Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0003873 (rheumatoid arthritis)
 53,068 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunogold ultracytochemistry and Western immunoblotting showed that polyclonal antibodies against human lactoferrin bind to the highly immunogenic 65-kilodalton (kDa) heat shock protein of mycobacteria. The fast-growing mycobacterial species Mycobacterium smegmatis showed a higher density of these receptors for antilactoferrin sera than the slow-growing M. avium. Polyclonal antibodies against mycobacteria (M. bovis BCG) recognized human lactoferrin. Comparison of the amino acid sequence of lactoferrin with that of the 65-kDa protein of M. tuberculosis revealed seven instances of four amino acid sequence homology between the microbial and the human iron-binding protein. Four of these tetrapeptide sequences were also shared with the human transferrin molecule. The shared amino acid sequence KDLL was also present in the DR1, DR3, and DR4 subsets of the DR beta subregion of major histocompatibility complex (MHC) class II molecules. The molecular mimicry between the 65-kDa mycobacterial protein and the human proteins (lactoferrin, transferrin, and MHC class II molecules) offers a molecular setting for mycobacteria-associated, T-cell-dependent autoimmune disease, namely, for rheumatoid arthritis.
 ...
PMID:Cross-reactivity and sequence homology between the 65-kilodalton mycobacterial heat shock protein and human lactoferrin, transferrin, and DR beta subsets of major histocompatibility complex class II molecules. 232 24

Alpha HLA-DR4 extended haplotypes have been established by family studies in children and adults with chronic arthritis, the children having polyarticular juvenile rheumatoid arthritis and the adults rheumatoid arthritis. These diseases are probably the same disorder presenting at different ages. The results demonstrate age-related differences in the frequency of HLA-DR4 extended haplotypes between the two groups of patients. The childhood onset was associated with the presence of the HLA-B44, SC30, DR4 extended haplotype, whereas the adult form was more strongly associated with the HLA-Bw62, SC33, DR4 haplotype. These results suggest that differences in the age at onset are influenced by the MHC in addition to the presence of the HLA DR4 gene itself.
 ...
PMID:HLA extended haplotypes in childhood and adult onset HLA-DR4-associated arthropathies. 234 52

Evidence has suggested a genetic link between the HLA-DR4 phenotype and rheumatoid arthritis (RA), particularly in its seropositive form. Such an association varies among different ethnic groups and remains controversial for seronegative patients. Data obtained for a group of 64 Chilean patients with RA (46 seropositive, 18 seronegative), as defined by the 1987 criteria of the American Rheumatism Association, and for 76 controls are reported here. The prevalence of HLA-DR4 and DR9 was significantly increased in the group of patients considered as a whole. The prevalence of HLA-DR4 was not significantly higher, however, when seronegative and seropositive patients were separately compared with controls. Also, it did not correlate with the severity of the disease within each subgroup of patients. On the other hand, HLA-DR9 showed a highly significant difference, not previously described, only for the seropositive patients in comparison with controls. The prevalence of DQ specificities showed no relevant differences among the groups. The HLA-DR4 serotype, therefore, is a weak marker for RA and does not differentiate any subgroup of patients in the Chilean group studied. This new finding, indicating an association between RA and the DR9 antigen, may be explained by the suggestion that susceptibility epitopes are shared among different DR molecules. This hypothesis might also account for the variation in the association of DR4 with RA.
 ...
PMID:Weak association between HLA-DR4 and rheumatoid arthritis in Chilean patients. 234 8

Patients selected for the presence of scleroderma-related antibodies (anti-DNA-topoisomerase I [anti-topo I; n = 43], anticentromere antibody [ACA; n = 63], or anti-Pm-Scl [n = 12]) were studied for class I and class II major histocompatibility complex antigens, as well as for Gm and Km allotypes. Anti-topo I was associated with HLA-DR5 (70% of patients versus 30.6% of controls; Pcorr = 0.0018, relative risk [RR] = 5.3). All patients with anti-Pm-Scl were positive for HLA-DR3 (versus 23.5% of controls; Pcorr less than 0.001); 6 of these patients were DR3/4 heterozygous (50% versus 3.5% of controls; Pcorr less than 0.001, RR = 27.3). Patients with ACA were frequently positive for HLA-DR1, DR4, or DRw8, with 73.7% demonstrating at least 1 of these alleles (versus 41.2% of controls; Pcorr = 0.0152, RR = 4.0). This group of ACA-positive patients who had DR1, DR4, and/or DRw8 consisted mainly of a subgroup of patients with rheumatoid arthritis. We conclude that different class II major histocompatibility complex antigens influence the formation of anti-topo I and anti-Pm-Scl. Important clinical differences between these patient groups and the immunogenetic heterogeneity support the notion of different antibody-defined scleroderma subsets.
 ...
PMID:Immunogenetic associations of scleroderma-related antinuclear antibodies. 234 21

To determine the HLA-DR4 subtypes associated with rheumatoid arthritis (RA), we performed amplification of DR4 DRB1 genes by the polymerase chain reaction and dot-blots with oligonucleotide probes. In 52 HLA-DR4+ RA patients, Dw4 was the predominant subtype. This subtype was found in 45 of 52 patients (86.5%) compared with 33 of 59 DR4+ controls (55.9%; P less than 0.001). In the whole population, Dw4 also gave the highest relative risk for RA (RR = 5.31). Relative risk was also associated with DR1.1, the common white DR1 (Dw1) type, which has a third hypervariable region amino acid sequence similar to some forms of DR4 and has glycine at position 86. Variants of DR1 (DR1.2) or DR4 (Dw13.1, Dw14.1) with valine at position 86 appeared less able to confer risk for RA. Substitution of residues in the third hypervariable region of the first domain of DRB1 appeared to correlate with relative risk for RA. Among subjects having 0-1 amino acid substitutions, RA developed in 53%, whereas in subjects with 2-4 amino acid changes, RA was present in only 17.4% (P less than 0.00001). DQw7 (formerly DQw3.1) was slightly increased in DR4+ RA patients compared with controls, but a striking excess of Dw4,DQw7 homozygous patients was observed. The results suggest that DQw7 may have an additional effect, possibly with a recessive mechanism, since it was observed only in DR4 homozygous patients.
 ...
PMID:HLA-DR alleles with naturally occurring amino acid substitutions and risk for development of rheumatoid arthritis. 205 43

Associations between HLA types and serum antibodies to native and denatured type II collagen were sought in 105 patients with rheumatoid arthritis (RA). Antibodies were measured using a solid phase radioimmunoassay. There were no significant associations between any HLA antigen (A, B, or DR) and a high antibody titre to native collagen. There were significant associations, however, between HLA antigens and high antibody titres to denatured collagen. Although DR4 did not show an association, the phenotype A2+DR4+ did; this was not related to A2 as A2+DR- was not associated with a high antibody titre. No single B locus antigen showed an association, but several B locus antigens, B12, B15, and B40, were included in phenotypes with A2 and DR4 which were associated with a high antibody titre to denatured collagen. These HLA associations with anticollagen type II are best explained by a gene other than DR4 (but in linkage with it) which may regulate the antibody response to denatured collagen. If so, this would represent an HLA gene in addition to DR4 that is active in RA.
 ...
PMID:Associations between HLA and antibodies to collagen in rheumatoid arthritis. 239 61

Since the first description of human leukocyte agglutination antibodies, knowledge of the MHC, particularly the Ia region, has grown immensely and it is now recognized as a major polymorphic multigene family involved in the regulation of immune response and disease susceptibility. This review examined the hypothesis that there is another level of complexity within the Ia system, beyond multiple loci and allelic series, that involves specific epitopes as the functionally important components of the Ia molecule. Certain of these epitopes are likely to be responsible for the regulation of immune responses and susceptibility to certain autoimmune diseases such as rheumatoid arthritis (RA). Evidence was presented that certain monoclonal antibodies recognize epitopes found in a significantly more positive association with susceptibility to RA than available markers such as DR4. Biochemical characterization of the Ia molecules bearing this epitope revealed that the same epitope was present on two different molecules. The possibility was considered that such epitopes are closely related but not identical to Ia determinants that are primarily involved in producing the abnormal immune state characterizing those with RA.
 ...
PMID:Ia antigens and susceptibility to rheumatoid arthritis. 241 7

We have determined the frequency of the DR4-associated Dw subtypes, defined by homozygous typing cells, in a group of rheumatoid arthritis (RA) patients on second-line drug therapy. The frequency of DR4 in these patients was 86%. Among Caucasians, the frequency of Dw4 in the DR4-positive patients was significantly increased (68%) as compared to DR4-positive normal individuals (46%; p less than 0.025). Dw4, as compared to the other DR4 subtypes tested, may also be associated with more severe disease as judged by indices of functional impairment and joint damage. In a small subgroup of non-Caucasian (black and Native American) patients, the Dw13 (DB3) subtype of DR4 was often seen, suggesting that RA may have different Dw associations in different ethnic groups.
 ...
PMID:Dw subtypes of DR4 in rheumatoid arthritis: evidence for a preferential association with Dw4. 241 83

Antigens of Mycobacterium tuberculosis, M leprae, M scrofulaceum, and M vaccae were injected intradermally in 86 caucasoid leprosy patients, and skin responses (measured in mm of induration at 72 h) were analysed in relation to HLA class II phenotypes. HLA-DR4 was associated with high responsiveness to antigens specific to M tuberculosis but not to antigens shared with other mycobacteria (p = 0.0005). Because DR4 is associated with rheumatoid arthritis (RA) and because a role for M tuberculosis antigens has been suggested both in experimentally induced autoimmune arthritis in rats and in RA, the DR4 associated regulation of the immune response to M tuberculosis may be relevant to the pathogenesis of RA.
 ...
PMID:Evidence for an HLA-DR4-associated immune-response gene for Mycobacterium tuberculosis. A clue to the pathogenesis of rheumatoid arthritis? 242 42

Adult rheumatoid arthritis (RA) is a very heterogeneous disease that is associated with HLA-antigens, although no absolute association has been found with any particular HLA type. Forty-one seropositive RA patients have been studied with a local monoclonal antibody named X1 21.4 (9w940), strongly associated with HLA-DRI, DR4, Drw10 antigens, to verify a possible correlation with the disease. The results obtained have also been compared with the data reported on MC1, a serologically defined determinant correlated with RA. X1 21.4 monoclonal antibody appears to be associated with the disease and it could identify one epitope involved in the susceptibility to RA.
 ...
PMID:HLA antigens and adult rheumatoid arthritis: a study with a monoclonal antibody. 243 46


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>