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Biomedical subjects

Leo B A van de Putte

Publications and source records attributed to Leo B A van de Putte.

9 recordsLinked to original sources

Intranasal administration of recombinant human cartilage glycoprotein-39. A phase I escalating cohort study in patients with rheumatoid arthritis.

OBJECTIVE: To investigate safety and tolerability and pilot efficacy of repeated single doses of Org39141 in patients with active rheumatoid arthritis (RA). Org 39141 is recombinant human cartilage glycoprotein-39, intended to induce mucosal tolerance upon intranasal administration. METHODS: RA patients with moderate disease activity were treated for 4 weeks and followed for another 8 weeks. The trial had a sequential cohort design: RA patients in the first cohort received 4 intranasal doses (one per week) of either 25 microg Org 39141 or placebo; in subsequent cohorts, treatment with 125microg, 625 microg, or 3125 microg Org39141 was compared to placebo. Safety was evaluated by means of reporting adverse events, standard laboratory testing, and nose examination. The primary efficacy endpoint was RA disease activity as measured by the Disease Activity Score 28 (DAS28). RESULTS: A total of 36 patients were randomized. Org39141 was well tolerated, and no severe or serious adverse events (AE) were reported. In the pooled placebo group, a decrease in DAS28 was observed, but to a lesser extent than in the Org 39141 treatment groups. After 4 weeks of treatment, the mean decrease in DAS in the 625 microg Org 39141 treatment group (-24%) was statistically (p = 0.02) and clinically (EULAR criteria) significantly larger than in the pooled placebo group (-3%). Once-weekly intranasal treatment with Org39141 was well tolerated, and no serious or severe AE were reported. A trend towards efficacy was observed. Our results are encouraging for further clinical development of Org39141.

Adipokines↗

Role of Fcgamma receptors IIA, IIIA, and IIIB in susceptibility to rheumatoid arthritis.

OBJECTIVE: To investigate the role of Fcg receptor (FcgR) genes in susceptibility to rheumatoid arthritis (RA) using family based studies, to examine possible interactions between FcgR genotypes and the shared epitope (SE), and to assess linkage disequilibrium between FcgR loci. METHODS: Association studies were performed in 95 Caucasian, single-case, nuclear Caucasian families with both parents alive using haplotype based haplotype relative risk (HHRR) and transmission disequilibrium test (TDT) statistics. Three FcgR polymorphisms (FcgRIIA-131H/R, FcgRIIIA-158V/F, and FcgRIIIB-NA1/NA2) were genotyped using polymerase chain reaction methods. Linkage analysis was performed using 3 microsatellite markers (D1S498, D1S2844, D1S2762) flanking the FcgR region in an independent set of 90 Caucasian, multiple-case families. Potential effects of disease heterogeneity, including sex and the presence of rheumatoid factor, SE, and erosive or nodular disease, were taken into account in the analysis. Logistic regression analysis was performed to determine whether FcgR alleles are independent risk factors for the susceptibility to and/or severity of RA. Linkage disequilibrium was calculated using pairwise linkage disequilibrium statistics. RESULTS: HHRR and TDT analysis showed no evidence of preferential transmission of any FcgR alleles studied, and there were no important associations with any given disease phenotype. Moreover, neither linkage to microsatellite markers close to the FcgR genes on chromosome 1 nor linkage disequilibrium between FcgR loci was present in our population. The distribution of inherited genotypes provided evidence for an interaction between the SE and the FcgRIIIA-158V allele and between the SE and the FcgRIIIA-158V-FcgRIIA-131H 2-locus haplotype since the combined presence of these factors increased the susceptibility to RA (OR 4.13, 95% CI 1.6-10.62 and OR 2.83, 95% CI 1.25-6.38, respectively). However, regression analysis showed that neither the 158V allele nor the 158V-131H haplotype contributed as independent factors to susceptibility or severity of RA. CONCLUSION: Isolated FcgR genes do not play a major independent role in susceptibility to RA. To a limited extent, the presence of high-binding alleles at the FcgRIIIA locus or at the FcgRIIIA-FcgRIIA haplotype might predispose to RA in SE positive individuals.

Adolescent↗

Research in complex diseases.

Many diseases that have a substantial effect on health have a complex pathogenesis. Examples are atherosclerosis, diabetes mellitus, and rheumatoid arthritis. Here, we discuss a hierarchy of goals of research in complex diseases, and introduce a stepwise approach for the development of disease models, paying specific attention to the position of genetic factors and stochastic variables in these models.

Arthritis, Rheumatoid↗

Reshaping the shared epitope hypothesis: HLA-associated risk for rheumatoid arthritis is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule.

OBJECTIVE: To further analyze the association of HLA-DRB1 alleles with disease susceptibility in recent-onset rheumatoid arthritis (RA). METHODS: One hundred sixty-seven Caucasian RA patients and 166 healthy controls were typed for HLA-DRB1. RESULTS: The association of susceptibility to RA with the group of alleles encoding the shared epitope susceptibility sequences (SESSs) was confirmed in recent-onset RA. Among non-SESS alleles, DRB1*07, *1201, *1301, and *1501 showed significant protective effects. Even after correction for the influence of SESS alleles, significant independent protective effects of DRB1 alleles were observed. Protective alleles shared a third hypervariable region motif. Independent homozygosity effects were observed both for susceptibility and for protective alleles. CONCLUSION: Nonsusceptibility alleles differ significantly with regard to RA risk. Protective alleles show clear homology at positions 67-74, often encoding isoleucine at position 67 or aspartic acid at position 70. Susceptibility and protective alleles both show homozygosity effects. Based on these results and on data reported in the literature, in order to incorporate the finding of differential risks among nonsusceptibility alleles, we propose to reshape the shared epitope hypothesis as follows: HLA-associated risk for RA is encoded by amino acid substitutions at positions 67-74 of the HLA-DRB1 molecule.

Adolescent↗

Key randomized trials of single agents in early rheumatoid arthritis.

Disease modifying antirheumatic drugs (DMARD) for treatment of rheumatoid arthritis (RA) are well established. As evidence has shown, considerable damage to the joints occurs early in the disease: thus DMARD therapy is being initiated earlier. Clinical trials with DMARD monotherapy in early RA are reviewed with consideration given to efficacy, onset of therapeutic effect, and the toxicity profile of currently available drugs.

Antirheumatic Agents↗