Risk of haematological malignancies in HLA‐B27 carriers

Human leucocyte antigen (HLA)‐B27 carriers are predisposed to inflammatory and autoimmune diseases. Among 1137 patients with haematological diseases, 59 HLA‐B27 carriers were identified. Compared with 18 774 volunteers, the incidence of HLA‐B27 was increased in patients with acute leukaemia (relative risk RR = 1·67, P = 0·002), for both acute myeloid leukaemia (AML) (RR) = 1·67, P = 0·007) and acute lymphoblastic leukaemia (ALL) (RR = 1·68, P = 0·094). Of all the HLA‐B27 carriers, four patients had ankylosing spondylitis (AS), all with lymphoid malignancies (three ALL, one Hodgkin's disease), whereas no HLA‐B27 carriers with myeloid leukaemia had AS symptoms (P = 0·006). This suggests that HLA‐B27 carriers may have an increased risk of acute leukaemia and those with concomitant AS may be predisposed to lymphoid malignancies.