Assessment of cell proliferation by Ki-67 staining and flow cytometry in fine needle aspirates (FNAs) of reactive lymphadenitis and non-Hodgkin's lymphomas

Assessment of Ki-67 Proliferative Index in Cytological Samples of Nodal B-Cell Lymphomas

BACKGROUND

The Ki-67 proliferative index (PI) is part of the diagnosis of nodal B-cell lymphoma (nBCL), but its determination in cytological samples is not standardized. We aimed to establish an approach for the accurate determination of the Ki-67 PI in cytological slides to differentiate between indolent and aggressive nBCLs.

METHODS

Patients diagnosed with nBCL by fine-needle aspiration biopsy and subsequent excision biopsy were included. Cell suspensions were prepared from biopsy samples for CD3/Ki-67 double immunocytochemical staining and flow-cytometric verification of lymphoma B-cell counts. The Ki-67 PI was assessed by manual counting and eyeballing in cytology and eyeballing in histology. The cut-off values for the differentiation between aggressive and indolent lymphomas were determined for each method.

RESULTS

A strong correlation between manual and flow-cytometric counting of lymphoma B cells was confirmed (interclass correlation coefficient (IC coef.) = 0.78). The correlation of the Ki-67 PI determined in cytological and histological slides was also strong (IC coef. > 0.80). Histologically, 55 cases were classified as indolent and 31 as aggressive nBCLs. KI-67 PI cut-off values of 28.5%, 27.5%, and 35.5% were established for manual counting and eyeballing in cytology and eyeballing in histology, respectively, with high sensitivity and specificity.

CONCLUSIONS

The Ki-67 PI, assessed by manual counting and eyeballing in cytological samples, accurately differentiates between indolent and aggressive nBCLs.

Classifying B-cell non-Hodgkin lymphoma by using MIB-1 proliferative index in fine-needle aspirates

BACKGROUND

MIB-1 proliferation index (PI) has proven helpful for diagnosis and prognosis in non-Hodgkin lymphomas (NHLs). However, validated cutoff values for use in fine-needle aspiration (FNA) samples are not available. We investigated MIB-1 immunocytochemistry as an ancillary technique for stratifying NHL and attempted to establish PI cutpoints in cytologic samples.

METHODS

B-cell NHL FNA cases with available cytospins (CS) MIB-1 immunocytochemistry results were included. Demographic, molecular, immunophenotyping and MIB-1 PI data were collected from cytologic reports. Cases were subtyped according to the current World Health Organization classification and separated into indolent, aggressive, and highly aggressive groups. Statistical analysis was performed with pairwise Wilcoxon rank sum test and linear discriminant analysis to suggest appropriate PI cutpoints.

RESULTS

Ninety-one NHL cases were subdivided in 56 (61.5%) indolent, 30 (33%) aggressive, and 5 (5.5%) highly aggressive lymphomas. The 3 groups had significantly different MIB-1 PIs from each other. Cutpoints were established for separating indolent (<38%), aggressive (> or =38% to < or =80.1%) and highly aggressive (>80.1%). The groups were adequately predicted in 76 cases (83.5%) using the cutpoints and 15 cases showed discrepant PIs.

CONCLUSIONS

MIB-1 immunohistochemistry on CS can help to stratify B-cell NHL and showed a significant increase in PI with tumor aggressiveness. Six misclassified cases had PIs close to the cutpoints. Discrepant MIB-1 PIs were related to dilution of positive cells by non-neoplastic lymphocytes and to the overlapping continuum of features between diffuse large B-cell lymphoma and Burkitt lymphoma. Validation of our approach in an unrelated, prospective dataset is required.

Tanzanian malignant lymphomas: WHO classification, presentation, ploidy, proliferation and HIV/EBV association

BACKGROUND

In Tanzania, the International Working Formulation [WF] rather than the WHO Classification is still being used in diagnosing malignant lymphomas (ML) and the biological characterization including the HIV/EBV association is sketchy, thus restraining comparison, prognostication and application of established therapeutic protocols.

METHODS

Archival, diagnostic ML biopsies (N = 336), available sera (N = 35) screened by ELISA for HIV antibodies and corresponding clinical/histological reports at Muhimbili National Hospital (MNH) in Tanzania between 1996 and 2006 were retrieved and evaluated. A fraction (N = 174) were analyzed by histopathology and immunohistochemistry (IHC). Selected biopsies were characterized by flow-cytometry (FC) for DNA ploidy (N = 60) and some by in-situ hybridization (ISH) for EBV-encoded RNA (EBER, N = 37).

RESULTS

A third (38.8%, 109/281) of the ML patients with available clinical information had extranodal disease presentation. A total of 158 out of 174 biopsies selected for immunophenotyping were confirmed to be ML which were mostly (84. 8%, 134/158) non-Hodgkin lymphoma (NHL). Most (83.6%, 112/134) of NHL were B-cell lymphomas (BCL) (CD20+), of which 50.9%, (57/112) were diffuse large B-cell (DLBCL). Out of the 158 confirmed MLs, 22 (13.9%) were T-cell [CD3+] lymphomas (TCL) and 24 (15.2%) were Hodgkin lymphomas (HL) [CD30+]. Furthermore, out of the 60 FC analyzed ML cases, 27 (M:F ratio 2:1) were DLBCL, a slight majority (55.6%, 15/27) with activated B-cell like (ABC) and 45% (12/27) with germinal center B-cell like (GCB) immunophenotype. Overall, 40% (24/60) ML were aneuploid mostly (63.0%, 17/27) the DLBCL and TCL (54.5%, 6/11). DNA index (DI) of FC-analyzed ML ranged from 1.103-2.407 (median = 1.51) and most (75.0%) aneuploid cases showed high (>40%) cell proliferation by Ki-67 reactivity. The majority (51.4%, 19/37) of EBER ISH analyzed lymphoma biopsies were positive. Of the serologically tested MLs, 40.0% (14/35) were HIV positive, mostly with high (> or =40.0%) Ki-67 reactivity.

CONCLUSIONS

According to the 2001 WHO Classification, most subtypes are represented in Tanzanian ML. Extranodal presentation was common among MNH lymphoma patients who also showed high aneuploidy, tumor proliferation (KI-67) and EBER positivity. DLBCL was frequent and phenotype heterogeneity appeared similar to observations in Western countries suggesting applicability of established intervention approaches. HIV was apparently associated with high ML cell proliferation but extended studies are needed to clarify this.

Inhibition of superoxide generation upon T-cell receptor engagement rescues Mart-1(27-35)-reactive T cells from activation-induced cell death

Cytotoxic T lymphocytes (CTL) may undergo massive expansion upon appropriate antigenic stimulation. Homeostasis is maintained by a subsequent "contraction" of these cells. Activation-induced cell death (AICD) and programmed cell death prevent the untoward side effects, arising from excessive numbers and prolonged persistence of activated CTL, that occur upon uncontrolled and/or continued expansion. However, effector cell persistence has been identified as a hallmark of successful T-cell-mediated adoptive immunotherapy. Thus, prevention of AICD may be critical to achieve more successful clinical results. We have previously shown that treatment with the c-Jun NH(2)-terminal kinase (JNK) inhibitor SP600125 protects human melanoma epitope Mart-1(27-35)-reactive CTL from apoptotic death upon their reencounter with cognate antigen. However, inhibition of JNK also interferes with the functional ability of the CTL to secrete IFN-gamma. Here, we show that reactive oxygen species (ROS) inhibitors, such as the superoxide dismutase mimetic Mn (III) tetrakis (5, 10, 15, 20-benzoic acid) porphyrin (MnTBAP), efficiently protected Mart-1(27-35)-reactive primary CTL from AICD without impairing their functional capability. MnTBAP prevented the increase in intracellular ROS, mitochondrial membrane collapse, and DNA fragmentation observed in control-treated cells upon cognate antigen encounter. Furthermore, the mechanism of AICD prevention in primary CTL included blockade of JNK activation. Finally, tumor-reactive in vitro expanded tumor infiltrating lymphocytes, which are used clinically in cancer immunotherapy, also benefit from MnTBAP-mediated antioxidant treatment. Thus, modulation of the redox pathway might improve CTL persistence and lead to better clinical results for T cell-based immunotherapies.

Biological factors, tumor growth kinetics, and survival after metastasectomy for pulmonary melanoma

INTRODUCTION

Approximately 23% of melanoma patients will eventually develop pulmonary metastases and have a median survival of only about 7-11 months. Because pulmonary metastasectomy can improve this statistic, we investigated clinicopathologic features and biological correlates that might be used to identify surgical candidates.

METHODS

Archived operative specimens and clinical records were retrieved for 20 melanoma patients who underwent resection of isolated pulmonary metastases at the John Wayne Cancer Institute, Saint John's Health Center. Five-year postmetastasectomy survival (PMS) rate was correlated with age, number of pulmonary metastases, tumor doubling time (TDT), tumor necrosis, and immunohistochemical expressions of four biological markers: Ki-67, glucose transporter-1 (Glut-1), caspase-3, and CD31.

RESULTS

Median TDT was 61 days. On multivariate analysis, TDT (P = 0.008), Glut-1 intensity (P = 0.04), and CD31 expression (P = 0.004) were the significant predictors of PMS. Age, number of pulmonary metastases, tumor necrosis, and expression of Ki-67 or caspase-3 did not significantly impact survival. Median TDT was 56 days with Glut-1 expression versus 165 days without Glut-1 expression (P = 0.002), and Glut-1 staining intensity independently affected TDT (P = 0.012).

CONCLUSIONS

Surgical resection may be preferable to toxic systemic therapies in melanoma patients whose isolated pulmonary metastases have a long TDT (> or = 61 days) and no biopsy evidence of Glut-1 expression.

Punção aspirativa por agulha fina no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes

OBJETIVO: Avaliar a importância diagnóstica da punção aspirativa por agulha fina (PAAF) em crianças e adolescentes portadores de linfadenopatias e tumores sólidos. MÉTODOS: Análise retrospectiva dos pacientes com idade igual ou inferior a 18 anos, atendidos no Centro de Pediatria Cirúrgica do Hospital Universitário de Brasília, Universidade de Brasília, no período de julho de 2000 a julho de 2005. Foram calculados: sensibilidade, especificidade, precisão (acurácia) diagnóstica, valor preditivo positivo e valor preditivo negativo. RESULTADOS: Em 50 pacientes estudados, os resultados da PAAF mostraram sensibilidade de 90,9%; especificidade de 100%, precisão diagnóstica de 95% e valores preditivos positivo e negativo de 100% e 90%, respectivamente. CONCLUSÃO: Em nossa experiência, a PAAF é um método preciso, simples e seguro, útil no diagnóstico de linfadenopatias e tumores sólidos em crianças e adolescentes.

Flow cytometric immunophenotyping including Bcl-2 detection on fine needle aspirates in the diagnosis of reactive lymphadenopathy and non-Hodgkin's lymphoma

BACKGROUND

Fine-needle aspiration (FNA) with immunophenotyping by immunocytochemistry (IC) on cytospins has recently received increased consideration in the diagnosis of lymphoma. The aim of our study was to establish the diagnostic value of a four-color flow cytometric (FCM) panel, including cytoplasmic Bcl-2, in cytologic diagnosis of malignant non-Hodgkin's lymphoma (NHL) and reactive lymphoid hyperplasia (RH).

METHODS

We investigated 424 FNAs from 396 patients. FCM panel included lambda/kappa/CD19/CD5, CD23/CD10/CD20/CD19, CD4/CD7/CD8/CD3 and Bcl-2/CD10/CD19/CD3 in fluorescein isothiocyanate, phycoerythrin, and peridinin chlorophyll protein or a tandem conjugate of R-phycoerythrin and indodicarbocyanine and allophycocyanin. Bcl-2 expression was evaluated separately for gated B and T cells.

RESULTS

In 97% of 172 RH samples, FCM was concordant with the diagnosis. FCM gave correct immunologic diagnosis in 95% of low-grade B-cell NHLs, 78% of high-grade B-cell NHLs, and 53% of T-cell lymphomas. Malignant B cells had higher Bcl-2 expression than did reactive B and T cells. This helped to establish a correct diagnosis especially in cases where no clear-cut monoclonality could be shown by kappa/lambda staining or where there was no expression of surface light chain. The highest Bcl-2 expression was found in follicular lymphomas.

CONCLUSION

Our FCM panel allowed precise classification of NHL in FNA material in 89.5% of all samples. Bcl-2 staining can be recommended for primary differentiation between reactive hyperplasia and NHL.

Examination of the proliferative activity of tumor cells in human lymphoid neoplasms using a morphometric approach

BACKGROUND

The genesis of lymphoid neoplasia is accompanied by alterations in cell proliferation control mechanisms. Thus, proliferative indices (PIs) provide valuable prognostic information in this setting. Nonetheless, one shortcoming of PI measurements is that they depend not only on the proliferative activity of the neoplastic cells in a given lesion, but also on the activity of any admixed reactive cells. The current report describes an approach to identifying neoplastic and reactive subpopulations in cytologic preparations and to comparatively characterizing the morphologic features of neoplastic cells and assessing their proliferative activity.

METHODS

Reactive and malignant lymph node samples were obtained from 37 patients during surgical biopsy. Giemsa stained touch imprints were used for morphometric and high-resolution videomicroscopic analyses. Immunofluorescence-based detection of pKi-67-positive cells was used in conjunction with morphometric analysis to assess the proliferative activity of tumor cells.

RESULTS

Morphometric analysis allowed the selective identification of neoplastic cells in large cell lymphomas (LCLs). The morphologic characteristics of neoplastic cells in primary and secondary LCLs were found to be similar. The PI was highly dependent on the proportion of tumor cells present in the tissue sample analyzed, and in some samples with large proportions of reactive cells, the overall percentage of pKi-67-positive cells was low, but the majority of neoplastic cells nonetheless were positive for pKi-67. Most primary LCLs had very high tumor cell PIs (80-100%), whereas all secondary LCLs had moderate tumor cell PIs.

CONCLUSIONS

Neoplastic cell subpopulations in LCLs can be identified on morphometric analysis, which can be performed using touch imprints; this technique allows evaluation of the proliferative activity of tumor cells. The authors propose that the use of tumor cell PIs rather than PIs for overall cell populations will result in more accurate assessment of disease prognosis.

Telomerase activity and proliferation index in aggressive mature B-cell lymphoma: comparison to germinal center phenotypic markers

Cell proliferation may be evaluated by various methods, including Ki-67 immunohistochemistry and measures of telomerase activity. Both methods would theoretically show comparable increases in a given case. To evaluate the relationship between these 2 markers of proliferation in aggressive mature B-cell lymphomas, 48 cases were studied. The study group included 5 cases of mantle cell lymphoma (MCL); 6 cases of Burkitt's/Burkitt's-like lymphoma (BL); 9 cases of follicular lymphoma, grade 3 (FLC); and 28 cases of diffuse large B-cell lymphoma (DLC). Telomerase activity was measured as total product generated (TPG) units, and TPG results for the aforementioned cases were compared to the TPG results for 10 cases of reactive follicular hyperplasia. An overlap in TPG scores between reactive cases and lymphoma cases was found. Significant differences in both log TPG (P = 0.0443) and Ki-67 (P = 0.0006) were seen in the different lymphoma types. A positive correlation between Ki-67 percentage and TPG score was identified in FLC (r = 0.9281; P = 0.0003), but a poor correlation between these 2 indicators was seen in the other lymphoma types. Cluster analysis identified distinct patterns for MCL, FLC, and BL, but heterogeneous patterns for DLC. Because increases in both Ki-67 proliferation and telomerase activity are reported in normal germinal centers (GCs), these tests were also evaluated for usefulness as markers of a GC cell phenotype. Among the FLC and DLC cases, features of a GC phenotype significantly correlated with increased Ki-67 percentage (P = 0.0152), but not with increased log TPG. An elevated log TPG correlated with CD10 expression, and elevated Ki-67 percentage correlated with both CD10 and BCL-6 expression. TPG level and Ki-67 percentage did not correlate with the presence of t(14;18) or BCL-2 protein expression. Although the proliferation patterns were fairly distinctive for MCL, FLC, and BL, these studies show that markers of cell proliferation do not by themselves,identify distinct subtypes of large cell lymphomas. With the exception of FLC, the tumors exhibited poor correlation between telomerase activity and Ki-67 proliferation index. These tests did show some correlation with expression of GC cell phenotypic markers, however.

Cytomorphologic spectrum of small lymphocytic lymphoma in patients with an accelerated clinical course

BACKGROUND

Patients with transformed large cell lymphoma (TLCL), or Richter syndrome, and patients with small lymphocytic lymphoma/leukemia (SLL) in accelerated phase (SLL-AP) frequently undergo fine-needle aspiration (FNA) to elucidate the cause of massive lymphadenopathy and a worsening clinical condition. It is well known that patients with Richter syndrome have poor clinical outcomes as a result of the biologic aggressiveness of the transformed large cells that often are refractory to therapy. The objective of this study was to evaluate reliable criteria for recognizing SLL-AP and SLL in transformation that are needed to determine the appropriate clinical management of individual patients.

METHODS

FNA specimens from 20 patients with SLL, 26 patients with SLL-AP, and 13 patients with TLCL or Richter syndrome were identified based on the reported diagnosis. Patients were included only if they had histologically confirmed SLL that also satisfied the immunophenotypic criteria of CD5/CD23 coexpression with negative CD10 and < 55% prolymphocytes. On the basis of an initial blind review of routinely stained slides from the FNA specimens, the authors defined four groups based on a consensus review diagnosis: Group 1: typical SLL; Group 2: low-grade SLL-AP; Group 3: high-grade SLL-AP; and Group 4: TLCL. Cytomorphologic features, including the proportion of intermediate-to-large cells with prominent nucleoli and intermediate-sized plasmacytoid lymphoid cells, increased numbers of mitotic figures, the presence of apoptotic bodies and necrosis, and a myxoid/dirty background, were considered features that indicated an accelerated phase. Specimens that had more than two grades of diagnostic discrepancy compared with the original reported diagnosis were reexamined using a Ki-67 immunostaining labeling index to reach a final review diagnosis.

RESULTS

On the basis of the review diagnosis, the specimens were recategorized as follows: Group 1: 20 patients with typical SLL; Group 2: 13 patients with low-grade-SLL-AP; Group 3: 16 patients with high-grade SLL-AP; and Group 4: 10 patients with TLCL. The mean Ki-67 labeling index (%) was correlated with the morphologic progression of SLL as follows: Group 1: 11%; Group 2: 16%; Group 3: 34%; and Group 4: 48%. The follow-up by subsequent FNA or biopsy demonstrated large cell transformation in 25% of patients in Group 1, 25% of patients in Group 2, and 100% of patients in Group 3. Among the clinical parameters, increased value of serum beta2-microglobulin and lactic dehydrogenase (LDH) levels were found to be well correlated with the cytomorphologic progression of SLL/chronic lymphocytic leukemia.

CONCLUSIONS

Aspirates from patients who had signs and symptoms clinically suspicious for SLL-AP demonstrated a spectrum of cytomorphologic features, ranging from low-grade SLL-AP and high-grade SLL-AP to TLCL. The results showed that the Ki-67 labeling index, as determined by immunohistochemical studies in FNA specimens, and the levels of serum beta2-microglobulin and LDH are valuable diagnostic adjuncts for recognizing a subset of patients with SLL-AP or SLL in transformation who may require more aggressive therapy.

Analysis of proliferating cell fraction determined by monoclonal antibody to M1-subunit ribonucleotide reductase and Ki-67 in relation to p53 protein expression in fine-needle aspirates from non-Hodgkin's lymphomas

The purpose of this study was to analyse the proliferative fraction with the monoclonal antibody M1-R-R to M1-subunit ribonucleotide reductase and with MIB-1 to Ki-67 antigen in relation to p53 protein expression in fine needle aspirates from B-cell non-Hodgkin's lymphomas. One hundred and thirty-seven cases, previously diagnosed and sub-typed according to the Kiel classification and characterized by immunophenotyping, were included in the study. The M-1 subunit ribonucleotide reductase (M1-R-R), Ki-67 and p53 antigens were detected using monoclonal antibodies on stored cytospin preparations. There was a good correlation (r = 0.72) between Ki-67 and M1-R-R positive cell fraction in both high and low grade lymphomas. High-grade lymphomas had a median percentage of M1-R-R/MIB-1 positive cells of 53.0/73.0 for lymphoblastic, 61.0/52.0 for immunoblastic and 33.5/41.0 for centroblastic lymphomas, respectively. In low grade lymphomas figures of median percentage of M1-R-R/MIB-1 were 9.0/15.0 for centroblastic/centrocytic, 11.0/9.5 for chronic lymphocytic leukaemia, 16.0/27.0 for centrocytic and 12.0/9.0 for immunocytomas, respectively. The median percentages of M1-R-R/MIB-1 for high and low grade lymphomas were 37.0/50.5 and 11.0/12.0, respectively. In the p53 positive cases the proliferation rate as measured by staining for M1-R-R and MIB-1 was higher than in p53 negative cases, but the difference was not statistically significant. The results show that cytospin material obtained by fine needle aspiration and stored at -70 degrees C for years can be used reliably for both peroxidase-avidin-biotin and three-step alkaline phosphatase immunocytochemical staining. In addition, proliferation fraction determined by M1-R-R monoclonal antibody staining correlates well with that measured by an established marker for cell proliferation, the Ki-67 antibody. However, the proliferation fraction as measured by the two antibodies differs in the various subtypes of non-Hodgkin's lymphoma which indicates that they may contribute different prognostic information.