Parvovirus B19 in an immunocompetent adult patient with acute liver failure: an underdiagnosed cause of acute non-A-E viral hepatitis.

There are occasional pediatric reports of parvovirus B19-associated transient acute hepatitis and hepatic failure. A case of a 34-year-old immunocompetent woman who developed severe and prolonged but self-limited acute hepatitis and myelosuppression following acute parvovirus B19 infection is reported. Parvovirus B19 may be the causative agent in some adult cases of acute non-A-E viral hepatitis and acute liver failure.

A clinicopathologic evaluation of follicular lymphoma grade 3A versus grade 3B reveals no survival differences.

CONTEXT: The World Health Organization classification recommends categorizing grade 3 follicular lymphomas based on the presence of centrocytes (grade 3A) or of sheets of centroblasts (grade 3B). The clinical significance of this practice is not known. OBJECTIVE: To determine whether grade 3 follicular lymphoma subtype is associated with prognosis. DESIGN: Multi-institutional retrospective case series. MAIN OUTCOME MEASURE: Overall survival. RESULTS: Forty-five cases of grade 3 follicular lymphoma without diffuse large B-cell lymphoma were studied (35 cases of grade 3A, 10 cases of grade 3B) from 21 men and 24 women (median age, 67 years; mean age, 63.8 years; range, 26-86 years). Follow-up information from the time of diagnosis was available in all patients, with a median follow-up time of 24 months (mean, 34 months; range, 2- 115 months). Treatment information was available in 40 patients. There was no difference in age (P =.45, Wilcoxon test) or stage (P =.76, Fisher exact test) between patients with follicular lymphoma of grade 3A or grade 3B. Furthermore, the Cochran-Armitage test for trends showed no evidence that the proportion of patients with follicular lymphoma grade 3A or 3B increased or decreased with increasing stage at presentation. Kaplan-Meier analysis showed a median overall survival of 44 months from the time grade 3 follicular lymphoma was diagnosed, with no significant difference between cases diagnosed as grade 3A or grade 3B (P =.14, log-rank test). Univariable Cox proportional hazards modeling showed no evidence that an anthracycline-containing chemotherapy regimen or history of lower grade follicular lymphoma affected overall survival. CONCLUSIONS: In this retrospective series, subclassification of grade 3 follicular lymphoma into type 3A and 3B categories had limited clinical and prognostic significance. However, the study was limited by lack of statistical power. Since morphology often provides clues for progress in defining biologic differences, subtyping may still be useful, particularly in the setting of prospective clinical studies.

Splenic marginal zone lymphomas presenting with splenomegaly and typical immunophenotype are characterized by allelic loss in 7q31-32.

Splenic marginal zone lymphoma (SMZL) is a rare non-Hodgkin's lymphoma that recently has been recognized as an entity. The first goal of this study was to identify potential chromosomal aberrations in this entity by cytogenetic analysis and comparative genomic hybridization (CGH). The second goal was to assess the frequency of 7q31-32 allelic imbalances in SMZL with primary involvement of the spleen and the typical immunophenotype (IgM+; IgD(dim); and CD5-, CD10-, and CD23-). We applied CGH and cytogenetics to 13 cases of SMZL with primary splenic involvement. By CGH, we found DNA copy number changes in 11 of 13 cases. Overall chromosomal gains were more frequent than chromosomal losses. Gains were most frequently detected for chromosome X, chromosome 3, and chromosome 18. Losses commonly involved chromosome 7 and chromosome 6.CGH and cytogenetic analysis showed a deletion in chromosome 7q31 in 4 cases. Loss of heterozygosity (LOH) analysis using three microsatellite markers located at 7q31 revealed LOH in 9 cases. Remarkably, 2 of the 4 cases that lacked a 7q31 deletion had an atypical immunophenotype because they were partially CD23 positive. The other 2 cases were not informative. The findings indicate that SMZL with primary splenic presentation and the typical IgM+, IgDdim, CD5-, CD10-, CD23- immunophenotype is characterized by the presence of deletions in chromosome 7q31-32.

Involvement of multiple signaling pathways in follicular lymphoma transformation: p38-mitogen-activated protein kinase as a target for therapy.

Follicular lymphoma (FL) is the most common form of low-grade non-Hodgkin's lymphoma. Transformation to diffuse large B cell lymphoma (DLBCL) is an important cause of mortality. Using cDNA microarray analysis we identified 113 transformation-associated genes whose expression differed consistently between serial clonally related samples of FL and DLBCL occurring within the same individual. Quantitative RT-PCR validated the microarray results and assigned blinded independent group of 20 FLs, 20 DLBCLs, and five transformed lymphoma-derived cell lines with 100%, 70%, and 100% accuracy, respectively. Notably, growth factor cytokine receptors and p38beta-mitogen-activated protein kinase (MAPK) were differentially expressed in the DLBCLs. Immunohistochemistry of another blinded set of samples demonstrated expression of phosphorylated p38MAPK in 6/6 DLBCLs and 1/5 FLs, but not in benign germinal centers. SB203580 an inhibitor of p38MAPK specifically induced caspase-3-mediated apoptosis in t(14;18)+/p38MAPK+-transformed FL-derived cell lines. Lymphoma growth was also inhibited in SB203580-treated NOD-SCID mice. Our results implicate p38MAPK dysregulation in FL transformation and suggest that molecular targeting of specific elements within this pathway should be explored for transformed FL therapy.

Follicular lymphoma grade 3B includes 3 cytogenetically defined subgroups with primary t(14;18), 3q27, or other translocations: t(14;18) and 3q27 are mutually exclusive.

Chromosomal translocations involving t(14;18)(q32;q21) and the chromosome 3q27 region are common in B-cell non-Hodgkin lymphoma of germinal center cell origin. Grade 3B follicular lymphoma (FL), consisting almost exclusively of centroblasts, is a distinct subgroup of follicular lymphomas that has more in common clinically with the aggressive diffuse large B-cell lymphomas than with their indolent FL grade 1 and 2 counterparts. We studied the cytogenetic and molecular genetic aberrations by classic cytogenetics, polymerase chain reaction, Southern blot hybridization, and fluorescence in situ hybridization, with special emphasis on t(14;18), affecting bcl-2, and 3q27 rearrangement, affecting bcl-6, in 32 cases of FL grade 3B. Three distinctive subgroups were identified based upon the existence of breakpoint 3q27, a translocation t(14;18), or the absence of both. Group I involved a t(14;18) and no 3q27 aberrations (n = 13); group II was without a t(14;18) and without 3q27 aberrations (n = 9), but had other cytogenetic aberrations; and group III was without a t(14;18) but with aberrations involving 3q27 (n = 10). None of the FL grade 3B cases harbored both a t(14;18) and 3q27 aberration. These results, in particular the finding of a mutual exclusiveness of bcl-2 and bcl-6 rearrangement, indicate at least 3 different pathways of oncogenesis in FL grade 3B. FL grade 3B with bcl-2 rearrangement probably is part of the same entity as the other follicular lymphomas (1, 2, 3A), whereas the cases with 3q27 abnormalities or other unrelated translocations are more closely related to the majority of diffuse large-cell lymphomas of germinal center cell origin.

Differential expression of human equilibrative nucleoside transporter 1 (hENT1) protein in the Reed-Sternberg cells of Hodgkin's disease.

Gemcitabine is a cytotoxic nucleoside analog with activity in relapsing/refractory Hodgkin's disease (HD). Because gemcitabine is hydrophilic, it requires plasma membrane nucleoside transporter proteins to access intracellular targets. The most abundant and widely distributed transporter in human cells is human equilibrative nucleoside transporter 1 (hENT1). Because our prior studies showed that a deficiency in hENT1 confers high-level resistance to gemcitabine toxicity in vitro, we developed an immunohistochemical method to assess the hENT1 abundance of cells in tumor tissue. We now report the application of this method for visualizing the hENT1 protein abundance in the plasma membranes of Reed-Sternberg cells in lymph nodes of HD patients. Frozen sections of 30 lymph nodes were stained with monoclonal antibodies (mAb 10D7G2) raised against a synthetic peptide comprised of residues 254-271 from the large intracellular loop of hENT1 and staining intensity was scored on a 0-4 + scale. hENT1-staining intensity varied among HD lymph node samples (score/n; 0/8; 1/10; 2/9; 3/3; 4/0) and suggested that at least 60% of the tumors appeared hENT1 deficient. Because Epstein-Barr virus (EBV) is often associated with HD, staining for Epstein-Barr early RNA was also examined. Although 9/30 patients tested positive for EBV, there was no correlation with hENT1 staining. hENT1-staining intensities were positively correlated with age of the patient but were independent of other clinical, laboratory or pathology features (tumor stage, histologic subtype, presence of B symptoms, staining for CD15 or CD30, serum biochemistry, disease free survival, and overall survival). We conclude that, because hENT1 deficiency has been previously related to nucleoside-drug resistance, immunohistochemical staining for hENT1 warrants evaluation as a predictive tool for guiding the appropriate use of gemcitabine in the treatment of HD.

Leukemic B cells clonally identical to myeloma plasma cells are myelomagenic in NOD/SCID mice.

OBJECTIVE: In multiple myeloma (MM), the immunoglobulin gene rearrangement characterizing malignant plasma cells is unique. For a patient with multiple myeloma who underwent a B-cell leukemic blast transformation, using the immunoglobulin molecular signature, we characterized the clonal relationship to autologous plasma cells and the impact on normal polyclonal B-lymphocyte populations. METHODS: Single-cell reverse transcriptase polymerase chain reaction (RT-PCR)/PCR was used to determine the clonal relationship between autologous MM plasma cells and leukemic B cells. A murine xenograft model was used to determine the myelomagenic potential of the leukemic B cells. RESULTS: Single-cell analysis showed that circulating leukemic-phase cells were clonotypic, with an IgH VDJ sequence identical to that of diagnosis plasma cells. Analysis of IgH transcripts indicates MM clonal dominance over normal B-cell components of the immune system at diagnosis and during leukemic disease. Leukemic B cells were xenografted to irradiated NOD/SCID mice, leading to lytic bone lesions and clonotypic cells in murine BM. Although human cells in murine BM expressed CD138, a marker largely absent from ex vivo leukemic cells, the expression of CD45, CD19, and CD20 confirmed that engrafting cells were mature, probably late-stage B cells rather than plasma cells. CONCLUSIONS: Leukemic B cells are able to exert strong clonal dominance over normal components of the immune system, colonize the murine BM in a xenograft model, and disrupt normal bone metabolism leading to lytic bone lesions. This supports the hypothesis that clonotypic MM B cells are reservoirs of disease that persist throughout therapy and give rise to relapse.

Immunohistochemical variation of human equilibrative nucleoside transporter 1 protein in primary breast cancers.

Gemcitabine and capecitabine are nucleoside analogues used in chemotherapy strategies for the treatment of breast cancer. We previously demonstrated that deficiency in hENT1, the most abundant and widely distributed plasma membrane nucleoside transporter in human cells, confers high-level resistance to gemcitabine toxicity in vitro, whereas the relationship between hENT1 activity and capecitabine toxicity is unknown. To determine the relationship between capecitabine cytotoxicity and hENT1 abundance, cultured MDA-MB-435s human mammary carcinoma cells were exposed to graded concentrations of the capecitabine metabolites, 5'-deoxy-5-fluorouridine or 5-fluorouracil, in the presence and absence of nitrobenzylmercaptopurine ribonucleoside (NBMPR), a tight-binding inhibitor of hENT1. The presence of NBMPR reduced the cytotoxic effects of 5'-deoxy-5-fluorouridine, indicating that hENT1 also enabled cellular uptake of this capecitabine metabolite by breast cancer cells. We report here the development of an immunohistochemical method to assess the hENT1 abundance of malignant cells in solid tumors. Frozen sections of 33 primary breast cancers were stained with monoclonal antibodies raised against a synthetic peptide derived from the large intracellular loop of hENT1, and staining intensity was scored on a 0-4+ scale. hENT1 staining intensity varied markedly among breast samples (4 with score 0, 5 with score 1+, 7 with score 2+, 14 with score 3+, 3 with score 4+), suggesting that at least 9 of the tumors were hENT1 deficient. We conclude that because hENT1 deficiency has previously been associated with nucleoside drug resistance, immunohistochemical staining of hENT1 warrants further study as a predictive tool for guiding the appropriate use of gemcitabine and capecitabine in the treatment of breast cancer.