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Biomedical subjects

C Antoni

Publications and source records attributed to C Antoni.

29 records · Page 2Linked to original sources
PubMed1996

In vivo blockade of TNF-alpha by intravenous infusion of a chimeric monoclonal TNF-alpha antibody in patients with rheumatoid arthritis. Short term cellular and molecular effects.

Due to the unknown etiology of RA, specific treatment is not available. Recently, in a double-blinded, placebo-controlled clinical trial, in vivo blockade of TNF-alpha by a single infusion of a chimeric TNF-alpha-blocking mAb, cA2, has proven to be highly effective in the treatment of RA. In parallel to this trial, we tested the consequences of cA2 infusion in ex vivo and in vitro experiments. In this paper, we describe an increase in CD4+ and CD8+ T lymphocyte counts on day 1 and a marked decrease in monocyte counts preferentially on day 7 after cA2 treatment, without major changes in B lymphocyte or NK cell counts. In addition, we found an increased responsiveness of PBMC to CD28 mAb/PMA, but not to CD3 mAb, superantigen staphylococcus enterotoxin B, or PHA on day 1 after infusion. The increase in DNA synthesis of PBMC was paralleled by increased IL-2 mRNA and IL-4 mRNA expression and IL-2 protein secretion in culture supernatants after in vitro stimulation of PBMC with CD28 mAb/PMA. In PBMC, we did not find any significant changes in mRNA or protein expression of CD28 Ag or CD28 ligands, B7-1 and B7-2. Serum concentrations of IL-1 beta, IL-6, and soluble CD14 were significantly diminished after in vivo TNF-alpha blockade. We did not see relevant changes in granulocyte function in vitro after cA2 infusion. Finally, we observed a statistically significant decrease in slCAM-1 molecules in the serum of patients treated with verum compared with that in the serum of subjects given placebo. This change in slCAM-1 concentration was evident on days 1 and 7 after the infusion of 10 mg/kg cA2, whereas it occurred only on day 7 in the serum of patients treated with the low dose (1 mg/kg) of cA2.

Adult↗
PubMed1995

One hundred anti-Ro (SS-A) antibody positive patients: a 10-year follow-up.

To explore further the varied clinical expression of anti-Ro(SS-A) antibody positive patients and to determine the outcomes of these patients, we followed 100 anti-Ro(SS-A) antibody positive patients, originally seen at the Johns Hopkins Medical Institutions in 1982 and 1983, over a 10-year period. The results of this study indicate that anti-Ro(SS-A) antibody positive patients have a diverse clinical presentation and that the anti-Ro(SS-A) antibody response generally persists for years. Some of these patients appear to have a static disease process for years. However, 65% (51, including 13 deaths, of 78 patients) of the patients for whom we had follow-up data had a chronic (10 years or greater) progressive disease process. Black patients, in general, have an earlier onset of disease and may have a more severe disease than white patients. At least 25% of our anti-Ro(SS-A) antibody positive patients demonstrated a dynamic change in clinical presentation with the development of Sjögren syndrome and/or a progressive "rheumatoid-like" arthritis. Interstitial pulmonary disease, central nervous system disease, and vasculitic insults occur frequently in these patients. Renal disease occurred in 19 anti-Ro(SS-A) positive patients, and in 47% of these renal disease patients, no anti-DNA antibodies (dsDNA or ssDNA) were detected. Cutaneous manifestations are prominent in anti-Ro(SS-A) antibody positive patients with lupus. Photosensitivity and a malar dermatitis were the most common features. Twenty percent of lupus patients had discoid lesions, and 20% had SCLE lesions. Based on this study, we believe that anti-Ro(SS-A) antibody positive patients should be routinely evaluated for the emergence of systemic features. Since these systemic features are at least in part, if not solely, the result of inflammation, early treatment with steroids and/or immunosuppressive agents may minimize the damage and influence in a positive manner the significant morbidity and mortality observed in some anti-Ro(SS-A) antibody positive patients.

Adolescent↗
PubMed1994

Randomised double-blind comparison of chimeric monoclonal antibody to tumour necrosis factor alpha (cA2) versus placebo in rheumatoid arthritis.

Tumour necrosis factor alpha (TNF alpha) is a critical inflammatory mediator in rheumatoid arthritis, and may therefore be a useful target for specific immunotherapy. In support of this hypothesis, we previously observed beneficial responses in patients with active rheumatoid arthritis after open-label administration of a chimeric monoclonal antibody to TNF alpha (cA2). We now report the results of a four-centre, randomised double-blind trial of a single infusion of 1 or 10 mg/kg cA2 compared with placebo in 73 patients with active rheumatoid arthritis. The primary endpoint of the study was the achievement at week 4 of a Paulus 20% response, an amalgam of six clinical, observational, and laboratory variables. Intention-to-treat analysis of data from individual patients showed only 2 of 24 placebo recipients responding at this time, compared with 11 of 25 patients treated with low-dose cA2 (p = 0.0083) and 19 of 24 patients treated with high-dose cA2 (p < 0.0001). Over half of the high-dose cA2 patients responded by the more stringent 50% Paulus criteria at this time (p = 0.0005). The magnitude of these responses was impressive, with maximum mean improvements in individual disease-activity assessments, such as tender or swollen-joint counts and in serum C-reactive protein, exceeding 60% for patients on high-dose treatment. There were two severe adverse events. 1 patient on 1 mg/kg cA2 developed pneumonia ("possibly" treatment-related) and 1 on 10 mg/kg had a fracture ("probably not" treatment-related). The results provide the first good evidence that specific cytokine blockade can be effective in human inflammatory disease and define a new direction for the treatment of rheumatoid arthritis.

Adolescent↗
PubMed1993

A soluble form of the human transferrin receptor is released by activated lymphocytes in vitro.

Soluble transferrin receptors (sTfR) were detected in culture supernatants of activated human peripheral blood mononuclear cells (PBMC) using a sandwich ELISA technique with two non-cross-reacting TfR MoAbs. Mitogenic stimulation of lymphoid cells induced both up-regulation of TfR surface density and release of sTfR to the medium. Peak levels of sTfR in culture supernatants occurred at day 4 after activation, 1 day later than maximum expression of TfR in the plasma membrane. Production of sTfR was independent of proliferation, as demonstrated by measuring sTfR release by PBMC, which had been irradiated with a dose of 20 Gy before activation. In addition to these in vitro experiments, we tested the sera of 85 patients with systemic lupus erythematosus (SLE), an autoimmune disease accompanied by in vivo activation of lymphocytes, for their sTfR levels. No correlation of these data was detectable to serum concentrations of the soluble alpha-chain of the IL-2 receptor, an unequivocal marker of lymphocyte activation. However, they correlated negatively to the haemoglobin content of the patients' erythrocytes, indicating that erythroid progenitors are the predominant source of sTfR in SLE patients' sera.

Antibodies, Monoclonal↗
PubMedDate not supplied

Leukocyte infiltration and mRNA expression of IL-20, IL-8 and TNF-R P60 in psoriatic skin is driven by TNF-alpha.

Anti-TNF-alpha therapy with a chimeric monoclonal antibody (Infliximab, Remicade) has been shown to be highly effective in the treatment of skin lesions as well as arthritis in patients with psoriatic arthritis. In this study we investigated the molecular consequences of the in vivo TNF-alpha blockade with infliximab in psoriatic skin lesions of 6 patients with severe psoriatic arthritis. Biopsies from lesional and non-lesional skin were taken before and 10 weeks after the initiation of treatment. Immunohistochemistry and semiquantative RT-PCR were performed focusing on proinflammatory gene products. Immunohistochemistry, after three infusions, revealed a marked decrease in the expression of TNF-alpha, HLA-DR, CD3, CD15, ICAM-1 and LFA-1 positive cells. By semiquantitative RT-PCR, we analysed mRNA expression of IL-8, IL-20, TNF-R (TNF-R p60 and TNF-R p80), IL-1R I and IL-1R II, as well as ICAM-2. Before therapy, m-RNA for IL-8, IL-20, TNF-R p60, TNF-R p80, IL-1R II and ICAM-2 were detected in lesional skin. mRNA expression of IL-8 and IL-20 completely disappeared and mRNA expression of TNF-R p60 was reduced after therapy. This effect on IL-8 expression was paralleled by a decreased infiltration of leukocytes in psoriatic skin. These data suggest that the clinical response of anti-TNF-alpha therapy in patients with psoriasis or psoriatic arthritis may be, at least in part, caused by the inhibition of the production of proinflammatory cytokines and by the decreased expression of adhesion molecules with the consequence of an impaired migration of proinflammatory cells into the inflamed tissue. These data further support a critical role for TNF-alpha in the pathology of psoriasis.

Antibodies, Monoclonal↗
PubMedDate not supplied

Combination therapy of the chimeric monoclonal anti-tumor necrosis factor alpha antibody (infliximab) with methotrexate in patients with rheumatoid arthritis.

Infliximab, a chimeric anti-TNF alpha antibody, showed in two double-blind placebo-controlled trials efficacy in combination with methotrexate (MTX) in patients with severe rheumatoid arthritis (RA). Whereas in the first trial low-dose MTX or placebo was compared to infliximab alone and in combination, the second trial compared infliximab to placebo in patients with active RA despite maximal tolerated MTX treatment. Infliximab showed synergistic effects in combination with MTX. The immunogenicity of infliximab was reduced by the combination. Infliximab in combination with high-dose MTX is effective and safe in long-term treatment up to 54 weeks.

Animals↗
PubMedDate not supplied

Enumeration of total viable microorganisms in an antibiotic raw material using ChemScan solid phase cytometer.

A preliminary study was performed for the enumeration of microorganism contamination of the macrolide antibiotic, Spiramycin, using epifluorescence with the ChemScan solid phase cytometer. The artificial spiking of Spiramycin powder antibiotic with pure culture of four microorganisms led to complete recovery of the tested organisms, whatever their sensitivity to the bacteriostatic activity of the drug. With the conventional plate method run in parallel, complete recovery was only obtained for Spiramycin resistant organisms. The spiked microorganisms that were sensitive to the antibiotic remained inhibited or stressed by the action of the Spiramycin and did not grow on the plate.

Anti-Bacterial Agents↗
PubMedDate not supplied

Infliximab for psoriasis and psoriatic arthritis.

Tumor Necrosis Factor alpha (TNF) as proinflammatory cytokine plays in the pathogenesis of many diseases an important role. In psoriasis and in psoriatic arthritis TNF is up-regulated in the skin lesion and in the synovitis. Recent trials showed that the blockade of TNF with the chimeric antibody infliximab is able to improve both, the skin lesions and the synovitis of the joints. In psoriasis in 82% of patients treated with infliximab achieved an over 75% response in the PASI index. In Psoriatic arthritis the skin improvement was correlating with the reduction of synovitis and in a small MRI controlled study all patients achieved an ACR 20 response within 10 weeks. Patients with psoriatic arthritis, who have been included in spondylarthopathy trials showed similar improvement rates. In all trials unexpected safety problems have not been reported, but the trials have been small in population and short in duration. Infliximab was used between 5 and 10 mg/kg at week 0, 2, 6 and every 8 week. It some trials the retreatment periods varied. In contrast to the treatment of rheumatoid arthritis with infliximab methotrexate was not always used as comedication. In some cases infliximab has been used in combination with other DMARDs but no trial did evaluate the combination treatment vs. the monotherapy.

Antibodies, Monoclonal↗
PubMedDate not supplied

Side effects of anti-TNF therapy: current knowledge.

The development of the anti-TNF therapies is a milestone in the therapy of rheumatic diseases. As in all new treatment opportunities it is of concern whether all potential undesired side effects have been evaluated within the clinical trials which have lead to approval of the drugs. Postmarketing experience and pharmacovigilance programs are necessary to determine the overall safety profile of the new agents. From the clinical trials and the practical experience of the first years we know that side effects have occurred in patients treated with anti-TNF agents. Sufficient knowledge about these partly specific side effects is critical for rheumatologists who treat their patients with these very effective biologic drugs.

Antibodies, Monoclonal↗