V originále
To the Editor: Takata et al. (1) reported that patients with diffuse large B cell lymphoma (DLBCL) relatively frequently (13% of patients) harbor a deletion at the 22q11.22 locus that involves the PRAME gene, and that PRAME loss is associated with poor outcomes and leads to cytotoxic T cell immune escape. The authors comment that “deletions...were located close to the Igλ gene.” I would like to bring to the attention of the authors and readers that the PRAME gene and neighboring ZNF280A, ZNF280B, and GGTLC2 genes are located between variable (V) subgenes for the immunoglobulin lambda (Igλ) light chain (Figure 1). The PRAME deletion is inevitable when a B lymphocyte (normal or malignant) rearranges the Igλ locus and utilizes one of the many V subgenes located more distantly from the J-C region. It is known that approximately 30% to 40% of B lymphocytes express Igλ (~60%–70% express Igκ, since this locus for the Ig light chain is rearranged before Igλ). Therefore, it is not surprising that the loss of PRAME has been previously noted in multiple B cell malignancies, especially chronic lymphocytic leukemia (2–4). Takata et al. (1) observed that patients with PRAME deletions more often have an Igλ rearrangement, but they also report cases of DLBCL with a PRAME deletion and rearranged Igκ.