HLA DRB1* typing and cartilage oligomeric matrix protein (COMP) as predictors of joint destruction in recent-onset rheumatoid arthritis

The carriage of a characteristic sequence of amino acids at position 67- 72in the third hypervariable region of the HLA DRB1 chain has been linked tosusceptibility to rheumatoid arthritis (RA). Whether this epitope is also apredictor of more severe disease remains controversial. Cartilageoligomeric matrix protein (COMP) is a protein, the serum levels of whichhave been found to correlate with large joint destructive disease inprevious work. In this paper, we compare DRB1* typing and serum COMP levelsin a prospectively observed group of RA patients with or without early hipjoint destruction. The COMP levels at study inclusion, median 11 monthsfrom onset of symptoms, were significantly higher in the patients withearly hip joint destruction compared to the patients in the more benigngroup. There was no difference in the number of diseasesusceptibility-related epitopes between the groups. DRB1*04, in contrast,was found among 8/8 patients with hip destruction, but also in 5/8 morebenign cases. We conclude that in this type of RA patient, COMP serumlevels are more informative predictors of aggressive disease than HLA DRB1*typing.