The lymph node microenvironment promotes B-cell receptor signaling, NF-kappaB activation, and tumor proliferation in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL), an incurable malignancy of mature B lymphocytes, involves blood, bone marrow, and secondary lymphoid organs such as the lymph nodes (LN). A role of the tissue microenvironment in the pathogenesis of CLL is hypothesized based on in vitro observations, but its contribution in vivo remains ill-defined. To elucidate the effects of tumor-host interactions in vivo, we purified tumor cells from 24 treatment-naive patients. Samples were obtained concurrently from blood, bone marrow, and/or LN and analyzed by gene expression profiling. We identified the LN as a key site in CLL pathogenesis. CLL cells in the LN showed up-regulation of gene signatures, indicating B-cell receptor (BCR) and nuclear factor-κB activation. Consistent with antigen-dependent BCR signaling and canonical nuclear factor-κB activation, we detected phosphorylation of SYK and IκBα, respectively. Expression of BCR target genes was stronger in clinically more aggressive CLL, indicating more effective BCR signaling in this subtype in vivo. Tumor proliferation, quantified by the expression of the E2F and c-MYC target genes and verified with Ki67 staining by flow cytometry, was highest in the LN and was correlated with clinical disease progression. These data identify the disruption of tumor microenvironment interactions and the inhibition of BCR signaling as promising therapeutic strategies in CLL. This study is registered at http://clinicaltrials.gov as NCT00019370.

Vaccine-induced tumor-specific immunity despite severe B-cell depletion in mantle cell lymphoma.

The role of B cells in T-cell priming is unclear, and the effects of B-cell depletion on immune responses to cancer vaccines are unknown. Although results from some mouse models suggest that B cells may inhibit induction of T cell-dependent immunity by competing with antigen-presenting cells for antigens, skewing T helper response toward a T helper 2 profile and/or inducing T-cell tolerance, results from others suggest that B cells are necessary for priming as well as generation of T-cell memory. We assessed immune responses to a well-characterized idiotype vaccine in individuals with severe B-cell depletion but normal T cells after CD20-specific antibody-based chemotherapy of mantle cell lymphoma in first remission. Humoral antigen- and tumor-specific responses were detectable but delayed, and they correlated with peripheral blood B-cell recovery. In contrast, vigorous CD4(+) and CD8(+) antitumor type I T-cell cytokine responses were induced in most individuals in the absence of circulating B cells. Analysis of relapsing tumors showed no mutations or change in expression of target antigen to explain escape from therapy. These results show that severe B-cell depletion does not impair T-cell priming in humans. Based on these results, it is justifiable to administer vaccines in the setting of B-cell depletion; however, vaccine boosts after B-cell recovery may be necessary for optimal humoral responses.

Lymphomatoid granulomatosis--a single institute experience: pathologic findings and clinical correlations.

Lymphomatoid granulomatosis (LYG) is a rare angiocentric and angiodestructive Epstein-Barr virus (EBV)-associated B-cell lymphoproliferative disorder. It is hypothesized that these patients have dysregulated immune surveillance of EBV. We reviewed the biopsies of 55 patients with LYG who were referred for a prospective trial at the National Cancer Institute (1995 to 2010) and evaluated the histologic, immunohistochemical, in situ hybridization, and molecular findings of these biopsies in conjunction with clinical information. Grading of the lesions was based on morphologic features and the number of EBV-positive B cells. The median age was 46 years (M:F 2.2:1). Clinically, all patients had lung involvement (100%), with the next most common site being the central nervous system (38%). No patient had nodal or bone marrow disease. All patients had past EBV exposure by serology but with a low median EBV viral load. We reviewed 122 biopsies; the most common site was lung (73%), followed by skin/subcutaneous tissue (17%); other sites included kidney, nasal cavity, gastrointestinal tract, conjunctiva, liver, and adrenal gland. Histologically, the lesions showed angiocentricity, were rich in T cells, had large atypical B cells, and were positive for EBV. Grading was performed predominantly on the lung biopsy at diagnosis; they were distributed as follows: LYG grade 1 (30%), grade 2 (22%), and grade 3 (48%). Necrosis was seen in all grades, with a greater degree in high-grade lesions. Immunoglobulin gene rearrangement studies were performed, and a higher percentage of clonal rearrangements were seen in LYG grade 2 (50%) and grade 3 (69%) as compared with grade 1 (8%). LYG is a distinct entity that can usually be differentiated from other EBV-associated B-cell lymphoproliferative disorders on the basis of the combination of clinical presentation, histology, and EBV studies. Grading of these lesions is important because it dictates the treatment choice.

Albumin enhanced morphometric image analysis in CLL.

BACKGROUND: The heterogeneity of lymphocytes from patients with chronic lymphocytic leukemia (CLL) and blood film artifacts make morphologic subclassification of this disease difficult. METHODS: We reviewed paired blood films prepared from ethylene-diamine-tetraacetic acid (ETDA) samples with and without bovine serum albumin (BSA) from 82 CLL patients. Group 1 adhered to NCCLS specifications for the preparations of EDTA blood films. Group 2 consisted of blood films containing EDTA and a 1:12 dilution of 22% BSA. Eight patients were selected for digital photomicroscopy and statistical analysis. Approximately 100 lymphocytes from each slide were digitally captured. RESULTS: The mean cell area +/- standard error was 127.8 microm(2) +/- 1.42 for (n = 793) for group 1 versus 100.7 microm(2) +/- 1.39 (n = 831) for group 2. The nuclear area was 88.9 microm(2) +/- 0.85 for group 1 versus 76.4 microm(2) +/- 0.83 for group 2. For the nuclear transmittance, the values were 97.6 +/- 0.85 for group 1 and 104.1 +/- 0.83 for group 2. The nuclear:cytoplasmic ratios were 0.71 +/- 0.003 for group 1 and 0.78 +/- 0.003 for group 2. All differences were statistically significant (P < 0.001). CONCLUSIONS: BSA addition results in the reduction of atypical lymphocytes and a decrease in smudge cells. BSA also decreases the lymphocyte area and nuclear area, whereas nuclear transmittance and nuclear:cytoplasmic ratio are increased. A standardized method of slide preparation would allow accurate interlaboratory comparison. The use of BSA may permit better implementation of the blood film-based subclassification of CLL and lead to a better correlation of morphology with cytogenetics and immunophenotyping. Published 2003 Wiley-Liss, Inc.

Treatment-induced oxidative stress and cellular antioxidant capacity determine response to bortezomib in mantle cell lymphoma.

PURPOSE: Proteasome inhibition disrupts protein homeostasis and induces apoptosis. Up to 50% of patients with relapsed mantle cell lymphoma (MCL) respond to bortezomib. We used gene expression profiling to investigate the connection between proteasome inhibition, cellular response, and clinical efficacy. EXPERIMENTAL DESIGN: We assessed transcriptional changes in primary tumor cells from five patients during treatment with bortezomib in vivo, and in 10 MCL cell lines exposed to bortezomib in vitro, on Affymetrix microarrays. Key findings were confirmed by western blotting. RESULTS: MCL cell lines exposed to bortezomib in vitro showed upregulation of endoplasmic reticulum and oxidative stress response pathways. Gene expression changes were strongest in bortezomib-sensitive cells and these cells were also more sensitive to oxidative stress induced by H2O2. Purified tumor cells obtained at several timepoints during bortezomib treatment in 5 previously untreated patients with leukemic MCL showed strong activation of the antioxidant response controlled by NRF2. Unexpectedly, activation of this homeostatic program was significantly stronger in tumors with the best clinical response. Consistent with its proapoptotic function, we found upregulation of NOXA in circulating tumor cells of responding patients. In resistant cells, gene expression changes in response to bortezomib were limited and upregulation of NOXA was absent. Interestingly, at baseline, bortezomib-resistant cells displayed a relatively higher expression of the NRF2 gene-expression signature than sensitive cells (P < 0.001). CONCLUSION: Bortezomib triggers an oxidative stress response in vitro and in vivo. High cellular antioxidant capacity contributes to bortezomib resistance.

Phase I trial of 7-hydroxystaurosporine and fludararbine phosphate: in vivo evidence of 7-hydroxystaurosporine induced apoptosis in chronic lymphocytic leukemia.

This is a phase I study of 7-hydroxystaurosporine (UCN-01) and fludararbine monophosphate (FAMP) in relapsed lymphoma. UCN-01 alone was administered in cycle 1 and with FAMP in cycles 2-6. FAMP was escalated in cohorts from 1 to 5 days. UCN-01 and FAMP pharmacokinetics and apoptosis of malignant lymphocytes was evaluated. Eighteen patients were enrolled. Standard FAMP with UCN-01 was tolerated without dose-limiting toxicity (DLT) and those seen were common to either agent alone. One patient died due to Stevens-Johnson syndrome. Seven of 18 patients responded. No pharmacological effect of UCN-01 by FAMP was noted. Lymphocytosis occurred in 15 of 18 patients following UCN-01 to paradoxically increase circulating tumor cells. UCN-01 induced apoptosis in six of eight patients with chronic lymphocytic leukemia (CLL). UCN-01 does not increase FAMP toxicity. Transient lymphocytosis followed by apoptosis occurs with UCN-01. Mobilization from tissue reservoirs may play a role in the induction of cell death in malignant lymphocytes.

The physiology of wound healing: injury through maturation.

Wound healing has evolved from a science of clinical observation to a study of molecular biology and cellular physiology. This article will review the medical literature to provide a basis for understanding the current science of wound healing.

Immunophenotypic features distinguishing familial chronic lymphocytic leukemia from sporadic chronic lymphocytic leukemia.

BACKGROUND: Familial chronic lymphocytic leukemia (CLL) has the most frequent familial aggregation among hematological malignancies. Familial CLL families have been studied to identify susceptibility genes and other factors that contribute in the etiology of CLL. To date no study has been conducted to evaluate and compare patterns of cell surface antigen expression in familial CLL and sporadic CLL. METHODS: The pattern of cell surface antigen expression was studied in familial and sporadic CLL to determine if unique identifiers of familial CLL could be detected. Survival in familial CLL verses sporadic CLL was compared and the association between prognosis and CD38 expression studied. RESULTS: Familial and sporadic CLL demonstrated the same characteristic immunophenotype (positive for surface immunoglobulin, CD5, CD19, and CD23 with dim CD20, and CD22). CD2 and CD13 expression, however, were more frequent (30% of cases) in familial CLL (P = 0.0003 for CD2, P = 0.006 for CD13) than in sporadic CLL (2-6%). There was no significant difference in survival in the two groups studied. Although the incidence of CD38 expression was similar in familial and sporadic CLL (47% and 44% respectively) the association with prognosis differed. There was a trend to decreased survival in CD38 positive sporadic (P = 0.06) but not familial CLL patients. CONCLUSIONS: We conclude that detection of CD2 or CD13 expression in CLL suggests familial CLL and examination of family history for additional affected members is warranted. Furthermore, CD38 expression does not carry the negative prognosis observed in sporadic CLL.

B-cell recovery following rituximab-based therapy is associated with perturbations in stromal derived factor-1 and granulocyte homeostasis.

The occurrence of delayed neutropenia following rituximab is poorly defined and of unknown cause. We hypothesized it may be related to perturbations of stromal derived factor-1 (SDF-1) and granulocyte homeostasis. Late-onset neutropenia (LON) was investigated in 130 patients with untreated aggressive B-cell lymphoma receiving DA-EPOCH (dose-adjusted etoposide, prednisone, Oncovin [vincristine], cyclophosphamide, and hydroxydaunorubicin) chemotherapy with or without rituximab. All patients were in remission and had no known causes for neutropenia. LON occurred in 6 (8%) of 76 patients receiving rituximab and 0 of 54 patients not receiving rituximab (P = .04). The median onset was 175 days (range, 77-204 days) after treatment with a median duration of 14 days (range, 11-16 days). In a subset of 24 patients, a significant correlation was found between rapid B-cell recovery and granulocyte decline over the 6-month recovery period (R = -0.53; P = .04). Rapid B-cell recovery directly correlated with prerecovery SDF-1 levels (R = 0.65; P = .015) and SDF-1 decline (R = -0.67; P = .013) after recovery. Our results suggest that early B-cell lymphopoiesis is important for B-cell recovery following rituximab, and that perturbation of SDF-1 during B-cell recovery retards neutrophil egress from the bone marrow. These findings illustrate the dual role of SDF-1 in human B-cell and granulocyte homeostasis.

Rituximab treatment of refractory fludarabine-associated immune thrombocytopenia in chronic lymphocytic leukemia.

Fludarabine can exacerbate idiopathic thrombocytopenia (ITP) in chronic lymphocytic leukemia (CLL). We report 3 CLL patients with refractory fludarabine-associated ITP who responded to rituximab. The patients had Rai stages III, III, and IV disease. Before fludarabine treatment, the platelet counts were 141 000/microL, 118 000/microL, and 70 000/microL. ITP developed within week 1 of cycle 3 in 2 patients and within week 2 of cycle 1 in 1 patient. Platelet count nadirs were 4000/microL, 1000/microL, and 2000/microL, respectively, and did not respond to treatment with steroids or intravenous immunoglobulin. Rituximab therapy (375 mg/m(2) per week for 4 weeks) was begun on days 18, 23, and 20 of ITP. Patient 1 achieved a platelet count of more than 50 000/microL at day 21 and more than 133 000/microL at day 28, patient 2 achieved a platelet count of more than 50 000/microL at day 4 and more than 150 000/microL at day 10, and patient 3 achieved a platelet count of more than 50 000/microL at day 5 and 72 000/microL at day 28 of rituximab therapy, with platelet response durations of 17+, 6+, and 6 months. These results suggest rituximab can rapidly reverse refractory fludarabine-associated ITP.