Interleukin-1 receptor blockade does not affect endotoxin-induced changes in plasma thyroid hormone and thyrotropin concentrations in man.

Interleukin-1 (IL-1) has been implicated as a mediator of the euthyroid sick syndrome. The effects of IL-1 can be blocked by the naturally occurring IL-1 receptor antagonist (IL-1ra). In the present study, iv administration of endotoxin was used as a human model of the euthyroid sick syndrome. To assess the role of endogenous IL-1 in endotoxin-induced changes in plasma thyroid hormone and TSH concentrations, 18 healthy postabsorptive humans were studied on a control study day, followed 3 days later by a study day on which they were randomly assigned to one of three treatments: a 6-h infusion of recombinant human IL-1ra alone (133 mg/h), endotoxin alone (lot EC-5; 20 U/kg), or both endotoxin and IL-1ra. Administration of IL-1ra alone did not affect the plasma concentrations of thyroid hormones or TSH compared with those on the control day. Endotoxin injection was associated with decreases in T4 (P = 0.06 vs. the control day), free T4 (P = 0.02), T3 (P < 0.001), and TSH (P < 0.0001) and a rise in rT3 (P < 0.001), reproducing the major features of the euthyroid sick syndrome. Coinfusion of IL-1ra did not influence these endotoxin-induced changes. Our results suggest that endogenous IL-1 does not play an important role in the alterations in plasma thyroid hormone and TSH concentrations induced by mild endotoxemia in healthy humans.

Initial evaluation of human recombinant interleukin-1 receptor antagonist in the treatment of sepsis syndrome: a randomized, open-label, placebo-controlled multicenter trial.

OBJECTIVES: To evaluate the safety, pharmacokinetics, and efficacy of human recombinant interleukin-1 receptor antagonist (IL-1ra) in the treatment of patients with sepsis syndrome. DESIGN: Prospective, open-label, placebo-controlled, phase II, multicenter clinical trial using three different doses of human recombinant IL-1ra. SETTING: Twelve academic medical center intensive care units in the United States. PATIENTS: Ninety-nine patients with sepsis syndrome or septic shock who received standard supportive care and antimicrobial therapy, in addition to infusion with escalating doses of IL-1ra or placebo. INTERVENTIONS: Patients received an intravenous loading dose of either human recombinant IL-1ra (100 mg) or placebo, followed by a 72-hr intravenous infusion of either one of three doses of IL-1ra (17, 67, or 133 mg/hr) or placebo. All patients were evaluated for 28-day, all-cause mortality. MEASUREMENTS AND MAIN RESULTS: A dose-dependent, 28-day survival benefit was associated with IL-1ra treatment (p = .015), as indicated by the following mortality rates: 11 (44%) deaths among 25 placebo patients; eight (32%) deaths among 25 patients receiving IL-1ra 17 mg/hr; six (25%) deaths among 24 patients receiving IL-1ra 67 mg/hr; and four (16%) deaths among 25 patients receiving IL-1ra 133 mg/hr. A dose-related survival benefit was observed with infusion of IL-1ra in patients with septic shock at study entry (n = 65; p = .002) and in patients with Gram-negative infection (n = 45; p = .04). Patients with an increased circulating interleukin-6 (IL-6) concentration of > 100 pg/mL at study entry demonstrated a dose-related survival benefit with IL-1ra treatment (p = .009). In patients with an increased IL-6 concentration at study entry, the magnitude of the decrease in IL-6 concentration 24 hrs after the initiation of therapy was correlated with increasing the IL-1ra treatment dose (p = .052). A significant dose-related reduction in the Acute Physiology and Chronic Health Evaluation (APACHE II) score was achieved by the end of infusion (p = .038). A renal elimination mechanism for IL-1ra was suggested by the positive correlation between IL-1ra plasma clearance and estimated creatinine clearance (p = .001; r2 = .51). Human recombinant IL-1ra was well tolerated. CONCLUSIONS: This initial evaluation suggests that human recombinant IL-1ra is safe and may provide a dose-related survival advantage to patients with sepsis syndrome. A larger, definitive clinical trial is needed to confirm these findings.

Modulation of airway inflammation in cystic fibrosis. In vivo suppression of interleukin-8 levels on the respiratory epithelial surface by aerosolization of recombinant secretory leukoprotease inhibitor.

Based on the knowledge that neutrophil elastase (NE) in cystic fibrosis (CF) epithelial lining fluid (ELF) can induce human bronchial epithelial cells to express the gene for interleukin 8 (IL-8), an 8.5-kD neutrophil chemoattractant, we have evaluated CF ELF for the presence of IL-8, and investigated the ability of aerosolized recombinant secretory leukoprotease inhibitor (rSLPI) to suppress NE, and hence IL-8, levels on the respiratory epithelial surface in CF. Enzyme-linked immunoassay revealed 21.9 +/- 4.8 nM IL-8 in CF ELF compared with none in normals. Active NE was detectable in ELF of all individuals with CF and was significantly decreased (P < 0.03) after aerosolization of rSLPI. Human bronchial epithelial cells exposed to CF ELF recovered before rSLPI therapy expressed IL-8 mRNA transcripts, but ELF recovered after rSLPI therapy induced far less bronchial epithelial cell IL-8 gene expression. Consistent with this, rSLPI aerosol therapy caused a marked reduction in CF ELF IL-8 levels (P < 0.05) and neutrophil number (P < 0.02). There was also a clear association between CF ELF active NE and IL-8 levels (r = 0.94). These data suggest that rSLPI therapy not only suppresses respiratory epithelial NE levels, but also breaks a cycle of inflammation on the CF epithelial surface.

Pharmacokinetics, safety and immunomodulatory effects of human recombinant interleukin-1 receptor antagonist in healthy humans.

A phase I study of human recombinant interleukin-1 receptor antagonist (IL-1ra) was conducted in healthy males between the ages of 18 and 30. Twenty-five volunteers received a single, 3 h continuous intravenous infusion of doses ranging between 1 mg/kg and 10 mg/kg IL-1ra. At 3 h into the infusion, plasma IL-1ra levels were 3.1 micrograms/ml and 29 micrograms/ml for the 1 mg/kg and 10 mg/kg doses, respectively. Post-infusion plasma IL-1ra levels declined rapidly, exhibiting an initial half-life of 21 min and a terminal half-life of 108 min. Clinical, hematological, biochemical, endocrinological and immunomodulatory effects were monitored over 72 h and compared to those of four subjects receiving a 3 h infusion of saline. There were no clinically significant differences between the drug and saline groups in symptoms, physical examinations, complete blood counts, mononuclear cell phenotypes, blood chemistry profiles, serum iron and serum cortisol levels. Peripheral blood mononuclear cells (PBMC) obtained after completion of the IL-1ra infusion synthesized significantly less interleukin 6 ex vivo than PBMC from saline-injected controls. These data suggest that transient blockade of interleukin 1 receptors is safe and does not significantly affect homeostasis.

A clinical and biochemical assessment of a nonthiol ACE inhibitor (pentopril; CGS-13945) in active rheumatoid arthritis.

Captopril, which is a thiol containing angiotensin converting enzyme (ACE) inhibitor that has a close structural similarity to D-penicillamine, behaves as a disease modifying antirheumatic drug (DMARD) in rheumatoid arthritis (RA). In order to ascertain whether the DMARD-like properties of captopril reside in its ability to inhibit ACE or in the thiol group, we evaluated pentopril (CGS-13945) in patients with active RA. This recently synthesized drug is a nonthiol containing ACE inhibitor. Pentopril produced little clinical improvement and no biochemical improvement in a group of 15 patients with RA, many of whom were unable to tolerate it because of in-effect or side effects. A reduction in serum ACE activity and a modest fall in blood pressure suggested that the drug was exerting its pharmacological effect. Our study strengthens the argument that the therapeutic benefit of captopril in RA probably lies in its thiol group rather than in its enzyme inhibition properties, and that the thiol group may be the effective moiety in some other DMARD.

A clinical and biochemical assessment of prinomide in patients with rheumatoid arthritis.

Prinomide (CGS-10787B), a potential disease modifying drug, was evaluated clinically and biochemically in 15 patients with active rheumatoid arthritis. The single group study design included monthly assessments of 7 clinical measures and 22 laboratory measures. Twelve patients completed 24 weeks' therapy with prinomide 1.2 g/day. All clinical variables showed improvement which consistently reached statistical significance for articular index from Week 8 (p less than 0.01), for summated change score from Week 12 (p less than 0.01) and for pain score from Week 16 (p less than 0.05). Sustained significant improvement in laboratory variables was seen by Week 2 for erythrocyte sedimentation rate and platelet count (both p less than 0.05), and by Week 4 for plasma viscosity (p less than 0.01), IgG, IgA, IgM (all p less than 0.05).

Worldwide safety experience with diclofenac.

Worldwide use of diclofenac sodium since 1974 has yielded an extensive body of data on the safety of this drug. Documentation is derived from clinical trials, post-marketing surveillance, special studies, and spontaneous reports of adverse drug reactions from foreign countries. Comprehensive safety data from foreign studies show that diclofenac is safer and better tolerated than aspirin and is comparable in safety to ibuprofen and naproxen. Safety data from clinical trials in the United States, in which most patients received 150 mg daily of diclofenac, show that patients receiving diclofenac had lower rates of adverse reactions than patients receiving any of the comparative nonsteroidal anti-inflammatory drugs, except for naproxen at 500 mg daily. Special safety studies performed outside the United States address organ systems and patient groups of particular concern with nonsteroidal anti-inflammatory drugs, i.e., effects of diclofenac on gastrointestinal, renal, hepatic, and hemostatic systems; use in children and the elderly; and interactions with concomitant medications.

Antibodies to Epstein-Barr virus associated antigens in Pima Indians with and without rheumatoid arthritis.

We investigated anti-rheumatoid arthritis-associated nuclear antigens (RANA) and other anti-Epstein-Barr virus (EBV) antibodies in a uniquely controlled study in female Pima Indians of Arizona, an RA prone population. Four groups of age and sex-matched individuals were formulated: (1) individuals positive for rheumatoid factor (RF) who had clinical evidence of rheumatoid arthritis (RA); (2) individuals seropositive for RF, but without arthritis; (3) individuals seronegative for RF, but with various kinds of arthritis; (4) those seronegative without arthritis. The mean anti-RANA in the seropositive RA group was significantly above those of the other groups but the anti-VCA and anti-EBNA titers did not differ. The anti-RANA was shown to be independent of RF. Comparing the Pima Indians to Caucasians in La Jolla, we found the mean anti-RANA titers of the Pimas to be significantly higher than those of the Caucasians. This study thus establishes clearly that elevated anti-RANA titers are characteristics of this American Indian group, just as they are of Caucasian groups. The elevated anti-RANA titers in RA patients may represent a unique hyperresponsiveness to this antigen, since there is no consistency in the reported levels of antibodies to other EBV-related antigens.

Discordant expression of 2 Epstein-Barr virus-associated antigens, EBNA and RANA, in man-rodent somatic cell hybrids.

The Epstein Barr nuclear antigen (EBNA) and the rheumatoid arthritis nuclear antigen (RANA) develop in human B lymphocytes that have been infected and transformed by Epstein Barr virus (EBV). Antibodies to RANA and EBNA are found only in individuals with prior exposure to EBV. The purpose of the present studies was to determine the relation of the 2 antigens to each other and to EBV genetic material, in human-rodent somatic cell hybrids. Cultured human B lymphoblastoid cells, Raji, Daudi, and RPMI 4098 were fused with thymidine kinase-deficient mouse or hamster fibroblasts. After selection and cloning in ouabain-HAT medium, the hybrid nature of the surviving cells was confirmed by isozyme analysis. The hybrid clones were analyzed for EBNA by anti-complement im,munofluorescence, and for RANA by anti-immunoglobulin immunofluorescence and immunodiffusion. The results showed that RANA and EBNA segregated entirely independently of each other in the hybrid clones. Two methods were used to detect the presence of EBV DNA sequences in the intracellular DNA of hybrid clones. The 1st method relied on the hybridization of labeled cRNA prepared from virion DNA with DNA from 8 hybrid clones affixed to nitrocellulose filters. The 2nd approach was to hybridize labeled intracellular DNA from 3 hybrid clones to Southern blots of cloned fragments of EBV DNA. These results suggested that the presence of EBV DNA was not sufficient for the expression of either antigen. One stable RANA-positive hybrid cell line contained at least 80% of the EBV genome in the absence of detectable EBNA.

Correlation between anti-RANA and anti-EBNA titers in normal subjects with and without HLA-DRw4.

We have determined the relationship of antibody titers to the rheumatoid arthritis nuclear antigen (RANA) and of antibody titers to the Epstein-Barr nuclear antigen (EBNA) to each other and to the DRw4 B cell alloantigen in the sera of 34 normal white adults. By a sensitive indirect immunofluorescence (IF) assay, 76% had RANA antibody, compared to 23% by a micro-immunodiffusion assay. The correlation coefficient for the tube dilution titers of anti-RANA and anti-EBNA was 0.61 (P < 10(-4)). The 14 DRw4-positive subjects and the 20 DRw4-negative subjects did not differ with respect to anti-RANA titers (P = 0.51) or anti-EBNA titers (P = 0.89). We conclude that: 1) most normal adults have RANA antibody by IF; 2) anti-RANA and anti-EBNA titers are closely related; 3) the titers of these antibodies cannot be related to the presence of the DRw4 determinant in normal persons.

Antibody to the rheumatoid arthritis nuclear antigen. Its relationship to in vivo Epstein-Barr virus infection.

Most patients with seropositive rheumatoid arthritis, and a variable but lesser percentage of normal subjects, have precipitating antibodies to a nuclear antigen, rheumatoid arthritis nuclear antigen, present in Epstein-Barr virus-infected human B lymphoblastoid cells. We have used a sensitive indirect immunofluorescence assay for antibody to rheumatoid arthritis nuclear antigen in a study of patients with infectious mononucleosis and healthy control subjects. Of 110 sera from normal, college-age cadets, 58 were from individuals without prior Epstein-Barr virus infection, as indicated by the lack of antibody to viral capsid antigen. All of these also lacked activity to rheumatoid arthritis nuclear antigen. 52 sera were positive for antibody to viral capsid antigen, and antibody to rheumatoid arthritis nuclear antigen was present in 26 (50%) of these. In 67 sequential sera from 11 college-age students with infectious mononucleosis who became positive for antibody to rheumatoid arthritis nuclear antigen, only 2 were positive during the 1 mo. Thereafter the incidence and titers increased progressively through the 1st yr after infection. This time-course resembled that for the development of antibody to Epstein-Barr nuclear antigen, another transformation antigen in Epstein-Barr virus-infected B lymphocytes. The development of positivity for both was much later than that of antibody to the structural viral capsid antigen, which in the current study was always positive by 1 wk. Thus, antibody to rheumatoid arthritis nuclear antigen is present in a large proportion of normal individuals and can now be clearly ascribed, from both in vivo and in vitro studies, to prior infection with Epstein-Barr virus.

Antibodies to Epstein-Barr virus-determined antigens in normal subjects and in patients with seropositive rheumatoid arthritis.

Prior studies have shown that patients with seropositive rheumatoid arthritis (RA) have an increased frequency of precipitating antibody against a nuclear antigen, the RA nuclear antigen, detected in human B lymphoblastoid cell lines infected by Epstein-Barr virus. The present investigations demonstrate that patients with seropositive RA also have specifically elevated titers of antibodies to another, better-characterized Epstein-Barr virus-associated B cell antigen, the Epstein-Barr nuclear antigen, which is detected by anti-complement immunofluorescence. Titers of these two antibodies were not affected by absorption of rheumatoid factor from serum. Furthermore, patients with RA did not have elevated titers of antibodies against the Epstein-Barr virus capsid antigen or to three other species of human herpesviruses: herpes simplex type 1, varicella-zoster virus, and cytomegalovirus. In both normal individuals and RA patients there was a significant association between the presence of antibodies to RA nuclear antigen and the titers of antibody to Epstein-Barr nuclear antigen. Thus, normal subjects with antibody to RA nuclear antigen had titers of antibody to Epstein-Barr nuclear antigen equivalent to those of patients with RA and significantly higher than normal subjects lacking antibody to RA nuclear antigen. One interpretation of these results is that patients with seropositive RA derive from a larger population with enhanced immune responsiveness to B lymphocyte nuclear antigens determined by the Epstein-Barr virus.

Metabolism of autologous and homologous IgG in rheumatoid arthritis.

The metabolism of radioiodinated IgG was studied in 20 patients with rheumatoid arthritis and 11 normal controls using autologous IgG and homologous IgG pooled from normal donors. Fractional catabolic rates in the controls were 4.44% of the autologous- and 4.29% of the homologous-labeled protein per day. The corresponding rates in the rheumatoid patients were 9.67% of the autologous- and 8.64% of the homologous-labeled protein per day. Extravascular catabolism occurred only in the rheumatoid group and accounted essentially for the entire increased catabolism of IgG observed in these patients. 10 patients were especially hypercatabolic, with fractional catabolic rates for autologous IgG greater than 10%. Moreover, they catabolized their autologous IgG significantly faster than the homologous IgG (12.6 vs. 9.9%). The increment of catabolism of autologous over homologous IgG also occurred in the extravascular compartment. These highly hypercatabolic patients had a significantly increased number of manifestations of extra-articular disease. The hypercatabolism of IgG could not be correlated with age, weight, sex, duration of disease, joint erosions, corticosteroid therapy, erythrocyte sedimentation rate, rheumatoid factor titer, serum IgG concentration, or circulating immune complexes as measured by the Raji cell radioimmunoassay. Conceivable sites of extravascular catabolism and possible causes of faster catabolism of autologous (rheumatoid) than of homologous (normal) IgG are discussed.

Radioimmunoassay of IgG and IgM rheumatoid factors reacting with human IgG.

Although IgG rheumatoid factor may play a central role in the pathogenesis of rheumatoid arthritis, previously there have been no precise methods for its specific measurement in serum and synovial fluid. This paper describes a solid phase radioimmunoassay for the independent quantification of IgM and IgG rheumatoid factor reacting with the Fc fragment of human IgG. As measured by this assay, serum IgG rheumatoid factor levels differed significantly between patients with seropositive and seronegative rheumatoid arthritis and normal control subjects. In addition, several sera and joint fluids from patients with seropositive rheumatoid arthritis, even without vasculitis, were shown by gel chromatography to have acid-dissociable complexes of IgG rheumatoid factor suggestive of IgG-IgG dimer or trimer formation.