Large genomic aberrations detected by SNP array are independent prognosticators of a shorter time to first treatment in chronic lymphocytic leukemia patients with normal FISH

BACKGROUND

Genomic complexity can predict the clinical course of patients affected by chronic lymphocytic leukemia (CLL) with a normal FISH. However, large studies are still lacking. Here, we analyzed a large series of CLL patients and also carried out the so far largest comparison of FISH versus single-nucleotide polymorphism (SNP) array in this disease.

PATIENTS AND METHODS

SNP-array data were derived from a previously reported dataset.

RESULTS

Seventy-seven of 329 CLL patients (23%) presented with a normal FISH. At least one large (>5 Mb) genomic aberration was detected by SNP array in 17 of 77 patients (22%); this finding significantly affected TTT. There was no correlation with the presence of TP53 mutations. In multivariate analysis, including age, Binet stage, IGHV genes mutational status and large genomic lesion, the latter three factors emerged as independent prognosticators. The concordance between FISH and SNP array varied between 84 and 97%, depending on the specific genomic locus investigated.

CONCLUSIONS

SNP array detected additional large genomic aberrations not covered by the standard FISH panel predicting the outcome of CLL patients.

Lymphotropic herpes virus (EBV, HHV-6, HHV-8) DNA sequences in HIV negative Castleman's disease

Aim-To evaluate the possible involvement of lymphotropic herpes viruses in Castleman's disease.Methods-Archival formalin fixed, paraffin wax embedded biopsy specimens from 16 HIV negative patients (11 with localised and five of multicentric disease) were studied. Epstein-Barr virus (EBV), human herpes virus-6 (HHV-6) and human herpes virus-8 (HHV-8) DNA was detected using PCR. PCR was also used to characterise the EBV genomes and the clonal status of the lesions.Results-EBV sequences were identified in nine (56%) cases. The main EBV genotype detected was type 1. Two (12%) cases were positive for both HHV-6 and EBV sequences. HHV-8 sequences were detected in one case of localised Castleman's disease, the sequence of which differed from that of the HHV-8 prototype. No clonal immunoglobulin gene rearrangements were found.Conclusions-EBV DNA was detected in a substantial proportion of cases, suggesting that it may have a role in the pathogenesis of Castleman's disease, unlike HHV-6 which was detected rarely. This is the first report of HHV-8 specific sequences in the localised from of the disease.

BACOP/FR combination chemotherapy as front-line treatment of follicular lymphoma. A phase II study of the Gruppo Italiano Studio Linfomi (GISL)

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Background: Doxorubicin, fludarabine and rituximab are all considered active drugs in the treatment of follicular lymphoma (FL). Howevere, the best induction regimen is still matter of debate. In 2003 the GISL started a phase II trial to assess efficacy and tolerability of a combination of bleomycin, adriamycin, ciclophosphamide, vincristine and prednisone (BACOP) followed by fludarabine and rituximab (FR). Methods: To be included in the study pts should have: histologically confirmed diagnosis of FL, stage II-IV disease, age 18–70, active disease. Pts were assessed for t(14:18) by PCR on bone marrow at diagnosis and at time of response assessment. Treatment consisted in three courses of BACOP followed by 4 courses of FR for pts in partial remission (PR) or complete remission with persistent t(14:18) positivity (CRM+). Pts achieving molecular complete remission (CRM-) stopped therapy after BACOP. The main endpoints of the study were overall response rate (CR+PR) (ORR) and failure free survival (FFS). A final accrual of 60 assessable pts was planned, however a faster accrual than expected allowed to enrol 91 pts between May 2003 and Dec 2005. Results: At time of present analysis 61 pts were valuable for final response: Median age was 56 yrs (25–70), male gender 56%, 18% with systemic symptoms, 88% in stage III-IV disease, 13% had elevated LDH and 21% bulky disease. Molecular marker was present in 30 out of 57 pts. 19 pts achieved a CR after three courses of BACOP; four of them, being in CRM- stopped therapy. 28 pts achieved CR with four additional courses of FR. At the end of treatment CR and ORR were 77% and 90% respectively; relatively to pts with molecular marker at diagnosis CRM- was 60%. Toxicity data are available for 57 patients: grade III/IV anemia and neutropenia were observed in two (3%) and 18 (32%) cases respectively; severe infections occurred in two cases, both bacterial pneumonia. After a median follow-up of 17 months (0.5–31) 12 events were observed: Major toxicity, four; non responders, two; relapse, six. Conclusions: BACOP/FR is a feasible and safe regimen for the treatment of patients with FL with promising efficacy. More mature follow-up is required to confirm these preliminary results.

No significant financial relationships to disclose.

Gene expression profiling of acute promyelocytic leukaemia identifies two subtypes mainly associated with Flt3 mutational status

Acute promyelocytic leukaemia (APL) is a well-defined disease characterized by a typical morphology of leukaemic cells, the presence of t(15;17) translocation and the unique sensitivity to the differentiating effect of all-trans retinoic acid. Nevertheless, some aspects are variable among APL patients, with differences substantially related to morphological variants, peripheral leukocytes count, the presence of a disseminated intravascular coagulopathy, different PML/RARalpha isoforms (long, variable or short) and Fms-like tyrosine kinase 3 (Flt3) mutations. In order to better define this variability, we investigated the gene expression profiles of 18 APL cases revealing, besides a high uniformity in gene expression pattern, the presence of few robust differences among patients able to identify, by an unsupervised analysis, two major clusters of patients characterized by different phenotypes (hypogranular M3v vs classical M3) and by the presence or absence of Flt3 internal tandem duplications (ITDs). Further supervised analysis confirmed that Flt3 status was the APL parameter best associated with these two subgroups. We identified, between Flt3 wild-type and Flt3-ITDs subsets, 147 differentially expressed genes that were involved in the cytoskeleton organization, in the cell adhesion and migration, in the proliferation and the coagulation/inflammation pathways as well as in differentiation and myeloid granules constitution suggesting a role of Flt3 mutations in the pathogenesis and clinical manifestations of APL.

The role of molecular monitoring in autotransplantation for non-Hodgkin's lymphoma

Seventy-two patients with non-Hodgkin's lymphoma were evaluated for the presence of molecular markers (IgH, bcl-1, bcl-2 rearrangement) on bone marrow, at diagnosis and after PBSCT, and on harvests in order to find a possible predictive role of minimal residual disease on treatment outcome. At diagnosis, 41 (59%) out of 69 available bone marrows showed molecular involvement. Fifty-six percent of leukaphereses were involved, mainly indolent lymphoma (P = 0.001) or advanced disease (P = 0.01). Ex vivo purging cleared only one stem collection out of 31 PCR-positive leukaphereses. Aggressive lymphomas showed both a longer overall survival (OS) (P = 0.03) and relapse-free survival RFS (P = 0.02) when transplanted with unpurged stem cells, whereas indolent NHL survival was not influenced by ex vivo purging. Twenty out of 26 samples taken during follow-up had bone marrow involvement at diagnosis. Of these, 15 cleared their bone marrow; both OS and RFS were significantly longer in the PCR-negative cases (P = 0.05 and P = 0.005). At 1 year after PBSCT, 75% of patients were PCR negative, with 50% molecular remissions; the relapse rate was 55% for patients still PCR positive vs 29% for those who were PCR negative. Thus, after high-dose chemotherapy, close molecular monitoring of MRD using qualitative PCR techniques seems to represent a reliable prognostic indicator.

Immunoglobulin gene mutations and frequent use of VH1-69 and VH4-34 segments in hepatitis C virus-positive and hepatitis C virus-negative nodal marginal zone B-cell lymphoma

Nodal marginal zone B-cell lymphoma (NMZL) is actually considered as a distinct entity that must be distinguished from extra-nodal and splenic marginal zone lymphomas. To define the cell origin and the role of antigen stimulation we determined the nucleotide sequence of the tumor-related immunoglobulin heavy chain variable genes in 10 cases of NMZL. The results were also evaluated on the basis of the presence of chronic hepatitis C virus (HCV) infection. All 10 cases harbored VH somatic mutations with a sequence homology compared to the closest germline gene, ranging from 83.33 to 98.28%. Interestingly, different VH segments were preferentially used in HCV-positive and HCV-negative patients: three of five HCV-negative NMZLs used a VH4-34 segment joined with different D and JH segments whereas three of five HCV-positive NMZLs used a VH1-69 gene joined with a D3-22 and a JH4 segment, with very strong similarities in the CDR3s among the three different cases. These data indicate: 1) NMZL is derived from B cells that have experienced the germinal center reaction; 2) the preferential usage of a VH1-69 segment in the majority of the HCV-positive NMZL cases with similar CDR3s suggests the presence of a common antigen, probably a HCV antigen epitope, involved in the B-cell selection; and 3) the use of a VH4-34 segment suggests a role of yet unknown B-cell superantigen(s) in the selection of tumor B-cell precursors in HCV-negative NMZL.

Bone marrow failure associated with human herpesvirus 8 infection after transplantation

BACKGROUND

Human herpesvirus 8 (HHV-8) infection has been linked to the development of Kaposi's sarcoma and to rare lymphoproliferative disorders.

METHODS

We used molecular methods, serologic methods, in situ hybridization, and immunohistochemical analyses to study HHV-8 infection in association with nonmalignant illnesses in three patients after transplantation.

RESULTS

Primary HHV-8 infections developed in two patients four months after each received a kidney from the same HHV-8-seropositive cadaveric donor. Seroconversion and viremia occurred coincidentally with disseminated Kaposi's sarcoma in one patient and with an acute syndrome of fever, splenomegaly, cytopenia, and marrow failure with plasmacytosis in the other patient. HHV-8 latent nuclear antigen was present in immature progenitor cells from the aplastic marrow of the latter patient. Identification of the highly variable K1 gene sequence of the HHV-8 genome in both the donor's peripheral-blood cells and the recipients' serum confirmed that transmission had occurred. HHV-8 viremia also occurred after autologous peripheral-blood stem-cell transplantation in an HHV-8-seropositive patient with non-Hodgkin's lymphoma. Reactivation of the infection was associated with the development of fever and marrow aplasia with plasmacytosis; there was no evidence of other infections. HHV-8 transcripts and latent nuclear antigen were expressed in the aplastic marrow but not in two normal marrow samples obtained before transplantation.

CONCLUSIONS

Primary HHV-8 infection and reactivation of infection may be associated with nonneoplastic complications in immunosuppressed patients.

Molecular evidence of organ-related transmission of Kaposi sarcoma-associated herpesvirus or human herpesvirus-8 in transplant patients

In transplant patients, Kaposi sarcoma (KS)-associated herpesvirus or human herpesvirus-8 (HHV-8) infection is associated with the development of KS, primary effusion lymphoma and Castleman disease. Whether HHV-8 is either reactivated in the recipient or transmitted by the donor has been investigated so far only by serologic studies. Thus, we addressed the issue of HHV-8 transmission in the transplantation setting by molecular methods. We exploited the high level variability of the orf-K1 gene and the polymorphism of the orf-73 gene of the HHV-8 genome to assess the genetic relatedness of the HHV-8 strains identified in the posttransplant KS lesions that developed, simultaneously, 20 months after transplantation, in 2 recipients of twin kidneys from the same cadaver donor. The 100% identity of nucleotide sequence of the most variable viral region and the presence of the same, single orf-73 type in both patients provides strong molecular evidence of organ-related transmission of HHV-8 in the setting of transplantation.

Nonmalignant disease associated with human herpesvirus 8 reactivation in patients who have undergone autologous peripheral blood stem cell transplantation

Fever, cutaneous rash, and hepatitis-for which an infectious cause was suspected-developed in an Italian patient with non-Hodgkin lymphoma after autologous peripheral blood stem cell (PBSC) transplantation. Polymerase chain reaction (PCR) with degenerate primers for the highly conserved DNA polymerase gene of herpesviruses detected herpesvirus sequences 100% identical to human herpesvirus-8 (HHV-8) in serial cell-free serum samples, collected immediately before or concomitant with the occurrence of clinical symptoms; no other common infections were documented. The presence of the HHV-8 genome (clade C) was confirmed by PCR with HHV-8-specific primers for orf 26 and orf-K1. HHV-8 viremia was undetectable either before transplantation or when the patient was clinically asymptomatic. Semiquantitative PCR analysis showed variations of the viral load correlating with the clinical status. Anti-HHV-8 antibodies were detected before and after transplantation by an immunofluorescence assay for lytic antigens. Active HHV-8 infection may be associated with nonmalignant illness after PBSC/bone marrow transplantation.

Late-appearing PML/RARalpha fusion transcript with coincidental t(12;13)(p13.2;q14) in acute promyelocytic leukemia lacking the t(15;17) cytogenetic anomaly

The late appearance of a cytogenetic/molecular hallmark in human leukemias is a rare event. We report on a case of acute myeloid leukemia with morphology, immunophenotype and clinical features typical of promyelocytic subtype (APL), in which the specific PML/RARalpha gene rearrangement was molecularly detected only at second relapse of disease, without cytogenetic evidence of the t(15;17). The emergence of the PML/RARalpha gene may be therapy-related or may represent the exceptional result of a clonal evolution during progression of neoplasia. At second relapse, a novel cell clone bearing a t(12;13)(p13.2;q14) was also observed and a molecular deletion and rearrangement of a locus at 13q14, distinct from retinoblastoma (Rb1) locus, was found. In this unusual case, the PML/RARalpha product seems to be not essential for the expression of the promyelocytic phenotype at diagnosis and, when detectable, it is not the sole genetic defect.

Missense mutations in the PML/RARalpha ligand binding domain in ATRA-resistant As(2)O(3) sensitive relapsed acute promyelocytic leukemia

BACKGROUND AND OBJECTIVE

Acute promyelocytic leukemia is characterized by the chromosomal translocation t(15;17) which yields the fusion product PML/RARa. All-trans retinoic acid probably induces differentiation of atypical promyelocytes and clinical remission in APL patients by binding to the ligand binding domain (LBD) of the RARa portion of the PML-RARa chimeric protein. Structural alterations of the LBD of the PML/RARa have been revealed in ATRA-resistant APL cell lines and in a few APL patients with acquired clinical resistance to ATRA therapy. Two APL relapsed patients with clinical resistance to ATRA therapy were evaluated for the presence of nucleotide mutations in the LBD of PML/RARa gene and then treated with arsenic trioxide (As2O3).

DESIGN AND METHODS

DNA fragments from the LBD of the PML/RARa chimeric transcript were obtained by reverse-transcribed polymerase chain reaction. Direct sequencing was performed by an unambiguous bi-directional automatic analysis. Samples representative of APL onset and relapse were analyzed from both patients.

RESULTS

In both patients, at the ATRA-resistant relapse, a missense point mutation in the LBD of the PML/RARa gene was found. The mutations, absent at APL onset, led to an Arg272Gln and to an Arg276Trp amino acid substitution, according to the sequence of the RARa protein. Both patients had complete clinical and hematologic remission after treatment with As2O3.

INTERPRETATION AND CONCLUSIONS

LBD missense mutations appear to be a significant mechanism of acquired ATRA-resistance in vivo, closely related to clinical APL relapse. The two cases reported here provide the first in vivo evidence of APL relapsed patients, who have become ATRA-resistant for molecular reasons, being sensitive to arsenic trioxide.

Expression of cell-homologous genes of human herpesvirus-8 in human immunodeficiency virus-negative lymphoproliferative diseases

Human herpesvirus-8 (HHV-8) genome encodes for genes homologous to human cellular genes such as interleukin-6 (IL-6), Cyclin-D, BCL-2, and IL-8 receptor (G-protein-coupled receptor [GCR]). We used reverse transcriptase-polymerase chain reaction to study the expression of these viral genes in lymphoproliferative disorders associated with HHV-8 infection. None of these genes was expressed in 1 case of benign, localized Castleman's disease (CD), and only viral IL-6 and viral Cyclin-D were transcribed in 2 cases of benign lymphadenopathies with giant germinal center hyperplasia and increased vascularity. In contrast, all 4 genes were transcribed in 1 case of multicentric CD of plasma cell type with aggressive clinical course and in 1 primary effusion lymphoma cell line. Our study provides the evidence that various HHV-8 genes, homologous to cellular genes involved in control of proliferation and apoptosis, may be differently expressed in different lymphoid disorders in vivo.

The oncogenic 30 and 69 bp deletion variants of the EBV LMP-1 gene are common in HIV-negative lymphoproliferations, both malignant and benign

BACKGROUND

In vitro studies have shown that the 30 and 69 base pair (bp) deletion variants of the latent membrane protein (LMP)-1 gene of the Epstein-Barr virus (EBV) have a higher transforming capacity than the wild-type variant. In recent years these studies have triggered an in vivo search for such potentially oncogenic variants in lymphoid tissues.

PATIENTS AND METHODS

We used polymerase chain reaction (PCR) to investigate the prevalence of LMP-1 gene variants in EBV-positive lymph nodes from 60 HIV-negative Italian patients with benign and malignant lymphoid disorders.

RESULTS

The 30 bp variant was detected in 10 of 39 (25.6%) malignant lymphomas but also in 4 of 13 (30%) reactive lymphadenitis with follicular hyperplasia. Of note is the fact that the 69 bp variant was detected in three cases of malignant lymphoproliferation but also in two cases of localized Castleman's disease of hyalin vascular type.

CONCLUSIONS

The molecular detection of the oncogenic variants of the LMP-1 gene in a lymph node biopsy as an indicator of the aggressiveness of the EBV-associated lymphoproliferative disease must be considered with caution. The relatively high frequency of the 69 bp variant in our series compared with that reported in the literature probably reflects a different incidence of LMP-1 variants in healthy populations from different geographical areas.

Human herpesvirus 6 latently infects early bone marrow progenitors in vivo

We have studied the in vivo tropism of human herpesvirus 6 (HHV-6) for hemopoietic cells in patients with latent HHV-6 infection. Having used a variety of cell purification, molecular, cytogenetic, and immunocytochemical procedures, we report the first evidence that HHV-6 latently infects early bone marrow progenitor cells and that HHV-6 may be transmitted longitudinally to cells which differentiate along the committed pathways.

Cellular localization of human herpesvirus 8 in nonneoplastic lymphadenopathies and chronic interstitial pneumonitis by in situ polymerase chain reaction studies

OBJECTIVES

To study the cellular localization of human herpesvirus 8 (HHV-8) in rare cases of HHV-8 infection from Italy that are associated neither with human immunodeficiency virus (HIV) infection nor Kaposi's sarcoma (KS).

METHODS

The presence and distribution of HHV-8-infected cells was investigated by direct in situ polymerase chain reaction (PCR) in the lymph node tissues from 2 patients with reactive lymphadenopathies with florid follicular hyperplasia and increased vascularity and in the lung tissue from 1 patient with chronic interstitial pneumonitis.

RESULTS

HHV-8 was localized in lymphoid and monocyte-macrophage cells scattered in the interfollicular regions of both lymph nodes but not in endothelial cells. In the lung tissue, HHV-8 was found in the inflammatory cells infiltrating the interalveolar interstitium, in endothelial cells of the pulmonary vasculature, and in rare pneumocytes.

CONCLUSIONS

HHV-8 can infect nonneoplastic lymph nodes of immunocompetent subjects, and the distribution of infected cells outside of the germinal centers resembles that of Epstein-Barr virus (EBV)-infected cells in the lymph nodes in the course of infectious mononucleosis. Endothelial cells and pneumocytes may be a target of HHV-8 infection out of the KS setting, at least in the presence of a chronic inflammatory process.

Expression of human herpesvirus-6 antigens in benign and malignant lymphoproliferative diseases

Immunohistochemistry was used to look for the expression of human herpesvirus-6 (HHV-6) antigens in a well characterized series of benign, atypical, and malignant lymphoid lesions, which tested positive for the presence of HHV-6 DNA. A panel of specific antibodies against HHV-6 antigens, characteristic either of the early (p41) or late (p101K, gp106, and gp116) phases of the viral cycle, was applied to the lymphoid tissues from 15 non-Hodgkin's lymphomas, 14 Hodgkin's disease cases, 5 angioimmunoblastic lymphadenopathies with dysproteinemia, 14 reactive lymphadenopathies, and 2 cases of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease). In lymphomatous tissues, the expression of late antigens was documented only in reactive cells, and mainly in plasma cells. Of interest, the expression of the early p41 antigen was detected in the so-called "mummified" Reed-Sternberg cells, in two Hodgkin's disease cases. In reactive lymphadenopathies, the HHV-6 late antigen-expressing cells were plasma cells, histiocytes, and rare granulocytes distributed in interfollicular areas. In both cases of Rosai-Dorfman disease, the p101K showed an intense staining in follicular dendritic cells of germinal centers, whereas the gp106 exhibited an intense cytoplasmic reaction in the abnormal histiocytes, which represent the histological hallmark of the disease. The expression of HHV-6 antigens is tightly controlled in lymphoid tissues. The lack of HHV-6 antigen expression in neoplastic cells and the limited expression in degenerating Reed-Sternberg cells argue against a major pathogenetic role of the virus in human lymphomagenesis. The detection of a rather unique pattern of viral late antigen expression in Rosai-Dorfman disease suggests a possible pathogenetic involvement of HHV-6 in some cases of this rare lymphoproliferative disorder.

Clinico-pathological characterization of hepatitis C virus-related B-cell non-Hodgkin's lymphomas without symptomatic cryoglobulinemia

BACKGROUND

Epidemiological evidence has suggested an association between hepatitis C virus (HCV) infection and B-cell lymphoproliferation. We studied the prevalence of HCV infection in a series of de novo B-cell non-Hodgkin's lymphoma (B-NHL) cases and correlated virological findings with clinico-histological features.

PATIENTS AND METHODS

One hundred fifty-seven patients with de novo B-NHL were included in the study. Their serum was examined by ELISA and RIBA for the presence of anti-HCV antibodies, and either the peripheral blood mononuclear cells or the pathology tissues of all of the patients were examined by reverse transcriptase polymerase chain reaction for the presence of HCV RNA sequences.

RESULTS

HCV infection occurred in 22.3% of B-NHL patients and was documented before the diagnosis in about half of the positive cases. Of interest, HCV infection was more frequently found in follicular center, marginal zone and diffuse large-cell lymphoma types, but was not associated with symptomatic cryoglobulinemia. The median survival time was 48 months in HCV-positive and 52 months in HCV-negative B-NHL patients.

CONCLUSIONS

Our findings strengthen the pathogenetic link between HCV and B-NHL and show that HCV infection may be associated with the malignant proliferation of defined B-cell subsets other than the immunoglobulin Mk B-cell subset involved in the pathogenesis of mixed cryoglobulinemia type II and associated lymphoplasmacytoid lymphoma type. HCV-related liver disease did not affect the survival of our B-NHL patients.

Chronic myeloid leukemia with thrombocythemic onset may be associated with different BCR/ABL variant transcripts

Ph-positive chronic myeloid leukemia (CML) mimicking essential thrombocythemia (ET) at onset seems to be a distinct clinical entity. Whether this rare clinical form of CML is associated with single, specific variants of BCR/ABL transcripts is a matter of debate. Among 82 consecutive patients with Ph-positive CML, we identified 3 patients in which the disease mimicked ET at presentation, because of marked thrombocytosis and moderate leukocytosis, with few immature myeloid cells in peripheral blood and blood basophilia in 2 of them. Molecular analysis with the reverse transcriptase-polymerase chain reaction technique showed the presence of b2a2, b3a2, and b3a2-b2a2 transcript variants in the three patients, respectively. The results of our study together with a review of literature data suggest that different BCR/ABL transcript variants may occur in CML mimicking ET, without an apparently significant prevalence of one type.

Hepatitis C virus-induced leuko-thrombocytopenia and haemolysis

Hepatitis C virus (HCV) has been recognized as the cause of thrombocytopenia occurring in patients with chronic hepatitis C, possibly through autoimmune mechanisms. A patient is described with B cell chronic lymphocytic leukaemia, presenting with a marked leuko-thrombocytopenia and an associated mild haemolysis secondary to HCV infection, in the absence of clinical and biochemical signs of hepatitis. Anti-HCV antibodies were detected in the serum both by ELISA and RIBA but not 2 months before the onset of cytopenia. The presence of HCV RNA was documented both in the peripheral blood mononuclear cells and in the bone marrow by reverse transcriptase polymerase chain reaction of the 5' untranslated region of the viral genome. Of interest, HCV RNA was also found in the serum, showing that viraemia was associated with the presence of circulating anti-HCV antibodies. HCV genotyping, performed by PCR amplification of the core region, revealed the presence of an unclassifiable genotype. The hypothetical mechanisms leading to HCV-induced cytopenia in this patient are briefly discussed. Treatment with corticosteroids was effective in controlling blood cell counts, without increasing viraemia and deterioration of liver disease. HCV infection should be considered in the differential diagnosis of possible causes of cytopenia, mainly in immunosuppressed patients, even in absence of clinical and biochemical signs of hepatitis.

P53 gene mutations in chronic myelogenous leukemia medullary and extramedullary blast crisis

Molecular alterations of the P53 gene were investigated in 27 unselected patients with chronic myelogenous leukemia (CML) blast crisis. A rearrangement of the P53 gene was evident by Southern blotting in 3 cases, one of which also showed the same alteration in the chronic phase. Single strand conformation polymorphism and sequencing analysis showed point mutations in 4 blast crisis cases. Of interest, P53 point mutations were evident in all the 3 cases of extramedullary blast crisis examined and the same point mutation was found in the myeloblastoma tissues and in the subsequent peripheral blast cells. These data indicate that: a) P53 gene mutations occur in a significant but not a large number of CML acute phase cases; b) P53 gene point mutations seem to correlate strongly with the infrequent extramedullary presentation of the blast crisis; c) the presence of the same P53 gene point mutation in extramedullary and bone marrow blast cells confirms the common clonal origin of the two cellular populations.

Sensitive detection of circulating breast cancer cells by reverse-transcriptase polymerase chain reaction of maspin gene

BACKGROUND

Maspin, a recently identified protein related to the family of serpins, is believed to play a role in human breast cancer. In an effort to improve the present methods of detection, we have developed a reverse-transcriptase polymerase chain reaction (RT-PCR) assay for maspin transcript to identify small numbers of mammary carcinoma cells in the peripheral blood and bone marrow of patients with breast cancer.

PATIENTS AND METHODS

Five non-neoplastic mammary tissue samples, 13 breast cancer specimens as well as 17 peripheral blood and 4 bone marrow samples from normal subjects were screened for the presence of maspin mRNA by RT-PCR. The same assay was applied to peripheral blood or bone marrow samples obtained from 29 patients with stages I to IV breast cancer.

RESULTS

By RT-PCR it was possible to amplify maspin mRNA in all of the primary and metastatic breast cancer specimens, but in none of the normal hemopoietic samples from healthy donors. Thus, detection of maspin transcript in the peripheral blood or marrow of a patient known to have breast cancer is indicative of the presence of mammary carcinoma cells. In reconstitution experiments, maspin RT-PCR reliably detected 10 mammary carcinoma cells in 1 million normal peripheral-blood mononuclear cells (PBMCs). None of the 9 patients with stages I, II, or III breast cancer had maspin transcript in peripheral blood. Of note, 3 of 9 patients with stage IV breast cancer receiving systemic therapy at the time of sample collection, but only 1 of 11 patients with stage IV not receiving therapy, had detectable maspin transcript in peripheral blood. Moreover, 3 marrow specimens from stage IV patients tested positive by this assay.

CONCLUSIONS

This pilot study suggests that maspin RT-PCR assay is a sensitive, specific and sufficiently rapid method for detection of small numbers of circulating cells and marrow micrometastases in breast cancer patients. The possibility of applying this assay in the detection of tumor cell contamination of both marrow and stem-cell apheresis harvests of breast cancer patients merits further investigation.

Additional neoplasms and HCV infection in low-grade lymphoma of MALT type

Several chronic inflammatory conditions and genetic alterations are likely to be involved in the pathogenesis of low-grade lymphoma of MALT type. In a well-characterized series of 27 patients with low-grade lymphoma of MALT type, we studied: (1) the incidence of other neoplasms, which might be indicative of genetic instability, apparently a characteristic of this disease; (2) the prevalence of serologic and molecular markers of HCV infection, which has been found in association with other lymphoproliferative disorders. Three patients had one or more additional cancers; a total of eight tumours, five of which occurred in the same patient, suggests the presence of some genetic instability in at least some cases of the disease. Rather unexpectedly, anti-HCV antibodies and HCV RNA sequences were documented in 50% of the patients examined, without elevation of serum transaminases. Of interest, the two patients with parotid and conjunctival MALT lymphomas, respectively, with a previous history of Sjögren's syndrome, were HCV positive. We suggest, for the first time, that HCV may be considered, in addition to Helicobacter pylori, as another potential infectious co-factor in the multistep pathogenesis of low-grade lymphomas of MALT type.

Frequency and distribution of herpesvirus-like DNA sequences (KSHV) in different stages of classic Kaposi's sarcoma and in normal tissues from an Italian population

The frequency and distribution of herpesvirus-like DNA sequences (KSHV) were investigated by PCR in the pathologic skin lesions of a series of 22 HIV-negative elderly patients with classic Kaposi's sarcoma (KS) from Italy, one of the few regions of the world where classic KS is prevalent. Viral sequences were clearly identifiable in 15 cases, in particular in 2 of 5 patch, in 3 of 6 plaque and in 10 of 11 nodular lesions. Our findings confirm the association of these herpesvirus-like DNA sequences with KS in unrelated populations, providing evidence of the putative KS-associated agent in all different histologic lesions of the disease, mainly in the nodular stage. The search for other herpesviruses by PCR showed that Epstein-Barr virus (EBV) sequences were present in 7 of 22 pathologic skin lesions. In 4 cases, both EBV and KSHV were present. On the contrary, all 22 classic KS specimens were negative for human herpesvirus-6 sequences. Two of 3 patch and the 1 nodular lesions from AIDS-related KS patients examined were positive for KSHV but negative for both EBV and HHV-6 sequences. Furthermore, we evaluated the prevalence of KSHV sequences in the normal population of the same geographical area. Thirteen peripheral blood mononuclear cell samples, 9 salivary gland tissues and 6 saliva samples from healthy subjects were invariably found negative for KSHV, using the same PCR technique. Of interest, 2 of 11 hyperplastic tonsils harboured these herpesvirus-like sequences, suggesting that, like other herpesviruses, the KS- associated agent may be harboured in a proportion of normal individuals and tonsils may represent at least one of the possible reservoirs of this putative lymphotropic gamma-herpesvirus in vivo.

Human herpesvirus-8 DNA sequences in human immunodeficiency virus-negative angioimmunoblastic lymphadenopathy and benign lymphadenopathy with giant germinal center hyperplasia and increased vascularity

Human herpesvirus-8 (HHV-8) DNA sequences have been reported to be strictly associated not only with various forms of Kaposi's sarcoma but also with an unusual subgroup of acquired immunodeficiency syndrome (AIDS)-related B-cell lymphomas. A possible relation of this putative virus also with multicentric Castleman's disease (MCD) has been recently suggested. We used polymerase chain reaction to look for the presence of HHV-8 sequences in a well characterized series of benign, atypical, and malignant lymphoid tissues from 45 Hodgkin's disease and 43 non-Hodgkin's lymphoma (NHL) cases, as well as from 5 MCD, 15 angioimmunoblastic lymphadenopathy (AILD), and 23 benign lymphadenopathy cases. Among the 38 AIDS-related lymphoid lesions, only 1 NHL and 1 persistent generalized lymphadenopathy (PGL) case were positive. Furthermore, among the 92 non-AIDS-related lymphoproliferative disorders, HHV-8 sequences were detected in 3 classic AILD cases and in 4 reactive lymphadenopathies. Six of 9 HHV-8 positive lymphoid lesions (1 NHL, 1 PGL, 1 AILD, and 3 reactive lymphadenopathy cases) were also positive for Epstein-Barr viral sequences. The four human immunodeficiency virus (HIV) negative lymphadenopathies positive for HHV-8 sequences showed an almost identical histology, characterized by a predominantly follicular lesion, with giant germinal center hyperplasia, and increased vascularity, resembling HIV-related lymphadenopathy and MCD. Our results, while providing the first evidence of the presence of HHV-8 sequences in AILD cases, suggest a possible association of these herpes viral sequences with a distinct histologic type of non-neoplastic lymphadenopathy, not associated with other common herpes infections.

Hepatitis C virus infection in subsets of neoplastic lymphoproliferations not associated with cryoglobulinemia

Hepatitis C virus (HCV) is both hepatotropic and lymphotropic and a clear-cut association has been proposed between HCV infection and mixed cryoglobulinemia (MC), a benign lymphoproliferative disorder, which sometimes evolves into a frank malignant B cell non-Hodgkin's lymphoma (B-NHL). Moreover, in the presence of antibodies to HCV, as well as of HCV-specific genomes has been reported in the sera of over 37% patients with B-NHL, not associated with MC. Thus, we decided to perform both a serologic and a molecular study to give insights into a possible relationship between HCV infection and neoplastic lymphoproliferations. We used ELISA and RIBA tests to show that anti-HCV antibodies were present in the serum of 29 out of 69 unselected B-NHL patients (42%), while seropositivity in a healthy population was about 1%. The prevalence of anti-HCV antibodies was low in definite subsets of B lymphoid disorders, including multiple myeloma, Waldenström's macroglobulinemia and monoclonal gammopathies of undetermined significance. Then, using reverse transcriptase polymerase chain reaction, we detected HCV sequences directly in the pathologic lymph node biopsies in 13 out of 34 B-NHL cases, and in particular in six out of eight low-grade lymphomas of MALT type and in five out of eight centroblastic-centrocytic follicular lymphomas. In contrast, the peripheral blood samples from 10 B cell chronic lymphocytic leukemia patients resulted negative for the presence of HCV genomes. Similarly, viral sequences were absent in 10 T cell NHL, while only one out of the 14 Hodgkin's disease cases tested resulted positive. Finally, we used a PCR-based assay to characterize the genotypes (I-IV) present in the positive lymphomatous tissues. The presence of both serologic and molecular markers of HCV infection in a high percentage of certain types of B-NHL, not associated with cryoglobulinemia, and its absence from other lymphoproliferative diseases extends the spectrum of HCV-associated lymphoproliferations arguing in favor of some role of this viral infection in the pathogenesis of the malignant proliferation of definite B lymphoid populations.

Human herpesvirus-6: a survey of presence and distribution of genomic sequences in normal brain and neuroglial tumors

In an attempt to study the frequency and distribution of human herpesvirus-6 (HHV-6) infection both in normal and neoplastic brain tissues in vivo, polymerase chain reaction was used to look for HHV-6 genomes: 1) in samples, obtained at necropsy, from different regions of the brain of immunocompetent adult subjects and of patients who died of AIDS; 2) in the surgical biopsies of a well-characterized series of primary brain tumors of neuroglial origin. HHV-6-specific sequences were identified in six of nine brain samples from immunocompetent subjects, and in four of seven brain samples from AIDS patients. Viral sequences were identified in the specimens derived either from the grey (frontal cortex and basal ganglia) or from the periventricular white matter. HHV-6 DNA was found only in 6 of the 37 primary brain tumor biopsies examined. This study provides for the first time molecular evidence of a wide distribution of HHV-6 infection in the brain tissues of a high proportion of subjects, both in normal and in impaired immunity. In this large series of tumor biopsies the presence of HHV-6 genomic sequences is a rare phenomenon, arguing against a major role of this herpesvirus in the pathogenesis of primary brain tumors of neuroglial origin in immunocompetent subjects.

Targeted integration of human herpesvirus 6 in the p arm of chromosome 17 of human peripheral blood mononuclear cells in vivo

Out of 64 cases of non-Hodgkin's lymphomas (NHL), 55 cases of Hodgkin's disease (HD) and 31 cases of multiple sclerosis (MS), 2 NHL, 7 HD and 1 MS cases were found positive by polymerase chain reaction (PCR) for the presence of HHV-6 sequences in pathologic lymph nodes of the lymphomas and in peripheral blood mononuclear cells (PBMCs) of MS. A further analysis of the PBMCs of the PCR positive cases by standard Southern blot technique revealed only 2 NHL, 3 HD and 1 MS cases as positive, indicating that these six patients have an unusually high viral copy number in the PBMCs. Restriction analysis, carried out using probes representative of different regions of the virus, showed that three cases retain only a deleted portion of the viral genome. In the remaining three cases a complete viral genome was present, containing the right end sequences in which the rep-like gene, possibly crucial to the viral and cellular life cycle, is located. The analysis by pulsed field gel electrophoresis (PFGE) of the total DNA of the PBMCs obtained directly, without culture from PBMCs of these last three cases (1 NHL, 1 HD, and 1 MS), using the same probes, showed the absence of free viral molecules and the association of viral sequences with high molecular weight DNA. These results are consistent with in vivo integration of the entire virus in the cellular genome. A further study of the same patients with chromosome fluorescence in situ hybridization (FISH) showed in all the three cases the presence of a specific hybridization site, located at the telomeric extremity of the short arm of chromosome 17 (17p13), suggesting that this location is at least a preferred site of an infrequent, but possibly biologically important, integration phenomenon.

p53 gene point mutations in relation to p53 nuclear protein accumulation in colorectal cancers

It is known that structural alterations of the p53 tumour suppressor gene cause malignant transformation and tumour progression in colorectal mucosa. In this study, 38 colorectal cancers were analysed for mutations detected in the p53 gene by single-strand conformational polymorphism and DNA sequence analysis, and the results were compared with p53 protein expression detected by immunohistochemistry. A very strict association (P < 0.0001) was found between genetic alterations and protein accumulation, as detected by the PAb 1801 monoclonal antibody. p53 expression and gene mutations were more frequent in rectal than in colonic cancers. No relation was observed with Dukes' stage, even though most of the mutations were at exon 7 in Dukes' A-B cancers and almost all mutations at exon 8 were observed in Dukes' C-D cancers. DNA ploidy was not generally associated with p53 protein expression or gene mutations. However, 83 per cent of cases with exon 5 and 6 mutations were diploid or near-diploid and 71 per cent of cases with mutations at exons 7 and 8 were aneuploid. Tumours with p53 gene mutations at exon 5 had a higher median [3H]thymidine labelling index (17 per cent) than those with mutations at exons 6, 7, and 8 (11.8 per cent).

Detection of PML-RAR alpha fusion transcript in Ph positive leukemia with acute promyelocytic phenotype lacking the t(15;17) cytogenetic abnormality

A 39-year-old woman was diagnosed with acute promyelocytic leukemia (APL) with disseminated intravascular coagulation syndrome. The hematologic examination showed a morphologic, cytochemical, and immunophenotypic picture typical of an APL, with a marked leukocytosis and a mixed population of hypergranular and microgranular promyelocytes. The cytogenetic analysis showed a 46,XX,t(9;22) karyotype, without any alterations of chromosomes 15 and 17. The t(15;17) translocation was not evident in FISH experiments, while a molecular analysis revealed the presence of a PML-RAR alpha chimera.

Spontaneous loss of Ph chromosome with maintenance of clonal hemopoiesis in an untreated patient with myeloproliferative disease and a long survival

The unusual case of myeloproliferative disease described here is characterized by the following features: (1) a clinically completely silent course for 11 years without splenomegaly, marrow fibrosis, or cellular morphologic alterations; (2) the presence, at the onset, of a Philadelphia (Ph) chromosome without DNA breakpoints in the M-bcr region; (3) the spontaneous loss of detectable Ph-positive cells, 5 years after the first finding of leukocytosis, in the absence of any therapy; (4) the maintenance of the clonal nature of hematopoiesis, as revealed by the PGK X-linked inactivation pattern, in the absence of the Ph chromosome; and (5) a biphasic trend in the levels of leukocytes, red cells, and platelets during the years of observation.