Efficacy and safety of biosimilar Peg-filgrastim after autologous stem cell transplant in myeloma and lymphoma patients: a comparative study with biosimilar Filgrastim, Lenograstim, and originator Peg-filgrastim

Data about biosimilar Peg-filgrastim (bioPEG) in autologous stem cell transplant (ASCT) are still scarce. The aim of this study has been to assess efficacy and safety of bioPEG among lymphoma and myeloma patients undergoing ASCT, comparing these data with historical controls receiving other G-CSFs. Furthermore, an economic evaluation has been included to estimate the savings by using bioPEG. This is a prospective cohort study comparing lymphoma and myeloma patients undergoing ASCT and receiving bioPEG (n = 73) with three historical consecutive cohorts collected retrospectively who received other G-CSFs (Lenograstim - Leno - n = 101, biosimilar Filgrastim - bioFIL n = 392, and originator Peg-filgrastim - oriPEG n = 60). We observed a significantly shorter time to neutrophils and platelet engraftment (p < 0.001) in patients treated with bioPEG and oriPEG. Moreover, patients who received bioPEG showed a shorter hospitalization time (p < 0.001) and a lower transfusion need (p < 0.001). We did not observe any significant difference in terms of transplant-related mortality, mucositis, and diarrhea among the four groups. No serious adverse events were associated with bioPEG. Similar data were obtained after running a stratified analysis for lymphomas and myeloma separately conducted by using a propensity score matching. The average total cost per patient of bioPEG was € 18218.9 compared to € 23707.8, € 20677.3 and € 19754.9 of Leno, oriPEG, and bioFIL, respectively. In conclusion, bioPEG seems to be as effective as the originator and more effective than short-acting G-CSFs in terms of post-transplant engraftment in myeloma and lymphoma patients undergoing ASCT. Moreover, bioPEG was cost-effective when compared with the other G-CSFs.

Overexpression in metastatic breast cancer supports Syndecan-1 as a marker of invasiveness and poor prognosis

BACKGROUND

Metastasis is the main cause of breast cancer (BC) mortality. Increasing evidence points to a role of syndecan-1 (CD138) expression as a prognostic marker involved in BC tissue and leptomeningeal metastasis. Aim of this study was to investigate and compare syndecan-1 tissue expression and localization in primary and secondary BC, focusing on brain metastases.

METHODS

Syndecan-1 expression was determined by immunohistochemistry. Focal vs diffuse (< or > 50% of cancer cells, respectively) pattern of expression, cellular localization (cytoplasm vs membrane) and intensity of immunostaining on neoplastic cells were evaluated. Moreover, the extent and pattern of expression of syndecan-1 were compared between primary tumors and paired metastases and correlated with the tumor intrinsic subtype.

RESULTS

A total of 23 cases, 10 with paired primary and metastatic tumor and 13 brain metastases, were evaluated. Syndecan-1 was expressed in both primary and metastatic BC. A diffuse cytoplasmic expression was observed in most primary BCs; by contrast, all metastatic lesions showed a membrane pattern of expression, suggesting a shift in cellular localization of syndecan-1 during the metastatic process. Concerning the extent of expression, we observed in metastatic lesions, a trend of association between intrinsic subtypes and extent of positivity. In particular, both BC characterized by overexpression of HER2 and triple-negative tumors were correlated with a diffuse pattern of expression with a moderate to strong intensity.

CONCLUSION

A diffuse cytoplasmic expression was observed in most primary BCs; by contrast, all metastatic lesions showed a membrane pattern of expression, suggesting a shift in cellular localization of syndecan-1 during the metastatic process.

Consensus for Flow Cytometry Clinical Report on Multiple Myeloma: A Multicenter Harmonization Process Merging Laboratory Experience and Clinical Needs

Flow cytometry is a highly sensitive and specific approach for discriminating between normal and clonal plasma cells in multiple myeloma. Uniform response criteria after treatment have been established by the International Myeloma Working Group and the EuroFlow Group; however, the way in which flow cytometry data are reported has suffered from no collaborative or multicentre efforts. This study, involving 8 expert laboratories and 12 clinical hematology units of the Lazio region in Italy, aims to produce a uniform and shared report among the various Centres. From the pre-analytical phase to sample processing, data acquisition, analysis, and evaluation of the potential limitations and pitfalls of the entire process, the study reaches a final conclusion shared by laboratories and clinicians according to the most updated principles and recommendations. The aim was to identify the necessary data to be included in the clinical report by using multiple-choice questionnaires at every single stage of the process. An agreement of more than 75% of the laboratories was considered mandatory for the data to be included in the report. By ensuring the operational autonomy of each laboratory, this study provides a clear report that limits subjective interpretations and highlights possible bias in the process, better supporting clinical decision-making.

Neoplastic bone marrow invasion:rapid exclusion of hematological disease by flow cytometric routine panels

Multiparametric flow cytometry is an extensively used technique to assess the presence of different cellular populations in immunology and hematology. During routine immunophenotyping analysis, it is not uncommon to face cells of non-hemopoietic origin, negative for CD45 and other myeloid, megakaryocytic, B and T lineage antigens and positive for at least one antibody among CD56, CD117 and CD138. If cytology cannot identify cell origin, especially in cases of unclear interpretation, the contribution of multiparametric flow cytometry analysis can be crucial. We report 6 patients with a clinical suspicion of hematological disease in which multiparametric flow cytometry was extremely useful to quickly exclude blood disorders in order to initiate patients to the most appropriate diagnostic process.

Stereotactic Ablative Radiation Therapy in 3 Fractions Induces a Favorable Systemic Immune Cell Profiling in Prostate Cancer Patients

The impact of radiotherapy (RT) on immune cell status in prostate cancer (PCa) is only partially determined. The aim of this study was to assess the effect of different RT strategies on peripheral B, T, and Natural killer (NK) lymphocytes at precise longitudinal time-points in PCa. 18 patients treated with stereotactic body radiation therapy (SBRT) (40 Gy/3FRX), definitive moderate-hypofractionation (62 Gy/20FRX), or post-operative conventional-fractionation RT (66-69 Gy/30FRX) were prospectively evaluated for the immune cell profile in terms of immune cell composition, differentiation stage, cytokine production and inhibitory receptor (IR) expression. The immune-monitoring of the 18 patients revealed that RT affects the balance of systemic immune cells, with the main differences observed between SBRT and conventionally fractionated RT. SBRT favorably impacts immune response in term of increased B cells, central-memory and effector-memory CD8⁺ T cells, along with decreased Treg cells after treatment. On the contrary, conventional fractionated RT had a long-term negative effect on the systemic immune profile, including a decrease of total lymphocyte counts accompanied by an increase of neutrophils-to-lymphocytes ratio. Total B and T cells decreased and Treg-to-CD8⁺ ratio increased. Functionality of T lymphocytes were not affected by any of the 3-fractionation schedules. Interestingly, SBRT significantly up-regulates the expression of V-domain immunoglobulin suppressor of T-cell activation (VISTA) in CD8⁺ T cells in the absence of other IRs. Our results indicate the relevance of systematic immunomonitoring during RT to identify novel immune-related target to design trials of combined radio-immunotherapy as a promising strategy in the clinical management of PCa.

Retraction Note: Exemestane blocks mesothelioma growth through downregulation of cAMP, pCREB and CD44 implicating new treatment option in patients affected by this disease

This article has been retracted. Please see the Retraction Notice for more detail: https://doi.org/10.1186/1476-4598-13-69.

Durable Molecular Remission in an Elderly Patient Affected by Relapsed Ph&apos;+ Acute Lymphoblastic Leukemia with T315I and Concomitant p190 and p210 Expression Achieved by Inotuzumab and Ponatinib

An unmet clinical need currently exists for elderly patients with relapsed/resistant (R/R) Philadelphia (Ph) positive acute lymphoblastic leukemia (ALL), nearly all who have a very poor prognosis. This includes patients already exposed to the first or second generation tyrosine kinase inhibitors (TKIs) and therefore has few treatment options available. New immunotherapies and targeted agents have shown encouraging activity in R/R ALL irrespective of age. Inotuzumab (InO), a humanized anti-CD22 monoclonal antibody, has potentially beneficial clinical effects in patients with resistant and difficult-to-treat disease in whom prior TKIs have failed. However, InO, as a single agent, did not show durable response and longer progression free survival and overall survival in R/R Ph positive ALL patients compared with those treated with standard chemotherapy. We observed a durable molecular remission (7 months) in an elderly patient affected by Ph&apos;+ ALL with T315I and concomitant p190 and p210 expression achieved by concomitant therapy of InO (for 4 cycles) and ponatinib (15 mg/daily) followed by ponatinib (15 mg/daily) only as maintenance therapy. These findings suggest that elderly R/R Ph positive patients who cannot proceed to the transplant might benefit by concomitant immunotherapy and TKIs aimed to deepen the responses and prolong CR and outcomes.

Major Differences in Lymphocyte Subpopulations Between Cerebrospinal Fluid and Peripheral Blood in Non-Hodgkin Lymphoma Without Leptomeningeal Involvement: Flow Cytometry Evidence of a Cerebral Lymphatic System

Cerebrospinal fluid (CSF) flow cytometry has a crucial role in the diagnosis of leptomeningeal disease in onco-hematology. This report describes the flow cytometry characterization of 138 CSF samples from patients affected by non-Hodgkin lymphoma, negative for disease infiltration. The aim was to focus on the CSF non-neoplastic population, to compare the cellular composition of the CSF with paired peripheral blood samples and to document the feasibility of flow cytometry in hypocellular samples. Despite the extremely low cell count (1 cell/µl, range 1.0-35) the study was successfully conducted in 95% of the samples. T lymphocytes were the most abundant subset in CSF (77%; range 20-100%) with a predominance of CD4-positive over CD8-positive T cells (CD4/CD8 ratio = 2) together with a minority of monocytes (15%; range 0-70%). No B cells were identified in 90% of samples. Of relevance, a normal, non-clonal B-cell population was documented in 5/7 (71%) patients with primary central nervous system lymphoma at diagnosis (p<0.0001), suggesting a possible involvement of blood-brain barrier cell permeability in the pathogenesis of cerebral B-cell lymphomas. The highly significant differences between CSF and paired peripheral blood lymphoid phenotype (p<0.0001) confirms the existence of an active mechanism of lymphoid migration through the meninges.

A novel biomarker score for the screening and management of patients with plasma cell proliferative disorders

OBJECTIVE

Monoclonal plasma cell proliferative disorders comprise a wide spectrum of diseases associated to clonal B-cell expansion. Serum protein electrophoretic profile (SPEP) and circulating free light chains (FLCs) levels are the mainstay of diseases management. Recently, soluble (s) Syndecan-1 (SDC1, CD138) produced by myeloma plasma cells has been suggested in the monitoring and follow-up of patients with myeloma. The aim of our study is to evaluate sCD138 in addition with FLCs and SPEP for the screening of patients with different evolutive disease pathways.

PATIENTS AND METHODS

Sera from 73 patients with monoclonal gammopathy of undetermined significance (MGUS), 120 smoldering and 42 multiple myeloma (SMM and MM, respectively), 70 HCV-related mixed cryoglobulinemia (MC), 35 B-cell non-Hodgkin's lymphoma (B-NHL) and sera from 50 healthy donors (HD), were tested for sCD138, FLCs (assessed by means of ELISA and turbidimetric assay, respectively) and electrophoresis pattern (performed on Capillarys system) for the generation of a novel biomarker score (BS).

RESULTS

Our results were grouped according to the two main lines of disease progression (vs. MM or B-NHL): in one group we found BS mean values of 0.2, 3.4, 5.3, 7.1 for HD, MGUS, SMM and MM, respectively; in the other group of 0.2, 4.4, 6.7 for HD, MC and B-NHL.

CONCLUSIONS

We showed that BS mean values follow the ingravescence disease status towards the two main lines of progression to cancerous conditions; it could represent an additional useful tool in the management of screening and/or follow-up.

Transcriptional activation of the miR-17-92 cluster is involved in the growth-promoting effects of MYB in human Ph-positive leukemia cells

MicroRNAs, non-coding regulators of gene expression, are likely to function as important downstream effectors of many transcription factors including MYB. Optimal levels of MYB are required for transformation/maintenance of BCR-ABL-expressing cells. We investigated whether MYB silencing modulates microRNA expression in Philadelphia-positive (Ph⁺) leukemia cells and if MYB-regulated microRNAs are important for the “MYB addiction” of these cells. Thirty-five microRNAs were modulated by MYB silencing in lymphoid and erythromyeloid chronic myeloid leukemia-blast crisis BV173 and K562 cells; 15 of these were concordantly modulated in both lines. We focused on the miR-17-92 cluster because of its oncogenic role in tumors and found that: i) it is a direct MYB target; ii) it partially rescued the impaired proliferation and enhanced apoptosis of MYB-silenced BV173 cells. Moreover, we identified FRZB, a Wnt/β-catenin pathway inhibitor, as a novel target of the miR-17-92 cluster. High expression of MYB in blast cells from 2 Ph⁺leukemia patients correlated positively with the miR-17-92 cluster and inversely with FRZB. This expression pattern was also observed in a microarray dataset of 122 Ph⁺acute lymphoblastic leukemias. In vivo experiments in NOD scid gamma mice injected with BV173 cells confirmed that FRZB functions as a Wnt/β-catenin inhibitor even as they failed to demonstrate that this pathway is important for BV173-dependent leukemogenesis. These studies illustrate the global effects of MYB expression on the microRNAs profile of Ph⁺cells and supports the concept that the “MYB addiction” of these cells is, in part, caused by modulation of microRNA-regulated pathways affecting cell proliferation and survival.

Serum free light chain quantitative assays: Dilemma of a biomarker

BACKGROUND

Serum free light chains detection assays are consistently meeting greater interest for the diagnosis and monitoring of monoclonal gammopathies and plasma cell dyscrasias. Nowadays, there are neither standardized methods nor reference material for the determination of free light chains; for this reason, it is important to compare two different assays used in clinical laboratory.

METHODS

We evaluated 300 serum samples from patients with B-cell disorders and compared the analytical performances of both assay. Each test was assayed on both testing platforms (Siemens Dade Behring BN II Nephelometer and SPAPLUS by The Binding Site). κ/λ ratios were determined and compared. Results were analyzed by Passing-Bablok and Bland-Altman plots to evaluate comparability of the two techniques and to determine bias.

RESULTS

The reproducibility of both assays is acceptable, reaching minimum and desirable analytical goals derived from biological variability. However, values are not interchangeable between systems. This study shows that the two systems do not allow results to be transferred from one method to the other even if they display good agreement.

CONCLUSION

Our study highlights the importance of elaborating an international standard for free light chains quantification in order to offer homogeneous results as well as guarantee harmonization of values among laboratories. Moreover, the assays should be validated in specific patient groups to determine that they are clinically fit for purpose.

Overexpression of syndecan-1, MUC-1, and putative stem cell markers in breast cancer leptomeningeal metastasis: a cerebrospinal fluid flow cytometry study

Background

Cancer is a mosaic of tumor cell subpopulations, where only a minority is responsible for disease recurrence and cancer invasiveness. We focused on one of the most aggressive circulating tumor cells (CTCs) which, from the primitive tumor, spreads to the central nervous system (CNS), evaluating the expression of prognostic and putative cancer stem cell markers in breast cancer (BC) leptomeningeal metastasis (LM).

Methods

Flow cytometry immunophenotypic analysis of cerebrospinal fluid (CSF) samples (4.5 ml) was performed in 13 consecutive cases of BCLM. Syndecan-1 (CD138), MUC-1 (CD227) CD45, CD34, and the putative cancer stem cell markers CD15, CD24, CD44, and CD133 surface expression were evaluated on CSF floating tumor cells. The tumor-associated leukocyte population was also characterized.

Results

Despite a low absolute cell number (8 cell/μl, range 1–86), the flow cytometry characterization was successfully conducted in all the samples. Syndecan-1 and MUC-1 overexpression was documented on BC cells in all the samples analyzed; CD44, CD24, CD15, and CD133 in 77%, 75%, 70%, and 45% of cases, respectively. A strong syndecan-1 and MUC-1 expression was also documented by immunohistochemistry on primary breast cancer tissues, performed in four patients. The CSF tumor population was flanked by T lymphocytes, with a different immunophenotype between the CSF and peripheral blood samples (P ≤ 0.02).

Conclusions

Flow cytometry can be successfully employed for solid tumor LM characterization even in CSF samples with low cell count. This in vivo study documents that CSF floating BC cells overexpress prognostic and putative cancer stem cell biomarkers related to tumor invasiveness, potentially representing a molecular target for circulating tumor cell detection and LM treatment monitoring, as well as a primary target for innovative treatment strategies. The T lymphocyte infiltration, documented in all CSF samples, suggests a possible involvement of the CNS lymphatic system in both lymphoid and cancer cell migration into and out of the meninges, supporting the extension of a new form of cellular immunotherapy to LM. Due to the small number of cases, validation on large cohorts of patients are warranted to confirm these findings and to evaluate the impact and value of these results for diagnosis and management of LM.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-017-0827-4) contains supplementary material, which is available to authorized users.

Follow-up of IgD-κ multiple myeloma by monitoring free light chains and total heavy chain IgD: A case report

Immunoglobulin (Ig)D-κ multiple myeloma (MM) is a rare neoplastic disease characterized by an aggressive and rapidly progressing course, which constitutes only a very small proportion of all MM cases. In the present report, the clinical case of a 51-year-old Caucasian woman diagnosed with IgD-κ MM is described. The patient underwent different chemotherapeutic treatments subsequently to a single autologous stem cell transplantation. Despite the inherent difficulty of monitoring IgD levels and performing serum immunofixation electrophoresis, the clinical outcome of the patient was almost uniquely monitored by measuring the levels of κ and λ free light chains (FLCs) and total heavy chain IgD. The data suggest the non-invasive potential and usefulness of FLCs evaluation for early detection of stringent complete remission, follow-up and early detection of disease relapse. In addition, this diagnostic procedure has successfully been employed for the therapeutic monitoring of the present patient, and may represent a very helpful, non-invasive tool for the follow-up of IgD myeloma patients without the requirement of serial bone marrow aspirate.

Brain stereotactic biopsy flow cytometry for central nervous system lymphoma characterization: advantages and pitfalls

BACKGROUND

Brain stereotactic biopsy (SB) followed by conventional histopathology and immunohistochemistry (IHC) is the gold standard approach for primary central nervous system lymphoma (PCNSL) diagnosis. Flow cytometry (FCM) characterization of fine-needle aspiration cytology and core needle biopsies are increasingly utilized to diagnose lymphomas however, no biological data have been published on FCM characterization of fresh single cell suspension from PCNSL SB. The aim of this study was to establish the feasibility and utility of FCM for the diagnosis and characterization of brain lymphomas from a tissue samples obtained by a single SB disaggregation.

METHODS

Twenty-nine patients with a magnetic resonance suggestive for PCNSL entered the study. A median of 6 SB were performed for each patient. A cell suspension generated from manual tissue disaggregation of a single, unfixed, brain SB, was characterized by FCM. The FCM versus standard approach was prospectively compared.

RESULTS

FCM and IHC showed an high degree of agreement (89 %) in brain lymphoma identification. By FCM, 16 out of 18 PCNSL were identified within 2 h from biopsy. All were of B cell type, with a heterogeneous CD20 mean fluorescence intensity (MFI), CD10 positive in 3 cases (19 %) with surface Ig light chain restriction documented in 11 cases (69 %). No false positive lymphomas cases were observed. Up to 38 % of the brain leukocyte population consisted of CD8 reactive T cells, in contrast with the CD4 positive lymphocytes of the peripheral blood samples (P < 0.001). By histopathology, 18 B-PCNSL, only one CD10 positive (5 %), 1 primitive neuroectodermal tumor (PNET) and 10 gliomas were diagnosed. A median of 6 days was required for IHC diagnosis.

CONCLUSION

Complementary to histopathology FCM can contribute to a better characterization of PCNSL, although necrosis and previous steroid treatment can represent a pitfall of this approach. A single brain SB is a valid source for accurate FCM characterization of both lymphoma and reactive lymphocyte population, routinely applicable for antigen intensity quantification and consistently documenting an active mechanism of reactive CD8 T-lymphocytes migration in brain lymphomas. Moreover, FCM confirmed to be more sensitive than IHC for the identification of selected markers.

Flow cytometry remission by Ig light chains ratio is a powerful marker of outcome in multiple myeloma after tandem autologous transplant: a real-life study

BACKGROUND

The achievement of complete response (CR) significantly correlates with a better clinical outcome in multiple myeloma (MM) patients treated with autologous stem cell transplant (ASCT). The depth of response is one of the most relevant factors to predict patient's outcome, however the definition of CR through standard criteria has shown several limitations.

METHODS

In this study we evaluated the minimal residual disease (MRD) in 50 consecutive MM patients who underwent an up-front tandem ASCT in our center, using a single-tube six-colors flow cytometry assay (FC) based on intra-cytoplasmic immunoglobulin (cy-Ig) light chains ratio evaluated on patient-specific plasma cells (PC) immune profile, in a real-life setting.

RESULTS

With a sensitivity up to 10(-5), clonal-PC were documented by FC in 36.4% (12/33) of patients in conventional CR after second transplant. The number of flow MRD-negative patients significantly increased after induction and first ASCT, but not between first and second transplant. The 5-years progression-free survival (5ys-PFS) of flow MRD-negative patients after second transplant was significantly better than patients who remained MRD-positive considering both all patients (5ys-PFS: 70% vs 5%) and patients in CR according to standard criteria (5ys-PFS: 67% vs 0%).

CONCLUSIONS

FC remission through cy-Ig light ratio on PC sub-populations is a sensitive, highly informative, low-cost and routinely applicable MRD assay, a powerful tool in treatment response evaluation and a crucial marker of outcome in MM.

Possibility of progenitor cell mobilization during the hematological recovery following peripheral blood stem cell autograft

Twenty-four patients with hematological malignancies were studied during recovery following autografting in order to establish the proportion of patients that show CD34+ cell mobilization and the kinetics of mobilized CD34-positive cells. The patients showed a peak in peripheral blood (PB) CD34+ cells after a median of 14 days (range 12-20) following reinfusion. According to the number of circulating CD34+ cells, two groups could be clearly distinguished: 17 patients (group A) with <10 PB CD34+ cells/microl (median 1.2, range 0-5) and 7 patients (group B) with >10 CD34+ cells/microl (median 51, range 13-123). Compared to group A, patients of group B showed a faster hematological reconstitution of both polymorphonuclear leukocytes >500/microl (12 vs. 15 days) and platelets >50,000/microl (12 vs. 17 days). The expression of the beta1 integrin CD49d was similar in the two groups of patients, while a lower expression of the beta2 integrin CD11a and a greater expression of the L-selectin CD62L were observed in the PB CD34+ cells of group B patients. Both in the PB and in the BM, the number of CFU-GEMM, CFU- GM, CFU-E and BFU-E of group B was significantly greater than that of group A. However, when the clonogenic potential of a single CD34+ cell was evaluated, no major differences in the number of colonies produced per CD34+ cell were found between the two groups.

Chronic myeloid leukemia cells resistant to interferon-alpha lack STAT1 expression

INTRODUCTION

Interferon-alpha (IFN) plays a role in the management of different neoplasias, particularly those of hematological origin. The mechanisms of action of IFN are still poorly understood and the individual response is unpredictable. In the present study, the pattern of intracellular gene expression following in vitro and in vivo exposure of chronic myeloid leukemia (CML) cells to IFN was evaluated and correlated with the response to in vivo treatment with IFN.

MATERIALS AND METHODS

CML patients in different phases of the disease were studied. The pattern of expression of two IFN-inducible proteins involved in IFN-mediated biological activities, the p91 and p84 proteins (STAT1alpha and STAT1beta), components of the IFN-stimulated gene factor 3 (ISGF3) complex and the enzyme 2'-5' oligoadenylate synthetase (2'-5' OASE) were investigated by Western blot in peripheral blood mononuclear cells stimulated or not in vitro by IFN.

RESULTS AND CONCLUSIONS

In 6/9 patients evaluated before starting treatment, STAT1 was expressed either constitutively or after in vitro stimulation by IFN. In three cases, STAT1 remained negative even after in vitro activation. The pattern of protein expression correlated with the subsequent hematological response to prolonged in vivo IFN administration: the presence of STAT1 being associated with the clinical response to IFN and the absence and non-inducibility of STAT1 with resistance to IFN. This was further substantiated by studies carried out in ten patients analyzed at the time of a documented clinico-hematological response or resistance to the in vivo administration of IFN. Finally, in order to establish whether the pattern of response to IFN treatment could be predicted at diagnosis, cells cyropreserved at diagnosis from patients with a documented complete response, confirmed also by cytogenetic negativity, or resistance, were studied. While complete responders proved STAT1 positive, none of the four resistant cases ever expressed STAT1. The expression of 2'-5' OASE did not correlate with the clinical response to IFN. This study documents the pivotal role of STAT1 in the in vitro and in vivo responses of CML cells to IFN. The constitutive or induced presence or absence of STAT1 shows a predictive correlation with the response or resistance to treatment with IFN and could be utilized to identify, at diagnosis, resistant patients who may be spared an expensive and unnecessary prolonged IFN administration.

High dose of idarubicin-based regimen for diffuse large cell AIDS-related non-Hodgkin's lymphoma patients: a pilot study

BACKGROUND AND OBJECTIVES

Intensive chemotherapy (CHT) in AIDS-related non-Hodgkin's lymphoma (AIDS-NHL patients) is a vexing problem. Our purpose was to evaluate the feasibility of a high dose idarubicin (HD-IDA)-based regimen in diffuse large cell (DLC) AIDS-NHL patients.

DESIGN AND METHODS

Fourteen stage I-IV untreated DLC AIDS-NHL patients with a performance status <3 and no prior AIDS-related diseases received CIOD: cyclophosphamide, HD-IDA (25 mg/m2 in 8 patients, 20 mg/m2 in 6 patients) vincristine and dexamethasone plus granulocyte colony-stimulating factor (G-CSF) and prophylaxis against infections. The outcomes measured were: rate of response, disease-free survival (DFS), overall survival (OS) and the impact of chemotherapy on immunologic and virological parameters.

RESULTS

Complete response was achieved in 13/14 cases (response rate: 93%). The median time of response and survival was 33 (range 5-79) and 35.5 (range 6-84) months, respectively. At 60 months the DFS and OS were 71% and 44%, respectively. CIOD with idarubicin 20 mg/m2 was better tolerated than that with 25 mg/m2 and was administered with a higher mean average-relative-dose-intensity (95.38+/-7% vs 83.35+/-15.59%, p=0.0001). Opportunistic infections were more frequent in patients with a baseline CD4 <100 than those with >100 cells/microL (4/5 vs 1/9: p=0.0229). After 3 CIOD courses the mean CD4 cells/microL was significantly lower (p=0.001) and the mean HIV.1 RNA load was significantly higher (p=0.045) than at baseline.

INTERPRETATION AND CONCLUSIONS

The proposed chemotherapeutic regimen for AIDS-related non-Hodgkin's lymphoma is feasible in an outpatient setting in selected patients with relatively well-preserved immune function.

Molecular remission following high-dose hydroxyurea and fludarabine plus cytarabine in a patient with simultaneous acute myeloid leukemia and low-grade lymphoma

The occurrence of acute myeloid leukemia (AML) as a secondary tumor has been frequently reported in patients who received various chemotherapy regimens for hematologic malignancies wile the concomitant development of chronic lymphoproliferative diseases (CLD) and AML in previously untreated patients is extremely rare. We report a case with an apparently spontaneous occurrence of AML and non Hodgkin low-grade lymphoma diagnosed by immunological, cytogenetical and molecular analyses. In particular genetic studies allowed to identify the coexistence of a clonal lymphoid population and a myeloid blast component characterized by inv(16) marker and CBFbeta-MYH11 gene fusion. Complete remission of AML and the CLD was obtained following high doses of hydroxyurea and two consolidation cycles of fludarabine plus intermediate dose cytarabine.

Acute myeloid leukemia and lung cancer occurring in a chronic lymphocytic leukemia patient treated with fludarabine and autologous peripheral blood stem-cell transplantation

An increased incidence of different malignancies associated to chronic lymphocytic leukemia (CLL) has been reported. The association of CLL and acute leukemia is a rare event described in < 1% of CLL, the type of acute leukemia being either from the lymphoid or more often from the myeloid lineage. The coexistence of acute myeloid leukemia (AML) and CLL in the same patient has been occasionally reported. Most of these cases have been associated with the administration of chemotherapy or radiotherapy for CLL, suggesting that the former may be a secondary leukemia. On the other hand, CLL could precede, but could also be diagnosed at the same, or delayed time as AML, suggesting the presence of other leukemogenic factors. We describe the exceptional development of AML and lung cancer in a patient with previously diagnosed CLL in minimal residual disease status after fludarabine treatment followed by autologous peripheral blood stem-cell transplantation.

Unmanipulated peripheral blood stem cell autograft in chronic lymphocytic leukemia: clinical findings and biological monitoring

BACKGROUND AND OBJECTIVES

To investigate the feasibility of peripheral blood stem cell (PBSC) transplantion in patients with high-risk chronic lymphocytic leukemia (CLL) in remission after fludarabine therapy, the clinical impact of minimal residual disease (MRD) monitoring and the immunologic reconstitution after transplantation.

DESIGN AND METHODS

Twenty CLL patients, in clinical complete remission (CR) after fludarabine, were offered an unmanipulated PBSC transplant and were longitudinally monitored for MRD and immunologic reconstitution.

RESULTS

Due to unsatisfactory PBSC collection, 4 patients received bone marrow cells. All patients engrafted. Two patients died, one due to infection and one because of another neoplasia. Thirteen patients are at present in clinical CR after a median follow-up of 17 months and 18 patients are alive with a survival probability of 0.87 (+/-0.04) at 52 months after transplant. Fifteen patients had a molecular remission. Three of them showed a molecular relapse 16-28 months after autograft, followed by a clinical relapse 10-16 months later. Three of the four patients who remained persistently rearranged could be revaluated over time and showed an immunologic relapse 11-26 months after transplant; two of these had a clinical relapse 12 and 7 months later. A marked and persistent impairment of both the B- and T-immunologic compartments was recorded in the horizontal follow-up.

INTERPRETATION AND CONCLUSIONS

Unmanipulated PBSC autograft is a feasible procedure that produces prolonged molecular remissions in high-risk CLL patients. Persistence or reappearance of a molecular signal after engraftment is predictive of subsequent immunologic and clinical CLL recurrence. The long -lasting impairment of the host immune repertoire after fludarabine followed by autograft has to be taken into account in the patients' management.

Chronic myeloid leukemia cells resistant to interferon-alpha lack STAT1 expression

INTRODUCTION

Interferon-alpha (IFN) plays a role in the management of different neoplasias, particularly those of hematological origin. The mechanisms of action of IFN are still poorly understood and the individual response is unpredictable. In the present study, the pattern of intracellular gene expression following in vitro and in vivo exposure of chronic myeloid leukemia (CML) cells to IFN was evaluated and correlated with the response to in vivo treatment with IFN.

MATERIALS AND METHODS

CML patients in different phases of the disease were studied. The pattern of expression of two IFN-inducible proteins involved in IFN-mediated biological activities, the p91 and p84 proteins (STAT1alpha and STAT1beta), components of the IFN-stimulated gene factor 3 (ISGF3) complex and the enzyme 2'-5' oligoadenylate synthetase (2'-5' OASE) were investigated by Western blot in peripheral blood mononuclear cells stimulated or not in vitro by IFN.

RESULTS AND CONCLUSIONS

In 6/9 patients evaluated before starting treatment, STAT1 was expressed either constitutively or after in vitro stimulation by IFN. In three cases, STAT1 remained negative even after in vitro activation. The pattern of protein expression correlated with the subsequent hematological response to prolonged in vivo IFN administration: the presence of STAT1 being associated with the clinical response to IFN and the absence and non-inducibility of STAT1 with resistance to IFN. This was further substantiated by studies carried out in ten patients analyzed at the time of a documented clinico-hematological response or resistance to the in vivo administration of IFN. Finally, in order to establish whether the pattern of response to IFN treatment could be predicted at diagnosis, cells cyropreserved at diagnosis from patients with a documented complete response, confirmed also by cytogenetic negativity, or resistance, were studied. While complete responders proved STAT1 positive, none of the four resistant cases ever expressed STAT1. The expression of 2'-5' OASE did not correlate with the clinical response to IFN. This study documents the pivotal role of STAT1 in the in vitro and in vivo responses of CML cells to IFN. The constitutive or induced presence or absence of STAT1 shows a predictive correlation with the response or resistance to treatment with IFN and could be utilized to identify, at diagnosis, resistant patients who may be spared an expensive and unnecessary prolonged IFN administration.

Interferon-alpha and bcr-abl antisense oligodeoxynucleotides in combination enhance the antileukemic effect and the adherence of CML progenitors to preformed stroma

We have studied the in vitro effect of IFN-alpha and bcr-abl antisense oligodeoxynucleotides (As ODN) alone and in combination with the aim of enhancing the antileukemic activity of the two single agents and evaluating whether the two agents in combination might restore the adherence capacity of chronic myeloid leukemia (CML) progenitors to preformed stroma. We have also correlated the increased adhesion found after in vitro treatment with the expression of adhesion molecules on leukemic progenitors. Incubation of the BV173 cell line with escalating doses of IFN-alpha (100-10000 U/ml) showed a colony growth inhibition between 10 and 30%. IFN-alpha and junction-specific As ODN in combination showed a greater antiproliferative effect compared to that observed with the two agents used alone. In particular, As ODN at a concentration of 40 microg/ml in combination with IFN-alpha at 100 and 1000 U/ml showed a greater inhibitory effect compared to that obtained with IFN-alpha only. Addition of As ODN to IFN-alpha at 10000 U/ml did not result in a greater BV173 inhibition. In a further set of experiments, primary cells from 16 CML patients at diagnosis were incubated with 40 microg/ml of J-spec As ODN, several control ODNs and IFN-alpha at 1000 U/ml alone and in combination. A significantly greater elimination of CML progenitors was found after treatment with the combination of IFN-alpha and J-spec As ODN, compared to any other treatment group, confirmed also by a more marked effect on p210 expression. The deficient adhesion of CML progenitors on human preformed stroma was restored at levels similar to that of normal bone marrow cells after treatment with IFN-alpha and/or J-spec As ODN, while the phenotypic analysis showed that the combined treatment increased significantly the expression of CD49b and CD62L on CML CD34+ cells. However, when the expression of adhesion molecules was blocked with specific monoclonal antibodies, only CD49d (expressed on more than 90% of CML CD34+ cells) appeared to influence the functional activity of adhesion molecules. In conclusion, IFN-alpha and bcr-abl As ODN in combination exert a marked in vitro antileukemic activity and could be a useful approach for in vitro purging of CML cells prior to autologous transplantation.

Clinical characteristics and outcome of young chronic lymphocytic leukemia patients: a single institution study of 204 cases

A retrospective analysis on chronic lymphocytic leukemia (CLL) patients </=55 years observed at a single institution was performed with the purpose of characterizing the clinical features and outcome of young CLL and of identifying patients with different prognostic features. Over the period from 1984 to 1994, 1,011 CLL patients (204 [20%] </=55 years of age and 807 [80%] >55 years of age) were observed. At diagnosis, younger and older patients displayed a similar distribution of clinical features, except for a significantly higher male/female ratio in younger patients (2.85 v 1. 29; P <.0001). Both groups showed an elevated rate of second primary cancers (8.3% v 10.7%), whereas the occurrence of Richter's syndrome was significantly higher in younger patients (5.9% v 1.2%; P <. 00001). Younger and older patients showed a similar overall median survival probability (10 years) but were characterized by a different distribution of causes of deaths: CLL unrelated deaths and second primary malignancies predominated in the older age group, whereas the direct effects of leukemia were prevalent in the younger age group. Although younger and older patients displayed a similar survival, the evaluation of the relative survival rates showed that the disease had a greater adverse effect on the expected survival probability of the younger population. Multivariate analysis showed that for young CLL patients only dynamic parameters, such as lymphocyte doubling time and other signs of active disease, were the independent factors that significantly influenced survival probability (P =.00001). A prolonged clinico-hematologic follow-up allowed us to identify two subsets of young CLL patients with a different prognostic outcome: a group of patients (40%) with long-lasting stable disease without treatment and an actuarial survival probability of 94% at 12 years from diagnosis and another group (60%) with progressive disease and a median survival probability of 5 years after therapy. For the latter patients, the therapeutic effect of innovative therapies with curative intents needs to be investigated in prospective, comparative clinical trials.

Monitoring of CD34+ cells during leukapheresis allows a single, successful collection of hemopoietic progenitors in patients with low numbers of circulating stem cells

We have studied a total of 188 patients with hematological malignancies, submitted to mobilization therapy with G-CSF associated or not with chemotherapy in order to: (1) establish the lower limit of circulating progenitor cells that allows the collection of 2 x 10(6) CD34+ cells/kg by a single leukapheresis, utilizing the instrument set on standard parameters; (2) evaluate whether the number and quality of CD34+ cells collected remain stable during leukapheresis; and (3) collect a sufficient number of circulating CD34+ cells by a single procedure in patients in whom such an approach would have been insufficient to reach the target with the instrument set on standard parameters. The retrospective analysis conducted in 85 patients showed that 19 circulating CD34+ cells/microl represented the cut-off number capable of discriminating between patients who will require one or more apheresis to collect 2 x 10(6) CD34+ cells/kg. The validity of this value was prospectively confirmed in 70 subsequent patients. Based on in vitro results that showed the stability in the number of CD34+ cells, the proportion of different CD34+ cell subpopulations and the clonogenic capacity of the stem cell compartment during leukapheresis both in the blood of the patients and in samples taken directly from the instrument, we have adapted the blood volume to be processed in 33 patients with <19 PB CD34+ cells/microl. Stem cell collection was monitored during the leukapheresis and the procedure was prolonged for a time period estimated to be sufficient to reach the target number of CD34+ cells with a single procedure. The median increment of the total blood volume processed, calculated from the volume set automatically by the instrument was 25.2%, with a median of 3.3-fold total blood volume processed. In all cases, a sufficient CD34+ cell collection was completed in a single procedure. After autograft, the pattern of blood reconstitution was similar to that of all the other patients.

Evaluation of marrow and blood haemopoietic progenitors in chronic lymphocytic leukaemia before and after chemotherapy

We have evaluated the number and differentiation pattern of CD34+ cells, as well as the CFU-GM, BFU-E and CFU-GEMM progenitors from the blood (PB) and marrow (BM) of 53 chronic lymphocytic leukaemia (CLL) patients. Twenty-four patients were untreated and 29 were studied at 2 months from the last course of fludarabine or chlorambucil; 6 patients, studied after fludarabine therapy, were further evaluated after mobilization with cyclophosphamide and G-CSF. PB of untreated patients showed a median number of CD34+ cells, CFU-GM, BFU-E and CFU-GEMM/10(5) seeded cells and per litre of PB similar to those of normal controls. No differences were also found in the number of clonogenic progenitors/10(5) cells in patients studied before and after therapy, while significantly fewer BFU-E/l of PB were found after fludarabine. The number of circulating CD34+ cells/l of PB was significantly lower in patients treated with fludarabine or chlorambucil compared to untreated patients. BM growth was significantly reduced in untreated CLL patients compared to healthy donors. Treatment with fludarabine or chlorambucil restored BM progenitors at levels similar to those of normal controls; this effect did not occur for CFU-GM in patients treated with fludarabine. Three-colour fluorescence analysis demonstrated a differentiation pattern of CD34+ cells, with a greater expression of CD13 and CD33 after treatment with fludarabine compared to untreated patients and normal controls. In 4 patients previously treated with fludarabine who underwent a successful cyclophosphamide and G-CSF mobilization therapy, 4x10(6) CD34+ cells/kg were collected. These 4 patients showed a notable increase of CD34+ cells and of clonogenic cells in the PB, but a marked decrease of BM progenitor cells. The 2 patients who failed CD34+ cell mobilization had a reduced CFU-GM growth both in the PB and in the BM. Taken together, these studies indicate that residual haemopoietic progenitors are present in untreated CLL patients and that stem cell mobilization and collection can be carried out following fludarabine treatment.

p53 expression in B-cell chronic lymphocytic leukemia: a marker of disease progression and poor prognosis

We have analyzed by immunocytochemistry (ICC) the frequency of p53 protein expression in 181 cases of B-cell chronic lymphocytic leukemia (CLL) followed at a single institution to assess the relationship between p53 and the clinical and morphological features of the disease, as well as the possible involvement of this protein in the pathogenesis of the more aggressive forms of CLL. The overall frequency of p53 protein positivity in CLL was 15% (27 of 181 cases). There were no significant differences in age, sex, absolute lymphocyte count, or lymphocyte doubling time between p53-positive and -negative patients. By contrast, p53-positive patients had a significantly higher percentage of prolymphocytes (P = .002) and a significantly lower percentage of residual CD3-positive T lymphocytes (P = .0001). No correlation was found between the percentage of p53-positive cells and the percentage of cells in cycle assessed by the monoclonal antibody Ki-67. When the percentage of p53 positivity was correlated with the clinical stage of the disease, the proportion of p53-positive cases increased significantly from Binet's stage A (8 of 108; 7.4%), to stage B (12 of 49; 24.4%) and C (7 of 24; 29.2%) (P = .002). p53 positivity correlated also with the phase of the disease, showing a low expression at diagnosis (8 of 112; 7.1%) and a significantly higher expression in patients studied during the course of the disease (7 of 35; 20%) and, to a further extent, with disease progression (12 of 34; 35.3%) (P = .0001). The association of p53 protein expression with mutations in the gene was confirmed by direct sequence of the entire cDNA in 15 of the 17 ICC positive cases tested (88%). A significantly shorter treatment-free interval from diagnosis (P = .003) and a poorer response to therapy (P = .007) was observed in p53-positive compared with p53-negative patients. Overall survival from the time of diagnosis, as well as from the time of p53 protein analysis, was significantly shorter in patients with p53 protein expression (P = .03 and .0001, respectively). Moreover, in multivariate analysis, p53 expression and stage C were independently associated with a short survival. The results of this study indicate that in CLL the expression of the p53 protein, analyzed by a simple and reliable immunocytochemical method, is strongly associated with p53 gene mutations, a morphological variant (CLL with >10% prolymphocytes), advanced clinical stage, progressive disease, poor response to therapy, and short survival.

Immunocytochemical diagnosis of acute promyelocytic leukemia (M3) with the monoclonal antibody PG-M3 (anti-PML)

Acute promyelocytic leukemia (APL) is characterized by a reciprocal 15; 17 chromosomal translocation, which fuses the promyelocytic leukemia (PML) and retinoic acid receptor alpha (RARalpha) genes, leading to the expression of the PML/RARalpha fusion oncoprotein. Immunocytochemical labeling of the wild-type PML protein with the PG-M3 monoclonal antibody (MoAb) directed against the amino terminal portion of the human PML gene product, produces a characteristic nuclear speckled pattern that is due to localization of the protein into discrete dots (5 to 20 per nucleus), named PML nuclear bodies. The architecture of PML nuclear bodies appears to be disrupted in APL cells that bear the t(15; 17), thus resulting in a change of the nuclear staining pattern from speckled (wild-type PML protein) to microgranular (PML-RARalpha fusion protein). To assess whether the PG-M3 MoAb could assist in the diagnosis of APL (M3), bone marrow and/or peripheral blood samples from 100 cases of acute nonlymphoid leukemias of different subtypes were blindly immunostained with the PG-M3 MoAb, using the immunoalkaline phosphatase (APAAP) or immunofluorescence technique as detection system. Notably, the abnormal (micropunctate) pattern of the PML/RARalpha fusion protein (usually >/=50 small granules/per nucleus) was observed in APL (M3) samples, but not in other types of acute nonlymphoid leukemias. Immunocytochemical labeling with PG-M3 was particularly useful in the diagnosis of microgranular variant of APL (M3V) (three cases misdiagnosed as M4 and M5), and also to exclude a morphologic misdiagnosis of APL (six of 78 cases). In all cases investigated, immunocytochemical results were in agreement with those of reverse transcription-polymerase chain reaction (RT-PCR) for PML/RARalpha. Because the epitope identified by PG-M3 is located in the aminoterminal portion of PML (AA 37 to 51), the antibody was suitable for recognizing APL cases characterized by breakpoint occurring at different sites of PML (bcr 1, bcr 2 and bcr 3). In conclusion, immunocytochemical labeling with PG-M3 represents a rapid, sensitive, and highly-specific test for the diagnosis of APL that bears the t(15; 17). This should allow an easy and correct diagnosis of this subtype of acute leukemia to any laboratory provided with a minimal equipment for immunocytochemistry work.

Immunophenotype of adult and childhood acute lymphoblastic leukemia: changes at first relapse and clinico-prognostic implications

The immunologic features of leukemic cells at the time of 1st hematologic relapse were compared to those obtained at initial diagnosis in 128 patients (69 children and 59 adults) with acute lymphoblastic leukemia (ALL) treated at a single institution. An immunophenotypic change was observed in 59 cases (46%), more frequently in T (20/25) than in B (39/103) lineage ALL (80 vs 38%, P=0.0008), but with a similar incidence in adults and children. Of these cases, 34 (24 B- and 10 T-ALL) changed at relapse their intralineage subgroup affiliation, although no complete shift from B to T lineage ALL, or vice versa, was observed. The myeloid antigens CD13 and/or CD33 were frequently lost (2/5 cases) or acquired (12/123 cases) at relapse. In 21 cases, the immunophenotype at relapse was more undifferentiated than at diagnosis, while it was more differentiated in 13 cases. Initial treatment intensity or preceding treatment with teniposide did not affect the phenotypic profile at relapse. Complete response (CR) rate to salvage therapy and event-free survival were not influenced by the immunophenotypic shifts, nor by the presence, at relapse, of leukemic cells expressing the myeloid antigens CD13 and/or CD33. Univariate analysis suggested that prognosis after relapse was dependent on the duration of 1st CR, patients' age and immunophenotype at the time of diagnosis, with a worse outcome for patients with T lineage ALL and for patients with the less differentiated subgroup of B lineage ALL (CD19+ and CD10-). Multivariate analysis showed that only two factors, duration of 1st CR and grade of immunologic differentiation at diagnosis, have independent prognostic value in relapsed ALL.

Ultrastructural investigation of circulating villous lymphoid cells: a tool in the differential diagnosis of splenic lymphoma with villous lymphocytes

Ultrastructural examination of circulating lymphoid cells was performed in three cases of splenic lymphoma with circulating lymphocytes (SLVL) in order to define morphological features helpful to distinguish this lymphoma from hairy cell leukemia (HCL). The samples for ultrastructural investigation were obtained by Ficoll sedimentation from peripheral blood and routinely processed for electron microscopy. The ultrastructural features examined were: morphology of villi, morphology of nuclei, presence of nucleoli, distribution of heterochromatin, type of cytoplasmic organelles, presence of specific intracytoplasmic structures such as the ribosome-lamella complex, lysosome-like bodies and perinuclear microfibrils. Our results and a careful review of the literature seemed to confirm that SLVL has electron microscopic features typical enough to be relevant in the differential diagnosis with HCL.

Diagnostic relevance of peripheral blood immunocytochemistry in hairy cell leukaemia

AIMS--(1) To assess the diagnostic relevance of peripheral blood immunocytochemistry in hairy cell leukaemia (HCL); (2) to compare the immunostaining of bone marrow biopsy specimens with bone marrow and peripheral blood cytospins; (3) to evaluate the sensitivity of the different markers used; (4) to identify the ultrastructural localisation of DBA.44 in HCL variant. METHODS--Immunoenzymatic staining procedures, immunoperoxidase and immunoalkaline phosphatase, were used with a panel of monoclonal antibodies directed to HCL associated antigens. Ultrastructural immunostaining was performed using colloidal gold conjugated antibodies. RESULTS--HCL showed strong cytoplasmic reactivity for CD22, CD25, CD103, DBA.44, kappa, or lambda light chains. Peripheral blood diagnostic hairy cells were found in all the cases with absolute counts ranging from 0.11 x 10(9)/l up to 6.4 x 10(9)/l and values increasing with the size of the spleen. A median of 36.5% of leukaemic cells was found in bone marrow aspirates and 70% in bone marrow trephine specimens. The monoclonal antibodies CD22 and DBA.44 showed the highest and the lowest percentage of positive hairy cells, respectively; this difference was statistically significant (p = 0.0025). Ultrastructural immunolabelling with DBA.44 showed a cytoplasmic membrane localisation of the antigen in one case of HCL variant. CONCLUSIONS--(1) Immunocytochemistry is a useful technique which enhances the accuracy of diagnosis in HCL; (2) peripheral blood immunocytochemistry is recommended because it highlights hairy cells in all cases; (3) CD22 appears to be the most sensitive of the markers tested; (4) ultrastructural analysis is a useful tool in selected cases of HCL variant.

Monoclonal antibody Ki-67 identifies B and T cells in cycle in chronic lymphocytic leukemia: correlation with disease activity

Ki-67 is a monoclonal antibody that recognises a nuclear antigen expressed during most phases of the cell cycle. We have analysed, by immunocytochemistry, the frequency, morphology, and clinical significance of Ki-67+ cells in 108 patients with B-cell chronic lymphocytic leukemia (CLL). Because in normal peripheral blood Ki-67+ cells are mainly T lymphocytes, we have also investigated, by double immunoenzymatic staining, the proportion of Ki-67+ T cells (Ki-67/CD3+) in CLL. Four groups of patients were identified: (i) 47 with stage A, (ii) 32 with stages B + C, (iii) 24 with greater than 10% of circulating prolymphocytes (CLL/PL) and (iv) five with Richter's syndrome. Within stage A CLL, two groups were considered: A' (Hb greater than or equal to 12 g/dl and lymphocytes less than 30 + 10(9)/l) and A" (Hb less than 12 g/dl or lymphocytes greater than or equal to 30 x 10(9)/l). The percentage and absolute number of Ki-67+ leukemic cells was found to increase with the stage of the disease and correlate with the proportion of prolymphocytes. On the other hand, the proportion of Ki-67+ T cells (CD3+) was significantly higher in patients with CLL stage A' (29.3 +/- 4.5), which includes patients with long-standing, stable disease, than in CLL stage A" (9.5 +/- 3.3), B + C (7.1 +/- 4.6), and CLL/PL (6.4 +/- 2.8). Ki-67 seems to identify patients with more aggressive forms of CLL, such as CLL/mu 2PL with more than 10% Ki-67+ cells (25% of the cases) and Richter's syndrome, in which all the large lymphoma cells are Ki-67+. Long-term follow-up will establish whether Ki-67 is a good prognostic marker and can predict disease outcome.

Expression of Ki-67 nuclear antigen in B and T cell lymphoproliferative disorders

AIMS

To determine whether the proliferation rates of tumour cells may relate to prognosis and reflect disease activity.

METHODS

Blood mononuclear cells from 155 patients with B cell (n = 120) or T cell (n = 35) chronic lymphoproliferative disorders were tested with the monoclonal antibody Ki-67 by indirect immunoperoxidase or immunoalkaline phosphatase techniques. B cell diseases included chronic lymphocytic leukaemia (CLL), CLL in prolymphocytic transformation (CLL/PL), prolymphocytic leukaemia (B-PLL) and non-Hodgkin's lymphoma (B-NHL) in leukaemic phase. The T cell diseases comprised large granular lymphocyte (LGL) leukaemia, T-PLL, and T-NHL.

RESULTS

These showed significantly higher proportions of Ki-67 positive cells in T cell (11.2%) than in B cell (2.9%) disorders (p < 0.001). The highest values were found in NHL of both B and T cell types, particularly when low grade disease transformed to high grade. The lowest percentages of Ki-67 positive cells were found in CLL (1.4%) and LGL leukaemia (1.7%); intermediate values were seen in B PLL (3.3%) and T PLL (5.8%).

CONCLUSIONS

There is a positive correlation between prognosis and proliferation rates in chronic B and T cell lymphoproliferative disorders. Estimation of Ki-67 in circulating leukaemic cells could be used to determine prognosis in low grade malignancies.

Characterisation of normal peripheral blood cells in cycle identified by monoclonal antibody Ki-67

AIMS

To investigate the numbers, morphology, and lineage assignment of Ki-67 positive cells in peripheral blood from normal subjects.

METHODS

Single and double immunoenzymatic staining procedures, immunoperoxidase, and immunoalkaline phosphatase were used with Ki-67, a monoclonal antibody that recognises a nuclear antigen present in proliferating cells, with markers expressed in B and T lymphocytes and monocytes.

RESULTS

In the five healthy donors 2.1% (range 1.6-3.7%) cells of the blood mononuclear fraction and 2.7% (range 2.3-3.9%) lymphocytes were Ki-67 positive. Of these, 88% (range 85-90%) were small cells and 12% (range 10-15%) were medium sized. Forty one per cent of the Ki-67 positive cells were CD3 positive by double immunoenzymatic staining and corresponded to T lymphocytes, and 11.4% were mature B cells expressing kappa or lambda light chains. Monocytes detected by the anti-lysozyme antibody were consistently Ki-67 negative. Half of the Ki-67 positive lymphocytes could not be accounted for by B or T cells with the markers used. Most Ki-67 positive cells were of small size; the B lymphocytes in cycle showed abundant cytoplasm and features suggestive of lymphoplasmacytic differentiation.

CONCLUSIONS

The methodology described is useful for the simultaneous detection of nuclear and cytoplasmic antigens. The demonstration that a proportion of normal blood lymphocytes are in cell cycle raises the issue of whether immunophenotypic analysis of Ki-67 positive cells in haemopoietic malignancies with peripheral blood disease should be carried out to define more precisely the proportion of normal and neoplastic cells in cycle.

Immunoglobulin heavy chain and T-cell receptor beta chain gene rearrangements in acute non lymphoid leukemia

The occurrence of immunoglobulin heavy chain (IgH) and/or T-cell receptor (TcR) gene rearrangements has been reported in some cases of acute non lymphoid leukemia (ANLL), and variously interpreted as reflecting "aberrant gene expression" or "lineage promiscuity" of the leukemic cell. In an attempt to verify the incidence, FAB distribution and immunophenotypic correlates of gene rearrangements in ANLL, we analyzed the configuration of IgH and TcR beta chain genes in 70 patients with ANLL. In all cases myeloid (CD13, CD33, CD14, CD15) and lymphoid (CD7, CD2, CD10, CD19, TdT) antigenic determinants were analyzed in conjunction with conventional morpho-cytochemical characterization. Clonal rearrangements of the IgH gene were identified in 6/70 ANLL patients (8.6%), whereas in only 2/48 (4.2%) were T beta rearrangements documented. Concerning FAB subtypes, IgH or T beta rearrangements were detected in the less differentiated forms MO and M1 (3 cases), as well as in 2 M4 and 1 M5a cases. With the exception of a higher incidence of gene rearrangements in TdT+ ANLL, no significant correlation was found with other immunophenotypic markers.