Recombinant Interferon Alpha-2a Research Articles

Combined effects of interferon-alpha2a and 13-cis-retinoic acid on human melanoma cell growth and STAT protein expression.

We assessed the antiproliferative effects of human recombinant interferon-alpha2a (IFNalpha2a) and 13-cis-retinoic acid (13cis-RA) on two human melanoma cell lines (JR8 and M14). Both cell lines showed a very modest sensitivity to IFNalpha2a and 13cis-RA as single agents. In JR8 cells, the combination of the two compounds consistently produced simple additive effects. In contrast, different effects of the combination were recorded in the M14 cell line depending on the treatment schedule. Specifically, an additive interaction was observed when IFNalpha2a and 13cis-RA were given in sequence, independently of the order of drug administration, whereas a supra-additive antiproliferative effect was seen when cells were simultaneously exposed to the two drugs. Exposure to 1000 IU/ml IFNalpha2a markedly increased the nuclear expression of signal transducers and activators of transcription (STAT) proteins in both cell lines. By itself 10 microM 13cis-RA did not affect STAT protein expression or modify the extent of activation of such proteins by IFNalpha2a. Results from our study showed an enhancement of the antiproliferative activity of IFNalpha2a and 13cis-RA when given in combination and suggest that such an enhancement is not mediated by a concomitant effect of 13cis-RA on STAT protein activation.

A comparison of four types of interferon alpha in the treatment of chronic hepatitis C

Several clinical trials and meta-analyses have shown that the efficacy of interferon (IFN)-alpha in the treatment of chronic hepatitis C is variable, depending on the type of IFN-alpha used. We randomly assigned 220 patients with hepatitis C to receive a 6-month treatment (3 megaunits three times per week) with lymphoblastoid IFN-alpha (group A), recombinant IFN alpha-2a (group B), leukocyte IFN-alpha (group C), or recombinant IFN alpha-2b (group D). The groups were homogeneous with reference to histologic severity of the disease (chronic persistent hepatitis, 21.4%; mild chronic active hepatitis, 28.2%; moderate chronic active hepatitis, 28.6%; and severe chronic active hepatitis, 21.8%). We used common laboratory techniques to detect and assess all serum variables. Liver biopsy was conducted according to Menghini's modified technique, and administration of IFN alpha was conducted according to a double-masked method. A total of 220 patients were enrolled in the study. Ninety-two patients dropped out because of side effects, comorbidity unrelated to the baseline disease, or voluntary termination and 128 patients (32 patients in each group) completed the treatment course and the follow-up period. At the 6-month end point, 14 of 32 patients were completed responders in group A, 13 of 32 in group B, 14 of 32 in group C, and 8 of 32 in group D. After completion of the follow-up period, 10 of 32 patients had a sustained response in group A, 9 of 32 in group B, 10 of 32 in group C, and 8 of 32 in group D. Treatment failure and relapse rates were higher in the patients treated with recombinant alpha IFNs than in patients treated with leukocyte or lymphoblastoid IFN alpha. We observed no relation between the relapse rate and baseline severity of the disease. Among the recombinant IFNs, a major rate of clinical response was observed in patients treated with recombinant IFN alpha-2a. Although leukocyte IFN-alpha and lymphoblastoid IFN-alpha treatments showed an overlapping efficacy in terms of complete or sustained response, the former achieved a lower rate of treatment failure or relapse.

Phase I evaluation of radiation combined with recombinant interferon alpha-2a and BCNU for patients with high-grade glioma

A Phase I study to determine the safety, toxicity, and maximum tolerated dose (MTD) of carmustine (BCNU) and interferon alpha-2a (IFN-a) when combined with radiation as initial therapy in high-grade glioma. Patients with newly diagnosed Grade 3 or 4 astrocytoma, oligoastrocytoma, or gliosarcoma were enrolled after surgery. All received radiation therapy to the brain (64.8 Gy/36 fractions), combined with a single dose of BCNU (200 mg/m2) at the start of radiation. Chemotherapy after completing radiation consisted of BCNU 150 mg/m2 once every 7 weeks, and IFN-a 12 x 10(6) units/m2 subcutaneously Days 1-3 each week of a 7-week cycle. Subsequent dose modification was based on constitutional symptoms for IFN-a and on myelosuppression for BCNU. Fifteen patients were entered on the study. Four were excluded because they did not receive IFN-a (3 refused treatment and 1 patient left the study due to multiple medical problems). Eleven were evaluable for toxicity and efficacy. Nonhematological toxicity, mainly lethargy and flu-like symptoms, were dose-limiting for IFN-a. After the first 6 patients were treated per the initial protocol, the frequency of IFN-a administration was decreased to Days 1-3 on weeks 1, 3, and 5 of the 7-week cycle for 5 additional patients. Lethargy, fever, chills, myalgias, alopecia, and anorexia occurred in all patients. Other toxicities included nausea and vomiting (91%), central-nervous-system depression or mood changes (64%), headaches (55%), and elevation of liver enzymes (36%). Grade 3-4 leukopenia occurred in 4 (45%) of 11 patients, and Grade 3-4 thrombocytopenia in 3 (27%) of 11 patients. Due to myelosuppressive effects, BCNU dose was not escalated. Median survival of the cohort was 44 months. Objective responses occurred in 5 (56%) of 9 patients and median duration of response was 33 months. The MTD of this combination after radiation therapy is IFN-a 12 x 10(6) units/m2 Days 1-3, on Weeks 1, 3, and 5 of a 7-week cycle and BCNU 150 mg/m2 Day 1, every 7 weeks. Treatment with radiation, IFN-a, and BCNU is feasible and effective in patients with high-grade gliomas, although constitutional symptoms from IFN-a are substantial.

Subcutaneous Low Doses of Interleukin-2 and Recombinant Interferon Alpha with Carboplatin and Vinblastine in Patients with Advanced Melanoma1

Twenty-three patients with advanced melanoma were treated with a combination of subcutaneous recombinant human interleukin-2 (IL-2), and recombinant interferon alpha-2a (IFN-α) with chemotherapy consisting of four cycles of carboplatin (300 mg/m², day 1) and vinblastine (6 mg/m², day 1), every 28 days (CV-IL-IF). IL-2 was given at a dose of 4.5 × 10⁶ U twice daily on days 3–6 and days 21–24 of each cycle; IFN-α dose was 4.5 × 10⁶ U, starting on day 2, thrice weekly. Immunotherapy was intended to continue for 6 months. Of the 23 analyzed patients, 4 (17%) achieved an objective response, including 1 complete and 3 partial responses, in nonvisceral metastatic disease. The median time to progression was 5 months and the median survival from onset of the treatment 6 months (range 1–14 months). Four patients discontinued the treatment, due to nonhaematologic toxicity; 3 for severe weakness and the 4th patient for long-lasting CNS side-effects. Other grade 3–4 toxicities included weight loss (22%), nausea and vomiting (17%) and alopecia (13%). The haematologic toxicity was acceptable. No toxic death was noted. It is con cluded that the CV-IL-IF regimen has limited activity and moderate toxicity.

Pharmacokinetics and effects on plasma retinol concentrations of 13-cis-retinoic acid in melanoma patients

The pharmacokinetics of 13-cis-retinoic acid (13cisRA) and its effects on retinol plasma levels were investigated after the first and the last doses in melanoma patients, who participated in a study run to assess tolerance over a long period of a treatment schedule of 13cisRA associated with recombinant interferon alpha2a (rIFN-alpha2a). Melanoma patients with regional node metastases after radical surgery were randomized to be treated for 3 months with rIFN-alpha2a, 3 x 10(6) IU s.c. every other day, associated with oral 13cisRA at doses of 20 mg day(-1) (five patients) or 40 mg every other day (seven patients). Maximum 13cisRA blood concentrations usually occurred 4 h after drug administration, with average values of 406 and 633 ng ml(-1) (i.e. 1.3 and 2.1 microM) after the 20 and 40 mg dose respectively. The average half-life (t(1/2)) was approximately 30 h. The maximum concentration, the t(1/2) and the area under the concentration-time curves from 0 to 48 h (AUC(0-48)) of 13cisRA did not change after multiple dosing, whereas the AUC(0-48) of its major blood metabolite, 4-oxo-13-cis-retinoic acid, increased. Immediately after 13cisRA treatment, retinol plasma levels started to decline and they reached the lowest values (approximately 20% reduction) shortly after the time of maximum 13cisRA concentrations (i.e. 4-12 h after drug intake). Afterwards, values returned to baseline. The amount of retinol reduction in time was correlated with 13cisRA maximum concentrations.

The incidence and clinical significance of antibodies to interferon-a in patients with solid tumors.

It is well known that natural and recombinant proteins can cause antibody formation in the host. We have studied the incidence of binding and neutralizing antibodies in carcinoid patients (n = 327). All together 204 patients received interferon-alpha 2b (Intron-A), median does 15 MU range 9-35 MU/week subcutaneously and 51% of the patients developed binding antibodies by immunoassay and 17% showed positive neutralization assay but high titer antibodies (> 800 NU/ml) were only found in 4% of the patients. The median time until the development of binding antibodies was 26 months and neutralizing antibodies 25 months. Twenty-nine patients received interferon-alpha 2a (Roferon), median does 18 MU/week subcutaneously and 45% developed binding antibodies, 38% had positive neutralization assay and 28% presented high titer antibodies. Binding and neutralizing antibodies occurred at the same time after median six months of treatment. Patients treated with Wellferon (n = 45) and leukocyte interferon (n = 48), median dose of 15 MU/week subcutaneously did not develop any neutralizing antibodies. The majority of the interferon-alpha 2 antibodies were of the IgG isotype. The clinical relevance of the development of high titer neutralizing antibodies was evaluated in the patients. All together 17 patients developed high titer neutralizing antibodies and of these 12 patients showed loss of antitumor response measured as increased level of tumor markers and of tumor progression. In nine of these patients a switch to human leukocyte interferon reinstituted an antitumor response. Neutralizing antibodies against recombinant interferon-alpha 2a and 2b might occur in patients with carcinoid tumors. The incidence of high titer neutralizing antibodies is significantly higher in patients treated with interferon-alpha 2a compared to interferon-alpha 2b. A significant number of patients lost the antitumor effect during development of neutralizing antibodies at high titers, but human leukocyte interferon can be used as rescue treatment.

Response to interferon-alpha 2a in patients with e antigen-negative chronic hepatitis B.

Sixty-eight consecutive patients with chronic hepatitis B received 702 million units of recombinant interferon-alpha 2a. Of the 24 patients negative for hepatitis B e antigen (HBeAg) in serum, the normalization of serum transaminase occurred in 14 (58%) at the completion of interferon therapy and in 13 (54%) at 12 months thereafter; it was normalized in 17 (39%) and 13 (30%), respectively, of the 44 HBeAg-positive patients. Of the HBeAg-negative patients, hepatitis B virus DNA was cleared from serum in six (25%) at the completion and in one (4%) at 12 months thereafter, in contrast to only one (2%, p < 0.05) and none of the HBeAg-positive patients, respectively. The 1896th nucleotide of G (G1896) for codon 28 for tryptophan or A (A1896) for the stop codon 28 in the precore region was determined by restriction fragment length polymorphism. The ten HBeAg-negative patients with A1896 only in the precore region had lower pretreatment levels of viral markers, which decreased more rapidly and extensively after interferon than in the 14 HBeAg-negative patients with a mixture of G1896 and A1896 or in the 44 HBeAg-positive patients. These results indicate that patients with HBeAg-negative chronic hepatitis B may respond better to interferon than HBeAg-positive patients, and that the precore mutant with the stop codon 28 may be sensitive to interferon.

Effect of interferon alpha on high serum androgen concentrations in HIV positive men with Kaposi's sarcoma.

AIM: To measure serum androgen concentrations in men with HIV related Kaposi's sarcoma (KS) who had been treated with recombinant interferon (IFN) alpha-2a to determine the role of androgens on...

Human recombinant interferon alpha-za plus 3′-azido-3′-deoxythymidine: Synergistic growth inhibition with evidence of impaired dna repair in human colon adenocarcinoma cells

We reported that 3′-azidothymidine-3′-deoxythymidine (AZT) plus 5-fluorouracil or methotrexate produces additive cytotoxicity in HCT-8 cells: a reflection of increased AZT metabolism when de novo thymidylate (dTMP) synthesis was inhibited. We now report that AZT plus human recombinant Interferon alpha-2a (rIFN-α2a) produces synergistic growth inhibition in these cells. Evaluation of the effect of rIFN-α2a on dTMP metabolism revealed that exposure to rIFN-α2a (± AZT) did not affect dTMP synthase activity significantly but increased thymidine (dThd) kinase activity significantly. Consequently, AZT nucleotide production and incorporation into DNA were increased by coexposure to rIFN-α2a. This alone, however, cannot explain the observed synergism. Therefore, the effect of these agents on DNA excision/repair processes was assessed. Isotope clearance studies demonstrated that rIFN-aZa did not alter the rate of [ 3H]AZT excision from DNA. In contrast, filter-elution studies revealed that rIFN-α2a (± AZT) produced more DNA damage and delayed repair compared with the effects produced by AZT alone. Since DNA polymerases alpha and beta are directly involved in gap-filling repair synthesis, experiments next assessed the effect of rIFN-α2a and/or 3′-azido-3′-deoxythymidine-5′-triphosphate (AZTTP) on their activities. Polymerase alpha was inhibited slightly by AZTTP but not by rIFN-aZa. Polymerase beta activity, however, was inhibited dramatically by rIFN-α2a + AZTTP. Finally, western analysis revealed that a Z4-hr exposure to 5000 lU/mL rIFN-aZa (± 20 μ,M AZT) significantly reduced wild-type p53 expression compared with AZT-exposed cells. We conclude that rIFN-α2a enhances AZT-induced tumor cell growth inhibition by (i) increasing AZT metabolism, and (ii) inhibiting DNA repair and p53-mediated cell cycle control processes.

Systemic high-dose recombinant-alpha-2a-interferon therapy modulates lymphokine production in multiple sclerosis

Chronic systemic high-dose recombinant alpha 2a-interferon (rIFNA) therapy reduces exacerbation rate and MRI signs of disease activity in relapsing/remitting multiple sclerosis (RR MS) patients. In order to clarify the possible mechanisms underlying the clinical efficacy of rIFNA in MS, several immunologic studies were performed as a part of a pilot clinical trial. Twenty RR MS patients were treated with 9 × 10 6 IU of rIFNA ( n = 12) or placebo ( n = 8) intramuscularly every other day for 6 months. Cytokine production by cultured lymphocytes, major histocompatibility complex class II (MHC-II) antigen expression on cultured macrophages, peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocyte phenotype, and IgG and beta 2 microglobulin levels were studied before therapy, after 6 months of therapy, and 6 months after stopping therapy. rIFNA therapy was associated with reduction of interferon-gamma and tumor necrosis factor-alpha production by PB lymphocytes ( p < 0.04), and with slight, not significant, increase of transforming growth factor-beta 2 or interleukin (IL)-10 production. IL-4 was undetectable in the culture supernatants both before and after therapy. rIFNA therapy had no effect on macrophage MHC-II molecule expression. An increased percentage of CD8 +, CD8 + high CD11b + low, and CD3 − CD16 + CD56 + cells, and of CD4 + absolute cell number was observed in CSF after rIFNA therapy. After rIFNA administration, IgG level significantly increased both systemically ( p < 0.02) and intrathecally ( p < 0.001). Serum beta 2 microglobulin level increased ( p < 0.01), as well. Only 1 out of the 12 rIFNA treated patients developed neutralizing antibodies against rIFNA during therapy. Six months after stopping therapy all the immunologic changes returned to baseline. These data suggest that the beneficial effect of rIFNA therapy on MS disease activity is probably mediated by a downregulation of proinflammatory cytokine synthesis by PB lymphocytes rather than by macrophage MHC-II antigen expression. The immunologic effects of high-dose systemic rIFNA therapy are temporary and restricted to the period of drug administration.

Cold activation of complement in sera from patients with persistent hepatitis C virus infection on interferon therapy.

The loss of haemolytic activity in sera during storage at low temperature (the cold activation of complement) was observed in 136 of 184 (74%) patients with chronic liver disease associated with hepatitis C virus (HCV) infection. This was more frequent than observed in the three of 40 (8%) patients with chronic hepatitis B (P < 0.001) or none in 43 normal controls (P < 0.001). Of 103 patients with chronic hepatitis C who had completed a full course of recombinant interferon-alpha 2a therapy (total dose: 516 x 10(6) U), 40 responded completely and 21 responded partially, as judged by the normalization or decrease of alanine aminotransferase levels 6 months after the completion of therapy; 42 patients did not respond at all. The cold activation of complement persisted in five (13%) complete responders, less often than in 33 (79%) non-responders (P < 0.001). At the completion of interferon therapy, the cold activation of complement persisted in 12 of 54 patients despite the normalization of alanine aminotransferase. Spontaneous exacerbation of hepatitis occurred in seven of 12 (58%) patients with cold activation, which was more frequent than in the four of 42 patients (10%) without it (P < 0.01). The cold activation of complement disappeared along with the loss of HCV-RNA in five of six responders during the 6 month period after the completion of interferon therapy, while both cold activation and HCV-RNA persisted in all eight non-responders. These results indicate that the cold activation of complement may be useful as a marker of HCV viraemia for monitoring the response to interferon in patients with HCV infection.

Genotype, serum level of hepatitis C virus RNA and liver histology as predictors of response to interferon-alpha 2a therapy in Japanese patients with chronic hepatitis C.

To determine whether pretreatment HCV-RNA level, hepatitis C virus genotypes, alanine aminotransferase and histology correlate with subsequent response to interferon-alpha therapy or not, serum HCV-RNA levels and genotype were determined by branched DNA signal amplification assay and genotype-specific polymerase chain reaction in 43 patients with chronic active hepatitis C. Response to recombinant interferon-alpha 2a (504 million units in total) was defined as complete and sustained CR-->SR, n = 12), complete response followed by relapse (CR-->Rel, n = 17), and no response (NR, n = 10), excluding dropouts (n = 4). Patients who showed CR-->SR had a lower HCV-RNA level (0.438 x 10(6) eq/ml) compared to CR-->Rel (2.452 x 10(6) eq/ml, p = 0.008) and NR (4.882 x 10(6) eq/ml, p = 0.009). A higher proportion of patients with CR-->SR had type 2a HCV (67%) compared to the CR-->Rel (28%) and the NR (0%). There was a trend for type 1b hepatitis C virus infection to have higher serum HCV-RNA levels. There was no correlation between pretreatment HCV-RNA level and alanine aminotransferase. However, no relation between pretreatment HCV-RNA level and liver histology was observed; a high proportion of patients with CAH2a showed CR-->SR, compared to those with CAH2b (p = 0.001). Moreover, the patients with CAH2b who had low level hepatitis C virus viremia did not show CR-->SR. These data indicate that pre-treatment serum HCV-RNA levels, genotype and liver histology are good predictors of subsequent response to interferon-alpha therapy in Japanese patients with chronic hepatitis C virus infection.

The modulating effect of interferon alpha-2a on the antitumor activity of UFT against a human gastric carcinoma xenograft, SC-1-NU, in nude mice.

The modulating effect of recombinant human interferon alpha-2a (IFN) on the antitumor activity of UFT, a mixed compound of tegafur and uracil at a molar ratio of 1:4, was investigated against SC-1-NU, a human gastric cancer xenograft serially transplanted in nude mice. IFN was administered subcutaneously at a dose of 60,000 IU/mouse daily for 14 days, and UFT was given at a dose of 15 mg/kg as tegafur daily, except on Sundays, for 3 weeks. The agents were administered either alone or simultaneously. Synergistic antitumor activity on SC-1-NU was produced by the combination of IFN and UFT without any increment of side effects, and the combination therapy also increased intratumoral thymidylate synthetase (TS) inhibition and the amount of 5-fluorouracil (5-FU) in the intratumoral RNA. Thus, IFN seems to modulate the antitumor activity of UFT against SC-1-NU through an inhibition of DNA synthesis and RNA distortion, and therefore this combination could be useful for clinical application.

Dual modulation by l-leucovorin and recombinant human interferon alpha 2a of 5-fluorouracil antitumor activity against the human colon carcinoma xenograft Co-4.

We investigated the dual modulation by l-leucovorin (LV) and recombinant human interferon-alpha 2a (IFN-alpha 2a) of 5-fluorouracil (5-FU) antitumor activity against human colon carcinoma cells (Co-4) using a nude mouse system. 5-FU was administered intraperitoneally (IP) at 10 or 90 mg/kg. 5-FU (10 mg/kg) was administered daily for 10 days, and 90 mg/kg was administered once. LV was administered IP 1 and 0 h before 5-FU treatment at 200 mg/kg. IFN-alpha 2a was administered subcutaneously (SC) daily for 14 days at 60,000 IU/mouse. When 5-FU was administered at 10 or 90 mg/kg with these two modulators, the antitumor effect was increased significantly, with T/C ratios of 18.1 and 6.1, respectively. These modulatory effects were assessed as synergistic, without associated severe side effects or death during the experimental period. LV augmented the antitumor activity of 5-FU through increment of thymidylate synthetase (TS) inhibition, and IFN-alpha 2a showed a modulatory effect in elevating the intratumoral concentration of fluorouridine without change in TS inhibition. These results suggest that 5-FU antitumor activity against human colon carcinoma could be significantly potentiated without severe side effects by these two modulators, which possess different modes of action.

Treatment of hepatitis B surface antigen carriers in the early stage of the infection using recombinant alpha‐interferon with steroid priming

Alpha-interferon has been found to inhibit hepatitis B virus (HBV) replication in Chinese patients with chronic HBV infection although a sustained effect was rarely achieved in those with normal pretreatment serum alanine amino transferase (ALT) levels. Prednisolone priming has been found to be beneficial over treatment with interferon alone in these subjects. We studied the effect of steroid pre-treatment followed by recombinant interferon alpha-2a in the treatment of asymptomatic HBV carriers with positive hepatitis Be antigen (HBeAg), hepatitis B viral DNA (HBV-DNA) and minimal changes in liver histology. The treatment regimen included a 6-week prednisolone priming, a 2 week rest followed by 14 weeks of three times weekly 9 mega units of interferon alpha-2a injection and 52 weeks of follow-up. There were seven patients in the treatment group and seven controls. The mean age, pre-treatment ALT (normal in all except for one in each of the treatment and control groups), HBV-DNA levels and histological scores were similar in the two groups. Serum HBV-DNA levels fell in six patients during treatment and became undetectable in two of them by the end. During follow-up, serum HBV-DNA returned to pre-treatment levels in all patients. None of the treated patients had HBeAg sero-conversion and none of the controls had spontaneous clearance of HBV-DNA or sero-conversion of HBeAg. No improvement of liver histology was observed in any of the treated patients. There were only mild flu-like side-effects noted and interferon alpha-2a was well tolerated at the doses given among treated patients. Prednisolone priming followed by interferon alpha-2a treatment has no beneficial effect on HBV carriers in the early stages of chronic hepatitis B infection.

A randomized study comparing a fixed-dose of recombinant interferon alpha 2a (ROFERON) versus a decreasing dose schedule in patients with chronic hepatitis C: A multicenter study in China

A randomized study comparing a fixed-dose of recombinant interferon alpha 2a (ROFERON) versus a decreasing dose schedule in patients with chronic hepatitis C: A multicenter study in China

Primary Centroblastic/Centrocytic Lymphoma of the Skin Detection of B-Cell Monoclonality by Polymerase Chain Reaction

A 60-year-old woman was examined for erythematous plaques and nodules on the back that had appeared 1 year earlier. Histologic examination of a skin biopsy specimen showed a dense, diffuse infiltrate throughout the dermis and subcutis, composed mainly of centroblasts and centrocytes. Immunohistochemistry confirmed positivity of the neoplastic cells for L26 (CD20) and LN1 (CDw75) antibodies and negativity for UCHL1 (CD45RO), polyclonal anti-CD3, anti-kappa, and anti-lambda antibodies. Polymerase chain reaction (PCR) analysis on paraffin-embedded tissue sections of the cutaneous lesion showed immunoglobulin heavy-chain (VDJ) and kappa-chain gene rearrangement. Routine laboratory studies were within normal limits. The staging workup of the patient (bone marrow biopsy, computed tomographic scans of the chest and abdomen) showed no abnormalities. Based on clinicopathologic findings and molecular analysis, a diagnosis of primary cutaneous centroblastic/centrocytic lymphoma was made. The patient was treated with intra- and perilesionally administered recombinant interferon alpha-2a (3 x 10(6) IU) three times a week for 2 months. Complete response was achieved, and no evidence of recurrence has been observed after 18 months of follow-up.

Granulocytopenia after combined therapy with interferon and angiotensin-converting enzyme inhibitors: Evidence for a synergistic hematologic toxicity

The purpose of this study was to assess whether granulocytopenia observed in 3 of 38 patients with essential mixed cryoglobulinemia who were treated with low-dose interferon was due to the underlying disease or to synergistic toxicity of interferon with other drugs. Adverse effects of interferon therapy were monitored in 38 patients affected with type II essential mixed cryoglobulinemia. Patients were treated with 3 million units (MU), daily or on alternate days, of recombinant interferon-alpha 2a (35 patients) or with natural interferon-beta (3 patients). The duration of treatment ranged between 6 and 15 months; the total duration of follow-up, including after therapy, ranged between 8 and 93 months. None of 35 patients treated with interferon alone developed significant hematologic alterations. In addition, none of 7 patients treated with angiotensin-converting enzyme (ACE) inhibitors alone showed hematologic toxicity. Three patients who were treated with a combination of interferon and ACE inhibitors developed severe granulocytopenia a few days after starting treatment. Granulocytopenia subsided within 1 to 2 weeks after suspending therapy. Resumption of treatment with this drug combination produced a granulocytopenia relapse in 1 patient. In these 3 patients, interferon treatment alone, or ACE inhibitor monotherapy, was not followed by granulocytopenia. Although severe hematologic toxicity rarely develops in patients treated with low-dose interferon, granulocytopenia occurred in all 3 of our patients with mixed cryoglobulinemia who were treated with a combination of low-dose interferon-alpha 2a and ACE inhibitors. Neither drug alone was toxic in any of our cryoglobulinemic patients, indicating a high risk of severe hematologic toxicity for this drug combination, at least in patients with this disease. Physicians should be aware of this danger when using interferon treatment in patients with this, or possibly other, disorder(s) that also require antihypertensive therapy.

Cultured human myocardial fibroblasts of pediatric origin: Natural human interferon-α is more effective than recombinant interferon-α 2a in carrier-state coxsackievirus B3 replication

Cultured human myocardial fibroblasts of pediatric origin seem to be a useful species-specific model for studying various heart diseases which involve the myocardial interstitium, for example enterovirus heart disease. Cells were propagated from small samples of human ventricular tissues (0.2 g) obtained from standard surgical procedure for the correction of Fallot-tetralogy. Cultured cells exhibited typical fibroblastoid morphology over a period of 4 months and were uniformly immunoreactive with a monoclonal antibody directed against prolyl-4-hydroxylase, a marker enzyme of fibroblasts. Infection of cell cultures with coxsackievirus B3, a cardiotropic enterovirus, resulted in a typical carrier-state type of virus persistence. Average virus titers of 2.3 x 10(5) plaque-forming units/ml (SD = 9.9 x 10(4)) were maintained over a period of up to 10 weeks by productive infection of about 8-10% of the cell population. Coxsackievirus B3 carrier cultures of human myocardial fibroblasts were used to evaluate in vitro the long-term antiviral effects of recombinant interferon alpha-2a and natural human interferon-alpha. Recombinant interferon-alpha reduced virus yields by 90% with a concentration of 423 IU/ml, whereas with natural interferon-alpha a 90% reduction of virus yields was achieved with concentrations as low as 21 IU/ml. Antiviral effects of both recombinant and natural interferon-alpha were highly specific and not related to inhibition of cell-proliferation (< 50% with interferon-alpha concentrations as high as 6250 IU/ml). Since effective concentrations of interferon-alpha can be easily attained in vivo with subcutaneous application, interferon-alpha (in particular: natural interferon-alpha) may become useful in the treatment of patients with enterovirus myocarditis and enterovirus induced dilated cardiomyopathy.

Autoimmunity and thyroid function in patients with chronic active hepatitis treated with recombinant interferon alpha-2a

The occurrence of thyroid abnormalities and the appearance of organ- and non-organ-specific autoantibodies during long-term recombinant interferon alpha-2a (IFN-alpha) therapy were studied in 86 and 51 consecutive outpatients with hepatitis C and B virus-related chronic active hepatitis (CAH-HCV and CAH-HBV), respectively. Most patients had longstanding community-acquired hepatitis. At baseline, 9.3% of CAH-HCV and 3.9% of CAH-HBV patients showed clinical and/or biochemical signs of thyroid dysfunction. The remaining patients were euthyroid, although anti-thyroid autoantibodies were found in 33/78 (42.3%) of CAH-HCV and in 5/49 (10.2%) of CAH-HBV patients. During IFN-alpha treatment, increased anti-thyroid autoantibody levels were seen in 40% of CAH-HCV initially negative patients, while they became detectable in no more than 10% of CAH-HBV patients. Interferon-alpha-induced hypo- or hyperthyroidism was recorded in 12 of 35 CAH-HCV patients treated for 12 months (34.3%). Only one CAH-HBV patient developed hyperthyroidism. High titers of anti-nuclear autoantibodies (ANA) were recorded at enrollment in 5/36 (13.8%) of CAH-HCV and in 3/16 (18.7%) of CAH-HBV patients. Only one CAH-HCV patient displayed anti-parietal cell antibodies (PCA). After IFN-alpha treatment, ANA were found in 10/28 (35.7%) and PCA in 2/28 (7.1%) of CAH-HCV patients, while an additional CAH-HBV patient developed PCA, but not ANA. However, no signs of systemic autoimmune disease were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)