Patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) who tested positive for human leukocyte antigen B27 (HLA-B27) had similar outcomes as the general CLL population, according to the results of a population-based study out of British Columbia.

HLA-B27 is associated with a group of immune-mediated inflammatory disorders, spondyloarthritis (SpA). Forms of SpA include ankylosing spondylitis (AS), psoriatic arthritis, inflammatory bowel disease-related arthritis, and reactive arthritis.

“It has been suggested that those with HLA-B27 have increased risk of acute leukemia and patients with AS may be predisposed to lymphoid malignancies,” according to study researchers. “However, HLA-B27 has recently been suggested to be protective against CLL by a study on HLA associations with CLL in patients referred for allogeneic hematopoietic stem cell transplantation using the National Marrow Donor Program.”

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To explore this possible association further, researchers conducted a retrospective study of 279 patients with CLL/SLL who were HLA typed for potential transplant.

Of the 279 patients, 34 were HLA-B27 positive. These patients had a median age of 53.5 years. Testing by CLL-specific FISH was performed in 25 of these patients; this analysis revealed that 7 of the 25 (28%) had an 11q deletion and 9 (36%) had a 17p deletion detected prior to first CLL therapy or at relapse. Eleven of the patients who tested positive HLA-B27 received a transplant.

“There are mixed views on whether to routinely test for HLA-B27 due to questions of its clinical importance as only a small percentage of patients with HLA-B27 will develop spondyloarthritis and high costs of the procedure,” the researchers wrote.

SpA-related disorders were diagnosed in 12 patients with HLA-B27; 1 patient (3%) had AS and 11 others (32%) had SpA-related features. There was no correlation with HLA-B27 and the development of CLL.

There were no differences in overall survival or treatment-free survival between patients who were HLA-B27–positive with or without SpA-related disorders, and no difference in clinical characteristics for patients who were positive or negative for HLA-B27. Median overall survival for HLA-B27–positive patients was 16.4 years compared with 13.6 years in patients without HLA-B27.

“HLA-B27 positivity does not appear to influence the clinical course of young patients with aggressive CLL/SLL who are being considered for an allo-HSCT,” the researchers concluded.

Reference

Huang SJ, Chan J, Bruyère H, Allan LL, Gerrie AS, Toze CL. Chronic lymphocytic leukemia patients with HLA-B27 referred for allogeneic hematopoietic stem cell transplantation do not have worse outcomes: Results of a population-based case series analysis in British Columbia, Canada. Leuk Res. 2019;84:106193.