Acquired potential N-glycosylation sites within the tumor-specific immunoglobulin heavy chains of B-cell malignancies.
OBJECTIVE
Among B-cell malignancies, follicular lymphomas (FL) more frequently show acquired, potential N-glycosylation sites (AGS) within tumor-specific immunoglobulin. The aim of this study was to extend this observation and to evaluate the pattern of presentation of AGS within five different forms of B-cell lymphoma.


METHODS
We sequenced the tumor-specific immunoglobulin heavy chain variable region fragment, including complementarity-determining regions 2 and 3, of forty-seven consecutive patients with a B-cell malignancy enrolled in idiotype vaccine clinical trials. This sequencing approach is known to allow the identification of most AGS. We then statistically analyzed differences in presentation pattern, in terms of tumor histology, immunoglobulin isotype, AGS location and amino acid composition.


RESULTS
All twenty-four FL cases presented with at least one AGS, whereas the vast majority of four B-cell lymphoma types other than FL did not. The non- FL group of tumors included four cases of Burkitt's lymphoma, six of diffuse large cell lymphoma, seven mantle cell lymphomas and six small lymphocytic lymphomas. Most IgM-bearing follicular lymphoma cases featured their AGS within complementarity-determining region 2, as opposed to those bearing an IgG, which mostly displayed the AGS within complementarity-determining region 3. The vast majority of AGS located within either complementarity-determining region ended with a serine residue, whereas those located within framework regions mostly featured threonine as the last amino acid residue.


CONCLUSIONS
In our series, all cases of FL had AGS within their tumor-specific immunoglobulin heavy chain variable regions. In contrast, most B-cell malignancies other than FL did not. Further studies are warranted in order to establish the possible meaning of these findings in terms of disease pathogenesis, their diagnostic value in doubtful cases and their potential implications for immunotherapy.
Zabalegui
Natalia
N
Cell Therapy Area, Department of Hematology, University Clinic, University of Navarre, Avda. Pio XII, 36 - 31008 Pamplona, Spain.
de Cerio
Ascensión López-Díaz
AL
Inogés
Susana
S
Rodríguez-Calvillo
Mercedes
M
Pérez-Calvo
Javier
J
Hernández
Milagros
M
García-Foncillas
Jesús
J
Martín-Algarra
Salvador
S
Rocha
Eduardo
E
Bendandi
Maurizio
M
D000595:Amino Acid Sequence; D006031:Glycosylation; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000032:analysis* / Q000235:genetics; D016393:Lymphoma, B-Cell / Q000737:chemistry*; D008224:Lymphoma, Follicular / Q000737:chemistry; D020522:Lymphoma, Mantle-Cell / Q000737:chemistry; D008969:Molecular Sequence Data; D009154:Mutation; D009363:Neoplasm Proteins / Q000032:analysis* / Q000235:genetics; D012189:Retrospective Studies
D007143:Immunoglobulin Heavy Chains; D009363:Neoplasm Proteins