Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0079731 (B-cell lymphoma)
 16,671 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

SWAP-70 is a recently discovered member of the Dbl (diffuse B-cell lymphoma) family of signal transduction molecules that is abundantly expressed in B cells. SWAP-70 mediates lipid second-messenger signals to the cytoskeletal-organizing GTPase Rac, functioning as a guanine-nucleotide exchange factor. SWAP-70 is strongly expressed in germinal center B cells, with low-level expression in resting B-cells. Expression of SWAP-70 in neoplastic B cells has not been described. We report the immunohistochemical expression of SWAP-70 in 86 B-cell neoplasms. SWAP-70 was strongly expressed in 59 of the 86 cases: 2 of 10 (20%) precursor B-cell lymphoblastic leukemias, 2 of 2 (100%) precursor B-cell lymphoblastic lymphomas, 2 of 4 (50%) mantle cell lymphomas, 7 of 9 (78%) Burkitt lymphomas, 9 of 9 (100%) diffuse large B-cell lymphomas, 8 of 8 (100%) follicular lymphomas, 6 of 6 (100%) nodular lymphocyte predominant Hodgkin lymphomas, 0 of 8 (0%) classic Hodgkin lymphomas, 12 of 13 (92%) chronic lymphocytic leukemias, 3 of 3 (100%) nodal marginal zone lymphomas, 5 of 5 (100%) extranodal marginal zone lymphomas, 1 of 2 (50%) splenic marginal zone lymphomas, 2 of 3 (66%) hairy cell leukemias, and 0 of 4 (0%) plasma cell neoplasms. All 4 T-cell lymphomas were nonreactive for SWAP-70: 0 of 3 peripheral T-cell lymphomas and 0 of 1 anaplastic large cell lymphoma. These results suggest that a spectrum of neoplastic B cells maintains activation of this signal transduction pathway. This is the first report of the expression of a Dbl family molecule in human lymphoma and leukemia tissues.
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PMID:Expression of the diffuse B-cell lymphoma family molecule SWAP-70 in human B-cell neoplasms: immunohistochemical study of 86 cases. 1516 14

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) is a rare B-cell lymphoma considered to be of germinal center (GC) derivation. Studies on immunoglobulin expression have been few, and post-switch immunoglobulin (IgG) has been identified in the majority of cases examined thus far. We reviewed 180 cases of NLPHL and observed the unexpected expression of IgD in 27% of cases. IgD is usually coexpressed with IgM in naive B cells but can also be seen as IgD-only in centroblasts (CD38-positive) or memory B cells (CD27-positive). We asked whether IgD-positive NLPHL differed from cases of NLPHL negative for IgD. Clinically, the IgD-positive cases presented at a younger median age (21 vs. 44 years) and had a striking male predominance (male-to-female ratio, 23:1 vs. 1.5:1). Cervical lymph nodes were more frequently involved (56% vs. 18.2%). L&H cells were localized in a predominantly extrafollicular distribution in the majority of IgD-positive cases (69%). The IgD-positive cases did not coexpress IgM or CD27 (a marker associated with memory B cells), and nearly all (93%) were weakly positive for CD38, supporting a GC derivation. The expression of Bcl-6, BOB.1, Oct2, and SWAP-70 was similar in the two groups. However, PU.1 expression was seen in 60% of the IgD-positive cases in contrast to 86% of the IgD-negative cases. The absence of PU.1 staining correlated with more L&H cells in an extrafollicular distribution, weakening the use of this marker in the differential diagnosis with T-cell rich/histiocyte rich B-cell lymphomas. To study IgD expression in "de-novo" T-cell rich/histiocyte rich B-cell lymphomas, we analyzed 20 cases and all but one were negative. In conclusion, cases of IgD-positive NLPHL do not differ from IgD-negative cases regarding cellular derivation and most other immunophenotypic characteristics. However, IgD-positive NLPHL exhibits distinctive clinical features, and more often involves the interfollicular region in a background relatively rich in T cells. IgD positivity may represent an additional useful marker in the diagnosis of NLPHL.
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PMID:IgD positive L&H cells identify a unique subset of nodular lymphocyte predominant Hodgkin lymphoma. 1669 12