Salivary gland mucosa-associated lymphoid tissue lymphoma immunoglobulin V-H genes show frequent use of V1-69 with distinctive CDR3 features

Salivary gland mucosa associated lymphoid tissue (MALT) type lymphomas are B-cell neoplasms that develop out of a reactive infiltrate, often associate d with Sjogren's syndrome. Previous reports from our laboratory involving 1 0 patients suggested these lymphomas expressed a restricted immunoglobulin (Ig) VH gene repertoire with over use of V1-69 gene segments. To better det ermine the frequency of V1-69 use and whether there may also be selection f or CDR3 structures, we sequenced the VH genes from 15 additional cases. Ove r half of the potentially functional VH genes (8 of 14) used a V(H)1 family V1-69 gene segment, whereas the other cases used different gene segments f rom the VH1 (V1-46), V(H)3 (V3-7, V3-11, V3-30.3, V3-30.5), and V(H)4 (V4-3 9) families, The 8 V1-69 V-H genes used 5 different D segments in various r eading frames, but all used a J4 joining segment. The V1-69 CDR3s showed re markable similarities in lengths (12-14 amino acids) and stretches of 2 to 3 amino acids between the V-D and D-J junctions. They did not resemble CDR3 s typical of V1-69 chronic lymphocytic leukemias. This study extends our ea rlier work in establishing that salivary gland MALT lymphomas represent a h ighly selected B-cell population. Frequent use of V1-69 appears to differ f rom MALT lymphomas that develop at other sites, The high degree of CDR3 sim ilarity among the V1-69 cases suggests that different salivary gland lympho mas may bind similar, if not identical epitopes, Although the antigen speci ficities are presently unknown, similar characteristic CDR3 sequences are o ften seen with V1-69 encoded antibodies that have anti-IgG or rheumatoid fa ctor activity. (C) 2000 by The American Society of Hematology.