[Practical significance of HL-A groups in rheumatology].

Since 1972, several relations have been demonstrated between some HL-A antigens and some articular diseases. The W27 antigen frequency is highly increased in ankylosing spondylitis (88%) and in Reiter disease (78%) compared with controls (5%). In peripheral forms of psoriatic rheumatism, the W17 and HL-A13 antigens are more fréquent (24% and 15%) than in healthy subjects (4% and 5%). In central forms of psoriatic rheumatism, there is a relation with W27 (48%) and still, we do not know if this association concerns only spondylitis or also sacro-ileitis. The HL-A typing may be useful for the diagnosis of some rheumatic diseases, when they present atypical appearances. W27 possesses a considerable value for the diagnosis of ankylosing spondylitis. The relation between W27 and ankylosing spondylitis is clearly stronger than that between Waaler-Rose reaction and rheumatoid arthritis.