Related Experiment Videos
[Distribution of HLA-DR antigens in unrelated giant cell arteritis]
J Ninet1, L Gebuhrer, B Bonvoisin
1Service de Médecine interne, Hôpital Edouard Herriot, Lyon.
Insights
The human leukocyte antigen (HLA) DR 4 antigen is significantly more common in patients with giant cell arteritis and Horton
Area of Science:
- Immunogenetics
- Rheumatology
- Molecular Biology
Context:
- Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are inflammatory conditions.
- Human Leukocyte Antigen (HLA) genes play a role in immune responses.
- Specific HLA antigen frequencies can be associated with autoimmune diseases.
Purpose:
- To investigate the distribution of HLA antigens, particularly HLA-DR, in patients with GCA and PMR.
- To compare HLA antigen frequencies between patient groups and a normal population.
- To identify potential genetic markers associated with these vasculitic syndromes.
Summary:
- A study analyzed HLA-A, B, C, and DR antigen frequencies in 124 (HLA-A,B,C) and 200 (HLA-DR) healthy individuals and compared them to patient cohorts.
- No significant variations were found for HLA-A, B, C antigens.
- The HLA-DR 4 antigen showed a significantly increased frequency in patients with giant cell arteritis (39.4%) and particularly in those with Horton's disease (46.8%), especially when associated with polymyalgia rheumatica (52.8%).
Impact:
- Identifies HLA-DR 4 as a potential genetic susceptibility factor for giant cell arteritis and related conditions.
- Suggests a role for specific immune system variations in the pathogenesis of these diseases.
- May inform future diagnostic or therapeutic strategies targeting immune pathways.
Abstract:
HLA-DR antigen distribution was determined by lymphotoxicity on total lymphocytes for locus A.B.C. antigens numbering 14,28 and 7 respectively, and by a search on B lymphocytes for the 12 antigens of locus DR. The normal population included 124 subjects typed for HLA-A.B.C. and 200 subjects typed for HLA-DR. The frequency of alleles was compared to that of the different groups of patients. Significant variations were evaluated by the X2 test, using Woolf's method; the P value obtained was multiplied by the number of antigens looked for (P corrected, or pc). No deviation in frequency was found with the HLA-A.B.C. antigens. Only the DR 4 antigen, present in 23% of the normal population, was increased in proportions that depended on clinical classification: 39.4% (Pc = 0.05) in all patients with giant cell arteritis: 27% (NS) in the 37 polymyalgia rheumatica patients with negative biopsy of the temporal artery; 46.8% (P 0.05) in the 62 patients with Horton's disease presenting either as clinical and histological temporal arteritis (26 cases; DR 4 = 38.5%; NS), or as clinical and/or histological temporal arteritis associated with polymyalgia rheumatica (36 cases; DR 4 = 52.8%; Pc less than 0.005). The frequency of DR 4 antigen in Horton's disease with typical temporal artery biopsy (37 cases) was 46% (Pc = 0.05).