Recombinant Alpha-interferon Therapy Research Articles

Cepeginterferon alfa-2b in the treatment of chronic myeloproliferative diseases

A comparative evaluation of the effectiveness of different therapeutic strategies in patients with polycythemia vera (PV) and essential thrombocythemia (ET). Patients with PV or ET, diagnosed according to the criteria WHO 2016 were included in the study. The primary endpoint - 6 months of therapy (clinical-hematological and molecular responses). The secondary endpoint - 12 months of therapy (clinico-hematologic, molecular, histological responses). Sixty three patients were included in the analysis: the first group consisted of 33 patients who received the therapy with ce-pegiterferone alpha-2b (ce-pegalpha-INF-α-2b), 10 of them received previous treatment; the second group - 23 patients btained hydroxycarbamide; the third group - 7 patients were treated with recombinant interferon alpha therapy (rINFα). In comparison groups, differences in age were revealed: patients receiving hydroxycarbamide therapy were older. Phlebotomy occurred in 36% of patients in the first group, 9% in the second group, and 14% in the third group. By the 6th month of therapy, 43% of the patients receiving the ce-pegalpha-INF-α-2b had complete clinical-hematologic response, 36% had partial clinical-hematologic remission and stabilization of the disease was established in 21% cases. No disease progression occured. By the 12th month of therapy, statistically significant differences in terms of efficacy between the different therapeutic groups (p = 0.2462, Fisher's exact test). In all three groups, the allelic load of JAK2V617F decreased: from 50 to 19%, from 22.3 to 15.8%, from 50 to 7.19%, respectively. The lower the allele load positively correlated with better response to therapy, which was observed in all analyzed groups. Hematologic adverse events (AEs) were more frequently observed in patients receiving ce-pegalpha-INF-α-2b therapy. Local reactions developed on 3-7 days of therapy as a hyperemic macula at the injection site. Both these reactions and hair loss did not influence on patient's condition. In the second group (patients with hydroxycarbamide therapy) there were changes in the skin and mucous membranes: dry skin, stomatitis, and in older patients new keratomas appeared. The flu-like syndrome was the most common adverse event associated with the therapy of ce-pegalpha-INF-α-2b, which fully relived during the first month of therapy. There was only one case with the flu-like syndrome we observed at the 11th month of therapy. As a rule, the biochemical blood test changes did not influence on patient's condition, were mostly associated with dietary violations, had a tendency to self-resolution and did not require medical interventions. Serious AEs were reported in one case - pulmonary embolism in a patient treated with rINFα. The reasons for the therapy discontinue in group 1: toxic hepatitis, intolerance, by the request of the patient, inadequate efficacy of therapy; in group 2: skin toxicity, in group 3: thromboses. Treatment of ce-pegalpha-INF-α-2b in patients with PV and ET is highly effective - the most patients pbtained clinical and hematological responses. There were no statistically significant differences in these parameters in comparison with hydroxycarbamide and rINFα. The use of the ce-pegalpha-INF-α-2b had an acceptable safety profile. The estimated therapeutic dose should be calculated according to body weight. To reduce the frequency of hematologic AE, titration of the drug dose is required.

Bell’s palsy and choreiform movements during peginterferon α and ribavirin therapy

Neuropsychiatric side effects of long-term recombinant interferon-alpha therapy consist of a large spectrum of symptoms. In the literature, cranial neuropathy, especially Bell's palsy, and movement disorders, have been reported much less often than other neurotoxic effects. We report a case of Bell's palsy in a patient with chronic hepatitis C during peginterferon-alpha and ribavirin therapy. The patient subsequently developed clinically inapparent facial nerve involvement on the contralateral side and showed an increase in choreic movements related to Huntington's disease during treatment.

Study of the relapse of patients with chronic hepatitis B undergoing first and repeated recombinant interferon-alpha therapy during long-term follow up

To investigate the relapse of patients with chronic hepatitis B (CHB) undergoing first and repeated recombinant interferon-alpha (rIFN-alpha) therapy during long-term follow up. Five hundred and twenty three patients with chronic hepatitis B including 403 hepatitis B e-antigen (HBeAg) positive patients and 120 HBeAg negative ones were treated with 5MU recombinant interferon-alpha 1b (rIFN-alpha1b) subcutaneously thrice weekly for 6 - 25 (median 10) months. For each patient, serum alanine aminotransferase (ALT) was measured biochemically and serum HBV DNA level was detected by fluorescent-quantitative PCR, HBeAg with enzyme immunoassay every 1 - 3 month during therapy and every 3 - 6 month during the follow up period. Some of the individuals who relapsed during the follow-up period were treated with interferon-alpha repeatedly. Ratios of early response to interferon-alpha were similar in HBeAg positive patients (55.8%, 225/403), and HBeAg negative patients (64.2%, 77/120) at the end of naive treatment (chi(2) = 2.633, P = 0.105). 39.4% (119/302) of early responders relapsed during 39 +/- 22-month follow up, and relapse rates in HBeAg negative group (55.8%, 43/77) were higher than those in HBeAg positive group (33.8%, 76/225) at the end of follow up (chi(2) = 19.335, P = 0.000). Divided the follow-up period into six fragments as 1 - 12 months, 13 - 24 months, 25 - 36 months, 37 - 48 months, 48 - 60 months and > or = 61 months, we found that the differences of relapse incidence were significant (chi(2) = 73.518, df = 5, P = 0.000), and accumulative relapse rates were significant too (chi(2) = 32.167, df = 5, P = 0.000) in all follow-up periods. Constituent ratios of HBeAg in relapsed patients of every follow-up period were similar. 57 relapsed individuals (25 in HBeAg positive group and 32 in HBeAg negative group) were retreated with interferon-alpha, and complete response were achieved in all cases at the end of repeated therapy. The relapse rates in HBeAg positive group (52.0%, 13/25) were higher than in HBeAg negative group (21.9%, 7/32) during the follow-up period after the end of retreatment (chi(2) = 5.592, P = 0.018). Rates of early response to interferon-alpha therapy were similar in HBeAg positive and HBeAg negative patients at the end of nave treatment, and relapse rates in HBeAg negative group were higher than in HBeAg positive group during long term follow-up. Combined response was achieved in all relapse cases received repeated interferon-alpha therapy at the end of retreatment. The relapse rates in HBeAg positive group were higher than in HBeAg negative group during the follow-up period after repeated therapy.

Sarcoïdose et comorbidité : étude rétrospective de 32 observations

Purpose. – A retrospective study was set up to investigate active pathologic processes associated with sarcoidosis diagnosed in 32 patients. Methods. – Eighteen patients had two identified granulomatous localizations (56%) and 14 patients had three localizations or more (27%). Comorbidity was noticed in nine patients (28% of cases). Sarcoidosis was associated with an infectious disease five times (hepatitis C virus 〚HCV〛 infection three times, including one case after recombinant interferon alpha therapy, and HIV and HCV co-infection two times). The association of sarcoidosis with a chronic immunologic inflammatory disease was noticed four times (lupus erythematosus two times, myasthenia and primary biliary cirrhosis). Finally, in two cases sarcoidosis was associated with a neoplasia (non-Hodgkin’s lymphoma in a co-infected HIV-HCV patient, ovarian cystadenocarcinoma in another patient). Sarcoidosis preceded or revealed the comorbidity four times. Conclusion. – Prospective studies should allow the finding of significant pathologic processes associated with sarcoidosis and to progress in the identification of its triggering factors; they should also help to define the relevant etiologic research to practice when faced with this granulomatosus.

High-dose interferon plus ribavirin in chronic hepatitis C not responding to recombinant alpha-interferon

Background. Recently, the combination treatment of recombinant alpha-interferon plus ribavirin has been proposed for chronic hepatitis C patients unresponsive to previous therapy with recombinant alpha-interferon alone. Aim. To determine the effectiveness of the combination therapy for the re-treatment of chronic hepatitis C patients unresponsive to previous interferon therapy. Immediate and long-term follow-up data are reported. Patients and Methods. A series of 100 patients with chronic hepatitis C not responding to recombinant alpha-interferon 3 MU tiw, were randomly assigned to two groups of 50 patients each: Group A, treated with recombinant alpha-interferon therapy for an additional six months but at a double dosage (6 MU tiw) in association with ribavirin. Group B, same treatment as group A but without ribavirin. All patients responsive to therapy were then followed-up for at least 12 months. At the end of the treatment and at the end of the follow-up period, we distinguished between complete responses (return to normal of alanine aminotransferase with undetectable serum HCV-RNA) and biochemical responses (return to normal of alanine aminotransferase still with detectable viraemia). Results. Side-effects were observed only in patients treated with recombinant alpha-interferon plus ribavirin: 12% discontinued the therapy due to haemolytic anaemia. In group A, the percentages of end-of-treatment complete response, end-of-treatment biochemical response, sustained complete response, and sustained biochemical response, were 38%, 20%, 8%, and 14%, respectively, whilst in group B, these percentages were 12%, 16%, 6%, and 16%, respectively. Conclusion. The results indicate that in patients with chronic hepatitis C unresponsive to previous recombinant alpha-interferon therapy, re-treatment with higher recombinant alpha-interferon doses, either alone or in combination with ribavirin, lead to mild long-term benefit. However, the satisfactory end of treatment complete response in group A suggests that a significant percentage of patients are sensitive to the combination therapy; and that a more aggressive therapeutic protocol in this selected subset of patients could result in a larger number of long-lasting responses leading, in turn, to a more favourable cost-effect ratio.

Reversible primary hypothyroidism with blocking or stimulating type TSH binding inhibitor immunoglobulin following recombinant interferon-alpha therapy in patients with pre-existing thyroid disorders.

Treatment with recombinant interferon-alpha (rIFN-alpha) may induce autoimmunity. We have evaluated the effect of rIFN-alpha on pre-existing thyroid disease with special reference to changes in TSH receptor antibody. Five patients, who had a history of autoimmune thyroid disease diagnosed between 2 and 16 years earlier (three patients had Graves' disease while two had Hashimoto's thyroiditis), were treated with rIFN-alpha for chronic hepatitis C. Before, during and after rIFN-alpha therapy, we determined thyroid function, antithyroid antibody, thyroid echogenicity and the surface phenotype of the peripheral and intrathyroidal lymphocytes. Four of the patients developed overt hypothyroidism after 4-7 months of rIFN-alpha therapy, and two of them had a preceding history of low-uptake thyrotoxicosis. Recovery of thyroid function was observed in all four patients. Strongly positive blocking type TSH receptor antibody was detected and an increase in the percentage of CD19 positive cells in the intrathyroidal lymphocytes was also observed in three of the patients even though the goitre size increased in two of them. One of the patients became thyrotoxic later when stimulating type TSH receptor antibody became positive. Another patient suffered from reversible hypothyroidism although stimulating type TSH receptor antibody remained strongly positive throughout the clinical course. Our data thus indicated a high incidence of an unusual type of reversible hypothyroidism with TSH receptor antibodies in patients with chronic hepatitis C and pre-existing autoimmune thyroid disease after recombinant interferon-alpha therapy through a mechanism involving both the humoral and cellular immune systems.

Efficacy of low-dose alpha interferon therapy in HBV-related chronic liver disease in Asian Indians: a randomized controlled trial

Background/Aims: Interferon therapy has been shown to be effective in Western patients with chronic hepatitis due to hepatitis B viral infection, but not in Asian Chinese. Its efficacy in Asian Indian subjects with chronic HBV infection is not known. Methods: Forty-one patients with HBV-related chronic liver disease received randomly either: (a) recombinant alpha 2b interferon ( n=20) 3 MIU, subcutaneously, three times a week for 4 months, or (b) no treatment ( n=21). Patients were followed up for 12 months after completion of therapy. Results: In the interferon-treated group, complete response (loss of HBV-DNA and HBeAg) was significantly higher than spontaneous clearance in the control group (50% vs. 4.8% p<0.05). Seroconversion to anti-HBe was seen in 35% of the treated and 4.8% of the control group ( p<0.05) at 4 months; it was noticeably higher in patients with chronic hepatitis than in those with cirrhosis. In the responders, alanine aminotransferase levels nearly normalized. One year after interferon therapy, HBeAg and HBV-DNA clearance was observed in 65% of patients, with HBsAg clearance in 15%. Reactivation was not seen in any patient. Side-effects were transient and minimal. Conclusion: Low-dose recombinant alpha interferon therapy is quite effective and safe in Asian Indians with chronic liver disease due to hepatitis B infection.

Autoimmune endocrine disease induced by recombinant interferon-alpha therapy for chronic active type C hepatitis

Autoimmune endocrine disease induced by recombinant interferon-alpha therapy for chronic active type C hepatitis

Autoimmune endocrine disease induced by recombinant interferon-alpha therapy for chronic active type C hepatitis.

To elucidate the role played by interferon-alpha (IFN alpha) in the pathogenesis of autoimmune endocrine disease, we determined the autoantibody status, thyroid function test results, hemoglobin-A1c levels, and clinical symptoms of 58 patients who received IFN alpha for treatment of chronic active type C hepatitis. Each patient was treated for 6 months with a total dose of 391 +/- 140 x 10(6) U (mean +/- SD). Thyroid microsomal and/or thyroglobulin antibodies newly appeared or were increased in titer in 6 patients, 2 of whom developed hypothyroidism during IFN alpha therapy. Neither islet cell antibodies nor insulin-dependent diabetes mellitus developed during IFN alpha therapy, although hemoglobin-A1c levels were increased in 2 patients. One patient became positive for antimitochondrial antibodies, and another patient with preexisting antimitochondrial antibodies also manifested deterioration in liver function test results. Parietal cell antibodies and smooth muscle cell antibodies were the most frequent newly developed antibodies in 7 patients. Adrenal medullary cell antibodies and nuclear antibodies newly developed in 2 and 1 patients, respectively. At least 1 of 8 autoantibodies newly appeared in 19 patients (32.8%) and hypothyroidism developed in 2 patients (3.4%) during IFN alpha therapy. On the other hand, in 19 age- and sex-matched patients who did not receive IFN alpha, no autoantibody appeared, and no autoimmune disease developed during a follow-up period of 3 months. These findings suggest that IFN alpha acts as an immunomodulatory agent, inducing autoantibody production and the development of autoimmune disease in susceptible patients. Special attention should be paid to the development of hypothyroidism during IFN alpha therapy.

Endocrine Evaluation in Patients Treated with Interferon-Alpha for Chronic Hepatitis C

The aim of our study was to evaluate the hormonal profile in a group of 31 subjects who underwent recombinant interferon-alpha therapy for chronic active hepatitis C. Hormonal determinations were performed before treatment began and at the end of the 3rd and 6th months of therapy. Free-T4 concentrations, though remaining in the normal range, showed a significant reduction (p < 0.05) after 3 and 6 months of therapy compared with pretreatment levels. A lesser decrease in free-T3 levels was also seen. TSH basal values did not show any variation, while an increased secretory response to TRH stimulation was observed at the end of the 6th month. Thyroglobulin and calcitonin levels remained normal, while an increase in antithyroglobulin and antithyreoperoxidase antibody levels was observed in 4 patients (12.9%). No modifications in the other pituitary hormones or in adrenal and sex steroid concentrations were noticed. A significant increase in IGF-I concentrations (p < 0.05) was observed during treatment, and an inverse correlation was seen between IGF-I and alanine aminotransferase levels (p < 0.01). This study supports the view that interferon treatment can influence thyroid function. The increase in IGF-I concentration observed during therapy may reflect an improvement in patients with hepatic disease, but a direct stimulatory effect of interferon on IGF-I secretion cannot be excluded.

Molecular cloning of HCV and clinical application.

Fifty-five clones encoding epitopes of HCV were isolated from Japanese patients. Their amino acid homology (AAH) to the sequence of prototype (HCV-1) ranged from 47% to 94%. These sequences cover 60% of the HCV genome lacking M/E and NS2 regions suggesting a very low or lacking immunogenicity for these regions. Two test kits for detection of anti-HCV antibody were developed using a combination of a synthetic peptide (AR142) containing the epitope of N14 (QRKTKRSTNRR) having a homology to the core of HCV of 8/11AA and a non-fusion recombinant protein Y19 starting from amino acid number (AAN) 1380 to 1507 in the NS3 region showing a AAH to the HCV-1 of 90%, and a combination of a mixture of three synthetic peptides of S29 AAN of 1-30, 38-65 and 47-74 of the core and a non-fused recombinant protein S4 AAN of 1287-1506 having a 93% AAH of the NS3 region. They showed almost the same order of sensitivity and specificity of the second-generation kits when tested with serum from blood donors and patients with non-A, non-B hepatitis. It should also be stressed that in all of the complete responders of a recombinant alpha-interferon therapy, the antibody levels against AR142 gradually decreased during and after the treatment. In 1992, studies performed for 125 patients with hepatocellular carcinoma in our clinic shows that of these 16 patients might developed from either chronic non-B, non-C liver diseases or chronic liver diseases caused by mutant(s) of HCV as their serum were negative for HBsAg and second-generation of anti-HCV.

Frequency of thyroid dysfunction after recombinant alpha-interferon therapy in Greek patients with chronic active hepatitis

Objective: To determine the frequency of organ and non-organ specific autoantibodies, autoimmune diseases, in particular thyroid dysfunction, as well as their influence on therapeutic results during alpha-interferon (alpha-INF) therapy in Greek patients with chronic viral hepatitis. Patients: The study included 32 patients (18 men and 14 women; aged 24-68 years) with clinically, biochemically, serologically and histologically proven chronic active hepatitis. Interventions: Recombinant alpha-2b-INF (5 × 10 6 units subcutaneously) three times weekly for 6 months. Main outcome measures: Signs and symptoms of autoimmune disease, including thyroid dysfunction, or development of autoantibodies to thyroid and nuclear antigens

Detection of hepatitis C virus RNA by reverse-transcriptase and polymerase chain reaction: clinical applications of quantitative analysis

Polymerase chain reaction (PCR) applications to diagnostics allowed the detection of viral nucleic acids in expected and unexpected clinical circumstances. This has raised some scepticism on the practical usefulness of PCR in the routine laboratory and emphasized the need for quatitative analysis. We addressed this question detecting HCV-RNA by a single step RT-PCR in serum samples from 50 patients with chronic non-A, non-B hepatitis included in clinical trials for recombinant alpha-interferon therapy. We obtained at least 5 serum specimens from each patient (baseline, during and after therapy samples) during an 18-month mean follow-up (range 12–45 months). RT-PCR was performed on total RNA extracted from 100 μl serum aliquots using primers for the highly conserved 5′NCR of HCV-RNA and 35 amplification cycles. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization against a P 32-oligonucleotide probe. Sensitivity was evaluated in separate experiments on tenfold dilutions of a reference Chimp serum containing 10 6 CID 50/ml. The overall sensitivity of our assay ranged between 10 2 and 10 3 genome Eq./ml. We establish a semiquantitative score system to evaluate viremia levels: 2 = HCV-RNA levels > 10 4 genome Eq./ml; 1 = levels between 10 3 and 10 4 g.Eq./ml; 0 = levels less than 10 2 g.Eq./ml. The reproducibility of this scoring system was confirmed testing repeatedly in duplicate end-point dilutions of positive serum samples. A statistically significant relation was observed between elevated HCV-RNA and ALT values (83.8%, chi-square 159.963 P < 0.0001). Response to IFN therapy was significantly better in patients with lower baseline HCV-RNA levels. A time relation was found between flare-ups of serum HCV-RNA levels and ALT elevations higher than 3 × normal values viremia elevations coincident or occuring about 1 month earlier than ALT elevations. This finding suggests that immuno pathogenesis might be responsible of HCV-induced liver damage as in chronic hepatitis B where identical relations were observed between viremia and ALT serum levels. In conclusion, single-step HCV-RNA RT-PCR can be a specific and reproducible semiquantitative assay and provides useful diagnostic informations for therapeutic decision making and monitoring of HCV-infected patients.

Long-term follow-up of patients with chronic hepatitis C treated with alpha-interferon.

We reanalyzed the results of a pilot study of recombinant alpha-interferon therapy for chronic non-A, non-B hepatitis in light of the recent discovery of the hepatitis C virus and the development of diagnostic assays for this agent. Stored serum samples from 10 patients treated between 1984 and 1986 were tested for antibody to hepatitis C virus and hepatitis C virus RNA before, during and after therapy. In addition, the current clinical, serum biochemical and virological statuses of these patients were evaluated to determine the long-term effects of interferon therapy. All patients had evidence of hepatitis C virus infection, with hepatitis C viral RNA, antibody to hepatitis C virus or both markers detectable in serum. Serum hepatitis C virus RNA was found to disappear in seven of eight patients whose aminotransferase levels became normal with interferon therapy but remained present in two patients who did not respond to therapy. Levels of hepatitis C virus RNA decreased and disappeared when serum aminotransferases fell to normal levels but rose with subsequent elevation of aminotransferase levels in two patients who had relapses in disease when interferon was stopped. During a follow-up of 3 to 6 yr, hepatitis C virus RNA remained undetectable in the six patients whose serum aminotransferase levels remained normal after interferon therapy. However, neither initial titers of hepatitis C virus RNA nor disappearance of viral RNA from serum during treatment predicted a sustained response. Thus long-term beneficial responses to alpha-interferon can occur in patients with chronic hepatitis C and are associated with sustained loss of hepatitis C virus RNA from serum.

Recombinant alpha-interferon and verruca plantaris. A review of the literature

The authors review the literature and report the mechanisms of action, chemical properties, pharmacokinetics, adverse effects, and clinical studies of recombinant alpha-interferon. The authors believe that clinical trials should be performed with recombinant alpha-interferon therapy on verruca plantaris to prove or disprove the effectiveness of interferon as a potential treatment modality for these commonly encountered lesions.

Recombinant Alpha-Interferons, Thyroid Irradiation and Thyroid Disease

Recombinant alpha-interferons are used as therapeutic agents in an increasing number of benign and malignant disorders. Long-term administration of recombinant alpha-interferon as a maintenance agent is associated with a small number of adverse side-effects which are responsible for patient intolerance of this drug. These include weight loss, alopecia and chronic fatigue, anorexia and depression syndrome. This latter syndrome needs to be distinguished from thyroid disease, which is documented in this report in a number of patients on recombinant alpha-interferon therapy.

Effects of recombinant leukocyte interferon on ribonuclease activities in serum in chronic hepatitis B

Alkaline ribonuclease (RNase; EC 3.1.27.5) activities and 2',5'-oligoadenylate synthetase (2-5 AS; no EC no. assigned) activities in serum were measured in nine patients with hepatitis B e antigen-positive chronic hepatitis B before, during, and after treatment with recombinant human interferon alpha-2b for four weeks at daily doses ranging from 3 to 10 mega-units. Alkaline RNase activities in serum significantly increased from 65.8 +/- 9.5 units/L (mean +/- SD) to 84.3 +/- 11.9 units/L after the first week of therapy (P less than 0.001). (One unit of RNase activity is defined as that increasing the absorbance at 260 nm by 1.0 in 1 min). This increase persisted during and until two weeks after the end of the therapy, at which time the mean RNase activity in serum was still significantly increased (70.8 +/- 9.4 units/L, P less than 0.01). Before therapy, phosphocellulose chromatography of RNase showed five active peaks of enzyme activity, which were similar to that observed even when RNase activity increased immediately after therapy. There was a close correlation between RNase activities and the logarithm of 2-5 AS activities, measured simultaneously in each patient. We conclude that recombinant alpha-interferon therapy increases RNase activities in serum, associated with the increased 2-5 AS activities.

Recombinant interferon-alpha therapy of Philadelphia chromosome-negative myeloproliferative disorders with thrombocytosis

purpose: The clinical course of patients with myeloproliferative disorders and excessive thrombocytosis may be complicated by serious hemorrhagic or thrombotic events. We have previously reported that interferon-alpha can control severe refractory thrombocytosis in patients with advanced chronic myelogenous leukemia. Therefore, we treated a group of thrombocythemic patients with Ph-negative myeloproliferative disorders, including polycythemia vera and essential thrombocythemia, with recombinant and interferon-alpha ( rIFN- α 2 a ). patients and methods: Eight patients with profound elevations in platelet counts received a median induction dose of 5.4 × 10 6 U/day (rante, 5.0 to 10.0 × 10 6 U/day) of rIFN- α 2 a administered intramuscularly or subcutaneously. result: We observed a significant decline in platelet counts from a median baseline value of 1,929 × 10 9/L (range, 960 to 2,960 × 10 9/L) to a median posttreatment value of 431 × 10 9/L (range, 71 to 1,150 × 10 9/L) ( p <0.01). Concomitantly, white blood cell counts declined from a median baseline value of 20.8 × 10 9/L (range, 10.5 to 40.8 × 10 9/L) to a median posttreatment value of 6.1 × 10 9/L (range, 2.9 to 29.0 × 10 9/L) ( p <0.02). Correction of thrombocytosis was rapid, with a median of only eight days from the start of therapy to the achievement of a platelet count less than 1,000 × 10 9/L. Six of eight patients have shown an ongoing response with a median follow-up period of 11 months (range, one to 30 months). There have been no bleeding or thrombotic events during the study. Side effects of rIFN- α 2 a therapy consisted of fever and flu-like symptoms, with tachyphylaxis developing after one to two weeks of therapy. conclusion: Our observations suggest that alpha interferon may be a promising therapeutic agent for myeloproliferative disorders characterized by thrombocytosis.

Soluble interleukin-2 receptors in the sera of patients with hairy cell leukemia: relationship with the effect of recombinant alpha-interferon therapy on clinical parameters and natural killer in vitro activity

In this study we provide evidence that the sera of patients with hairy cell leukemia (HCL) contain a factor that can prevent the binding of a monoclonal antibody specific for interleukin-2 receptor (IL-2R) to its target. This factor corresponds to the soluble form of IL-2R (sIL-2R), as assessed by a specific enzyme-linked immunosorbent assay test, and appears to be released by neoplastic hairy cells. The serum sIL-2R levels were very high at diagnosis and significantly reduced during recombinant alpha-interferon (rIFN alpha 2) therapy. Values of sIL-2R appeared to be inversely related to the natural killer in vitro function displayed by peripheral blood mononuclear cells from the same patients. The presence of sIL-2R in the serum of patients with HCL might be involved in the impairment of cell-mediated immunity observed in these patients and could represent a valuable marker for monitoring different phases of the disease and for modulating IFN therapy.