Biomedical subjects

K Maenaut

Publications and source records attributed to K Maenaut.

4 recordsLinked to original sources

PubMed2000

Noninherited maternal antigens do not play a role in rheumatoid arthritis susceptibility in Europe. European Consortium on Rheumatoid Arthritis Families.

OBJECTIVE: It has been proposed that noninherited maternal antigens (NIMA) (HLA-DR antigens) might play a role in susceptibility to rheumatoid arthritis (RA), especially in patients who are not genetically predisposed, such as those who are HLA-DR4 and/or shared epitope (SE) negative. The present study was undertaken to test the NIMA hypothesis in a large cohort of European RA patients assembled by the European Consortium on RA Families (ECRAF). METHODS: HLA-DRB1 oligotyping was performed in families of European RA patients for whom both parents were alive. These families were consecutively recruited by the ECRAF between 1996 and 1998, for association studies. The frequencies of HLA-DR NIMA were compared with those of the noninherited paternal antigens (NIPA) after stratification for HLA-DR*04, *0401 and/or *0404, and SE status. NIMA or NIPA that coincided with inherited HLA-DR antigens were considered redundant and excluded from analysis. Calculations concerning the whole group and restricted to patients lacking parental RA were performed. RESULTS: One hundred seventy families from France (n = 81), Belgium (n = 23), Spain (n = 24), Italy (n = 19), Portugal (n = 14), and The Netherlands (n = 9) were oligotyped. The group of probands was predominantly female (88%), positive for rheumatoid factor, DR*04, and SE (71%, 58%, and 75%, respectively), and had erosive disease (75%). Parental RA was reported in 21 families. Using the NIPA as control, the frequency of HLA-DRB1*04, *0401 and/or *0404-, or SE-positive NIMA was not found to be increased in patients lacking these susceptibility alleles. The same was true when the 21 probands with parental RA were excluded from analysis. In DRB1*04-positive patients, we found no evidence of a relevant effect of HLA-DR3 or DR6 in the NIMA. CONCLUSION: Our results do not support the notion that noninherited maternal antigens have a role in susceptibility to RA in the offspring.

Adult↗

PubMed1998

New susceptibility locus for rheumatoid arthritis suggested by a genome-wide linkage study.

Rheumatoid arthritis (RA), the most common autoimmune disease, is associated in families with other autoimmune diseases, including insulin-dependent diabetes mellitus (IDDM). Its genetic component has been suggested by familial aggregation (lambdas = 5), twin studies, and segregation analysis. HLA, which is the only susceptibility locus known, has been estimated to account for one-third of this component. The aim of this paper was to identify new RA loci. A genome scan was performed with 114 European Caucasian RA sib pairs from 97 nuclear families. Linkage was significant only for HLA (P < 2.5.10(-5)) and nominal for 19 markers in 14 other regions (P < 0.05). Four of the loci implicated in IDDM potentially overlap with these regions: the putative IDDM6, IDDM9, IDDM13, and DXS998 loci. The first two of these candidate regions, defined in the RA genome scan by the markers D18S68-D18S61-D18S469 (18q22-23) and D3S1267 (3q13), respectively, were studied in 194 additional RA sib pairs from 164 nuclear families. Support for linkage to chromosome 3 only was extended significantly (P = 0.002). The analysis of all 261 families provided a linkage evidence of P = 0. 001 and suggested an interaction between this putative RA locus and HLA. This locus could account for 16% of the genetic component of RA. Candidate genes include those coding for CD80 and CD86, molecules involved in antigen-specific T cell recognition. In conclusion, this first genome scan in RA Caucasian families revealed 14 candidate regions, one of which was supported further by the study of a second set of families.

Arthritis, Rheumatoid↗

PubMed1996

Methotrexate osteopathy, does it exist?

We describe 2 postmenopausal women with rheumatoid arthritis (RA). They developed fractures during their treatment with weekly low dose methotrexate (MTX). The adverse effect of longterm low dose regimens of MTX on bone metabolism has been described as "methotrexate osteopathy," an analogy of the syndrome known in pediatric oncology. MTX may be an additional risk factor for osteoporosis and fractures in RA. This therapy should be relatively contraindicated in patients with multiple risk factors for osteoporosis.

Antirheumatic Agents↗

PubMedDate not supplied

Osteoporosis in rheumatoid arthritis.

OBJECTIVE: To answer and comment on a number of controversial issues in relation to osteoporosis and rheumatoid arthritis (RA), including: Is osteoporosis an extra-articular manifestation of rheumatoid arthritis? Does periarticular osteoporosis reflect disease activity in early arthritis? Is there a threshold for corticosteroid-induced osteoporosis? Can anti-resorbing drugs prevent rheumatoid arthritis progression? Are stress fractures rare in rheumatoid arthritis Is methotrexate toxic for bone? METHODS: Confrontation of current literature and our own experience in order to formulate a general opinion. RESULTS AND CONCLUSIONS: Because most studies agree that osteoporosis in postmenopausal women and in men with RA is more evident at the hip and radius than at the spine, and that the most important determinants of bone loss are disability, local disease activity and cumulative corticosteroid dose, osteoporosis is not a common systemic extra-articular manifestation of RA. In early arthritis, periarticular osteoporosis does indeed reflect disease activity because it is closely related to the acute phase reactants, but once periarticular osteoporosis is established it is no longer a marker of disease activity. The threshold does for corticosteroid-induced osteoporotic fractures is the cumulative rather than the actual dose. Statements based on quantitative computed tomography concerning the acute effects (and their reversal) of corticosteroids on bone have to be interpreted with care because of important body composition changes, in particular in bone marrow fat, during corticosteroid treatment. At present there is no evidence that anti-resorbing drugs can change the progress of RA erosions, probably because erosions are the result of non-osteoclast mediated mechanisms. Stress fractures in RA are underdiagnosed and are often confused with synovitis, and therefore it is likely that they are more frequent than commonly thought, in particular at the lower limbs. Methotrexate osteopathy is known in oncological practice. Whether low dose methotrexate is toxic for bone is not clear, but a number of clinical observations suggest that the occurrence of spontaneous fractures and lower extremity pain is more frequent in methotrexate treated patients than expected. Prospective studies are necessary to confirm these impressions.

Adrenal Cortex Hormones↗