HLA-DRB, -DQA, and -DQB polymorphism in celiac disease and enteropathy-associated T-cell lymphoma. Common features and additional risk factors for malignancy.

CD is a gluten-sensitive enteropathy, strongly associated with expression of the DQA1*0501, DQB1*0201 genotype. CD patients have an increased risk of malignancy, particularly EATCL. However, it is controversial as to whether adults with EATCL represent a subgroup of patients with CD or should be regarded as a distinct entity. To investigate the genetic relationship between CD and EATCL, HLA class II DRB1, DQA1, and DQB1 typing of peripheral blood, frozen or paraffin-embedded biopsy tissue obtained from Caucasian patients with CD (n = 91) or EATCL (n = 47) was performed by PCR-SSOP typing. Genotype frequencies were compared with those observed in 151 unrelated control individuals. A total of 83 (91%) of 91 CD patients were of DQA1*0501, DQB1*0201 genotype (pc < 10(-6), RR = 522.2), compared with 40 (93%) of 43 EATCL patients (pc < 10(-6), RR = 44.2) with amplifiable DNA versus 35 (23%) of 151 controls. DRB1*03 frequencies were also elevated in both patient groups (79 of 91 in CD [87%; pc < 10(-6), RR = 24.5] and 38 of 40 in EATCL [95%; pc < 10(-6), RR = 70.7]) compared with controls (32 of 151, 21%). These results confirm previous studies of HLA associations in CD and also suggest that EATCL arises in individuals with the DQA1*0501, DQB1*0201 CD-predisposing genotype. However, the frequency of DRB1*03,04 heterozygotes was significantly increased in the EATCL group (16 of 40, 40%) compared with both control individuals (3 of 151, 2%; pc < 10(-6), RR = 32.9) and uncomplicated CD patients (6 of 91, 7%; pc = 0.04, RR = 9.4).(ABSTRACT TRUNCATED AT 250 WORDS)