Impaired recruitment of bone-marrow-derived endothelial and hematopoietic precursor cells blocks tumor angiogenesis and growth.

The role of bone marrow (BM)-derived precursor cells in tumor angiogenesis is not known. We demonstrate here that tumor angiogenesis is associated with recruitment of hematopoietic and circulating endothelial precursor cells (CEPs). We used the angiogenic defective, tumor resistant Id-mutant mice to show that transplantation of wild-type BM or vascular endothelial growth factor (VEGF)-mobilized stem cells restore tumor angiogenesis and growth. We detected donor-derived CEPs throughout the neovessels of tumors and Matrigel-plugs in an Id1+/-Id3-/- host, which were associated with VEGF-receptor-1-positive (VEGFR1+) myeloid cells. The angiogenic defect in Id-mutant mice was due to impaired VEGF-driven mobilization of VEGFR2+ CEPs and impaired proliferation and incorporation of VEGFR1+ cells. Although targeting of either VEGFR1 or VEGFR2 alone partially blocks the growth of tumors, inhibition of both VEGFR1 and VEGFR2 was necessary to completely ablate tumor growth. These data demonstrate that recruitment of VEGF-responsive BM-derived precursors is necessary and sufficient for tumor angiogenesis and suggest new clinical strategies to block tumor growth.

Intensive treatment strategies may not provide superior outcomes in mantle cell lymphoma: overall survival exceeding 7 years with standard therapies.

BACKGROUND: Reported median overall survival (OS) in patients with mantle cell lymphoma (MCL) has been reported to be just 3-4 years. As a consequence, first-line treatment has become more aggressive. Single-center studies with R-Hyper-CVAD and/or autologous stem-cell transplant (ASCT) have produced 3-year OS rates >80%, prompting many to adopt their use. We evaluated outcomes from a single-center cohort managed in a more traditional fashion. METHODS: We identified patients with MCL evaluated at Weill Cornell Medical Center since 1997, and included those with known date of diagnosis. An online social security database was used to verify survival. RESULTS: We identified 181 patients with MCL, and date of diagnosis could be determined in 111. Three-year OS from diagnosis was 86% [95% confidence interval (CI) 78% to 92%]. Median OS was 7.1 years (95% CI 63-98 months). Adequate information on therapy was available for 75 patients. Only five were treated upfront with (R)-Hyper-CVAD or ASCT while an additional four patients received one of these regimens subsequently. Treatment type had no significant effect on OS. CONCLUSION: Outcomes with standard approaches can yield similar survival to that achieved with more intensive approaches. Biases may account for the perceived superiority of aggressive strategies.

Immunophenotypic analysis of the Kaposi sarcoma herpesvirus (KSHV; HHV-8)-infected B cells in HIV+ multicentric Castleman disease (MCD).

AIMS: Kaposi sarcoma herpesvirus (KSHV) is aetiologically related to Kaposi sarcoma, classical and extracavitary primary effusion lymphoma (PEL; EC-PEL) and multicentric Castleman disease (MCD), entities preferentially occurring in HIV-infected individuals. Characterization of HIV-associated PELs/EC-PELs suggests that the KSHV-infected malignant cells originate from a pre-terminal stage of B-cell differentiation. However, only limited phenotypic studies have been performed on HIV+ MCD, including for PR domain containing 1 with zinc finger domain/B lymphocyte-induced maturation protein 1 (PRDM1/BLIMP1), a key regulator of terminal B-cell differentiation. The aim was to characterize KSHV-infected cells in 17 cases of HIV+ MCD. METHODS AND RESULTS: Double immunohistochemistry and immunohistochemistry-in situ hybridization were used to characterize the KSHV-infected cells in MCD; the results were compared with the phenotypic profiles of 39 PELs/EC-PELs and seven PEL cell lines. Whereas the immunophenotype of KSHV-infected cells in MCD and malignant KSHV+ PEL cells was similar (PAX5, Bcl-6-; PRDM1/BLIMP1, IRF4/MUM1+; Ki67+), the MCD KSHV-infected cells differed, as they expressed OCT2, cytoplasmic lambda immunoglobulin; variably expressed CD27; lacked CD138; and were Epstein-Barr virus negative. CONCLUSIONS: Although both PEL and MCD originate from KSHV-infected pre-terminally differentiated B cells, these findings, with previously reported genetic studies, indicate HIV+ MCD may arise from extrafollicular B cells, whereas PELs may originate from cells that have traversed the germinal centre.

Autocrine stimulation of VEGFR-2 activates human leukemic cell growth and migration.

Emerging data suggest that VEGF receptors are expressed by endothelial cells as well as hematopoietic stem cells. Therefore, we hypothesized that functional VEGF receptors may also be expressed in malignant counterparts of hematopoietic stem cells such as leukemias. We demonstrate that certain leukemias not only produce VEGF but also express functional VEGFR-2 in vivo and in vitro, resulting in the generation of an autocrine loop that may support leukemic cell survival and proliferation. Approximately 50% of freshly isolated leukemias expressed mRNA and protein for VEGFR-2. VEGF(165) induced phosphorylation of VEGFR-2 and increased proliferation of leukemic cells, demonstrating these receptors were functional. VEGF(165) also induced the expression of MMP-9 by leukemic cells and promoted their migration through reconstituted basement membrane. The neutralizing mAb IMC-1C11, specific to human VEGFR-2, inhibited leukemic cell survival in vitro and blocked VEGF(165)-mediated proliferation of leukemic cells and VEGF-induced leukemic cell migration. Xenotransplantation of primary leukemias and leukemic cell lines into immunocompromised nonobese diabetic mice resulted in significant elevation of human, but not murine, VEGF in plasma and death of inoculated mice within 3 weeks. Injection of IMC-1C11 inhibited proliferation of xenotransplanted human leukemias and significantly increased the survival of inoculated mice. Interruption of signaling by VEGFRs, particularly VEGFR-2, may provide a novel strategy for inhibiting leukemic cell proliferation.

Apc gene mutation is associated with a dominant-negative effect upon intestinal cell migration.

Apc-associated intestinal tumor formation appears to require functional loss of both Apc alleles. Apc has, therefore, been classified as a tumor suppressor gene. Loss of APC protein function results in increased intracellular beta-catenin, a molecule important to both cell-cell adhesion and regulation of cellular growth. In mice bearing a germ-line Apc mutation, we found that enterocyte beta-catenin expression was also increased in histologically normal intestinal mucosa. Enterocyte crypt-villus migration was decreased by 25%, and treatment of Min/+ animals with sulindac sulfide normalized both beta-catenin expression and enterocyte migration. Our data suggest that alterations in enterocyte migration occur in cells bearing a single mutant Apc allele, and that sulindac sulfide may normalize enterocyte growth in these cells.

Cyclooxygenase-2 overexpression and tumor formation are blocked by sulindac in a murine model of familial adenomatous polyposis.

Inducible cyclooxygenase (Cox-2), also known as prostaglandin H synthase 2 (PGH-2) is a key enzyme in the formation of prostaglandins and thromboxanes. Cox-2 is the product of an immediate-early gene that is expressed in response to growth factors, tumor promoters, or cytokines. Overexpression of Cox-2 is associated with both human colon cancers and suppression of apoptosis in cultured epithelia] cells, an activity that is reversed by the nonsteroidal anti-inflammatory drug, sulindac sulfide. To address the relationship between Cox-2, apoptosis, and tumor development in vivo, we studied C57BL/6J-Min/+(Min) mice, a strain containing a fully penetrant dominant mutation in the Apc gene, leading to the development of gastrointestinal adenomas by 110 days of age. Min mice were fed AIN-76A chow diet and given sulindac (0.5 +/- 0.1 mg/day) in drinking water. Control Min mice and homozygous C57BL/6J-+/+ normal littermates lacking the Apc mutation (+/+) were fed AIN-76A diet and given tap water to drink. At 110 days of age, all mice were sacrificed, and their intestinal tracts were examined. Control Min mice had 11.9 +/- 7.8 tumors per mouse compared to 0.1 +/- 0.1 tumors for sulindac-treated Min mice. As expected, +/+ littermates had no macroscopic tumors. Examination of histologically normal-appearing small bowel from Min animals revealed increased amounts of Cox-2 and prostaglandin E(2) compared to +/+ littermates. Using two different in situ techniques, terminal transferase-mediated dUTP nick end labeling and a direct immunoperoxidase method, Min animals also demonstrated a 27-47% decrease in enterocyte apoptosis compared to +/+ animals. Treatment with sulindac not only inhibited tumor formation but decreased small bowel Cox-2 and prostaglandin E(2) to baseline and restored normal levels of apoptosis. These data suggest that overexpression of Cox-2 is associated with tumorigenesis in the gastrointestinal epithelium, and that both are inhibited by sulindac administration.

Proliferative response of mantle cell lymphoma cells stimulated by CD40 ligation and IL-4.

Mantle cell lymphoma (MCL) is a tumor of intermediate-size, IgM+, IgD+ B cells derived from the mantle zone of the germinal center. Little is known about its specific immunologic features or responsiveness to T cell-derived signals. In this work, we evaluated the proliferation and cell cycle properties of freshly isolated MCL cells after CD40 ligation, in the absence and presence of interleukin 4 (IL-4). In each MCL case examined, there was a marked growth-enhancing effect of these two stimuli characterized by improved viability, augmented expression of Ki-67, and induction of the proliferating cell nuclear antigen (PCNA). Cyclin D1 was expressed throughout the cell cycle in MCL cells induced to enter S phase. From these investigations, we conclude that the biology of MCL B lymphocytes is affected by CD154 (CD40 ligand) and IL-4, two signals usually provided by CD4+ T cells. The capacity to manipulate the activation and cell cycle state of MCL cells by these specific immunological stimuli may be exploited to confer susceptibility to chemotherapy agents and develop novel therapies in this disease.

The spleen: anatomy and anatomical function.

In this review, our knowledge concerning the structure and function of the spleen is summarized. The unique architecture of the spleen allows for interactions between the circulatory, reticuloendothelial, and immune systems. Based on these interactions in conjunction with its microanatomy, the spleen is able to maintain the integrity of the blood and respond to circulating antigens. However, this can be a double-edged sword in the case of patients suffering from autoimmune diseases such as immune thrombocytopenic purpura since the spleen can be the site of both antibody production and circulating cell destruction.

Progressive lymph node histology and its prognostic value in patients with acquired immunodeficiency syndrome and AIDS-related complex.

Seventy-four sequential lymph node biopsies from 30 acquired immunodeficiency syndrome (AIDS)/AIDS-related complex (ARC) patients showed temporal histologic progression from explosive follicular hyperplasia (EFH) to mixed follicular hyperplasia/involution (mixed) to follicular involution (FI) to lymphocyte depletion (LD). This histologic progression correlated with symptoms, development of opportunistic infections (OI), and mortality. At initial biopsy, only 50% of the AIDS/ARC patients with EFH/mixed compared to 100% with FI/LD were symptomatic with weight loss, night sweats, diarrhea, fever, or fatigue. 31% of ARC patients with EFH and 63% with FI developed an OI in a median of 69 months and 5 months, respectively; 86% with LD had a concurrent or previous OI. Ninety percent of ARC patients progressing to FI/LD died; 85% of those persisting with EFH/mixed remained alive 18 to 50 months after initial biopsy. AIDS patients with EFH lived twice as long as those with FI/LD. Progressive histology did not correlate with lymphoma. The number of ARC patients developing Kaposi's sarcoma was too small to draw definitive conclusions.

Monoclonal antibody OPD4 detects neoplastic T cells but does not distinguish between CD4 and CD8 neoplastic T cells in paraffin tissue sections.

Monoclonal antibody (MoAb) OPD4, reported to preferentially react with benign CD4 T cells in formalin-fixed tissue sections, was examined for its reactivity with 56 T-cell neoplasms after formalin or Bouin's fixation to determine if it also preferentially detects neoplastic CD4 T cells in paraffin tissue sections. Monoclonal antibody OPD4 did not preferentially detect neoplastic CD4 T cells, since it reacted with 22 of 38 (58%) CD4-positive compared with nine of 14 (64%) CD4-negative T-cell neoplasms. However, MoAb OPD4 appears to detect neoplastic T cells in Bouin's-fixed (11 of 20 cases [55%]) about as well as in formalin-fixed (20 of 32 cases [63%]) tissues. Since MoAb OPD4 does not preferentially react with neoplastic CD4 T cells, the utility of this MoAb as a pan-T-cell marker in routinely processed tissues was also explored and compared with that of Leu-22, UCHL-1, and CD3. All four antibodies reacted with approximately the same percentage of T-cell malignancies (51% to 57%). However, examination of different clinicopathologic groups and types of fixative highlighted differences. Monoclonal antibodies OPD4 and Leu-22 reacted with 62%, while CD3 detected only 41% of formalin-fixed, postthymic T-cell neoplasms. OPD4, UCHL-1, and CD3 each reacted with 55%, but Leu-22 recognized only 45% of Bouin's-fixed, postthymic T-cell malignancies. OPD4 reacted with none, but CD3 reacted with all four T-cell lymphoblastic lymphomas. Various antibody combinations were examined to determine an optimal panel for the recognition of T-cell neoplasms in paraffin sections. The combination of MoAbs OPD4 and Leu-22 detected 86% of postthymic T-cell neoplasms in formalin-fixed tissue sections. Furthermore, MoAb OPD4 appears to be relatively specific for T-cell neoplasms, detecting 31 of 56 (55%) T-cell malignancies, while only reacting with two of 39 (5%) B-cell neoplasms. Therefore, while not preferentially reactive with neoplastic CD4 T cells, MoAb OPD4 may be useful as a pan-T-cell marker of postthymic T-cell neoplasms in routinely processed, formalin-fixed tissues, especially when used in conjunction with MoAb Leu-22.

An angiocentric orbital lesion with an immature natural killer cell immunophenotype.

In this report, a unique case of a large unilateral orbital tumor occurring in a 5-year-old white girl is described. The lesion, which was associated with no systemic clinical symptoms, waxed and waned in size over 12 months and eventually spontaneously resolved. Multiple biopsies were performed, which showed an angiocentric and angioinvasive infiltrate composed of a monotonous population of atypical, immature-appearing, large lymphocytes. Extensive molecular and immunophenotypic studies led to the diagnosis of an Epstein-Barr virus-negative angiocentric lymphoproliferative disorder with an immature natural killer (NK) cell immunophenotype (CD16+CD56-), specifically an immunophenotype expressed by normal cord blood NK cells. HUM PATHOL 32:339-342.

Incidence and outcome of primary Epstein-Barr virus infection and lymphoproliferative disease in pediatric heart transplant recipients.

BACKGROUND: The objective of this study was to assess the relationship between Epstein-Barr virus (EBV) infection and posttransplantation lymphoproliferative disease (PTLD) in pediatric heart transplant recipients. EBV is implicated in the development of PTLD. However, the relationship between primary EBV infection and PTLD is not well understood. METHODS: Serial EBV titers were determined prospectively in 50 children before and after heart transplantation. Results were correlated with the development of PTLD. The clinical presentation, management, and outcome of PTLD were characterized. RESULTS: Before transplantation, EBV titers were positive in 19 and negative in 31 patients. After transplantation, all EBV-positive patients remained positive; 1 developed PTLD. Among EBV-negative patients, 12 of 31 remained negative; none developed PTLD. Nineteen patients demonstrated serologic evidence of primary EBV infection after heart transplantation; 12 developed PTLD. Mean follow-up after heart transplantation was 3.3 years (range 0.4 to 8.4 years). Mean time from heart transplantation to histologic confirmation of PTLD was 29 months (range 3 to 72 months). Survival with PTLD was 92%. CONCLUSIONS: Twelve of 13 pediatric heart transplant recipients who developed PTLD had evidence of primary EBV infection. Serial monitoring of EBV titers may lead to earlier identification and improved treatment of PTLD.

Paraffin-resistant antigens detectable by antibodies L26 and polyclonal CD3 predict the B- or T-cell lineage of 95% of diffuse aggressive non-Hodgkin's lymphomas.

The reactivity of eight preferential B-cell (L26, 4KB5, and KiB3) and T-cell (polyclonal CD3, Leu22, MT-1, UCHL-1, and OPD4) antibodies which detect paraffin-resistant antigens was examined by a three-step immunoperoxidase technique in 111 formalin-fixed, paraffin-embedded diffuse aggressive non-Hodgkin's lymphomas (NHLs) to determine the optimal panel for accurate lineage assignment. L26 (CD20) and polyclonal CD3 (CD3) were the most sensitive (> 95%) and specific (100%) antibodies. They identified the B- or T-cell lineages correctly in 106 (95%) cases. The five L26-negative, polyclonal CD3-negative cases included all three precursor B lymphoblastic NHLs and two (one B and one T) diffuse large-cell NHLs. Immunostaining with the second most sensitive preferential B-cell (4KB5) and T-cell (Leu22) antibodies correctly identified the lineage in two additional NHLs, but one false-positive result occurred. Preferential B-cell antibody KiB3 reacted with two precursor B lymphoblastic NHLs. Use of additional paraffin-reactive antibodies did not increase the number of NHLs assigned to the correct cell lineage. In conclusion, it appears that a two-tiered approach, with a first-line panel consisting of L26 and polyclonal CD3, followed by 4KB5 and Leu22 in nonlymphoblastic NHLs and by KiB3 in lymphoblastic NHLs, represents the most efficient method of correctly identifying the B- or T-cell lineage of diffuse aggressive NHLs by paraffin tissue section immunohistochemistry.

Lymph node biopsy in patients with human immunodeficiency virus infections.

Twenty-one male homosexuals were followed up by repeated lymph node biopsy for a mean (+/- SEM) follow-up of 99 +/- 18 weeks. Four histologic patterns were seen on biopsy: explosive follicular hyperplasia (EFH), follicular involution (FI), a mixed pattern of EFH with FI in the same node, and lymphocyte depletion. Patients with FI and lymphocyte depletion had mean survival times that were significantly less than those for the subjects with EFH. The percentage of lymph node follicles with suppressor cell clusters (T8) in EFH lymph nodes was significantly higher (43% vs 8%) than in nodes from patients without risk for human immunodeficiency virus infection. Helper/suppressor T-cell ratios in control nodes were 1.6; in EFH nodes, 0.97; and in FI nodes, 0.88. A remarkable 33% of patients in this lymphadenopathy group ultimately developed large-cell (B-cell) lymphoma, suggesting that the follicular stimulation noted histologically played a role in the development of this neoplasm. These data show that there is a progressive destruction of lymph node follicles that correlates with the progression of the disease and that lymph node histologic features may provide important prognostic information.

Management of lymphoproliferative disorders after cardiac transplantation.

We conducted a retrospective study of 516 cardiac recipients who underwent transplantation between April 1983 and April 1992, 19 of whom had development of post-transplantation lymphoproliferative disorders (PTLDs). These 19 patients presented with involvement of lung (5), gastrointestinal tract (5), disseminated disease (6), and adenoids and lymph nodes (3). B-cell proliferations ranging from an atypical hyperplasia to malignant lymphoma developed in 18 patients, and mixed cellularity Hodgkin's disease developed in 1 patient. The 19 patients with PTLD displayed a predominance of both women and cardiomyopathy as the indication for transplantation when compared with two separate control populations. No correlation was found between demographic criteria analyzed and (1) early versus late diagnosis of PTLD after transplantation, (2) the site of PTLD involvement, or (3) the histopathologic category of the PTLD lesion. Patients with gastrointestinal tract and lung PTLD involvement enjoyed an improved survival after both transplantation and PTLD diagnosis when compared with patients with PTLD involvement of all other extranodal sites. We report a high incidence of PTLD involving the lung and gastrointestinal tract in our cohort study. These sites of involvement responded better to a reduction in immunosuppression than did the other extranodal sites of involvement.

Erdheim-Chester disease of the central nervous system. Report of two cases.

The authors report two cases of Erdheim-Chester disease (ECD), an illness of unknown pathogenesis. Generally, this disease process involves the metaphyseal and diaphyseal portions of the long bones, the lungs, and the retroperitoneum; however, other tissues may be involved including the central nervous system (CNS). To date only two cases of CNS-related ECD have been reported. The present report adds to the literature by documenting two more recent cases of ECD involving the CNS. The clinical presentations of these cases, their radiological findings with special reference to magnetic resonance imaging, pathological determination, and clinical management are briefly reviewed.

Molecular pathology of posttransplantation lymphoproliferative disorders.

Posttransplantation lymphoproliferative disorders (PT-LPDs) represent a heterogeneous group of Epstein-Barr virus (EBV) associated lymphoid proliferations occurring in the setting of immunosuppression associated with solid organ transplantation. Some PT-LPDs regress after a reduction in immunosuppression, whereas others progress despite aggressive therapy. Previously defined histopathologic categories do not correlate with clonality, and neither histopathology nor clonality has reliably predicted their clinical behavior. Recently, correlative clinical, morphological, and molecular genetic analysis has suggested that PT-LPDs are divisible into three distinct clinically relevant categories as follows: (1) plasmacytic hyperplasia: most commonly arise in the oropharynx or lymph nodes, are nearly always polyclonal, usually contain multiple EBV infectious events or only a minor cell population infected by a single form of EBV, and lack oncogene or tumor suppressor gene alterations; (2) polymorphic lymphoproliferative disorders: may arise in lymph nodes or extranodal sites including the gastrointestinal tract and lungs, are nearly always monoclonal based on the presence of clonal immunoglobulin gene rearrangements, usually contain a single form of EBV, and lack oncogene or tumor suppressor gene alterations; and (3) malignant lymphoma or multiple myeloma: present with widely disseminated disease frequently including the bone marrow, are monoclonal based on clonal immunoglobulin gene rearrangements, contain a single form of EBV, and contain alterations of one or more oncogenes or tumor suppressor genes (c-myc, ras, p53). Thus, proto-oncogene and tumor suppressor gene alterations appear to be associated with disease progression and an often fatal clinical outcome. Furthermore, multiple PT-LPD lesions occurring in the same individual but in multiple anatomic sites, either simultaneously or dysynchronously over time, may show distinct clonal immunoglobulin gene rearrangement patterns and evidence of infection by different forms of EBV, suggesting that each lesion represents a distinct clonal neoplasm that may show distinctive clinical behavior. Therefore, whenever possible, a biopsy of each one of the several PT-LPD lesions occurring in an individual should be obtained to derive a true assessment of the pathobiological nature and clinical aggressiveness of an individual's disease.

Megakaryocytes in bronchial brush cytology. A case report.

Megakaryocytes were detected in a transbronchial brush cytology specimen. Their detection led to a diagnosis of essential thrombocythemia.