrier state may arise. In 5% to 10% of adults, a relative deficiency of alpha interferon production exists, and this defect is found in the majority of HBV carriers in Western Europe. In these, interferon acts as a replacement therapy and excellent results may be obtained if the patient is treated early in the course of the disease. It would appear that as the duration of the infection increases, the virus may integrate into interferon-reactive consensus sites and prevent the cell from responding to interferon. In patients infected at birth, transplacental anti-HBc appears to modulate the immune response and, along with immaturity of the immune system at this age, results in failure to lyse infected cells. These patients do not benefit from interferon treatment: some form of immune manipulation is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Foscarnet decreases serum and liver duck hepatitis B virus DNA in chronically infected ducks

Foscarnet (trisodium phosphonoformate) is a new antiviral compound with in vitro inhibitory effects against the DNA polymerases of hepadna viruses. To study the effects of the drug in chronic hepadna virus infection, we treated ducks chronically infected with duck hepatitis B virus for 10 days with either low-dose foscarnet (50 mg/kg i.p. b.i.d.), high-dose foscarnet (250 mg/kg i.p. b.i.d.), or sterile water injections. Serum duck hepatitis B virus DNA and intrahepatic replicative forms of the virus were measured using molecular biological techniques with both a double-stranded radiolabeled DNA probe and a plus-strand (noncoding) specific RNA probe. We found a dose-related decrease in serum and intrahepatic duck hepatitis B virus DNA during treatment, with a rapid return toward baseline values after the cessation of treatment. There was a disproportionate decrease in the plus strand of viral DNA with treatment. We conclude that foscarnet exerts its effect in hepadna virus infection through inhibition of viral DNA polymerase. Further study is necessary to determine whether foscarnet, by itself or in combination with other treatment modalities, has a role to play in the treatment of chronic hepatitis B infections in humans.

Modification of hepatitis B virus infection by recombinant leukocyte alpha A interferon

A defect in alpha interferon production in patients with chronic type B hepatitis offers a rationale principle for treating this disease with interferon. Two trials with interferon in chronic type B hepatitis indicate that this therapy achieves an elimination of HBsAg and HBeAg significantly higher than spontaneous. Our study and that of others indicate, however, that the response to interferon therapy is dependent on many variables including: the type of interferon, the interferon dose, duration of interferon treatment, sex, sexual preference in men and coinfection with other viruses. As of the multiple modes of action of interferon, a better understanding of viral replication, of the antiviral action of interferon in hepatitis B virus (HBV) infection and of the immunomodulatory action of interferon in HBV infection will help to improve the treatment of chronic HBV infection with interferon.

Regulation of interferon receptor expression in human blood lymphocytes in vitro and during interferon therapy

Interferons (IFN) elicit antiviral and antineoplastic activities by binding to specific receptors on the cell surface. The binding characteristics of IFN to human lymphocytes were studied using IFN alpha 2 labeled with 125I to high specific activity. The specific binding curves generated were analyzed by the LIGAND program of Munson and Rodbard to determine receptor numbers. The number of receptors in peripheral blood lymphocytes (PBL) and tonsillar B-lymphocytes (TBL) from normal individuals were 505 +/- 293 (n = 10) and 393 +/- 147 (n = 3) respectively. When these cells were preincubated in vitro with unlabeled IFN alpha 2, the receptor number decreased to 82 +/- 45 and 61 +/- 16 respectively. Receptor binding activities recovered gradually over a period of 72 h when the cells were incubated in IFN-free medium. This recovery of receptors could be blocked by the addition of actinomycin D to the incubation medium. A similar decrease in receptor expression was observed in vivo in PBL from patients being treated daily with 5 X 10(6) units/m2 per d of IFN alpha 2 by subcutaneous injection, for acute lymphoblastic leukemia or papilloma virus infections. Receptor numbers in PBL in vivo were further reduced concurrent with the progression of IFN therapy. Thus the reduction in IFN receptor expression observed in vitro can be demonstrated in vivo. These studies indicate that monitoring IFN receptor expression in vivo can provide information regarding the availability of IFN receptors at the cell surface for the mediation of IFN actions during the course of IFN therapy.

Interferons in the treatment of chronic hepatitis B virus infection

Hepatitis B virus offers several properties that may help to determine how antiviral substances, such as interferon, work. A description of the phases of chronic hepatitis B virus infection is presented, as well as the rationale for interferon therapy as treatment.

Hepatitis in clinical practice. 1. Hepatitis A and B

As is evident from the foregoing discussion, hepatitis A and hepatitis B are not static, passé disease. Knowledge concerning these illnesses continues to expand at a fantastic rate--all of it of extreme practical clinical significance. Most interesting is the elucidation of the etiology of the acquired immune deficiency syndrome (AIDS) and the increase this knowledge is hoped to produce on the utilization of hepatitis B vaccine. Also extremely important is the development of recombinant DNA vaccine, which will permit total circumvention of the question of AIDS and safety of the hepatitis B vaccine.

Lymphoblastoid alpha-interferon weekly, daily and combined with acyclovir for chronic HBeAg-positive hepatitis

Patients with chronic hepatitis B and active viral replication had no change in DNA-polymerase (DNA-p) and HBeAg when treated with weekly injections of lymphoblastoid alpha-interferon (IFN) for 4-10 weeks. Daily IFN (2.5 MU/m2 for a period of 4 weeks) was associated with a significant fall (P less than 0.05) in DNA-p but not in HBeAg; DNA-p remained or became negative in 3 out of 10 patients after stopping therapy. Combination of IFN and intravenous acyclovir (ACV, 15 mg/kg twice daily) led to a significantly greater fall in DNA-p and HBeAg, while tolerance of the combination therapy was excellent. Four out of 5 patients became DNA-p-negative and three HBeAg-negative; subsequently two became HBsAg-negative with anti-HBs. We conclude that weekly IFN appears ineffective. Daily IFN depressed hepatitis B virus replication, but does not change markedly the natural course of the disease. Combination therapy with ACV may be more effective than IFN alone and is well tolerated.

Identification of factors influencing response rate to antiviral therapy of chronic hepatitis B virus infection. A review of the efficacy of adenine arabinoside and lymphoblastoid interferon in the Royal Free Hospital studies

We have reviewed the results of treating over 100 HBV carriers with adenine arabinoside, adenine arabinoside monophosphate and lymphoblastoid interferon. In the homosexual group of carriers, adenine arabinoside and its monophosphate have no value. However, in this group, lymphoblastoid interferon will produce a response in over 50% of cases. The lack of effectiveness of adenine arabinoside monophosphate in this group may stem from its immunosuppressant properties. In heterosexual carriers both adenine arabinoside monophosphate and lymphoblastoid interferon are effective in approximately 50-60% of cases. However, the response rate is different in the various racial groups. Northern European and Mediterranean people appear to respond whereas those from the Far East do not. This may reflect the fact that there are at least 2 mechanisms by which the chronic carrier state may arise. In 5-10% of adults, a relative deficiency of alpha-interferon production exists and this defect is found in the majority of HBV carriers in Western Europe. In these, interferon acts as a replacement therapy and excellent results may be obtained if the patient is treated early in the course of the disease. It would appear that as the duration of the infection increases, the virus may integrate into interferon-reactive consensus sites and prevent the cell from responding to interferon. In patients infected at birth, transplacental anti-HBc appears to modulate the immune response and along with immaturity of the immune system at this age, results in failure to lyse infected cells. These patients do not benefit from interferon treatment: some form of immune manipulation is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Immune effects of alpha-interferon in chronic liver disease

The effect of prolonged alpha-interferon therapy on immune function was studied in patients with chronic type B hepatitis. These patients with chronic type B hepatitis have been shown to have a defect in their in vitro response to human recombinant alpha-interferon. This defect consists of a failure to augment pokeweed mitogen-stimulated immunoglobulin production at low concentrations of interferon and an increased susceptibility to the suppressive effects of interferon. After 2 weeks therapy with interferon, immunoglobulin production was further suppressed. However, after 4 months of therapy with interferon, pokeweed mitogen-stimulated immunoglobulin production partially returned towards the pretreatment values. Antibody to hepatitis B core antigen was less affected by interferon therapy. This altered response to interferon was not specific as it was seen in some patients with other forms of liver disease. The suppression of B cell differentiation appears to be separate from its antiviral and antiproliferative effects.

Pilot study of recombinant human alpha-interferon for chronic type B hepatitis

Nine patients with chronic type B hepatitis were entered into a preliminary study of recombinant, human alpha-interferon therapy. Patients received one to four courses of interferon, each consisting of a fixed dose of 18, 36, 50, 68, or 100 million units given three times a week for 2 wk. Side effects including fever, chills, fatigue, myalgias, headache, and neutropenia were common and especially severe with higher doses. Serum hepatitis B virus DNA polymerase activity fell during therapy to 15%-30% of the pretreatment levels irrespective of interferon dose, but rose to the initial level by 10 days after the course ended. During follow-up, 2 patients had a sustained clinical remission in which hepatitis B virus DNA, DNA polymerase, and hepatitis B e antigen disappeared from serum and amino-transferase activities fell to normal. One patient became hepatitis B surface antigen negative. We conclude that higher doses (50 and 68 million units) of interferon have greater side effects than lower doses (18 and 36 million units), without having any greater antiviral efficacy. Further studies should be directed at therapy with lower doses given over longer periods.

Effect of 28 consecutive days lymphoblastoid interferon (alpha-IFN) administration on hepatitis B virus related chronic liver disease

Eight HBsAg, HBeAg, DNA-p, HBV-DNA-positive patients with biopsy-proven chronic hepatitis were treated with human lymphoblastoid interferon (Wellferon) given for 28 consecutive days at a dosage ranging from 2.5 to 7.5 MU/m2 i.m.; 10 patients were used as controls. Our results suggest that certain chronic carriers may respond to the treatment with this agent. In fact, the treated patients showed a permanent inhibition of HBV replication sooner and in higher percentage with respect to untreated patients (37.5% vs 20%). IFN administration does not induce any important changes in the immunoregulatory wetwork, but is able to increase significantly the cytolytic activity of NK cells in the patients who respond to the therapy with a permanent inhibition of HBV replication.

Recombinant leucocyte interferon treatment of chronic hepatitis B. An analysis of two therapeutic trials

We have investigated the efficacy of recombinant alpha-interferon treatment of chronic hepatitis B virus (HBV) infection in two therapeutic trials. Forty-four patients positive for HBsAg, HBeAg, DNA polymerase and HBV-DNA were studied. Fourteen carriers were treated in the first trial with doses ranging from 18 to 50 million units (mu)/m2 3 times per week. Six of 14 treated carriers (43%) have a sustained loss of HBeAg, HBV-DNA and DNA polymerase. Four lost HBsAg (29%). Two of 11 (18%) untreated carriers lost HBeAg, but none lost HBsAg (P = 0.05). Nineteen patients were entered in a second trial to assess dose response. Fourteen were treated with doses ranging from 2.5 to 10 mu/m2. Five patients were untreated. Two treated patients seroconverted to anti-HBe, and a third cleared HBsAg and seroconverted to anti-HBs. None of the controls was anti-HBe-positive. Thus 9/28 (32%) carriers have lost replicating HBV versus 2/16 (13%) of untreated patients. Elevated pretreatment serum ALT concentrations and severe chronic active hepatitis were associated with inhibition of viral replication in treated patients suggesting that seroconversion may require an appropriate host response. The efficacy of recombinant interferon is restricted, but it may be of benefit in a proportion of carriers.

Preliminary trial of recombinant fibroblast interferon in chronic hepatitis B virus infection

Five patients with chronic hepatitis B were treated with 8-day courses of leukocyte (alpha) interferon (5 X 10(6) U/day) and with 8-day courses of recombinant fibroblast (betaser) interferon at dosages of 5 X 10(6), 35 X 10(6), and 105 X 10(6) U/day. Inhibition of hepatitis B virus replication as evidenced by a decrease in DNA polymerase (DNAP) activity was seen during all treatment courses. Equivalent reduction in DNAP was seen from the low-dose alpha and beta ser regimens, but beta ser interferon at 35 X 10(6) U/day achieved a significantly greater decrease in DNAP activity than did the low-dose regimens. In no patient, however, was permanent loss of DNAP noted. Because of dose-limiting toxicity, only two patients were escalated to the 105 X 10(6)-U/day dosage level. Transient proteinuria was noted in two patients while they were receiving interferon. This has not been noted in other patients receiving this preparation and could not be explained by the development of anti-interferon antibodies. This study has defined an appropriate dosage for future longer-term trials of this agent alone and in combination with other antivirals for the treatment of chronic hepatitis B.

The mode of action of interferons in viral infections and their possible role in the control of hepatitis B

Interferons can alter the course of virus infections by inhibiting virus replication at the intracellular level and by modifying the aspecific and specific immune response to viral antigens in body fluids and on cellular surfaces. Treatment of isolated cells with interferon renders them resistant to infections by viruses belonging to virtually any family. Knowledge of the mechanism of this effect is derived from studies employing both DNA (especially vaccinia virus and SV40) and RNA-viruses (especially picorna-, toga-, rhabdo-, reo- and retroviruses). Interferon induces multiple alterations in the level and state of intracellular regulatory molecules, leading to inhibition of virus replication at several possible steps. In the case of certain DNA viruses, transcription of viral DNA seems to be inhibited. In the case of RNA viruses the target for interferon action is mainly translation. The retroviridae constitute a special case and, in view of their analogy with the hepadnaviridae, are of particular relevance to the possible effects of interferon on the replication of HBV. Interferon inhibits one or more initial stages of primary infection of cells by transforming or nontransforming retroviruses, thereby preventing or delaying the synthesis and/or integration of viral DNA. In cells that already contain an integrated and fully expressed retrovirus genome, interferon treatment results in a reduced release of viral particles as well as a downward shift of the ratios between the numbers of infectious vs noninfectious particles. Immuno-modulatory properties of interferon which might alter the course of HBV-infection include: potentiation of cytotoxic activity of lymphocytes and macrophages; direct anti-inflammatory effects; enhancement or depression in antibody formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of hepatitis B surface antigen (HBsAg)-positive chronic hepatitis with recombinant leucocyte alpha-A interferon

A total of 32 individuals with HBsAg-positive and anti-delta-negative chronic hepatitis were treated with recombinant alpha-A interferon in phase I and phase II studies. In 5/32 patients HBsAg could be eliminated and in 19/32 individuals HBeAg became negative including all those who also eliminated HBsAg. Side-effects were tolerable in most patients and were readily reversible upon discontinuation of interferon therapy. In conclusion, treatment of HBsAg-positive chronic hepatitis with interferon seems to be a promising therapeutic approach. Future studies will have to establish the optimal dose, duration of treatment and factors predicting a favourable outcome of the treatment.

A randomized study of the effects of adenine arabinoside 5'-monophosphate (short or long courses) and lymphoblastoid interferon on hepatitis B virus replication

A previous randomized controlled study has shown a 30% rate of HBe antigen/antibody seroconversion within 1 year of a month course of adenine arabinoside-5'-monophosphate; no seroconversion occurred in the control group. In this study of patients derived from the same population, 45 hepatitis B virus carriers with chronic liver disease were randomized to receive either a short (4-week) course of adenine arabinoside-5'-monophosphate, a long (7 to 8-week) course of adenine arabinoside-5'-monophosphate or a 12-week course of lymphoblastoid interferon. Long-lasting suppression of hepatitis B virus replication with disappearance of serum hepatitis B virus DNA and clearance of HBeAg occurred within 12 months of treatment in four patients who received the short course of adenine arabinoside-5'-monophosphate and in five who received interferon. Of the nine responders, four also lost HBsAg. A response to antiviral therapy was accompanied by clinical and biochemical evidence of improvement in liver disease. None of the patients who received a long course of adenine arabinoside-5'-monophosphate responded. Peripheral neuropathy and myalgia were the most serious adverse effect affecting three recipients of the short course of adenine arabinoside-5'-monophosphate and eight recipients of the long course. Thrice weekly administration of interferon was well-tolerated. Further studies to identify the characteristics of the "responder patients" and large-scale controlled trials of antiviral therapy in these subgroups are indicated.

Changes of hepatitis B virus DNA in liver and serum caused by recombinant leukocyte interferon treatment: analysis of intrahepatic replicative hepatitis B virus DNA

Twenty patients with HBeAg-positive chronic liver disease were given large doses of recombinant leukocyte interferon for 4 weeks. Changes of hepatitis B virus DNA in livers and sera were analyzed by the molecular hybridization technique in paired biopsies obtained before and 2 weeks after treatment. Serum hepatitis B virus DNA was examined before, during and after the treatment until 4 weeks post-interferon. Analysis of hepatic hepatitis B virus DNA revealed species that appeared to represent various forms of replicative hepatitis B virus DNA, i.e., relaxed circular, linear, supercoiled and single-stranded hepatitis B virus DNA, respectively. No evidence of integration of hepatitis B virus DNA in genomic DNA was obtained. Of 15 cases which were positive for hepatic hepatitis B virus DNA before treatment and in which paired biopsies were obtained, hepatic hepatitis B virus DNA became negative in 4, decreased in 5 and unchanged in 6. Among several types of replicative viral DNA in liver tissue, supercoiled hepatitis B virus DNA tended to remain after other forms were reduced. A close correlation between hepatic and serum hepatitis B virus DNA was found in 37 liver biopsy samples and corresponding sera. These results indicate that interferon treatment reduces serum hepatitis B virus levels by inhibiting viral replication in the liver and that persistence or reappearance of hepatitis B virus in serum after interferon is associated with replication.

Recombinant leukocyte interferon treatment of chronic hepatitis B

We have investigated the efficacy of a relatively prolonged course of recombinant leukocyte interferon treatment in 14 chronic HBsAg-, HBeAg-, hepatitis B virus DNA- and DNA polymerase-positive carriers. alpha-Interferon was administered for 9 weeks. Six of 14 treated carriers have a sustained loss of HBeAg, hepatitis B virus DNA and DNA polymerase. Four subsequently lost HBsAg (28.5%). Elevated pretreatment SGPT concentrations, histologic chronic active hepatitis, an exacerbation of chronic hepatitis with an increase in SGPT concentrations in the last weeks of treatment and possibly recent onset of the carrier state was associated with complete inhibition of viral replication. None of 11 matched, untreated HBsAg-, HBeAg-, hepatitis B virus DNA- and DNA polymerase-positive carriers monitored during the same period lost HBsAg. The effect of recombinant leukocyte interferon may require an appropriate host-immune response. The efficacy of recombinant leukocyte interferon therapy is restricted, but it may be of benefit in a proportion of carriers, if these carriers can be precisely identified.

Recombinant leukocyte a interferon treatment in patients with chronic hepatitis B virus infection. Pharmacokinetics, tolerance, and biologic effects

Large doses of recombinant leukocyte A interferon were administered to 20 patients with deoxyribonucleic acid polymerase- and hepatitis B e antigen-positive chronic hepatitis B to study the maximum tolerated dose, its pharmacokinetics, and its antiviral activity. The first group of 5 patients received a constant dose of 36 X 10(6) U/day for 28 consecutive days. When it was well tolerated, the second, third, and fourth groups (5 patients each) received 50, 72, and 100 X 10(6) U/day, respectively. All 20 patients completed the 28-day treatment. Hourly and daily profile of serum interferon level showed a dose-dependent effect with an increasing dosage, and cumulative effects during the treatment. The mean peak serum interferon concentration ranged from 93 U/ml on day 1 in the first group to 1271 U/ml on day 28 in the fourth group. Inhibition of serum deoxyribonucleic acid polymerase activity and hepatitis B virus-deoxyribonucleic acid during the treatment was compared between the groups with low doses (36 and 50 X 10(6) U) and high doses (72 and 100 X 10(6) U). Low doses of interferon suppressed deoxyribonucleic acid polymerase activity to the same extent as did the high doses. Prednisolone withdrawal was combined with interferon in 5 patients. Three patients treated with such combination became seronegative for hepatitis B e antigen during the treatment, whereas all 15 with interferon alone remained seropositive. These results suggest that a maximum antiviral effect of recombinant leukocyte A interferon is below the maximum tolerated doses.

Therapeutic effect of human fibroblast interferon on premalignant lesions arising in oral mucosa. A pilot study

Human fibroblast interferon (HuIFN-beta) was topically administered to 20 premalignant lesions histopathologically showing epithelial dysplasia such as leukoplakia and lichen planus which arose in the oral mucosa. HuIFN-beta was prepared in the water-soluble gel form containing 2% carboxymethylcellulose, 45% glycelin, 0.1 M citrate buffer (pH 4.5) and 0.2% SDS as stabilizing agents. This preparation was found to be effective for herpetic gingivostomatitis and zostal lesions arising along the intercostal nerve. Thus, the HuIFN-beta preparation (10(4) to 5 X 10(3) IU) was applied to the oral mucosal lesion for 1 h twice a week. The lesion with topical administration of HuIFN-beta was covered tightly with the mucosal bandage which was coated with carboxymethylcellulose, glycelin and CaCl2 on vinyl acetate matrix. The 14 oral lesions with erosion or ulcer formation accompanied by severe pain by touch, had complete remission after approximately 10 successive applications of this preparation. Although subjective symptoms such as irritation pain in the other 6 patients with severe hyperkeratotic lesion subsided, white coatings and streaks could not be completely removed by this therapy. No other side-effects excluding slight pain and reddish swelling which occurred intermittently during HuIFN-beta administration were observed.

Interactions between hepatotropic viruses in patients with haemophilia

Infections with the hepatotropic viruses non-A, non-B (NANB), hepatitis B (HBV) and delta agent (HDV) are described in two patients with haemophilia. The first patient illustrates the phenomenon of interference following a simultaneous exposure to NANB and HBV. The second patient, a carrier of hepatitis B surface antigen (HBsAg), acquired superinfection with HDV which resulted in acute hepatitis progressing to chronic hepatitis. Liver disease seen in multitransfused haemophiliacs may be significantly different to that seen in other patients. As a consequence of the infusion of blood clotting factor concentrates, these patients become the site of complex viral interactions.

Treatment of HBeAg-positive chronic hepatitis with a streptococcal preparation (OK-432)

Forty-two patients with hepatitis Be antigen (HBeAg)-positive chronic hepatitis were treated by intramuscular injections with OK-432, an immunopotentiator possessing interferon-inducing activity. They were monitored with serial measurements of virological parameters to evaluate therapeutic effectiveness, and compared with a group of seventy-five untreated patients (natural course group). In the group receiving OK-432 therapy, twenty-seven patients (64.3% of the forty-two patients) became negative for HBeAg in an average observation period of 20.1 months. Of these, fourteen patients (33.3% of the forty-two patients) underwent seroconversion from HBeAg to anti-HBe antibody (anti-HBe). In the natural course group, twenty-three patients (30.7% of the seventy-five patients) lost HBeAg reactivity in a mean follow-up period of 32.3 months, and thirteen patients (17.3% of the seventy-five patients) became seroconverted. Thus, the drug group showed significantly higher percentages of patients with disappearance of HBeAg and seroconversion, notwithstanding the shorter duration of the follow-up. Young males and females, females generally, or patients with high serum GPT levels were more likely to respond to the therapy. The serum GPT level tended to stabilize more in patients receiving OK-432.

Electroencephalographic abnormalities in interferon encephalopathy: a preliminary report

Although several studies have shown that interferon does not readily cross the blood-brain barrier, recent reports have described central nervous system effects in patients receiving interferon. At our institution, we encountered three patients who had symptoms of toxicity of the central nervous system (somnolence, confusion, and gait difficulties) in association with electroencephalographic abnormalities while receiving alpha 2-interferon therapy for multiple myeloma. The electroencephalogram showed diffuse slow-wave abnormalities in two of the patients and generalized sharp-wave discharges in the third patient. Because the use of interferon is increasing, physicians should be aware of the central nervous system complications and the electroencephalographic changes that can be associated with such therapy.

Determination of the affinity of antibodies to hepatitis B surface antigen in human sera

The measurement of the affinity of anti-HBs antibody in human sera using 3 HBsAg-related antigens is described. The antigens used were (i) a synthetic linear peptide corresponding to amino acids 139-147 of the major polypeptide of HBsAg, (ii) a cyclical form of this same peptide and (iii) a polypeptide complex of a 28,000 MW glycoprotein and a 23,000 MW protein from purified HBsAg. The method was established with a pooled human anti-HBs immunoglobulin preparation and a monoclonal anti-HBs antibody reactive to the 'a' determinant of HBsAg. The results indicate that both these antibody preparations effectively bind the 3 antigens with affinity values of between 2 X 10(6) to 9 X 10(7) litres/mole. However, the affinity of both antibody preparations for the cyclical form of the peptide was higher than for the linear form. The level of antibody (expressed as Abt, molar antigen binding sites) in the pooled human immunoglobulin for each of the 3 antigens was similar. Measurements of anti-HBs antibodies in the sera of recovered acute hepatitis B patients and from HBsAg negative chronic liver disease patients showed that the cyclical form of the antigen was bound with a higher affinity than the linear form. Affinity values of antibody in the sera of the latter group of patients was significantly lower (3 X 10(5) to 2.7 X 10(6) litres/mole) than those observed in sera from other individuals. The implication of these results in determining the importance of the measurement of affinity in the assessment of the efficacy of vaccines is discussed.

Efficacy of aerosolized recombinant interferons against vesicular stomatitis virus-induced lung infection in cotton rats

Cotton rats (Sigmodon hispidus) were inoculated intranasally with vesicular stomatitis virus (VSV) and exposed to different regimens of small particle aerosols of either recombinant human alpha interferon A (rIFN-alpha A) or hybrid recombinant human alpha interferon A/D (rIFN-alpha A/D). Preliminary in vitro tests indicated that both recombinant IFNs were effective in protecting primary cotton rat pulmonary cells against VSV replication. However, rIFN-alpha A/D was 20-fold more active than rIFN-alpha A in these tests. In the in vivo tests, in contrast to control animals inoculated with VSV, but not treated, or treated only with aerosols of saline, animals exposed to either rIFN-alpha A or -alpha A/D for 8 h per day before and/or following VSV inoculation had no detectable virus titers in their lungs. In experiments in which groups of animals were treated for shorter periods, rIFN-alpha A was less effective than rIFN-alpha A/D in suppressing replication of VSV in lungs of these animals.

Acute type A hepatitis during chronic hepatitis B virus infection: association of depressed hepatitis B virus replication with appearance of endogenous alpha interferon

Two patients with chronic type B hepatitis and intercurrent episodes of acute type A hepatitis are presented. Serological markers of hepatitis B virus replication decreased or became undetectable in both patients during the acute illness, while interferon activity was transiently detected in serum. The presence of serum leukocyte (alpha) interferon was confirmed by neutralization with specific antisera and tests of pH2 stability. These observations suggest a role for natural leukocyte (alpha) interferon in the modulation and control of hepatitis B virus infection and provide further evidence to support trials of exogenous leukocyte (alpha) interferon in the chronic infection.

Interferon--present and future prospects

The interferons are a group of proteins that have inspired a new era of investigation into biological modification. The interferons are now divided into subgroups characterized by chemical means and correspond to different biological responses which can be observed in terms of the inducer used, and the timing of the response. Identified originally as antiviral agents when homologous cell systems were treated prior to infection, new studies have extended these observations to place the interferons in a central role as a strong force in the regulation of immunologic responses. A marriage of interferonology and cell immunology is enlarging both our understanding of the action of these proteins and our ability to follow the course of an illness and eventually to control its outcome . Genetic engineering has provided a way to process quantities of interferon and provided the molecular sequence of all three classes of IFN including a model of the active site for IFN-alpha. The offshot of the technology developed to study the intracellular processes after interferon treatment have already led to increased sensitivity to detect virally treated diseases. Both the variety of the interferon inducers and the scope of parasites in which it can exert its influence provide a frontier of biological investigation which has at the root of its nature the very secret of life. In addition to cellular phenomena, the positive effects on tumor-bearing organisms and the ill effects on infant animals highlight the potential power of the interferons.

Decreased interferon synthesis and responsiveness to interferon by leukocytes from multiple sclerosis patients given natural alpha interferon

Despite the use of interferon (IFN) in numerous clinical trials, relatively little is known about how IFN therapy influences leukocyte function. To evaluate some of its effects, leukocytes from multiple sclerosis (MS) patients given daily treatments of natural alpha IFN (IFN-alpha) were evaluated for IFN synthesis and two responses to IFN in vitro: enhancement (priming) of IFN synthesis and suppression of Concanavalin A (Con A)-induced T-cell mitogenesis. The IFN therapy had no effect on the sensitivity of Con A-stimulated leukocytes to the antiproliferative action of IFN-alpha. However, using Newcastle disease virus (NDV), measles virus, or poly I:C to stimulate IFN synthesis, cells from IFN-treated patients produced less IFN in response to all inducers, with titers ranging between 11% and 44% of pretherapy values. Also, unlike cells from these same patients before therapy or from the placebo recipients, cells from the IFN recipients were not primed by either IFN-alpha or -beta even though IFN-beta had not been used for therapy. The loss of these priming reactivities suggests that resistance to IFN had developed in IFN-treated patients.

Analysis of T cell subsets in cancer patients treated with interferon

T cell subsets were analyzed in 33 patients with advanced cancer who were treated with either of two interferon preparations: a partially purified human leukocyte interferon (HulFN-alpha (Le] and a highly purified recombinant interferon (lFLrA). Included in the lFLrA-treated group were eight patients with immunodeficiency and Kaposi's sarcoma. The OKT4+/OKT8+ ratio was used to define the balance between helper/inducer and suppressor/cytotoxic T cell subsets. With both interferon preparations, the mean OKT4+/OKT8+ ratio decreased 24 hours after the first interferon dose. Within the HulFN-alpha (Le) group, the decrease in ratio was related to an increase in OKT8+ cells; in the lFLrA group, it was accompanied by a small decrease in the proportion of OKT4+ cells that was greater than the decrease in OKT8+ cells. Patients treated with lFLrA were followed for the first three weeks of therapy. Most patients treated with lFLrA at all dose levels, ranging from 1 X 10(6) to 54 X 10(6) units per day, had a decrease in OKT4+/OKT8+ ratio on Day 1. No substantial change in the ratio was observed on Days 7, 14, and 22. Patients with immunodeficiency and Kaposi's sarcoma had responses similar to those of patients with other cancers treated with lFLrA. In conclusion, although both HulFN-alpha (Le) and lFLrA induce immediate decreases in the OKT4+/OKT8+ ratio, the T cell subset(s) primarily responsible for the decrease varies with the source of interferon.

Involvement of interferon in virus-induced lymphopenia

Intraperitoneal injection of vesicular stomatitis virus (VSV) into mice causes marked and rapid changes in leukocyte distribution. The virus induces an increase in peripheral blood (PB) granulocytes and an extensive decrease in the lymphocyte count which reaches a nadir of less than 10% of preinfection values, 12 hr after virus inoculation. In the lymph nodes and spleen extensive lymphocyte translocation and granulocyte infiltration are observed. Most changes abate 48 hr following virus inoculation. Injection of poly(rI):(rC) causes similar changes to those observed with VSV. The lymphocyte changes observed after injection of VSV or poly(rI):(rC) coincide with high levels of interferon (IFN) in the serum. We have examined the effects of anti-IFN antibody on those changes and investigated whether they can be mimicked by injecting IFN. Our findings suggest that the IFN induced by VSV or poly(rI):(rC), rather than those agents themselves, causes the observed lymphopenia as well as some of the changes observed in the spleen. On the other hand, the effects of VSV on granulocyte localization do not appear to be mediated by IFN.

Safety and tolerance of recombinant leukocyte A interferon in bone marrow transplant recipients

Five bone marrow transplant recipients with cytomegalovirus infections were treated with pure recombinant leukocyte A interferon produced by recombinant DNA technology from Escherichia coli. All five patients had documented interstitial pneumonia. The daily intramuscular dose of interferon ranged from 18 X 10(6) to 50 X 10(6) U; the mean duration of therapy was 11.0 days (range, 5 to 18 days). Two patients recovered, one improved, and two died. Clinical side effects (usually fever and chills) occurred in three patients. A 60% or greater reduction in the pretherapy peripheral granulocyte counts occurred in four patients, and four patients had a 37 to 80% reduction in their pretherapy platelet counts. Hematological toxicity was reversible, and there was no loss of marrow graft function. The toxicity of pure recombinant leukocyte A interferon in marrow transplants is similar to that of partially pure leukocyte interferon derived from human cells. Further controlled studies to establish the efficacy of recombinant leukocyte A interferon in marrow transplants are warranted but may be limited by hematological toxicity.

Human lymphoblastoid interferon in the treatment of small cell lung cancer

Ten patients with small cell lung cancer were treated with high dose human lymphoblastoid interferon (50-100 megaunits m-2) for 5 days, followed by low dose interferon (3 megaunits m-2) for 3 weeks. At the end of treatment, and one month later, there was no evidence of either complete or partial response. The treatment produced fever, anorexia and weight loss, with transient leucopenia and thrombocytopenia; there was evidence of a non-cholestatic elevation of serum alanine aminotransferase, with clinical deterioration in the condition of three patients presenting with hyponatraemia. A transient hypocalcaemia during high dose therapy was also noted. It seems that lymphoblastoid interferon as a single agent is unlikely to have a role in the treatment of small cell lung cancer, and that its administration as employed in this study is associated with considerable toxicity.