Systemic amyloidosis from A (AA) to T (ATTR): a review.

Systemic amyloidosis is a rare protein misfolding and deposition disorder leading to progressive organ failure. There are over 15 types of systemic amyloidosis, each caused by a different precursor protein which promotes amyloid formation and tissue deposition. Amyloidosis can be acquired or hereditary and can affect various organs, including the heart, kidneys, liver, nerves, gastrointestinal tract, lungs, muscles, skin and soft tissues. Symptoms are usually insidious and nonspecific resulting in diagnostic delay. The field of amyloidosis has seen significant improvements over the past decade in diagnostic accuracy, prognosis prediction and management. The advent of mass spectrometry-based shotgun proteomics has revolutionized amyloid typing and has led to the discovery of new amyloid types. Accurate typing of the precursor protein is of paramount importance as the type dictates a specific management approach. In this article, we review each type of systemic amyloidosis to provide the practitioner with practical tools to improve diagnosis and management of these rare disorders.

Phase I trial of rituximab, cladribine, and temsirolimus (RCT) for initial therapy of mantle cell lymphoma.

BACKGROUND: We conducted this trial to determine the maximum tolerated dose (MTD) of temsirolimus added to an established regimen comprised of rituximab and cladribine for the initial treatment of mantle cell lymphoma. PATIENTS AND METHODS: A standard phase I cohort of three study design was utilized. The fixed doses of rituximab and cladribine were 375 mg/m(2) i.v. day 1 and 5 mg/m(2)/day i.v. days 1-5 of a 28-day cycle, respectively. There were five planned temsirolimus i.v. dose levels: 15 mg day 1; 25 mg day 1; 25 mg days 1 and 15; 25 mg days 1, 8 and 15; and 25 mg days 1, 8, 15, and 22. RESULTS: Seventeen patients were treated: three each at levels 1-4 and five at dose level 5. The median age was 75 years (52-86 years). Mantle Cell International Prognostic Index (MIPI) scores were low in 6% (1), intermediate in 59% (10), and high in 35% (6) of patients. Five patients were treated at level 5 without dose limiting toxicity. Hematologic toxicity was frequent: grade 3 anemia in 12%, grade 3 thrombocytopenia in 41%, grade 4 thrombocytopenia in 24%, grade 3 neutropenia in 6%, and grade 4 neutropenia in 18% of patients. The overall response rate (ORR) was 94% with 53% complete response and 41% partial response. The median progression-free survival was 18.7 months. CONCLUSIONS: Temsirolimus 25 mg i.v. weekly may be safely added to rituximab and cladribine at 375 mg/m(2) i.v. day 1 and 5 mg/m(2)/day i.v. days 1-5 of a 28-day cycle, respectively. This regimen had promising preliminary activity in an elderly cohort of patients with mantle cell lymphoma. CLINICALTRIALSGOV IDENTIFIER: NCT00787969.

Denileukin diftitox in combination with rituximab for previously untreated follicular B-cell non-Hodgkin's lymphoma.

Follicular lymphoma exhibits intratumoral infiltration by non-malignant T lymphocytes, including CD4+CD25+ regulatory T (T(reg)) cells. We combined denileukin diftitox with rituximab in previously untreated, advanced-stage follicular lymphoma patients anticipating that denileukin diftitox would deplete CD25+ T(reg) cells while rituximab would deplete malignant B cells. Patients received rituximab 375 mg/m(2) weekly for 4 weeks and denileukin diftitox 18 mcg/kg/day for 5 days every 3 weeks for 4 cycles; neither agent was given as maintenance therapy. Between August 2008 and March 2010, 24 patients were enrolled. One patient died before treatment was given and was not included in the analysis. Eleven of 23 patients (48%; 95% confidence interval (CI): 27-69%) responded; 2 (9%) had complete responses and 9 (39%) had partial responses. The progression-free rate at 2 years was 55% (95%CI: 37-82%). Thirteen patients (57%) experienced grade ≥3 adverse events and one patient (4%) died. In correlative studies, soluble CD25 and the number of CD25+ T cells decreased after treatment; however, there was a compensatory increase in IL-15 and IP-10. We conclude that although the addition of denileukin diftitox to rituximab decreased the number of CD25+ T cells, denileukin diftitox contributed to the toxicity of the combination without an improvement in response rate or time to progression.

Recurrent translocations involving the IRF4 oncogene locus in peripheral T-cell lymphomas.

Oncogenes involved in recurrent chromosomal translocations serve as diagnostic markers and therapeutic targets in hematopoietic tumors. In contrast to myeloid and B-cell neoplasms, translocations in peripheral T-cell lymphomas (PTCLs) are poorly understood. Here, we identified recurrent translocations involving the multiple myeloma oncogene-1/interferon regulatory factor-4 (IRF4) locus in PTCLs. IRF4 translocations exist in myeloma and some B-cell lymphomas, but have not been reported earlier in PTCLs. We studied 169 PTCLs using fluorescence in situ hybridization and identified 12 cases with IRF4 translocations. Two cases with t(6;14)(p25;q11.2) had translocations between IRF4 and the T-cell receptor-alpha (TCRA) locus. Both were cytotoxic PTCLs, unspecified (PTCL-Us) involving bone marrow and skin. In total, 8 of the remaining 10 cases were cutaneous anaplastic large-cell lymphomas (ALCLs) without TCRA rearrangements (57% of cutaneous ALCLs tested). These findings identified IRF4 translocations as a novel recurrent genetic abnormality in PTCLs. Cytotoxic PTCL-Us involving bone marrow and skin and containing IRF4/TCRA translocations might represent a distinct clinicopathologic entity. Translocations involving IRF4 but not TCRA appear to occur predominantly in cutaneous ALCLs. Detecting these translocations may be useful in lymphoma diagnosis. Further, due to its involvement in translocations, MUM1/IRF4 protein may play an important biologic role in some PTCLs, and might represent a possible therapeutic target.

Overexpression of Syk tyrosine kinase in peripheral T-cell lymphomas.

Peripheral T-cell lymphomas (PTCLs) are fatal in the majority of patients and novel treatments, such as protein tyrosine kinase (PTK) inhibition, are needed. The recent finding of SYK/ITK translocations in rare PTCLs led us to examine the expression of Syk PTK in 141 PTCLs. Syk was positive by immunohistochemistry (IHC) in 133 PTCLs (94%), whereas normal T cells were negative. Western blot on frozen tissue (n=6) and flow cytometry on cell suspensions (n=4) correlated with IHC results in paraffin. Additionally, western blot demonstrated that Syk-positive PTCLs show tyrosine (525/526) phosphorylation, known to be required for Syk activation. Fluorescence in situ hybridization showed no SYK/ITK translocation in 86 cases. Overexpression of Syk, phosphorylation of its Y525/526 residues and the availability of orally available Syk inhibitors suggest that Syk merits further evaluation as a candidate target for pharmacologic PTK inhibition in patients with PTCL.

Novel FISH probes designed to detect IGK-MYC and IGL-MYC rearrangements in B-cell lineage malignancy identify a new breakpoint cluster region designated BVR2.

Detection of translocations involving MYC at 8q24.1 in B-cell lineage malignancies (BCL) is important for diagnostic and prognostic purposes. However, routine detection of MYC translocations is often hampered by the wide variation in breakpoint location within the MYC region, particularly when a gene other than IGH, such as IGK or IGL, is involved. To address this issue, we developed and validated four fluorescence in situ hybridization (FISH) probes: two break apart probes to detect IGK and IGL translocations, and two dual-color, dual-fusion FISH (D-FISH) probes to detect IGK-MYC and IGL-MYC. MYC rearrangements (four IGK-MYC, 12 IGL-MYC and four unknown partner gene-MYC) were correctly identified in 20 of 20 archival BCL specimens known to have MYC rearrangements not involving IGH. Seven specimens, all of which lacked MYC rearrangements using a commercial IGH/MYC D-FISH probe, were found to have 8q24 breakpoints within a cluster region >350-645 kb 3' from MYC, provisionally designated as Burkitt variant rearrangement region 2 (BVR2). FISH is a useful ancillary tool in identifying MYC rearrangements. In light of the discovery of the distally located BVR2 breakpoint cluster region, it is important to use MYC FISH probes that cover a breakpoint region at least 1.0 Mb 3' of MYC.

Primary pulmonary MALT lymphomas show frequent and heterogeneous cytogenetic abnormalities, including aneuploidy and translocations involving API2 and MALT1 and IGH and MALT1.

API2-MALT1 fusion and aneuploidy are common chromosomal abnormalities in MALT lymphoma. In studying their incidence and relationship in primary pulmonary MALT lymphomas, a translocation involving MALT1 and IGH was also identified. In all, 28 primary pulmonary MALT lymphomas were studied by fluorescence in situ hybridization using an API2-MALT1 probe and multiple centromeric probes, as well as IGH-BCL2, IGH-MALT1, and MALT1 breakapart probes in selected cases. Seven (25%) had API2-MALT1 fusion; all seven lacked aneuploidy except for two with trisomy 3 in a small clone. Three (11%) had IGH-MALT1 fusion; two also showed trisomy 3 and 12. A total of 11 (39%) had aneuploidy only, with trisomy 3 and 18 being the most common. Ectopic nuclear bcl-10 expression, which has been previously associated with API2-MALT1, was seen by immunohistochemistry in 86% of API2-MALT1 fusion-positive cases, one IGH-MALT1 fusion-positive case, two aneuploidy-only cases, and two normal cases. In primary pulmonary MALT lymphomas, cytogenetic abnormalities are common (75%) and heterogeneous, encompassing API2-MALT1 and IGH-MALT1, which are mutually exclusive, as well as aneuploidy, which may be present in the latter but is rare in the former. Ectopic nuclear bcl-10 expression is associated with API2-MALT1 but may also be seen in IGH-MALT1 fusion-positive, aneuploidy-only, and normal cases.

The power of the third dimension: tissue architecture and autoimmunity in rheumatoid arthritis.

Lymphoid organs are the anatomic solution to the challenge of responding to minute amounts of antigen with powerful effector mechanisms. By arranging interacting cells in complex three-dimensional topographies lymphoid organs provide an optimal match between form and function. This principle is exploited in ectopic lymphoid structures that characteristically appear in rheumatoid synovitis. Synovial tissue T cells and B cells cooperate in different types of lymphoid organizations. Dendritic cell networks in the inflamed synovial membrane optimize antigen collection, storage, processing, and presentation. Synovial tissue cells participate in lymphocyte recruitment and the formation of tissue architectures that amplify immune responses. Recent data support the concept that the tissue organization in the rheumatoid joint fosters a breakdown in self-tolerance by promoting a phase transition from self-limited immune responses to self-perpetuating autoimmune responses.

Cutaneous involvement by angioimmunoblastic T-cell lymphoma with remarkable heterogeneous Epstein-Barr virus expression.

INTRODUCTION: Initially described as an abnormal immune reaction, most cases of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD)-like T-cell infiltrates are now regarded as a peripheral T-cell lymphoma (AILD T-NHL). AILD T-NHL is characterized clinically with constitutional symptoms, generalized lymphadenopathy, hepatosplenomegaly, skin rash, and polyclonal hypergammaglobulinemia. Epstein-Barr virus (EBV) is frequently detected in involved lymph nodes, but the presence of EBV in cutaneous infiltrates of AILD T-NHL has rarely been examined. We present a patient with AILD T-NHL with cutaneous involvement that shows marked heterogeneity of EBV expression in the lymph node and skin biopsies, and review the histological findings of AILD T-NHL in the skin. METHODS: Two skin biopsies of a diffuse maculopapular rash and a lymph node were examined and immunophenotyped. In situ hybridization for detection of EBV in the lymph node and skin biopsies was utilized. In order to attempt to delineate which lymphocytes were EBV positive, skin biopsies were dual labeled with CD3, CD45RO, CD20 and EBV. The skin biopsies and lymph node were submitted for gene rearrangement studies by polymerase chain reaction (PCR). Capillary electrophoresis of fluorescently labeled PCR products was utilized for PCR product quantitation. RESULTS: The histological features of the lymph node were diagnostic of AILD T-NHL and a T-cell clone was identified by PCR. The skin biopsies showed an atypical superficial and deep perivascular polymorphous infiltrate consistent with cutaneous involvement by AILD T-NHL. Both skin biopsies showed the same clonal T-cell receptor gene rearrangement as the lymph node. In situ hybridization of the lymph node and one skin biopsy showed a few scattered EBV-positive lymphocytes (<1% of the infiltrate). A second skin biopsy revealed 40-50% of the lymphocytes as EBV positive. Dual staining for CD20 and EBV identified a minority of EBV-infected lymphocytes as B-cells, but most of the EBV-positive cells lacked staining for CD3 and CD45RO. CONCLUSIONS: In our patient, the same T-cell receptor gene rearrangement was found by PCR in all three biopsy sites. Most cases of AILD T-NHL contain only a few EBV-positive cells, but in our patient the extent of EBV expression ranged from <1% to 40-50% of the AILD T-NHL cutaneous infiltrate. To our knowledge, this case is the most extensive and heterogeneous expression of EBV in cutaneous AILD T-NHL to date.

Pulmonary marginal zone lymphoma of MALT type as a cause of localised pulmonary amyloidosis.

AIM: To describe six patients with pulmonary marginal zone lymphoma in whom amyloid deposition was identified. Marginal zone lymphoma is a recently recognised type of low grade non-Hodgkin's lymphoma. METHODS: A computerised search was performed of all patients seen at the Mayo Clinic with a diagnosis of pulmonary amyloidosis. Six patients with pulmonary amyloidosis who had biopsy confirmed extranodal marginal zone lymphoma of mucosa associated lymphoid tissue type were identified. All were women, ranging in age from 45 to 85 years. RESULTS: Five patients had amyloid deposition in conjunction with pulmonary marginal zone lymphoma at the time of the original diagnosis. One patient was referred for evaluation of localised pulmonary amyloidosis and was found to have coexisting pulmonary marginal zone lymphoma. Clinical presentation was limited to pulmonary symptoms (two of the six) or constitutional symptoms (two), or was asymptomatic (two). In all six cases, initial findings of nodular densities on screening chest roentgenograms led to further evaluation and eventual lobectomy; these findings included multiple pulmonary nodules (four), single nodule (one), and single nodule with diffuse bilateral interstitial infiltrates (one). Bone marrow was examined in five patients and was normal in all. Protein studies performed in four patients revealed no monoclonal protein. No patients had manifestations of systemic amyloidosis, such as renal, neurological, or cardiac involvement, at a median follow up of 50 months. Four of the six patients remain alive at a median of five years. CONCLUSIONS: Pulmonary marginal zone lymphoma may be found in association with localised amyloid deposition and should be considered in the differential diagnosis of localised pulmonary amyloidosis.

Pathologic and clinical features of primary pulmonary extranodal marginal zone B-cell lymphoma of MALT type.

We reviewed pathologic, phenotypic, and clinical features of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) type primarily involving lung to address unresolved questions regarding behavior and pathologic features of unambiguously diagnosed pulmonary MALT lymphoma. Lung specimens from 50 patients were reviewed. Forty-one had low-grade MALT lymphoma. Nine had low-grade MALT lymphoma and diffuse large B-cell lymphoma. The patients included 32 women and 18 men with a median age of 68 years (range 34-88 years). Half of the patients were asymptomatic at the time lymphoma was diagnosed. Radiographic abnormalities were more commonly unilateral (37 patients) than bilateral (12 patients). Localized masses or nodules occurred in 39 patients. Associated autoimmune disorders (29%) and monoclonal gammopathies (43%) were common. Low-grade lymphomas formed intraparenchymal masses composed of centrocyte-like cells, plasmacytoid lymphocytes, and plasma cells that formed lymphoepithelial lesions and exhibited a lymphangitic growth pattern. Mediastinal lymph nodes were involved histologically in 44% of cases. Lymphoma-specific survival was 71.7% at 10 years, and overall survival was significantly worse than age-and gender-matched control patients. None of the following features predicted those patients who had an adverse outcome: systemic symptoms, presence of autoimmune disorders or paraproteinemia, anatomic distribution and number of pulmonary lesions, lymph node involvement, or presence of anthracycline-treated large B-cell lymphoma.

Lymphoid neogenesis in rheumatoid synovitis.

In rheumatoid arthritis (RA), tissue-infiltrating lymphocytes can be arranged in sophisticated organizations that resemble microstructures usually formed in secondary lymphoid organs. Molecular pathways and host risk factors involved in this process of lymphoid neogenesis remain to be defined. In a series of 64 synovial tissue biopsies, lymphoid follicles with germinal centers (GCs) were found in 23.4% of the patients. Follicular dendritic cells (FDCs) were exclusively present in tissues with GCs, suggesting that the recruitment or in situ maturation of FDCs is a critical factor for GC formation in the synovial membrane. Primary follicles were absent, emphasizing the role of Ag recognition in the generation of inflammation-associated lymphoid organogenesis. Multivariate logistic regression analysis of tissue cytokines and chemokines identified two parameters, in situ transcription of lymphotoxin (LT)-beta and of B lymphocyte chemoattractant (BLC; BLC/CXCL13), that were predictors for FDC recruitment and synovial GC formation. LT-beta and BLC/CXCL13 were found to be independent variables that could, in part, compensate for each other to facilitate GC formation. Prediction models incorporating in situ transcription of LT-beta and BLC/CXCL13 had high negative yet moderate positive predictive values, suggesting that LT-beta and BLC/CXCL13 are necessary but not sufficient. LT-beta protein was detected on a subset of mantle zone and GC B cells, but also on T cells in follicular structures. BLC/CXCL13 was produced by FDCs in follicular centers, but was predominantly found in endothelial cells and synovial fibroblasts, suggesting heterotypic signaling between cells of the synovial membrane and infiltrating lymphocytes in regulating extranodal lymphoid neogenesis.

Clinicopathologic, immunophenotypic, and molecular characterization of primary cutaneous follicular B-cell lymphoma.

OBJECTIVE: To determine the clinicopathologic, immunophenotypic, and molecular characteristics of primary follicular cutaneous B-cell lymphoma (CBCL) as defined by the revised European-American lymphoma classification. DESIGN: A retrospective survey of the medical records, an immunohistochemical study of archival biopsy specimens. and molecular studies of preserved DNA of all patients with follicle center lymphoma-follicular (FCL-F) primary CBCL from 1987 to 1997. SETTING: A single-center outpatient specialty clinic at an academic medical center. PATIENTS: Twenty-one patients (68% of all new primary CBCL cases), including 14 men and 7 women (age range, 33-88 years; mean, 55 years). RESULTS: The head and neck region was the most frequent primary site. Following treatment, recurrences were relatively frequent, but the overall mortality rate during 1.0 to 11.3 years (mean, 6.3 years) of follow-up was 4.8%. Immunohistochemical analysis for B- and T-cell lineages was helpful in enhancing the folliclelike structures. CD10, bcl-2, and CD43 were expressed by the neoplastic cells in 9 (47%) of 19 cases, 4 (21%) of 19 cases, and 2 (13%) of 16 cases, respectively. Immunohistochemical detection of cytoplasmic immunoglobulin light chains, using steaming in EDTA as the antigen-retrieval technique, was successful in 12 (71%) of 17 cases. The Ig heavy-chain gene rearrangements, using the Southern blot technique, detected clonality in 17 (94%) of 18 cases. The bcl-2 gene rearrangements were detected in only 2 (13%) of 15 of the primary cutaneous FCL-F cases, compared with 9 (75%) of 12 of the primary nodal FCL-F cases (P =.002). CONCLUSIONS: Primary cutaneous FCL-F is a relatively common subtype of CBCL, with a relatively indolent course. It has many features in common with primary nodal FCL-F, except for low rates of bcl-2 expression and bcl-2 gene rearrangements.

Orbital lymphoma: radiotherapy outcome and complications.

BACKGROUND AND PURPOSE: Orbital non-Hodgkin's lymphomas (NHL) have traditionally been treated with radiation. Forty-eight patients presenting with orbital NHL were treated with radiation and were evaluated for local control, overall survival, cause-specific survival, and complications. MATERIALS AND METHODS: Forty-five patients had low-grade and 3 patients had intermediate-grade histologic findings. Orbit-only disease occurred in 22 patients, the conjunctiva in 16, both in five, and lacrimal gland only in five. Patient age ranged from 35 to 94 years (median, 68). Ann Arbor stages were cIEA (34), cIIEA (six), cIIIEA (two), and cIVEA (six). Radiation doses ranged between 15 and 53.8 Gy (median, 27.5 Gy). RESULTS: Follow-up ranged from 0.14 to 18.23 years (median, 5.35). Median overall survival and cause-specific survival were 6.5 and 15.5 years, respectively. Patients with clinical stage I or II disease had significantly better overall and cause-specific survival than patients with stage III or IV disease. Ten-year relapse-free survival in 41 patients with stage I or II disease was 66%. However, there was continued downward pressure on relapse-free survival out to 18 years. One local failure occurred. Twenty-five patients sustained acute complications. There were 17 minor and four major late complications. All major late complications occurred with doses more than 35 Gy. CONCLUSIONS: Excellent local control with radiation doses ranging from 15 to 30 Gy is achieved. Patients with stage I or II disease have better overall and cause-specific survival than patients with stage III or IV disease. Late relapse occurs in sites other than the treated orbit, even in patients with early-stage disease. Doses 35 Gy or higher result in significant late complications and are therefore not indicated for patients with low-grade tumors.