Recurrent partial trisomy 1q22-q44 in clonal intraepithelial lymphocytes in refractory celiac sprue

Background & aims: Refractory celiac sprue, a low-grade intraepithelial lymphoma characterized by expansion of clonal intraepithelial lymphocytes with intracellular CD3ϵ but no surface CD3-T-cell receptor complexes, can be an intermediary step between celiac disease and overt T-cell lymphoma. To gain insight into the mechanisms of lymphomagenesis in celiac disease, we have performed the first cytogenetic study in refractory celiac sprue. Methods: Karyotypes were performed on: (1) 7 cell lines derived from clonal intraepithelial lymphocytes of patients with refractory celiac sprue; (2) 14 control T-cell lines, either from 4 of 7 patients with refractory celiac sprue or from 10 patients with uncomplicated celiac disease; and (3) bone marrow and peripheral blood lymphocytes in 1 of 7 patients with refractory celiac sprue. Rearrangements were confirmed by in situ hybridization using whole-chromosome painting probes and by comparative genomic hybridization in one patient. Results: A recurrent structural chromosomal aberration leading to partial trisomy of the long arm of chromosome 1 was found in 6 of 7 cell lines from patients with refractory celiac sprue but in none of the control T-cell lines. In one patient with circulating abnormal intraepithelial lymphocytes, the partial trisomy 1q was confirmed on cells freshly isolated from bone marrow and blood. Conclusions: Refractory celiac sprue is strongly associated with partial trisomy of the 1q region. Gain of chromosome 1q, recently found in 16% of enteropathy-type T-cell lymphoma, may be an early event in lymphomagenesis related to celiac disease and provides a key to investigating molecular mechanisms of lymphoid transformation in this disease.