Does Taking the Fellowship In-Service Hematopathology Examination and Performance Relate to Success on the American Board of Pathology Hematology Examination?

OBJECTIVES: The biannual Fellow In-Service Hematopathology Examination (FISHE) assesses knowledge in five content areas. We examined the relationship between taking the FISHE and performance on it with outcomes on the first attempted American Board of Pathology Hematology subspecialty certifying examination (ABP-HE). METHODS: The pass rate between the ABP-HE candidates who took the spring FISHE and those who did not were compared. The likelihood of fellows passing the ABP-HE based on their percentiles on the FISHE was also assessed. RESULTS: ABP-HE candidates who took the spring FISHE had a higher pass rate (96.4%) than those who did not (76.1%, P < .001). Spring FISHE performance, including total percentile and percentiles in four of five FISHE content areas, was only a weak predictor of passing the ABP-HE. CONCLUSIONS: Candidates who take the spring FISHE do better on the ABP-HE than those who do not. Most fellows passed the first attempted ABP-HE regardless of FISHE performance. Whether this is due to fellows making use of the FISHE as a self-evaluation tool to help identify and then correct their knowledge deficiencies remains to be determined.

Inferior outcome after allogeneic transplant in first remission in high-risk AML patients who required more than two cycles of induction therapy.

While some patients with high-risk acute myeloid leukemia (AML) require one or two cycles of induction chemotherapy to achieve a complete remission (CR), others require more than two cycles. We examined the outcomes of patients with high-risk AML who received allogeneic HPC transplant in CR1. Forty five consecutive high-risk AML patients in CR1 were included. All 45 patients had adverse cytogenetics, FLT 3 mutations, or secondary AML. Group A patients (n = 33) received one or two cycles, and Group B (n = 12) three or more cycles of induction chemotherapy. The patients were comparable in age, sex, white cell count at presentation, and time from diagnosis and from last chemotherapy to transplant. The 100-day mortality rate was higher in Group B patients (50% vs. 9%, P = 0.006). They had a higher non-relapse mortality (33% vs. 6%, P = 0.035) and a longer length of hospital stay from the day of stem cell infusion (median 21 vs. 20, P = 0.02; third quartile 22 vs. 28, P = 0.02). There was also a trend toward inferior event-free survival and overall survival. High-risk AML patients undergoing allogeneic transplant in CR1 after three or more cycles of induction chemotherapy have an inferior outcome and higher mortality when compared to those who only needed one or two cycles of induction chemotherapy. Novel strategies are needed to reduce the transplant-related mortality in high-risk AML patients needing more than two cycles of induction chemotherapy prior to allogeneic transplant in CR1.

Intestinal γδ T-cell lymphomas are most frequently of type II enteropathy-associated T-cell type.

Enteropathy-associated T-cell lymphoma includes type I cases and distinctive type II cases that, according to 2008 and 2010 World Health Organization descriptions, are T-cell receptor ß+. Although T-cell receptor γδ enteropathy-associated T-cell lymphomas are reported, it is unknown if they have distinctive features and if they should be categorized as enteropathy-associated T-cell lymphoma or as a mucocutaneous γδ T-cell lymphoma. To address these questions, the clinicopathologic, immunophenotypic, molecular, and cytogenetic features of 5 γδ-enteropathy-associated T-cell lymphomas were investigated. Only 1 patient had celiac disease and had type I enteropathy-associated T-cell lymphoma, and the others fulfilled the histopathologic criteria for type II enteropathy-associated T-cell lymphoma. All lacked cutaneous involvement. A celiac disease-associated HLA type was found in the patient with CD and one of four others. All were T-cell receptor γ+, T-cell receptor δ+, ßF1-, CD3+, CD7+, CD5-, CD4-, and TIA-1+ with variable staining for CD2 (3/5), CD8 (2/5), Granzyme B (1/5), and CD56 (4/5). Fluorescence in situ hybridization demonstrated 9q34 gains in 4 cases, with 9q33-34 gains by single nucleotide polymorphism in 3 of these. Single nucleotide polymorphism analysis also demonstrated gains in 5q34-q35.1/5q35.1 (4/5), 8q24 (3/5), and in 32 other regions in 3 of 5 cases. Vδ1 rearrangements were identified in 4 of 4 cases with documented clonality showing the same clone in normal-appearing distant mucosa (3/3 tested cases). Thus, γδ-enteropathy-associated T-cell lymphomas share many features with other enteropathy-associated T-cell lymphoma and are mostly of type II. Their usual nonactivated cytotoxic phenotype and Vδ1 usage are features unlike many other mucocutaneous γδ T-cell lymphomas but shared with hepatosplenic T-cell lymphoma. These findings support the conclusion that a γδ T-cell origin at extracutaneous sites does not define a specific entity.

Primary central nervous system post-transplant lymphoproliferative disorders following allogeneic hematopoietic stem cell transplantation.

Post-transplant lymphoproliferative disorder (PTLD) is a serious complication after allogeneic hematopoietic stem cell transplantation (HSCT). Extra nodal involvement is common in PTLD, but isolated involvement of the central nervous system (CNS) is extremely rare. Given the rarity of primary CNS-PTLD there is no consensus on optimal treatment. We report a patient who developed Epstein-Barr virus related primary CNS-PTLD following allogeneic HSCT who was treated with the monoclonal anti-CD20 antibody rituximab and reduction of immunosuppression. In addition, we review the literature and discuss treatment options for patients with primary CNS-PTLD following allogeneic HSCT.

Increased numbers of IgG4-positive plasma cells may rarely be seen in lymph nodes of patients without IgG4-related sclerosing disease.

IgG4-related sclerosing disease (IRSD) is a steroid-responsive fibroinflammatory disorder characterized by increased IgG4+ cells. Nodal involvement usually lacks the dense sclerosis seen in extranodal sites, with histologic patterns overlapping with other reactive processes. Twenty-six lymph nodes showing IRSD-related histologic patterns were evaluated for IgG and IgG4 positive cells by immunohistochemistry and correlated with the clinical features. Cases included 7 Castleman disease-like cases (type I pattern), 10 follicular hyperplasia (type II), and 9 plasmacytosis (type III). The mean numbers of IgG4+ cells per high-power field (HPF) were 4.8 (I), 8.4 (II), and 26.6(III), and the mean IgG4/IgG ratios were 0.05 (I), 0.04 (II), and 0.08 (III). Using >50 IgG4+cells/HPF and IgG4/IgG ratio of >0.4 for absolute and relative increases, only 1 case fulfilled both criteria for increased IgG4+ cells, a patient with Hashimoto's thyroiditis without clinical evidence of IRSD. The results suggest that increased IgG4+ cells may rarely be seen in non-IRSD lymph nodes.

Natural killer cell subsets and natural killer-like T-cell populations in benign and neoplastic B-cell proliferations vary based on clinicopathologic features.

Microenvironmental factors play a critical role in B-cell lymphomas. Most studies emphasize the role of lymphoma-infiltrating T-cells and macrophages, with few studies on natural killer cells. Natural killer cells include a less mature (CD56(bright)/CD16-) subset that is more common in lymph nodes and a more mature (CD56(dim)/CD16+) subset that is more numerous in peripheral blood. Therefore, the proportions of natural killer cells, natural killer subsets, and natural killer-like T-cells (CD3+, CD56+, and/or CD16/57+) were determined by flow cytometry in 150 cases of tissue-based B-cell non-Hodgkin lymphoma and 89 nonneoplastic tissue biopsies. Results were correlated with the clinicopathologic findings. A higher percentage of natural killer cells was found in nonneoplastic spleen versus other nonneoplastic tissue (P < .001), in splenic-based B-cell non-Hodgkin lymphoma versus other B-cell non-Hodgkin lymphoma (P < .01), and in stage II to IV diffuse large B-cell lymphoma versus stage I diffuse large B-cell lymphoma (n = 19, P = .02). The more mature natural killer subset was increased in benign spleen (P < .001) and nonsplenic B-cell non-Hodgkin lymphoma (P < .01) versus nonsplenic, nonneoplastic tissue; in diffuse large B-cell lymphoma versus other B-cell non-Hodgkin lymphoma (P < .001); and in follicular lymphoma with an intermediate follicular lymphoma international prognostic index score (n = 17, P = .04). A higher proportion of natural killer-like T-cells was seen in diffuse large B-cell lymphoma versus other B-cell non-Hodgkin lymphoma (P = .001), whereas chronic lymphocytic leukemia/small lymphocytic lymphoma contained fewer natural killer-like T-cells (P < .001). The proportions of natural killer cells, natural killer subsets, and natural killer-like T-cells vary with tissue site, type of B-cell non-Hodgkin lymphoma, and clinical stage in diffuse large B-cell lymphoma and follicular lymphoma. A higher proportion of CD56(dim)/CD16/57+ natural killer cells is found in spleen, in more aggressive B-cell non-Hodgkin lymphoma, and in follicular lymphoma with an intermediate follicular lymphoma international prognostic index score. This may be of importance with increasing therapeutic use of immunomodulatory agents.

The spectrum of coincident entities with small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) diagnosed by cytology.

BACKGROUND: The cytologic diagnosis of Small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) often relies on finding a small lymphoid population with the characteristic immunoprofile by ancillary testing. There are only a few reports of other processes identified with SLL/CLL. The aim of this study was to review the fine needle aspiration (FNA) and touch prep (TP) diagnoses of SLL/CLL in order to identify any coincident entities. MATERIALS AND METHODS: We retrospectively reviewed all FNA and TP cytology cases between January 2005 and May 2009 with a diagnosis of SLL/CLL to determine the presence of any coincident process. RESULTS: We identified 29 cases, including 23 FNAs and six TPs, from 23 patients. Ancillary studies were utilized in 97% of the cases, including flow cytometry (FC, 79%), immunohistochemistry (IHC, 55%), fluorescent in situ hybridization studies (24%) and special stains (7%). Coincident entities were identified in nine cases (31%) and included seven (28%) neoplastic entities (Hodgkin lymphoma [HL], adenocarcinoma, squamous cell carcinoma, seminoma) and two (7%) non-neoplastic entities (infection and immunoglobulin containing cells). Six cases (21%) suspicious for large cell transformation were also identified. CONCLUSION: In our review of SLL/CLL, coincident entities were present in 31% of the cases and included a spectrum of non-neoplastic and neoplastic processes. FC was the most frequently utilized ancillary test, but IHC provided important information by excluding a mantle cell lymphoma or confirming a coincident process. Thus, cytomorphologic evaluation in these patients is important due to the high risk of a coincident process that may not be apparent by FC alone and may require clinical management.

Expression of p21 protein predicts clinical outcome in DLBCL patients older than 60 years treated with R-CHOP but not CHOP: a prospective ECOG and Southwest Oncology Group correlative study on E4494.

PURPOSE: To prospectively investigate the prognostic significance of p21 and p53 expression in diffuse large B-cell lymphoma in the context of the U.S. Intergroup trial comparing conventional cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy to rituximab-CHOP (R-CHOP) induction, with or without maintenance rituximab. EXPERIMENTAL DESIGN: Immunohistochemical staining of 197 paraffin-embedded biopsy specimens was scored by an independent panel of experts. RESULTS: The cyclin-dependent kinase inhibitor, p21, was expressed in 55% of cases examined. In a multivariable analysis adjusting for International Prognostic Index score and BCL2 status, p21 expression was a significant, independent, favorable predictive factor for failure-free survival (relative risk, 0.3; P = 0.001) and overall survival (relative risk, 0.3; P = 0.003) for patients treated with R-CHOP. Expression of p21 was not predictive of outcome for CHOP-treated patients. Only p21-positive cases benefited from the addition of rituximab to CHOP. Among p21-positive patients, treatment with R-CHOP was associated with a higher failure-free survival rate at 5 years compared with CHOP (61% versus 24%; P = 0.01). In contrast, no significant differences were detected in failure-free survival according to treatment arm for p21-negative patients. Expression of p53, alone or in combination with p21, did not predict for outcome in univariable or multivariable analyses. CONCLUSIONS: In this study, p21 protein expression emerged as an important independent predictor of a favorable clinical outcome when rituximab was added to CHOP therapy. These data suggest that rituximab-related effects on lymphoma survival pathways may be functionally linked to p21 activity.

Clinicopathologic features of histiocytic lesions following ALL, with a review of the literature.

We describe the clinicopathologic features of 15 patients who had histiocytic lesions that followed acute lymphoblastic leukemia (ALL). Twenty-one separate histiocytic lesions were evaluated that covered a wide spectrum, some conforming to the usual categories of juvenile xanthogranulomas (5), Langerhans' cell histiocytosis (1), Langerhans' cell sarcoma (4), Rosai-Dorfman disease (1), and histiocytic sarcoma (4). Most were atypical for the category by histology, phenotype, or abnormally high turnover rate. Seven low-grade lesions defied easy categorization and were characterized only as "atypical histiocytic lesion" following ALL. For those evaluated, the molecular signature of the prior leukemia was present in the histiocytic lesion. In 3 of 15 patients, the leukemia and histiocytic lesion shared immunoglobulin H or monoclonal TCR gene rearrangements and, in 4 of 15 patients, clonal identity was documented by fluorescence in situ hybridization. Four patients died of progressive disease, 3 of whom had histiocytic sarcoma and 1 who had an atypical lesion. One patient died of recurrent ALL. The other 10 patients are alive, 7 after recurrences and treatment with surgery and/or chemotherapy. The post-ALL lesions are more aggressive than their native counterparts, but despite the demonstration of the presence of the leukemia signature in 7 of 15 patients, the prognosis is generally favorable, except for patients with histiocytic sarcoma. It remains unclear whether the histiocytic lesions arise as a line from the original ALL or whether transdifferentiation is involved.

Defining the borders of splenic marginal zone lymphoma: a multiparameter study.

Classic splenic marginal zone lymphomas are CD5-, CD10-, CD23-, CD43-, and usually IgD+ with biphasic white pulp nodules. However, the 2008 World Health Organization classification accepts splenic marginal zone lymphomas with monophasic marginal zone-like white pulp nodules and recognizes a group of unclassifiable splenic small B-cell lymphomas. To explore the relationship of classic splenic marginal zone lymphomas to these other less well-defined splenic lymphomas, a multiparameter study of 47 splenic marginal zone lymphomas and unclassifiable splenic small B-cell lymphomas was performed. Seventeen of 31 splenic marginal zone lymphomas were biphasic, and 14 were monophasic (90%-100% marginal zone-like white pulp nodules). Sixteen cases were unclassifiable splenic small B-cell lymphomas, most lacking a marginal zone-type component. There were many clinical similarities between the 3 groups, including similar survivals. Monophasic and unclassifiable cases were less likely to have a typical splenic marginal zone lymphoma phenotype (28.6%, 23.1%) compared with biphasic cases (86.7%), usually because of IgD negativity (P < .003). Thirty-four of 42 (81%) cases had cytogenetic abnormalities by fluorescence in situ hybridization; and 17 of 20 (85%), by classical cytogenetics. The most frequent fluorescence in situ hybridization abnormalities among the splenic marginal zone lymphomas were del(7)(q31) (26%), +12 (25%), and +3q27 (27%); and among the unclassifiable cases, +12 (50%) and +3q27 (36%). Five of 6 unclassifiable cases with exclusively small non-marginal zone-like lymphocytes involving both white and red pulp had +12 compared with 9 of 34 other cases (P < .02). CDK6 (2 cases) and BCL3 (1 case) rearrangements were only seen in the unclassifiable group. These results support including both biphasic and monophasic cases as splenic marginal zone lymphomas, but suggest that the lack of a non-marginal zone-like population in the monophasic group is associated with some biologic differences. They also demonstrate a relatively large proportion of unclassifiable cases, including a group with frequent +12.

Fluorescence in situ hybridization studies on direct smears: an approach to enhance the fine-needle aspiration biopsy diagnosis of B-cell non-Hodgkin lymphomas.

BACKGROUND: In the fine-needle aspiration biopsy (FNAB) diagnosis of B-cell non-Hodgkin lymphomas (B-NHL), the role of flow cytometry (FC) can be limited because of nondiagnostic findings. Fluorescence in situ hybridization (FISH) studies, similar to FC, can be helpful in establishing clonality and in subclassifying the lymphoma. The aim of the current study was to determine whether FISH studies performed on unstained direct smears improved the ability to diagnose and/or subclassify B-NHL on FNAB. METHODS: A total of 181 cases of B-NHL diagnosed by FNAB were retrieved. The cytomorphology, ancillary study results, clinical information, and available pathologic follow-up were reviewed. RESULTS: Of the 181 cases, FISH studies were performed in 106 cases (59%). The indications for FISH studies were for subclassification (59 cases; 56%) and nondiagnostic or unavailable FC results (47 cases; 44%). Of the 59 cases submitted for subclassification, 23 cases (39%) were successfully subclassified. The 47 cases with nondiagnostic or unavailable FC results included cases in which FC demonstrated a surface immunoglobulin-negative population (19 cases; 40%), had insufficient cellularity (18 cases; 38%), yielded negative results (6 cases; 13%), or had no specimen submitted (4 cases; 9%). In this group, 26 cases (55%) demonstrated an immunoglobulin heavy-chain gene rearrangement and/or chromosomal translocation. CONCLUSIONS: The results of the current study illustrate that FISH studies performed on unstained direct smears play a complementary role to FC in establishing the diagnosis and/or subclassification of B-NHL. Thus, the preparation of unstained smears at the time of FNAB can be helpful for potential FISH studies.

56-year-old male with left-sided weakness.

A 56-year-old male with a 3-year history of multiple myeloma that was treated with tandem autologous stem cell transplantations. He presented in July 2006 with a left partial hemiparesis and ataxia. MRI of the brain revealed an enhancing large right frontoparietal lesion with heterogeneously hyperintense nodular septations on T2WI, with no significant surrounding edema. The differential diagnosis of this lesion placed a high-grade glioma at the top of the list. The patient underwent surgical resection of the lesion. Pathology confirmed the diagnosis of a relapse of his multiple myeloma. The specimen demonstrated a monomorphic neoplasm arranged in sheets and trabeculae floating in a background of a proteinaceous substance. Immunohistochemistry showed the neoplastic cell was a CD138 positive plasma cell. The nature of the background substance is still undetermined and is a very unusual appearance for multiple myeloma. Flow cytometry revealed a monoclonal plasma cell population with an immunophenotype identical to the initial diagnostic bone marrow aspirate. A completely intraparenchymal manifestation of multiple myeloma is rare in itself but the unusual radiographic and histological appearance of this case is extraordinary.

Detection of clonality in lymphoproliferations using PCR of the antigen receptor genes: does size matter?

A biopsy of a nasal mass that had morphologic and immunostaining features consistent with a B-cell lymphoma was studied for clonality using PCR of the IgH gene. An unexpectedly low molecular weight DNA fragment of approximately 140bp (acceptable size limit: 250-295bp) was obtained using FR2 and JH primers. The sequence of this DNA was consistent with a clonal IgH rearrangement followed by a deletion that removed most of the downstream portion of the V segment. Thus, the biopsy contained a monoclonal population of B-lymphocytes, consistent with a diagnosis of lymphoma. This work illustrates that bands outside of the size range expected from PCR of the antigen receptor genes may still be consistent with a monoclonal result.

CpG DNA activation and plasma-cell differentiation of CD27- naive human B cells.

Unmethylated CpG DNA activation of naive CD27- B cells has been reported to require B-cell-receptor (BCR) cross-linking. We describe a culture system using CpG DNA with sequential steps for T-cell-independent activation of naive CD19+CD27- human peripheral blood B cells that induces efficient CD138+ plasma-cell differentiation. CD27+ and CD27- B cells were cultured in a 3-step system: (1) days 0 to 4: CpG, IL-2/10/15; (2) days 4 to 7: IL-2/6/10/15 and anti-CD40L; (3) days 7 to 10: IL-6/15, IFN-alpha, hepatocyte growth factor, and hyaluronic acid. Both CD27+ and CD27- B cells up-regulated intracytoplasmic TLR-9 following CpG DNA activation. CD27- B-cell activation required cell-cell contact. Both naive and memory B cells progressed to a plasma-cell phenotype: CD19lowCD20lowCD27+CD38+HLA-DRlow. Seventy percent of the CD27--derived CD138+ cells demonstrated productive V chain rearrangements without somatic mutations, confirming their origin from naive precursors. Plasma cells derived from CD27+ B cells were primarily IgG+, while those from CD27- B cells were IgM+. Our results indicate that under certain conditions, naive B cells increase TLR-9 expression and proliferate to CpG DNA stimulation without BCR signaling. In addition to its immunologic significance, this system should be a valuable method to interrogate the antigenic specificity of naive B cells.

The novel triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO) induces apoptosis of human diffuse large B-cell lymphoma cells through a peroxisome proliferator-activated receptor gamma-independent pathway.

OBJECTIVE: Ligands for the transcription factor peroxisome proliferator-activated receptor gamma (PPAR gamma) are emerging as a new class of antitumor agents. Herein, we investigated the triterpenoid CDDO, a PPAR gamma ligand, for its potential as an anticancer agent on human diffuse large B-cell lymphoma (DLBCL) cells. METHODS: The ability of CDDO to induce apoptosis in human DLBCL cells of both the germinal center and activated B-cell subtypes was determined by MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) assay, (3)H-thymidine incorporation, and Annexin-V/propidium iodide staining. Small molecule antagonists of PPAR gamma, transfection assays, DNA binding assays, immunofluorescence, Western blotting, and NF-kappaB inhibitors were utilized to determine the contribution of PPAR gamma and NF-kappaB to the cytotoxic effects of CDDO. RESULTS: Human DLBCL cells express PPAR gamma and PPAR gamma is activated by CDDO. In both subtypes of DLBCL cells CDDO inhibited proliferation, was cytotoxic, and induced apoptosis. The ability of CDDO to kill DLBCL cells was found to be independent of PPAR gamma activation. Interestingly, CDDO exposure resulted in activation of the p50 and p65 subunits of NF-kappaB. Moreover, the combination of CDDO with NF-kappaB inhibitors resulted in enhanced DLBCL cell death, indicating that NF-kappaB activation was a prosurvival signal. CONCLUSION: These findings support the potential of CDDO, alone or in combination with NF-kappaB inhibitors, as a novel therapy for patients with DLBCL.

Prognostic significance of Bcl-6 protein expression in DLBCL treated with CHOP or R-CHOP: a prospective correlative study.

Bcl-6 protein expression, a marker of germinal center origin, has been associated with a favorable prognosis in diffuse large B-cell lymphoma (DLBCL). To determine the prognostic significance of this marker when rituximab (R) was added to cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy, we prospectively studied Bcl-6 protein expression by immunohistochemical staining of 199 paraffin-embedded specimens from patients enrolled in the US Intergroup phase 3 trial comparing R-CHOP to CHOP with or without maintenance R. In Bcl-6(-) patients, failure-free survival (FFS) and overall survival (OS) were prolonged for those treated with R-CHOP alone compared to CHOP alone (2-year FFS 76% versus 9%, P < .001; 2-year OS 79% versus 17%, P < .001). In contrast, no differences in FFS and OS were detected between treatment arms for Bcl-6(+) cases. In the multivariate analysis, treatment arm (CHOP versus R-CHOP) was the major determinant of both FFS (P < .001) and OS (P < .001) for the Bcl-6(-) subset, whereas the International Prognostic Index risk group was the only significant predictor of outcome among Bcl-6(+) cases. Bcl-2 protein expression was not predictive of outcome in either group. In this study, we observed a reduction in treatment failures and death with the addition of R to CHOP in Bcl-6(-) DLBCL cases only. Our finding that Bcl-6(+) cases did not benefit from the addition of R to CHOP requires independent confirmation.

Constitutive and activation-inducible cyclooxygenase-2 expression enhances survival of chronic lymphocytic leukemia B cells.

We recently reported that activated normal human B lymphocytes express Cox-2. These findings prompted us to evaluate whether human B-CLL cells express Cox-2 and synthesize prostaglandins. In contrast to naive human B cells, B-CLL cells constitutively expressed Cox-2 protein and produced PGE2, PGF2alpha, and TXA2. Elevated Cox-2 expression was seen in a subgroup of B-CLL cells that exhibit poor prognostic factors, including unmutated variable heavy chain status and increased CD38 expression. Furthermore, stimulation of B-CLL cells with CD40 ligand plus TNFalpha increased Cox-2 levels. The role of Cox-2 in promoting B-CLL survival was investigated using nonselective and selective Cox-2 inhibitors. Significant reductions in B-CLL survival occurred following Cox-2 inhibition. These new findings support that constitutive Cox-2 expression in B-CLL cells promotes their survival and possibly their expansion in vivo. It will therefore be important to evaluate drugs that inhibit Cox-2 as potential therapeutic agents in B-CLL in vivo.

Apoptosis and complement-mediated lysis of myeloma cells by polyclonal rabbit antithymocyte globulin.

Current monoclonal antibody therapies for multiple myeloma have had limited success, perhaps due to narrow target specificity. We have previously described the ability of polyclonal rabbit antithymocyte globulin (rATG) to induce caspase- and cathepsin-mediated apoptosis in human B and plasma cells. We now extend this observation to myeloma cells. Complement independent cell death was measured after addition of rATG (1-1000 microg/mL) to cultures of myeloma cell lines or primary CD138+ isolates from patient bone marrow aspirates. rATG induced significant levels of apoptosis in myeloma cells as assayed by caspase induction, annexin V binding, subdiploid DNA fragmentation, plasma-membrane permeability, and loss of mitochondrial-membrane potential. Addition of complement greatly augmented myeloma-cell death. Binding of rATG to individual myeloma cell-surface proteins, primarily CD38, CD52, CD126, and CD138, was demonstrated by competitive inhibition experiments with targeted monoclonal antibodies. Three pathways of cell death were identified involving caspase activation, cathepsin D, and the genistein sensitive tyrosine kinase pathway. Fab'2 fragments of rATG had reduced proapoptotic activity, which was restored by coincubation with Fc fragments, and anti-CD32 or anti-CD64 antibodies. We conclude that rATG is an effective agent for in vitro induction of apoptosis in multiple myeloma, and that exploratory clinical trials may be warranted.

Is there an association between ocular adnexal lymphoma and infection with Chlamydia psittaci? The University of Rochester experience.

Various subsets of extranodal marginal zone lymphomas of mucosa-associated lymphoid tissues (MALT lymphomas) have been associated with infectious organisms. Most notable of these is the association of gastric MALT lymphomas with Helicobacter pylori infection. In a recent publication Ferreri et al. [Ferreri AJ, Guidoboni M, Ponzoni M, De Conciliis C, Dell'Oro S, Fleischhauer K, et al. Evidence for an association between Chlamydia psittaci and ocular adnexal lymphomas. J Natl Cancer Inst 2004;96:586-94] reported the presence of C. psittaci DNA in 80% of 40 ocular adnexal lymphomas. Similar to the gastric MALT lymphoma data, a subset of these patients responded well to antibiotic treatment. We analyzed a set of ocular adnexal lymphomas and benign (non-neoplastic) lesions for evidence of C. psittaci DNA in patients from New York State. No evidence of C. psittaci DNA was seen in seven MALT-type ocular adnexal lymphomas, four non-MALT ocular lymphomas, one Langerhans histiocytosis, and five reactive lymphoproliferations. We eliminated several possible reasons that would cause our study to fail to find C. psittaci DNA, including the presence of PCR inhibitors, inadequate template DNA, and sequence diversity in the target region in C. psittaci. The positive data were based primarily on patients from Italy, while our study involved only patients living in the Northeastern United States. This would suggest possible geographic differences in the etiology of ocular adnexal lymphomas.