Detection of t(14;18) by PCR of IgH/BCL2 fusion gene in follicular lymphoma from archived cytological smears

According to WHO classification follicular lymphoma (FL) is a neoplasm composed of follicle centre (germinal centre) B-cells, which usually has at least a partially follicular pattern. Bone marrow (BM) infiltration by lymphoma occurs in 40-70% of cases at the time of diagnosis. The characteristic chromosomal translocation of follicular lymphoma is t(14;18)(q32;q21) with transposition of BCL2 oncogene to the regulatory region of immunoglobulin heavy chain gene IgH. Aim of this study was to determine the frequency of PCR detection of IgH/BCL2 in DNA samples isolated from archival cytological slides of lymph node aspirates, bone marrow and/or peripheral blood (PB) obtained from patients with histologically confirmed follicular lymphoma using primers and protocol proposed by BIOMED-2 consortium. We also compared molecular with cytomorphological findings in bone marrow/peripheral blood and tested this method of detection of IgH/BCL2 molecular marker in monitoring minimal residual disease (MRD) in routine clinical setting. DNA was successfully isolated from all archival cytological slides obtained by fine needle aspiration of lymph nodes as well as from 75% of smears of bone marrow aspirates from 19 patients. Fusion oncogene was detected in 10 of 19 patients (52%). For patients with PCR IgH/BCL2 positive lymph nodes, molecular test found BM infiltration in 5 cases (83%), while cytomorphology detected infiltration in three of eight cases (37%) available for comparison. May-Grünwald-Giemsa stained cytological smears can be used for PCR-based ancillary methods and the rate of detection of IgH/BCL2 rearrangement is similar to results reported for paraffin-embedded tissues. For patients with detectable baseline molecular marker, PCR is a highly suitable method for detection of bone marrow involvement and monitoring MRD.

Cytogenetics of multiple myeloma

Great studies of multiple myeloma (MM) strongly suggested that specific chromosomal changes are of prognostic significance in patients with MM1. We have performed cytogenetic analysis and recently fluorescent in situ hybridization (FISH) on 43 cases of MM. Clonal chromosomal changes were present in 24 (56%) cases. Hyperdiploid karyotype was found in 12 (50%) cases, hypodiploid in 8 (33%) cases, and 4 (17%) cases had a pseudodiploid karyotype. The most common numerical abnormalities were gains of whole chromosomes 15, 11, 3 and 6. Whole chromosome losses were also frequent involving chromosomes X, 13, 14, and 8. Most cases showed also structural rearrangements 71% (n = 17): del(1p), dup(1q), del(5q), del(13q), del(17p) and t(11;14)(q13;q32) (n = 4, 17%). Chromosome -13/13q deletion was found in 42% (n = 10) cases; complete loss of 13 was observed in 67% (n = 7) cases, whereas 33% (n = 3) had interstitial deletions. In the majority of the cases there was a mixture of abnormal and normal metaphases.

Bone morphogenetic proteins and receptors are over-expressed in bone-marrow cells of multiple myeloma patients and support myeloma cells by inducing ID genes

We assessed the expression pattern and clinical relevance of BMPs and related molecules in multiple myeloma (MM). MM bone-marrow samples (n=32) had increased BMP4, BMP6, ACVR1 and ACVR2A, and decreased NOG expression compared with controls (n=15), with BMP6 having the highest sensitivity/specificity. Within MM bone-marrow, the source of BMPs was mainly CD138(+) plasma-cell population, and BMP6 and ACVR1 expression correlated with plasma-cell percentage. Using myeloma cell lines NCI H929 and Thiel we showed that BMPs induced ID1, ID2 and IL6, and suppressed CDKN1A and BAX gene expression, and BAX protein expression. Finally, BMPs partially protected myeloma cells from bortezomib- and TRAIL-induced apoptosis. We concluded that BMPs may be involved in MM pathophysiology and serve as myeloma cell biomarkers.

[Single cell--definitive diagnosis! Where the profession ends and the art begins?]

Cell is a morphologically and functionally the tiniest living organism, present from the very beginning of life on the Earth. Specialized cell types make up specific tissues and organs of the human body. Cell itself and cell elements are liable to morphological, functional, phenotypic and genotypic alterations in various physiological and pathological states. These alterations are studied by cytodiagnosis to diagnose the disease at cellular level. Cytologic examinations belong to the group of morphological, non-aggressive or minimally invasive tests that are easy to perform for both the patient and the professional. In addition, these tests are highly reliable and preferred to the related diagnostic procedures for providing immediate orientation and definitive diagnosis, thus saving both time and money. With the introduction of adjunctive technologies such as cell-surface marker analysis, computer image analysis, molecular and cytogenetic technologies performed on cytologic smears, cytology has become an ever more important factor in the diagnosis, subtyping and prognosis of malignant tumors. Thorough knowledge of cell morphology is a basis for proper performance and understanding of cytology techniques. A cytologist needs to be familiar with clinical manifestations of the disease and to be informed on all relevant data on the patient and his current and previous medical history, in order to be able to issue findings that are understandable and usable to all clinicians and patients. It requires close collaboration between the cytology laboratory and the ward, and among the cytologist, the patient and the clinician. Good collaboration with other diagnostic professions such as pathology, laboratory, molecular and cytogenetic diagnosis is by no means less important. Cytology as a profession implies knowledge of the morphological characteristics of normal cells and cells in various physiologic states, along with due knowledge of the morphology, phenotypic and genetic features of pathologic alterations. However, synchronizing and combining cytologic morphology with other sophisticated diagnostic procedures to reach an accurate diagnosis, subtyping and prognosis of tumor disease is artistry indeed.

Successful treatment of diffuse large B-cell non-hodgkin lymphoma with modified CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy and rituximab in a patient with Nijmegen syndrome

A 17-year-old Croatian boy with Nijmegen breakage syndrome (NBS) who developed diffuse large B-cell non-Hodgkin lymphoma is presented. The majority of the patients with this rare autosomal recessive disease are of Slavic origin and, in most of them, the disease is caused by NBS1 mutation 657del5, as was found in our patient. Nijmegen breakage syndrome is characterized by microcephaly, growth retardation, abnormal facial appearance, spontaneous chromosomal rearrangements, immunodeficiency, and a high predisposition to cancer development, predominantly lymphoma. Because of increased sensitivity to radiation therapy and chemotherapy, the treatment of malignancies in patients with NBS can be difficult. To our knowledge, our patient is the first with NBS reported in the literature who was successfully treated for diffuse large B-cell lymphoma with the anti-CD20 monoclonal antibody rituximab in addition to a modified dose of CHOP (cyclophosphamide/doxorubicin/vincristine/prednisone) chemotherapy. He has been in complete remission for 3 years after finishing the treatment.

Spontaneous tumor apoptosis, caspase 3 and the survival outcome in medulloblastoma patients treated by postoperative radiotherapy and chemotherapy

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Background: The role of apoptosis in neurooncology is still an unexplored area. Only a small number of studies which have combined clinically relevant data and treatment modalities, with the apoptotic activity have been published. Methods: The influence of spontaneous tumor apoptosis and its potential regulators caspase 3, BAX, p53 and bcl-2 was analyzed in 30 medulloblastoma patients with a long follow-up period, after the treatment at the Clinic of Oncology and Radiotherapy by postoperative radiotherapy with or without postirradiational chemotherapy. The mean apoptotic and mitotic index ratio (AI/MI) was measured in all tumor samples obtained by the initial neurosurgical procedure. Results: Significantly different survival groups of adequately treated patients were found only if the apoptotic indexes measured by the morphometrical analyzes (AIM) had been correlated with the TUNEL-essay results (AIT) in the same tumor sample, (log rank test=2.0287, p=0.04). The mean apoptotic index measured in the described combined way had slightly higher values AIM+T=38.2±20.3 (median=32.0), than when measured only by morphometrical analysis AM=23.9±24.9 (median=15.0). In the multivariate analysis according, the most relevant variables were the disease free interval (p<0.001) and the number of CT cycles (0.005<p<0.01). Further parameters of significance were the modality of postoperative radiotherapy, and the general condition of patients measured according to the WHO grading system at the end of treatment (p<0.001) as well as on the late controls, ater completion of the treatment (p<0.001) Conclusions: Our expirience in evaluating the metodology of apoptotic index measurement has confirmed the advantage of combined method of detection of the apoptotic index AIM+T over the use of each of the described methods alone. The apoptotic index has shown a significant influence on survival of the medulloblastoma patients only when divided with the mitotic index MI. Using clinical data of our medulloblastoma patients, the index of apoptosis alone as a prognostic factor has not appeared to be of significant relevance.

No significant financial relationships to disclose.

Bone marrow renin-angiotensin system expression in polycythemia vera and essential thrombocythemia depends on JAK2 mutational status

Recent observations raise possibility for constitutively active, mutated JAK2 to modulate expression of RAS genes in CMPD. We analyzed the expression of AGT, renin, AT2R1 and ACE genes in normal and bone marrows of PV and ET patients with the respect to the presence of V617F JAK2 mutation. PV and ET had different expression patterns of major RAS components compared to normal BM which was primarily associated with the JAK2V617F mutation and less with PV or ET disease phenotype. However, AT2R1 was exclusively markedly upregulated only in PV, while ET showed moderate expression irrespective of the JAK2 mutational status.

The FOXP1 transcription factor is expressed in the majority of follicular lymphomas but is rarely expressed in classical and lymphocyte predominant Hodgkin's lymphoma

The expression of the FOXP1 forkhead/winged helix transcription factor has been investigated in normal and neoplastic lymphoid tissues using the FOXP1-specific monoclonal antibody, JC12. Using single and double immunoenzymatic staining, FOXP1 expression has been studied in a series of classical and lymphocyte predominant Hodgkin's lymphomas, follicle centre lymphomas and Hodgkin's lymphoma-derived cell lines. Neoplastic cells in the majority of classical and lymphocyte predominant Hodgkin's lymphoma were FOXP1-negative. In two cases of classical Hodgkin's lymphoma, the tumour cells showed mislocalisation of FOXP1 to the cytoplasm, while in one case of lymphocyte predominant Hodgkin's lymphoma, and in the Hodgkin's lymphoma cell line KMH2, scattered tumour cells showed nuclear expression of FOXP1. In contrast, the tumour cells in the majority of follicle centre lymphomas showed strong nuclear FOXP1 reactivity. Double labelling studies of lymphoid tissue indicated that a variable proportion of CD20-positive germinal centre B cells express FOXP1 while the vast majority of CD30-positive cells are FOXP1-negative. The heterogeneity of FOXP1 expression in germinal centre-derived lymphomas, may have more to do with the transforming events underlying these distinct types of lymphoma than with their common origin.

hTERT, the catalytic component of telomerase, is downregulated in the haematopoietic stem cells of patients with chronic myeloid leukaemia

Telomere shortening is associated with disease progression in chronic myeloid leukaemia (CML). To investigate the biology and regulation of telomerase in CML, we evaluated expression of the telomerase components, its regulators and several telomeric-associated proteins. Quantitative real-time-polymerase chain reaction (PCR) was used to compare gene expression in the CD34+/leukaemic blast cells of 22 CML patient samples to the CD34+ cell population of healthy individuals. hTERT, the catalytic component of telomerase, was downregulated in eight of 12 chronic phase (CP) patients (P = 0.0387). Furthermore, hTERT was significantly downregulated in two of three patients in accelerated phase (AP) and seven of seven patients in blast crisis (BC), P = 0.0017. Expression of hTR and telomeric-associated proteins TEP1, TRF1, TRF2, tankyrase and PinX1 was high in the majority of CP and AP patients. With the exceptions of TEP1 and hTR, expression of these factors was highest in CP and decreased during disease progression. Expression of c-Myc, a positive regulator of hTERT transcription, correlated with hTERT expression and decreased with disease progression, falling below control levels in BC. hTERT levels were increased in CP patients following successful treatment with imatinib, relative to untreated CP patients. We suggest that reduced hTERT expression directly causes the shortened telomeres observed in CML.

Mutation of JAK2 in the myeloproliferative disorders: timing, clonality studies, cytogenetic associations, and role in leukemic transformation

The identification of an acquired mutation of JAK2 in patients with myeloproliferative disorders has raised questions about the relationship between mutation-positive and mutation-negative subtypes, timing of the JAK2 mutation, and molecular mechanisms of disease progression. Here we demonstrate that patients with V617F(-) essential thrombocythemia do not commonly progress to become V617F(+). Consistent with the concept of distinct pathogenetic mechanisms, we show that patients with and without the JAK2 mutation have different patterns of cytogenetic abnormality, with virtually all patients carrying the 20q deletion or trisomy 9 being V617F(+). We also investigated the existence of a "pre-JAK2" phase by comparing the proportion of clonally derived granulocytes, estimated from X-chromosome inactivation patterns (XCIPs), with the proportion of V617F(+) granulocytes. Our results demonstrate that inherent XCIP variability between granulocytes and T cells produces a systematically biased pattern of results that may be misinterpreted as evidence for an excess of clonally derived granulocytes, an observation that limits the utility of XCIP analysis in this context. Lastly, we studied 4 patients with V617F(+) myeloproliferative disorders who subsequently developed acute myeloid leukemia. In 3 patients the leukemic cells were V617F(-), suggesting that in these patients the leukemia arose in a V617F(-) cell.

Primary Mediastinal Large B-Cell Lymphoma: A Single-Center Study of Clinicopathologic Characteristics

Primary mediastinal large B-cell lymphoma (PMLBCL) is a subset of LBCL with unique clinicopathologic features. Some studies have raised the question of differences in biological features and clinical course among patients from different parts of the world. We conducted a retrospective clinicopathologic analysis of 24 patients with PMLBCL from a single center in Croatia. We also conducted the first investigation of the frequency of lymphotropic viruses human herpesvirus 6 (HHV-6) and HHV-8 in lymphoid lesions of this disease. The clinical characteristics of the patients were as expected, with high International Prognostic Index scores, elevated serum lactate dehydrogenase (LDH) levels, and bulky disease being adverse prognostic factors. Only 6 patients (25%) showed CD30 expression, and Bcl-6 protein expression was, in our series, prognostically favorable (P = .0401). One patient's tumor had detectable HHV-6 genome sequence, but no HHV-8 sequences were detected in any tumors. Two thirds of the patients received CHOP chemotherapy (cyclophosphamide, hydroxydaunomycin, vincristine, and prednisone) with a relatively low complete remission rate (43.8%; median follow-up, 33.8 months). This study confirmed the moderate preponderance among PMLBCL patients of young females with B symptoms and elevated LDH levels. The CHOP regimen proved effective as first-line therapy only in patients with limited disease. Therefore, other third-generation chemotherapy protocols may be considered for treatment, especially in patients with bulky and advanced disease.

Application of the FICTION technique for the simultaneous detection of immunophenotype and chromosomal abnormalities in routinely fixed, paraffin wax embedded bone marrow trephines

The use of interphase fluorescence in situ hybridisation (FISH) to study cytogenetic abnormalities in routinely fixed paraffin wax embedded tissue has become commonplace over the past decade. However, very few studies have applied FISH to routinely fixed bone marrow trephines (BMTs). This may be because of the acid based decalcification methods that are commonly used during the processing of BMTs, which may adversely affect the suitability of the sample for FISH analysis. For the first time, this report describes the simultaneous application of FISH and immunofluorescent staining (the FICTION technique) to formalin fixed, EDTA decalcified and paraffin wax embedded BMTs. This technique allows the direct correlation of genetic abnormalities to immunophenotype, and therefore will be particularly useful for the identification of genetic abnormalities in specific tumour cells present in BMTs. The application of this to routine clinical practice will assist diagnosis and the detection of minimal residual disease.

V617F mutation in JAK2 is associated with poorer survival in idiopathic myelofibrosis

Most patients with polycythemia vera and half with idiopathic myelofibrosis and essential thrombocythemia have an acquired V617F mutation in JAK2. Using sensitive polymerase chain reaction (PCR)-based methods, we genotyped 152 patients with idiopathic myelofibrosis to establish whether there were differences in presentation and outcome between those with and those without the mutation. Patients positive for V617F had higher neutrophil and white cell counts (P = .02) than did patients negative for V617F, but other diagnostic features were comparable between the 2 groups. Patients positive for V617F were less likely to require blood transfusion during follow-up (P = .03). Despite this, patients positive for V617F had poorer overall survival, even after correction for confounding factors (P = .01).

T- and B-cell clonality and frequency of human herpes viruses-6, -8 and Epstein Barr virus in angioimmunoblastic T-cell lymphoma

Angioimmunoblastic T-cell lymphoma (T-AIL) is a peripheral T-cell lymphoma of unknown etiology. Previous clonality studies have shown a heterogeneous composition of this disease with varying restrictions of B- and T-cell populations in the tumour. For the first time in a single study and in the same pathological materials, we have analysed, lymphoid cell clonality and occurrence of human herpes viruses and Epstein Barr virus. Of 18 cases 12 (66.6%) had clonal T- and three (16.6%) had clonal B-cells. Presence of the lymphotropic viral genome of HHV6 was detected in four of 18 lymph node biopsies from T-AIL patients (22%), all were TCRgamma clonal. No HHV8 were found. Epstein Barr genome was found in 40% of cases. There was no significant association between T-cell clonality and HHV-6 or EBV infection, or between B-cell clonality and any virus infection. We conclude that T-AIL is a biologically and clinically heterogeneous entity whose true nature remains to be clarified.

Response criteria for myelofibrosis with myeloid metaplasia: results of an initiative of the European Myelofibrosis Network (EUMNET)

The European Myelofibrosis Network (EUMNET), a European research network on myelofibrosis with myeloid metaplasia (MMM), has developed a definition of response for the disease by using clinicohematologic, histologic, and cytogenetic criteria. A core set of 5 clinicohematologic criteria was selected out of 9 candidates on the basis of their sensitivity to change measured in 196 patients treated either during clinical trials or routine clinical practice. A consensus panel of 16 international experts was convened and asked to score the level of response in 104 patient profiles as major, moderate, minor, or no response according to changes of the clinicohematologic criteria. Using the experts' consensus as the gold standard, the performance of 100 possible definitions of response was evaluated. Criteria for major or moderate clinicohematologic response were determined to be changes in hemoglobin (Hb) and spleen size and the presence of constitutional symptoms, while changes in platelet count and white blood cell (WBC) count served as complementary criteria and were of value for defining minor responses. A histologic response was defined by changes in bone marrow fibrosis and cellularity grades. The combined use of these response definitions should help standardize the design and reporting of future clinical studies in MMM.

B and CTL responses to the ALK protein in patients with ALK-positive ALCL

Anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) has a good prognosis compared to ALK-negative ALCL, possibly as a result of the immune recognition of the ALK proteins. The aim of our study was to investigate the presence of both a B and cytotoxic T cell (CTL) response to ALK in ALK-positive ALCL. We confirmed the presence of an antibody response to ALK in all 9 ALK-positive ALCL patients investigated. An ELISpot assay was used to detect a gamma-interferon (IFN) T cell response after short term culture of mononuclear blood cells with 2 ALK-derived HLA-A*0201 restricted peptides: ALKa and ALKb. A significant gamma-IFN response was identified in all 7 HLA-A*0201-positive ALK-positive ALCL patients but not in ALK-negative ALCL patients (n = 2) or normal subjects (n = 6). CTL lines (>95% CD8-positive) raised from 2 ALK-positive ALCL patients lysed ALK-positive ALCL derived cell lines in a MHC-Class I restricted manner. This is the first report of both a B cell and CTL response to ALK in patients with ALK-positive ALCL. This response persisted during long-term remission. The use of modified vaccinia virus Ankara (MVA) to express ALK is also described. Our findings are of potential prognostic value and open up therapeutic options for those ALK-positive patients who do not respond to conventional treatment.

Bone marrow lymphoid aggregates in malignant lymphomas

AIM

To examine the usefulness of molecular analysis of IgH gene rearrangement in assessment of clonality in bone marrow biopsies with lymphoid aggregates (LA) and/or nodular lymphoid hyperplasia (NLH) in patients with different subtypes of malignant lymphomas.

METHOD

Five hundred and twenty nine samples of bone marrow biopsies, taken in a staging procedure at the time of the initial presentation of illness, were processed routinely. Results were grouped in positive, negative, and cases with LA or NLH. In 43 samples with present LA/NLH, polymerase chain reaction (PCR) analysis of the CDR3 region of immunoglobulin heavy chain gene (IgH) for B-cell clonality was performed.

RESULTS

Bone marrow malignant lymphoma infiltrates were present in 33.8% of lymphoma cases. The incidence of LA/NLH in bone marrow was 8.1%. LA/NLH were more frequently found in patients with extranodal disease and aggressive subtypes of B cell non-Hodgkin lymphoma (B-NHL), but there was no significant difference among the incidence according to the biological behavior of malignant lymphoma (P=0.232). Results of IgH-CDR3 region PCR analysis showed a monoclonal pattern in 1 case of Hodgkin lymphoma and in 1 control case, an oligoclonal pattern in 2 cases of extra nodal B-NHL, whereas all other had polyclonal.

CONCLUSION

The results support our initial hypothesis that LA/NLH could be differentiated from malignant infiltrates in bone marrow staging procedure of malignant lymphoma by topographic pattern and histocytomorphology of LA/NLH. Surprisingly, our patients with aggressive B-NHL, nodal, as well as extranodal, had LA/NLH in bone marrow biopsies more often than patients with indolent B-NHL.