The Effect of Number of Gait Cycles on Principal Activation Extraction

To cope with the high intra-subject variability of muscle activation intervals, a large amount of gait cycles is necessary to clearly document physiological or pathological muscle activity patterns during human locomotion. The Clustering for Identification of Muscle Activation Pattern (CIMAP) algorithm has been proposed to help clinicians obtaining a synthetic and clear description of normal and pathological muscle functions in human walking. Moreover, this algorithm allows the extraction of Principal Activations (PAs), defined as those muscle activations that are strictly necessary to perform a specific task and occur in every gait cycle. This contribution aims at assessing the impact of the number of gait cycles on the extraction of the PAs. Results demonstrated no statistically significant differences between PAs extracted considering different numbers of gait cycles, revealing, on average, similarity values higher than 0.88.Clinical Relevance-This contribution demonstrates the potential applicability of the CIMAP algorithm to the analysis of subjects affected by neurological disorders, for whom the assessment of motor functions may be of the uttermost importance and only a reduced number of gait cycles can be acquired.

Anticancer innovative therapy: Highlights from the ninth annual meeting

The Ninth Annual Conference of "Anticancer Innovative Therapy", organized by Fondazione IRCCS Istituto Nazionale dei Tumori di Milano (Fondazione IRCCS INT) and hosted by Hotel Michelangelo, was held in Milan on 25 January 2019. Cutting-edge science was presented in two main scientific sessions: i) pre-clinical evidences and new targets, and ii) clinical translation. The Keynote lecture entitled "Cancer stem cells (CSCs): metabolic strategies for their identification and eradication" presented by M. Lisanti, was one of the highlights of the conference. One key concept of the meeting was how the continuous advances in our knowledge about molecular mechanisms in various fields of research (cancer metabolism reprogramming, epigenetic regulation, transformation/invasiveness, and immunology, among others) are driving cancer research towards more effective personalized antineoplastic strategies. Specifically, recent preclinical data on the following topics were discussed: 1. Polycomb group proteins in cancer; 2. A d16HER2 splice variant is a flag of HER2 addiction across HER2-positive cancers; 3. Studying chromatin as a nexus between translational and basic research; 4. Metabolomic analysis in cancer patients; 5. CDK4-6 cyclin inhibitors: clinical activity and future perspectives as immunotherapy adjuvant; and 6. Cancer stem cells (CSCs): metabolic strategies for their identification and eradication. In terms of clinical translation, several novel approaches were presented: 1. Developing CAR-T cell therapies: an update of preclinical and clinical development at University of North Carolina; 2. Vγ9Vδ2 T-cell activation and immune suppression in multiple myeloma; 3. Predictive biomarkers for real-world immunotherapy: the cancer immunogram model in the clinical arena; and 4. Mechanisms of resistance to immune checkpoint blockade in solid tumors. Overall, the pre-clinical and clinical findings presented could pave the way to identify novel actionable therapeutic targets to significantly enhance the care of persons with cancer.

Innovative Therapy, Monoclonal Antibodies and Beyond

The seventh Edition of "Innovative Therapy, Monoclonal Antibodies and Beyond" Meeting took place in Milan, Italy, on January 27, 2017. The two sessions of the meeting were focused on: 1) Preclinical assays and novel biotargets; and 2) monoclonal antibodies, cell therapies and targeted molecules. Between these two sessions, a lecture entitled "HLA-antigens modulation and response to immune checkpoint inhibitor immunotherapy" was also presented. Despite the impressive successes in cancer immunotherapy in recent years, the response to immune based interventions occurs only in a minority of patients (∼20%). Several basic and translational mechanisms of resistance to immune checkpoint blockers (ICBs) were discussed during the meeting: 1. the impact of tumor microenvironment on the activity of immune system; 2. strategies to inhibit the cross-talk between extracellular matrix and myeloid-derived suppressor cells (MDSC) in the preclinical setting; 3. microRNA expression as a biomarker and as a target of therapy in non-small cell lung cancer (NSCLC); 4. the significance of complement activation pathways in response to immune checkpoint inhibitors; 5. the immunosuppressive activity of the microbiota by inducing IL-17 producing cells; and 6. modulation of HLA antigens as possible markers of response to ICB therapy. In order to overcome the deficiency in active anti-tumor T cells, several clinically applicable combination strategies were also discussed: 1. strategies to enhance the anticancer effects of immunogenic cell death inducing-chemotherapy; 2. the use of CAR T-cells in solid tumors; 3. the use of combination strategies involving oncolytic viruses and ICBs; 4. combinations of new ICBs with anti-PD-1/CTLA-4 therapy; and 4. combinations of targeted therapies and ICBs in melanoma. Overall, this conference emphasized the many novel strategies that are being investigated to improve the overall patient response to cancer immunotherapy. Optimization of biomarkers to accurately select patients who will respond to immunotherapy, coupled with combination strategies to improve long term patient survival remain critical challenges in the immuno-oncology field.

Cord blood NK cells engineered to express IL-15 and a CD19-targeted CAR show long-term persistence and potent antitumor activity

Chimeric antigen receptors (CARs) have been used to redirect the specificity of autologous T cells against leukemia and lymphoma with promising clinical results. Extending this approach to allogeneic T cells is problematic as they carry a significant risk of graft-versus-host disease (GVHD). Natural killer (NK) cells are highly cytotoxic effectors, killing their targets in a non-antigen-specific manner without causing GVHD. Cord blood (CB) offers an attractive, allogeneic, off-the-self source of NK cells for immunotherapy. We transduced CB-derived NK cells with a retroviral vector incorporating the genes for CAR-CD19, IL-15 and inducible caspase-9-based suicide gene (iC9), and demonstrated efficient killing of CD19-expressing cell lines and primary leukemia cells in vitro, with marked prolongation of survival in a xenograft Raji lymphoma murine model. Interleukin-15 (IL-15) production by the transduced CB-NK cells critically improved their function. Moreover, iC9/CAR.19/IL-15 CB-NK cells were readily eliminated upon pharmacologic activation of the iC9 suicide gene. In conclusion, we have developed a novel approach to immunotherapy using engineered CB-derived NK cells, which are easy to produce, exhibit striking efficacy and incorporate safety measures to limit toxicity. This approach should greatly improve the logistics of delivering this therapy to large numbers of patients, a major limitation to current CAR-T-cell therapies.

T cell therapies

T cell therapies are increasingly used for the treatment of malignancies and viral-associated diseases. Initial studies focused on the use of unmanipulated T cell populations after allogeneic stem cell transplantation. More recently, the use of antigen-specific T cells has been explored. This chapter reviews the clinical experience with polyclonal Epstein-Barr virus (EBV)-specific cytotoxic T cells (CTL) for the treatment of EBV-associated malignancies. Strategies on how to improve the antitumor activity of EBV-specific CTL are being discussed. If effective, these strategies will have broad implications for T cell therapies for a range of human tumors with defined antigens.

Addition of the CD28 signaling domain to chimeric T-cell receptors enhances chimeric T-cell resistance to T regulatory cells

T cells can be engineered to target tumor cells by transduction of tumor-specific chimeric receptors, consisting of an extracellular antigen-binding domain and an intracellular signaling domain. However, the peripheral blood of cancer patients frequently contains an increased number of T regulatory cells, which appear to inhibit immune reactivity. We have investigated the effects of T regulatory cells on chimeric T cells specific for the B-cell antigen CD19, as B-cell malignancies are attractive targets for chimeric T-cell therapy. When a CD19 single-chain Fv antibody was coupled to the CD3 zeta (zeta) chain, there was sharply reduced activity on exposure to T regulatory cells, measured by CD19+ target-induced proliferation and cytotoxicity. By contrast, expression in T cells of a chimeric receptor consisting of the intracellular portion of the CD28 molecule fused to the zeta-chain and CD19 single-chain Fv not only produced a higher proliferative response and an increased nuclear factor kappaB activation but also sustained these activities in the presence of T regulatory cells. These effects are seen whether the chimeric T cells are derived from normal donors or from patients with B-cell chronic lymphocytic leukemia, indicating the potential for clinical application in B cell malignancies.

Current status of genetic modification of T cells for cancer treatment

Clinical studies of adoptive immunotherapy with T cells have shown activity directed at hematologic and solid malignancies and viral infections. Genetic modification of infused T cells offers the prospect of improving such therapies and has already been used to track infused T cells, insert suicide genes and redirect the immune response towards specific Ag. Pre-clinical studies are evaluating novel approaches to genetically modify T cells to confer resistance to tumor evasion mechanisms. There is also increasing interest in developing suicide gene strategies as a failsafe mechanism to eradicate genetically modified cells should adverse effects occur.

Adenovector-induced expression of human-CD40-ligand (hCD40L) by multiple myeloma cells. A model for immunotherapy

OBJECTIVE

CD40L restores the antigen-presenting cell (APC) function of some B-cell tumors and induces professional APC maturation. We therefore evaluated the effects of transgenic CD40L expression on the behavior and immunogenicity of human multiple myeloma (MM) cells.

MATERIALS AND METHODS

CD40L expression was induced in a CD40(+) (RPMI 8226) and a CD40(-) (U266B1) human myeloma cell line (HMCL) by adenoviral vector gene transfer. The viability and proliferative activity of control HMCL and HMCL/CD40L were determined by daily trypan blue staining and methyl-3H-thymidine incorporation. Mixed lymphocyte reaction (MLR) with allogeneic mononuclear cells (MNCs) and coculture of allogeneic dendritic cells (DCs) with HMCL expressing transgenic CD40L were used to evaluate the APC function of modified HMCL as well as the role of bystander DCs in inducing an anti-tumor immune response.

RESULTS

CD40L expression significantly inhibited the growth of the CD40(+) HMCL and induced apoptosis. These effects were less evident for the CD40(-) HMCL. There was no upregulation of costimulatory molecules on either HMCL following CD40L expression. Both HMCL expressing transgenic CD40L induced maturation of bystander DCs and enhanced their ability to stimulate the proliferation of MNCs. DCs cultured with the poorly immunogenic RPMI 8226 expressing CD40L upregulated T-lymphocyte release of IFN-gamma and other Th1 cytokines (interleukin-2, tumor necrosis factor-alpha).

CONCLUSIONS

Our data suggest that transgenic expression of CD40L exerts a dual effect favoring generation of an immune response to human MM. Where the tumor cells are CD40(+), the engagement of CD40 antigen by CD40L on tumor cells induces their apoptosis, allowing uptake of tumor-associated antigen by professional APC. Independently of tumor-cell expression of CD40, transgenic expression of CD40L on tumor cells allows them to stimulate CD40(+) APC, to increase their maturation and their capacity to stimulate cytotoxic T lymphocytes (CTL) that recognize the tumor-derived antigens the APC may have engulfed.

Streptococcus pyogenes collected in Torino (northwest Italy) between 1983 and 1998: survey of macrolide resistance and trend of genotype by RAPD

We surveyed macrolide resistance in 1,086 isolates of Streptococcus pyogenes, collected between 1983 and 1998, from throat swabs of children with untreated pharyngotonsillitis living in Torino (northwest Italy). In 1983 and 1985, the frequency of erythromycin resistance was 10%, and from 1990 to 1992 it was 4%. However, it rose to 16.6% in 1994 and reached 51% in 1996 before decreasing to 38.5% in 1998. Characterization of the phenotype of resistant isolates revealed the prevalence of constitutive resistance (CR) in 1996, whereas the M phenotype, characterized by resistance to 14- and 15-membered macrolides with susceptibility to clindamycin and streptogramin B, prevailed in 1998. Moreover, in 1997 we observed an increase in the frequency of autoagglutinating bacteria and, in 1998, of OF-negative S. pyogenes. Meanwhile, penicillin tolerance, assessed in the isolates collected from 1990 to 1996, decreased and disappeared. Random amplification of polymorphic DNA (RAPD) was used to obtain the genomic profile of 32 S. pyogenes strains. Four main DNA profiles were demonstrated, generally related to the macrolide-resistance phenotype and for the major part to the T serotype. These results indicate that RAPD is reliable as a first screening method in the epidemiological characterization of resistant S. pyogenes.

Anti-CD20 antibody (rituximab) administration in patients with late occurring lymphomas after solid organ transplant

BACKGROUND AND OBJECTIVES

Aggressive diffuse large cell non-Hodgkin's lymphoma (DLCL) occurring late after a solid organ transplant fails to regress after discontinuation of immunosuppression. Moreover, chemotherapy treatment is associated with a high mortality rate due to severe toxicity. Since the majority of post-transplant lymphoproliferative disorders derive from B-lineage lymphocytes, the administration of anti-B monoclonal antibodies represents a rational therapeutic option.

DESIGN AND METHODS

Five patients who developed CD20-positive DLCL more than two years after heart or liver transplantation were treated with a weekly chemotherapy program (2 patients), radiotherapy (2 patients) and surgery (1 patient) followed by a minimum of 4 intravenous doses of rituximab (375 mg/m(2)).

RESULTS

A favorable clinical outcome was observed in three patients in whom surgery or radiotherapy had produced significant tumor debulking. Only a partial clinical effect was documented in the two patients with advanced clinical stage disease.

INTERPRETATION AND CONCLUSIONS

Rituximab can be safely administered to patients with aggressive CD20-positive DLCL occurring late after a solid organ transplant. However, a positive clinical outcome may be expected only in patients in whom surgery or radiotherapy has achieved significant regression of tumor burden.

Autologous antileukemic immune response induced by chronic lymphocytic leukemia B cells expressing the CD40 ligand and interleukin 2 transgenes

Although the B cells of chronic lymphocytic leukemia (B-CLL cells) express both tumor-specific peptides and major histocompatibility complex (MHC) class I antigens, they lack the capacity for costimulatory signaling, contributing to their protection against host antitumor immunity. To stimulate CLL-specific immune responses, we sought to transfer the human CD40 ligand (hCD40L) gene to B-CLL cells, using an adenoviral vector, in order to upregulate costimulating factors on these cells. Because efficient gene transduction with adenoviral vectors requires the expression of virus receptors on target cells, including the coxsackievirus B-adenovirus receptors (CAR) and alpha(v) integrins, we cocultured B-CLL cells with human embryonic lung fibroblasts (MRC-5 line). This exposure led to increased expression of integrin alpha(v)beta3 on B-CLL cells, which correlated with higher transduction rates. Using this novel prestimulation system, we transduced B-CLL cells with the hCD40L gene. The Ad-hCD40L-infected cells had higher expression of B7 molecules and induced activation of autologous T cells in vitro, but these T cells could not recognize parental leukemic cells. By contrast, an admixture of Ad-hCD40L-positive cells and leukemic cells transduced with the human interleukin 2 (IL-2) gene produced greater T cell activation than did either immunostimulator population alone. Importantly, this combination generated autologous T cells capable of specifically recognizing parental B-CLL cells. These findings suggest that the combined use of genetically modified CD40L-expressing B-CLL cells in combination with IL-2-expressing B-CLL cells may induce therapeutically significant leukemia-specific immune responses.

Pharmacokinetic study of the new cyclosporine-A formulation (Neoral) in adult allogeneic bone marrow transplant recipients

BACKGROUND AND OBJECTIVES

A major problem encountered during oral cyclosporin-A (CsA) administration to prevent acute graft-versus-host-disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT) is its irregular pharmacokinetics. The aim of this study was to evaluate the pharmacokinetics of Neoral, a new water-free microemulsion formulation of CsA.

DESIGN AND METHODS

Eighteen patients aged over 18 were enrolled into the study. When able to eat normally after allo-BMT, patients received CsA orally and after 4 days a 12-hour CsA pharmacokinetic profile was constructed. Three patients received Sandimmune 10 mg/kg/day, 5 patients received Neoral 7.5 mg/kg/day and 10 patients Neoral 5 mg/kg/day. CsA concentration was analyzed on whole blood by high-performance liquid chromatography (HPLC).

RESULTS

Neoral showed concentration-time profiles characterized by a smooth and faster rise to the Cmax value compared to that produced by Sandimmune. The comparison between pharmacokinetic parameters obtained in patients receiving Neoral 5 mg/kg/day or 7.5 mg/kg/day showed a proportional increase of the AUC (4776+/-1084 vs. 7746+/-2006 ng/mL h) and C(max) (1027+/-203 vs. 1514+/-231 ng/mL). In all patients to whom 7.5 mg/kg/day of Neoral were given, C(trough) levels were always above the threshold of 200 ng/mL.

INTERPRETATION AND CONCLUSIONS

Our data suggest that oral administration of Neoral 7.5 mg/kg/day early after allo-BMT may represent an appropriate dose resulting in adequate CsA C(trough) levels without significant renal toxicity.

Need for an accurate molecular diagnosis to assess the donor origin of leukemia relapse after allogeneic stem cell transplantation

BACKGROUND AND OBJECTIVES

Leukemia relapse occurring in donor cells after allogeneic hematopoietic stem cell transplantation has been reported in rare cases. Cytogenetic analysis and molecular probing of variable number of tandem repeats (VNTRs) have been used to confirm this unusual event in the few cases so far reported in the literature. The aim of this study was to demonstrate that extensive molecular characterization of leukemic cells at diagnosis and relapse may be necessary to avoid many technical pitfalls possibly leading to an erroneous diagnosis of leukemia relapse in donor cells after allogeneic transplantation.

DESIGN AND METHODS

We report the case of a 49- year old man who received an allogeneic transplantation from his HLA-identical sister because of BCR-ABL+ acute lymphoblastic leukemia (ALL). After having achieved complete hematologic and molecular remission, two years later an overt leukemia relapse occurred with cytogenetic findings suggesting a leukemia relapse in donor cells. The donor or patient origin of leukemic cells at relapse was further investigated by fluorescence in situ hybridization (FISH) karyotyping, reverse transcription (RT) polymerase chain reaction (PCR) analysis of BCR-ABL chimeric transcripts, PCR amplification of several VNTRs and the Y chromosome-specific DYS14 sequence and finally by amplification, cloning and sequencing of the CDRIII region of the immunoglobulin heavy chain (IgH) gene.

RESULTS

At the time of relapse, conventional and FISH karyotyping revealed the presence of a Phl+ chromosome and a female karyotype in all the 25 metaphases analyzed and PCR amplification of the Y chromosome-specific DYS14 sequence was negative. Moreover, the molecular evaluation of hematopoietic chimerism performed by the NZ-22 VNTR allowed us to demonstrate that at the time of relapse, a consistent proportion of hematopoietic cells was of donor origin. However, the molecular cloning and sequencing of the CDRIII region of the immunoglobuin heavy chain (IgH) gene rearrangement in leukemic blasts at diagnosis and relapse demonstrated their identity thus formally proving the patient origin of both leukemic clones.

INTERPRETATION AND CONCLUSIONS

While the simplest interpretation of the apparent female karyotype at relapse is the consequence of a loss of the Y chromosome which in leukemic blasts took place along with duplication of an X-chromosome, this case strongly emphasizes the need for accurate and extensive molecular characterization to prove the donor origin of a leukemia relapse after allogeneic transplantation.

Epstein-Barr virus-negative lymphoproliferate disorders in long-term survivors after heart, kidney, and liver transplant

BACKGROUND

Solid organ transplant patients undergoing long-term immunosuppression have high risk of developing lymphomas. The pathogenesis of the late-occurring posttransplantation lymphoproliferative disorders (PTLD) have not yet been extensively investigated.

METHODS

We studied 15 patients who developed PTLD after a median of 79 months (range 22-156 months) after organ transplant. Clonality, presence of Epstein-Barr virus (EBV) genome, and genetic lesions were evaluated by Southern blot analysis or polymerase chain reaction.

RESULTS

All monomorphic PTLD and two of three polymorphic PTLD showed a monoclonal pattern. Overall, 44% of samples demonstrated the presence of the EBV genome. Within monomorphic PTLD, the EBV-positive lymphomas were even lower (31%). A c-myc gene rearrangement was found in two cases (13%), whereas none of the 15 samples so far investigated showed bcl-1, bcl-2, or bcl-6 rearrangement. The modulation of immunosuppression was ineffective in all patients with monomorphic PTLD independent of the presence of the EBV genome. The clinical outcome after chemotherapy was poor because of infectious complications and resistant disease. With a median follow-up of 4 months, the median survival time of these patients was 7 months.

CONCLUSIONS

Late occurring lymphomas could be considered an entity distinct from PTLD, occurring within 1 year of transplant, because they show a histological and clinical presentation similar to lymphomas of immunocompetent subjects, are frequently negative for the EBV genome, are invariably clonal, and may rearrange the c-myc oncogene. New therapeutic strategies are required to reduce the mortality rate, and new modalities of long-lasting immunosuppression are called for.

Molecular profile of Epstein-Barr virus infection in HHV-8-positive primary effusion lymphoma

Primary effusion lymphoma (PEL) selectively involves the serous body cavities, occurs predominantly in immunodeficient patients and is infected consistently by human herpesvirus type-8. PEL is also frequently infected by Epstein-Barr virus (EBV). The precise pathogenetic role of EBV coinfection in PEL is not fully understood. The lymphoma fails to express the EBV transforming proteins EBNA-2 and LMP-1, whereas it expresses EBNA-1 (latency I phenotype). Some studies have hypothesized that other EBV-positive lymphomas expressing the latency I phenotype may associate with specific molecular variants of EBNA-1, although this issue has not been addressed in PEL. On this basis, this study is aimed at a detailed molecular characterization of EBV in PEL. Fifteen EBV positive PEL (12 AIDS-related, one post-transplant, two arising in immunocompetent hosts) were subjected to molecular characterization of the viral genes EBNA-1 and LMP-1, as well as definition of EBV type-1/type-2. The EBNA-1 gene displayed a high degree of heterogeneity in different cases of PEL, with seven distinct recognizable variants and subvariants. A wild-type LMP-1 gene was detected in 10/15 cases, whereas in 5/15 cases the LMP-1 gene harbored a deletion spanning codons 346-355. EBV type-1 occurred in 11/15 PEL whereas EBV type-2 occurred in 4/15 cases. Despite a high degree of genetic variability of the virus in different PEL cases, each single PEL harbored only one EBV variant, consistent with monoclonality of infection and suggesting that infection preceded clonal expansion. Overall, our results indicate that: (1) individual PEL cases consistently harbor a single EBV strain; (2) EBNA-1 displays a high degree of heterogeneity in different PEL cases; (3) no specific EBV genotype preferentially associates with PEL.

Macrolide resistance in group A streptococci

Two hundred and twenty one Streptococcus pyogenes isolates collected from throat swabs of untreated children with uncomplicated pharyngotonsillitis living in two centres situated in the north of Italy were tested to evaluate their macrolide resistance phenotype. Isolates were also typed for T protein and assayed for opacity factor (OF) and protease production. Resistance to macrolides was found to be similar in the two centres. Fifty-one point two per cent of Torino strains and 43.5% of Pinerolo strains were not inhibited by erythromycin. Resistant strains belonged to one of three phenotypes: CR, constitutive resistance (37.9 and 42.5% in Torino and Pinerolo, respectively); IR, inducible resistance (40.9 and 17. 5%); NR, new resistance phenotype (21.2 and 40%). All the resistant and some of the susceptible strains were analysed by pulsed-field gel electrophoresis and genomic patterns were defined on the basis of band size and number. Five DNA profiles were found among erythromycin-resistant strains: three patterns characterized the NR resistance phenotype and one each the IR and CR phenotypes. The distribution of resistant strains according to their genomic patterns appears to be related to the resistance phenotype and only in some cases to the T serotype of bacteria. We conclude that the S. pyogenes strains analysed are genetically heterogeneous and therefore the high rate of erythromycin resistance observed is not caused by the spread of a single clone nor is it related to a particular serotype.

Standardized RT-PCR analysis of fusion gene transcripts from chromosome aberrations in acute leukemia for detection of minimal residual disease. Report of the BIOMED-1 Concerted Action: investigation of minimal residual disease in acute leukemia

Prospective studies on the detection of minimal residual disease (MRD) in acute leukemia patients have shown that large-scale MRD studies are feasible and that clinically relevant MRD-based risk group classification can be achieved and can now be used for designing new treatment protocols. However, multicenter international treatment protocols with MRD-based stratification of treatment need careful standardization and quality control of the MRD techniques. This was the aim of the European BIOMED-1 Concerted Action 'Investigation of minimal residual disease in acute leukemia: international standardization and clinical evaluation' with participants of 14 laboratories in eight European countries (ES, NL, PT, IT, DE, FR, SE and AT). Standardization and quality control was performed for the three main types of MRD techniques, ie flow cytometric immunophenotyping, PCR analysis of antigen receptor genes, and RT-PCR analysis of well-defined chromosomal aberrations. This study focussed on the latter MRD technique. A total of nine well-defined chromosome aberrations with fusion gene transcripts were selected: t(1;19) with E2A-PBX1, t(4;11) with MLL-AF4, t(8;21) with AML1-ETO, t(9;22) with BCR-ABL p190 and BCR-ABL p210, t(12;21) with TEL-AML1, t(15;17) with PML-RARA, inv (16) with CBFB-MYH11, and microdeletion 1p32 with SIL-TAL1. PCR primers were designed according to predefined criteria for single PCR (external primers A <--> B) and nested PCR (internal primers C <--> D) as well as for 'shifted' PCR with a primer upstream (E5' primer) or downstream (E3' primer) of the external A <--> B primers. The 'shifted' E primers were designed for performing an independent PCR together with one of the internal primers for confirmation (or exclusion) of positive results. Various local RT and PCR protocols were compared and subsequently a common protocol was designed, tested and adapted, resulting in a standardized RT-PCR protocol. After initial testing (with adaptations whenever necessary) and approval by two or three laboratories, the primers were tested by all participating laboratories, using 17 cell lines and patient samples as positive controls. This testing included comparison with local protocols and primers as well as sensitivity testing via dilution experiments. The collaborative efforts resulted in standardized primer sets with a minimal target sensitivity of 10-2 for virtually all single PCR analyses, whereas the nested PCR analyses generally reached the minimal target sensitivity of 10-4. The standardized RT-PCR protocol and primer sets can now be used for molecular classification of acute leukemia at diagnosis and for MRD detection during follow-up to evaluate treatment effectiveness.

Primary effusion lymphoma after heart transplantation: a new entity associated with human herpesvirus-8

Deep immunosuppression and Epstein-Barr virus (EBV) infection promote the emergence of lymphoproliferative disorders in patients undergoing solid organ transplantation. In the last few years a new herpesvirus, named human herpesvirus-8 (HHV-8), has been identified in Kaposi's sarcoma and primary effusion lymphoma (PEL) developing in AIDS patients. Subsequently, the same viral DNA sequences have been identified in almost all cases of Kaposi's sarcoma emerged outside HIV infection, thus suggesting their possible pathogenetic role in this tumor. Similarly, the association between HHV-8 and PEL also emerged in cases without HIV infection, even though the total number of these patients is still limited. Here, we focus on the emergence of this unusual lymphoma in patients undergoing solid organ transplant and underline once again its association with the HHV-8. Moreover, despite the characteristic local growth of this peculiar type of lymphoma, we demonstrate at the molecular level, an early neoplastic spread to the bone marrow suggesting the need to investigate in more detail the origin of the disease, as well as the molecular mechanisms controlling its systemic dissemination.

Leucocyte alkaline phosphatase identifies terminally differentiated normal neutrophils and its lack in chronic myelogenous leukaemia is not dependent on p210 tyrosine kinase activity

Leucocyte alkaline phosphatase (LAP) is a marker of post-mitotic granulocytes and its activity is reduced or absent in chronic myelogenous leukaemia (CML) granulocytes as a consequence of LAP messenger RNA (mRNA) deficiency. We provide evidence that along the granulocytic maturation in normal marrow, the acquisition of LAP surface expression, identified by the monoclonal antibody 1B12.1, was restricted to CD11bbright/CD16bright positive cells. Moreover, in normal granulocytes, exposure to granulocyte colony-stimulating factor (G-CSF) in vitro and in vivo increased the cell surface expression of LAP. Although G-CSF was able to induce the LAP surface expression in CML granulocytes, the inhibition of p210 tyrosine kinase activity by genistein or CGP75148B failed to restore LAP mRNA expression and LAP protein synthesis. In conclusion, the acquisition of LAP protein on the cell surface of granulocytes follows CD16 antigen expression and can be considered as the last marker of terminally differentiated neutrophils. G-CSF is a potent regulator of the LAP mRNA expression and protein synthesis in normal and CML-derived neutrophils. The lack of direct activity of p210 tyrosine kinase on LAP mRNA expression in CML neutrophils supports the notion that the LAP defect in this disease could be related to a precocious and uncontrolled release of white blood cells from the bone marrow into the blood stream.

Innovative two-step negative selection of granulocyte colony-stimulating factor-mobilized circulating progenitor cells: adequacy for autologous and allogeneic transplantation

A major obstacle in purifying either autologous or allogeneic hematopoietic stem cells from granulocyte colony-stimulating factor (G-CSF) mobilized circulating progenitor cells (CPC) is represented by the huge cellularity present in each apheretic product. To obtain a significant debulking of unwanted cells from the leukapheresis, we developed a modified protocol of immune rosetting whereby human ABO-Rh- compatible red blood cells (RBCs) are treated with chromium chloride and then coated with murine monoclonal antibodies (MoAbs) against leukocyte antigens. When experiments were performed with leukaphereses obtained from normal donors or from T-cell acute lymphoblastic leukemia (T-ALL) patients, RBCs were coated with murine MoAbs against human mature myeloid cells (CD11b) and T cells (CD6); whereas, in the case of patients with B-precursor ALL, B-cell non-Hodgkin's lymphoma (B-NHL), or multiple myeloma (MM), RBCs were coated with anti-CD11b only. After incubation with CPC, rosetting cells (myeloid precursor cells, granulocytes, monocytes, and T cells) were removed by Ficoll-Hypaque density gradient centrifugation with a blood cell processor apparatus, COBE (Lakewood, CO) 2991. After this step, a significant reduction of the initial cellularity was consistently obtained (range, 72% to 97%), whereas the median absolute recovery of the CD34+ cells was above 85% (range, 64 to 100), with a 10-fold relative enrichment ranging from 3% to 41%. In a second step, CPC can be further purged of contaminating T or B cells by incubation with lymphoid-specific magnetic microbeads (anti-CD2 and -CD7 to remove T cells; anti-CD19 to remove B cells) and elution through a type-D depletion column (composed of ferromagnetic fiber) inserted within a SuperMACS separator device (Miltenyi Biotech, Bergisch-Gladbach, Germany). By this approach, a highly effective (three to four logs) T-cell depletion was achieved in all experiments performed with normal donors or T-ALL patients (median loss of CD3+ cells: 99.8% [range 99.2 to 100]) and an equally efficient B-cell depletion was obtained from B-precursor ALL, B-NHL, or MM patients. At the end of the procedure the T- or B-cell depleted fraction retained a high proportion of the initial hematopoietic CD34+ stem cells, with a median recovery above 70% (range 48% to 100%) and an unmodified clonogenic potential. In five patients (two follicular NHL and three ALL) the purified fraction of stem cells was found disease free at the molecular level as assessed by polymerase chain reaction (PCR) analysis of the t(14;18) chromosome translocation or clono-specific DNA sequences of IgH or T-cell receptor gamma and delta chain genes. Purified autologous and allogeneic CPCs were transplanted in three and six patients, respectively, who showed a prompt and sustained hematologic engraftment. In conclusion, this method represents a simple and reproducible two-step procedure to obtain a highly efficient purging of T or B cells from G-CSF expanded and mobilized CPCs. This approach might lead to the eradication of the neoplastic clone in the autologous stem cell inoculum as well as for T-cell depletion during allogeneic transplantation.

Reverse transcription polymerase chain reaction is a reliable assay for detecting leukemic colonies generated by chronic myelogenous leukemia cells

Single-colony karyotyping (SCK) and reverse-transcription polymerase chain reaction (RT-PCR) are two increasingly used techniques for the quantification of leukemic colonies generated by chronic myelogenous leukemia (CML) cell fractions purged or selected in vitro. Recently, the existence of Philadelphia (Ph) chromosome positive progenitors with a silent BCR-ABL gene has been reported, thus raising concerns on the use of RT-PCR for detecting BCR-ABL positive progenitors. In order to investigate this issue further, colonies (n = 204) generated by mononuclear (MNC) or CD34+ CML cells were individually harvested, divided into two aliquots and analyzed both at the cytogenetic level to detect the Ph chromosome, and the molecular level to detect BCR-ABL transcripts. The mean (+/- s.d.) percentages of colonies analyzable by either SCK or RT-PCR were 74 +/- 16% and 86 +/- 16%, respectively. A significant percentage of colonies (67 +/- 19%) could be successfully analyzed by both SCK and RT-PCR. Although the majority of these colonies (97 +/- 5%) were Ph-positive and BCR-ABL-positive, a negligible percentage (4%) of progenitors were Ph-positive but BCR-ABL-negative. In order to test the influence of colony size on the outcome of molecular analysis, the efficiency of our RT-PCR assay in detecting BCR-ABL transcripts was investigated by means of experiments in which the number of cells used to start RNA extraction was serially reduced. These experiments showed that at least 150 cells were necessary to achieve a reproducible amplification of BCR-ABL transcripts. By correlating the size of harvested colonies with the outcome of molecular analysis, it was evident that BCR-ABL-negative but Ph-positive colonies represented false negative results occurring when a number of leukemic cells below the detection limit of our RT-PCR assay was analyzed. In conclusion, our data demonstrate that individual CML colonies grown in semisolid culture assays can be indifferently analyzed by SCK or RT-PCR, and support an extensive use of a carefully standardized RT-PCR assay to estimate the leukemic burden within samples which have been purged and selected in vitro.

Selection of myeloid progenitors lacking BCR/ABL mRNA in chronic myelogenous leukemia patients after in vitro treatment with the tyrosine kinase inhibitor genistein

Chronic myelogenous leukemia (CML) is a clonal disorder of the hematopoietic stem cell characterized by a chimeric BCR/ABL gene giving rise to a 210-kD fusion protein with dysregulated tyrosine kinase activity. We investigated the effect of genistein, a protein tyrosine kinase inhibitor, on the in vitro growth of CML and normal marrow-derived multi-potent (colony-forming unit-mix [CFU-Mix]), erythroid (burst-forming unit-erythroid [BFU-E]), and granulocyte-macrophage (colony-forming unit-granulocyte-macrophage [CFU-GM]) hematopoietic progenitors. Continuous exposure of CML and normal marrow to genistein induced a statistically significant and dose-dependent suppression of colony formation. Genistein doses causing 50% inhibition of CML and normal progenitors were not significantly different for CFU-Mix (27 mumol/L v 23 mumol/L), BFU-E (31 mumol/L v 29 mumol/L), and CFU-GM (40 mumol/L v 32 mumol/L v 32 mumol/L). Preincubation of CML and normal marrow with genistein (200 mumol/ L for 1 to 18 hours) induced a time-dependent suppression of progenitor cell growth, while sparing a substantial proportion of long-term culture-initiating cells (LTC-IC) from CML (range, 91% +/- 9% to 32% +/- 3%) and normal marrow (range, 85% +/- 8% to 38% +/- 9%). Analysis of individual CML colonies for the presence of the hybrid BCR/ABL mRNA by reverse transcription-polymerase chain reaction (RT-PCR) showed that genistein treatment significantly reduced the mean +/- SD percentage of marrow BCR/ABL+ progenitors both by continuous exposure (76% +/- 18% v 24% +/- 12%, P < or = .004) or preincubation (75% +/- 16% v 21% +/- 10%, P < or = .002) experiments. Preincubation with genistein reduced the percentage of leukemic LTC-IC from 87% +/- 12% to 37% +/- 12% (P < or = .003). Analysis of individual colonies by cytogenetics and RT-PCR confirmed that genistein-induced increase in the percentage of nonleukemic progenitors was not due to suppression of BCR/ABL transcription. Analysis of nuclear DNA fragmentation by DNA gel electrophoresis and terminal deoxynucleotidyl transferase assay showed that preincubation of CML mononuclear and CD34+ cells with genistein induced significant evidence of apoptosis. These observations show that genistein is capable of (1) exerting a strong antiproliferative effect on CFU-Mix, BFU-E, and CFU-GM while sparing the more primitive LTC-IC and (2) selecting benign hematopoietic progenitors from CML marrow, probably through an apoptotic mechanism.

Effect of the protein tyrosine kinase inhibitor genistein on normal and leukaemic haemopoietic progenitor cells

Receptor and nonreceptor protein tyrosine kinases (PTKs) play a key role in the control of normal and neoplastic cell growth. The availability of PTK inhibitors prompted us to evaluate the effects of genistein, a natural inhibitor of PTKs, on in vitro colony formation by normal multilineage colony-forming units (CFU-Mix), erythroid bursts (BFU-E), granulocyte-macrophage colony-forming units (CFU-GM), long-term culture-initiating cells (LTC-IC) and acute myelogenous leukaemia colony-forming units (CFU-AML). Continuous exposure of normal marrow and blood mononuclear non-adherent cells, blood CD34+CD45RA- cells, and leukaemic blasts to increasing doses of genistein (1-100 microM) resulted in a statistically significant (P < or = 0.05) dose-dependent suppression of CFU-Mix, BFU-E, CFU-GM and CFU-AML growth. Regression analysis showed that growth inhibition was linearly related to genistein concentration. Genistein dose causing 50% inhibition (ID50) of CFU-AML was significantly lower compared to CFU-GM ID50 for marrow (19 v 32 microM, P < or = 0.017), unseparated blood (19 v 44 microM, P < or = 0.028) or CD34+CD45RA- blood (19 v 36, P < or = 0.04). Preincubation of leukaemic blasts with genistein (200 microM) for 1-2h confirmed that CFU-AML were significantly more sensitive than normal marrow and blood CFU-GM to genistein. Preincubation conditions which maximally suppressed leukaemic and normal colony growth spared a substantial percentage of marrow (29 +/- 4%) and blood (40 +/- 3%) LTC-IC. In conclusion, our data demonstrate that: (a) genistein strongly inhibits the growth of normal and leukaemic haemopoietic progenitors; (b) growth inhibition is dose- and time-dependent; (c) leukaemic progenitors are more sensitive than normal progenitors to genistein-induced growth inhibition; (d) genistein exerts a direct toxic effect on haemopoietic cells while sparing a substantial proportion of LTC-IC. The potent CFU-AML growth inhibition associated with the relative resistance of normal LTC-IC strongly supports the use of genistein for marrow purging.

Granulocyte colony-stimulating factor (G-CSF) prevents dose-limiting neutropenia in lymphoma patients receiving standard dose chemotherapy

In this study, nine patients with non-Hodgkin's lymphoma (n = 6) and Hodgkin's disease (n = 3) receiving different cytotoxic chemotherapy regimens were given granulocyte colony-stimulating factor (G-CSF) (5 micrograms/kg/day) from 48 hours after the end of chemotherapy to 48 hours before the next chemotherapy administration. The decrease in mean absolute neutrophil counts (ANC) and in mean platelet (Plt) counts was not significant when pre-therapy counts were compared with post-therapy ones (p < 0.375 and p > 0.4, respectively). The mean actual dose intensity was 92% (range 68-100%). G-CSF treatment after chemotherapy reduces neutropenia and permits administration of the full chemotherapy program. A wash-out period between G-CSF treatment and chemotherapy administration is needed to prevent the detrimental effect of chemotherapy on leukocyte and platelet recovery when repeated cycles of cytotoxic drugs and G-CSF are administered.

Non-radioactive detection of the most common mutations in the cystic fibrosis transmembrane conductance regulator gene by multiplex allele-specific polymerase chain reaction

A rapid, simple, nonradioactive method for detection of four common mutations causing cystic fibrosis (CF) has been developed combining multiplexing with allele-specific polymerase chain reaction amplification. This approach (MASPCR) provides an easy assay for direct genotyping of normal and mutant CF alleles in homozygotes and heterozygotes. The strategy involves multiplex PCR of exons 10, 11, and 21 within the cystic fibrosis transmembrane conductance regulator (CFTR) gene in a single reaction containing three common oligoprimers and either the four normal or four mutant oligos corresponding to the delta F508, G551D, G542X, and N1303K mutations. Primers are chosen so that the size of the four PCR products differ, thereby facilitating detection on agarose gels following amplification in the same reaction. Patient samples are primed with either four normal or four mutant oligo mixtures, and PCR products run in parallel on gels to detect band presence or absence. This approach provides a simple and potentially automated method for cost-effective population screening.

Detection of the most common mutations causing beta-thalassemia in Mediterraneans using a multiplex amplification refractory mutation system (MARMS)

A rapid, simple, cost-effective, non-radioactive method for detection of the most common mutations causing beta-thalassemia in Mediterranean people has been developed by combining multiplexing with the amplification refractory system. This approach, the multiplex amplification refractory mutation system (MARMS), provides an easy assay for direct detection of normal and mutant beta-globin genes in homozygotes and heterozygotes. The strategy involves multiplex PCR of four of the five regions of interest within the beta-globin gene in a single reaction containing a common oligoprimer and either the normal or mutant oligonucleotides corresponding to IVS-1 nucleotide 1 or IVS-1 nucleotide 6, IVS-1 nucleotide 110, codon 39, and IVS-2 nucleotide 1 regions. Primers are chosen so that the sizes of the four PCR products differ, thereby facilitating detection on agarose gels following amplification. Patient samples are primed with either four normal or four mutant oligonucleotide mixtures and the common oligoprimer, and PCR products run in parallel on gels to detect band presence or absence. This approach simplifies mutation detection and shows promise for automation employing fluorescent-tagged primers.

[Gianotti-Crosti acrodermatitis. Description of a case of rare etiology]

Originally described in 1955, papular acrodermatitis is considered a rare disease whose manifestations are mainly cutaneous. The disease is characteristically associated to a non icteric hepatitis with B serologic tests positive. We recently observed a case whose etiology is unusual and, therefore, in our opinion worth of a brief description.

[Bacterial meningitis. Study from 1970 to 1988 at the Regina Margherita Children's Hospital in Turin]

From 1970 to 1988, 330 cases of bacterial meningitis were diagnosed at the Children's Hospital Regina Margherita of Turin. Neisseria meningitidis was the most frequent cause of bacterial meningitis (45%); meningitis caused by Haemophilus influenzae increased from 4% in 1970-1983 to 19% in 1984-1988, and meningitis with pathogen unknown decreased from 28% in 1970-1983 to 7% in 1984-1988. The neonatal meningitis in 1984-1988 were caused by Streptococcus B in 90% of cases.