Genetic markers in rheumatoid arthritis

• Main Author: Rantapää Dahlqvist, Solbritt
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Umeå universitet, Reumatologi 1985
• Subjects: Rheumatoid arthritis; family history; genetic marker; HLA B27; HLA DR4; properdin factor B; C3 complement; -antitrypsin; haptoglobin; transferrin; Rheumatology and Autoimmunity; Reumatologi och inflammation; Northern Sweden
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-101305

Genetic as well as environmental factors are believed to be of importance in the etiology of rheumatoid arthritis (RA). There are a number of previous studies of genetic markers in RA, but so far no genetic linkage and only a few associations have been found. Of the associations only one (with the HLA antigen DR4) appears to be well documented. In most previous association studies the patients have not been divided according to sex and family history of RA. In this investigation the HLA antigens A, B and DR and five serum protein systems (Bf, C3, Pi, Hp and Tf) were studied in patients with erosive rheumatoid arthritis (RA), from northern Sweden. Special attention was paid to variations in the strength of associations accord­ing to sex and family history of polyarthritis. The following results were found: The frequency of the HLA antigen B27 was significantly increased in the North-Swedish population (16.6%) and among patients with a family history of polyarthritis (42.6%). In agree­ment with previous investigations a significantly increased frequency of the DR4 antigen was found in the RA patients. In the properdin factor B (Bf) system the S phenotype was found to be significantly in­creased in male patients and in patients with a family history of polyarthritis, more severe form of RA and high titres of rheumatoid factor. No significant differences with respect to phenotype or gene frequencies were found in the C3 complement system. Thus, the association between RA and C3 found in previous investiga­tions was not confirmed. A significant increase of rare alpha-1-antitrypsin (Pi) types (MS, MZ, MF and SZ) was found among RA patients. However, the increase concerned mainly Z heterozygotes and was more strongly pronounced among male patients. In the haptoglobin system a significant increase of the Hp^ gene and the Hp2-2 type was found among patients with a family history of polyarthritis, more pronounced among males. A significant increase of the transferrin gene and of the 2 type was found among male RA ...