Biomedical subjects

D Catovsky

Publications and source records attributed to D Catovsky.

At least 109 records · Page 6Linked to original sources

PubMed1997

Growth of human T-cell lineage acute leukemia in severe combined immunodeficiency (SCID) mice and non-obese diabetic SCID mice.

Primary leukemic cells from patients with acute lymphoblastic leukemia (ALL) can be injected intravenously into mice with severe combined immunodeficiency (SCID) to create a model of human leukemia. Leukemic cells disseminate to murine tissues in a clinicopathologic pattern similar to that seen in humans. Thus far, reports of engraftment of lymphoid leukemia in SCID mice have mainly been from patients with B-cell lineage ALL, for which engraftment occurs more frequently with cells from high-risk patients. There are few data on the engraftment of T-cell lineage ALL in SCID mice. Leukemic cells from 19 patients (16 adult and three pediatric) with T-cell lineage ALL were injected into SCID mice, with overt engraftment of 12 cases (63%). Engraftment of leukemia in SCID mice was associated with earlier death due to leukemia of the patient donors (P < .01, log-rank test). The recently developed non-obese diabetic (NOD)/SCID mouse may expand the uses of the SCID model. Cells from the seven patients with T-cell lineage ALL that failed to cause leukemia in SCID mice were injected into NOD/SCID mice. Overt leukemia engraftment was observed in all seven cases. Thus, growth of human T-cell lineage ALL cells in SCID mice was associated with a high-risk patient group. However, this association was not observed when NOD/SCID mice were used, suggesting that this model would no longer predict patients likely to die early of leukemia, but may provide a more realistic system for studying the biology and treatment of the disease.

Acute Disease↗

PubMed1997

HTLV-I and HTLV-II infections in hematologic disorder patients, cancer patients, and healthy individuals from Rio de Janeiro, Brazil.

To clarify the seroprevalence of human T-cell lymphotropic virus type I (HTLV-I) among hematologic and cancer patients in the State of Rio de Janeiro, Brazil, we investigated sera from 2430 individuals from the following groups: 152 patients with T-cell diseases, 250 with B-cell disorders, 67 with myeloid leukemia, 41 with Hodgkin's disease, 351 with a history of multiple blood transfusions, 235 patients with solid tumors of different types, and 109 family members of HTLV-I-infected patients. Antibodies to HTLV-I were screened by enzyme-linked immunosorbent assay or particle agglutination assays (or both). Repeatedly reactive samples were tested by Western blot and polymerase chain reaction assay to differentiate HTLV-I from HTLV-II. We found an increased seroprevalence rate of HTLV-I among those with lymphoid malignancies, mainly in T-cell diseases (28.9%), and these results were important in characterizing 44 cases of adult T-cell leukemia/lymphoma. We confirmed the presence of HTLV-I and HTLV-II infections in blood donors (0.4% and 0.1%, respectively), in patients exposed to multiple blood transfusions (10.2% and 0.8%, respectively), and in 30 (27.5%) of 109 family members of HTLV-I- or HTLV-II-infected patients. We also confirmed the high rate occurrence of adult T-cell leukemia/lymphoma among lymphoproliferative disorders in Rio de Janeiro, Brazil.

Adolescent↗

PubMed1997

p53 abnormalities in B-cell prolymphocytic leukemia.

B-cell prolymphocytic leukemia (B-PLL) is an aggressive disorder of mature B cells with distinct clinical and pathologic features. To determine the incidence of abnormalities of p53, we analyzed 19 cases of B-PLL by DNA blot to assess loss of heterozygosity (LOH) at 17p13.3, by immunocytochemistry to assess p53 expression, and by direct DNA sequencing of polymerase chain reaction-amplified exons 5 to 9 of the p53 gene. LOH was detected in 10 of 19 (53%) cases, p53 expression was detected in 8 of 17 (47%), and p53 mutations were detected in 10 of 19 (53%) cases. The pattern of mutations was distinct from that observed in other B-cell malignancies. Six cases exhibited missense mutations; 4 were transversions and 2 were transitions. The G:C --> A:T transition at cathepsin G dinucleotides commonly reported in p53 mutations in chronic lymphocytic leukemia (CLL) and other hematologic malignancies was observed in only 1 case of B-PLL. Three cases exhibited deletions (ranging from 3 to 35 bp in length) and one case exhibited a 2-bp insertion. In 1 case, a 27-bp deletion resulted in the expression of a p53 protein lacking 9 amino acids from the DNA binding region. All samples with p53 mutation showed loss of germline p53 sequences. However, 3 of 10 showed no LOH by Southern blot, indicating a localized deletion around the p53 locus at 17p13.1. Five of the 10 cases with p53 mutation exhibited detectable p53 expression, including 4 cases with p53 missense mutation and 1 case with deletion. Two of 7 cases with no detectable mutation of p53 nevertheless overexpressed p53. Therefore, there was no correlation between protein expression and p53 mutation in B-PLL. Our data indicate that the overall abnormalities of p53 occurred in 14 of 19 (75%) cases of B-PLL. The frequency of p53 mutation (53%) in B-PLL is the highest reported in B-cell malignancies and may be responsible for the frequent resistance to therapy of this disease. In addition, the pattern of p53 mutation was different from that observed in CLL and other hematologic malignancies and may indicate that a distinct pathogenic mechanism operates in B-PLL.

Aged↗

PubMed1997

The search for genetic clues in chronic lymphocytic leukemia.

Research on the genetic basis of CLL is progressing at a rapid pace. The development of new techniques such as FISH, comparative genomic hybridisation (CGH) and a whole range of molecular methods is being applied to identify abnormalities in this relatively common B-cell leukaemia. The abnormalities may be of a different nature. There are some which are clearly associated with particular forms of the disease and usually with aggressive characteristics. The best examples are deletions at 11q23 seen in younger patients with generalised lymphadenopathy and inferior prognosis; trisomy 12, commonly associated with an increased proportion of prolymphocytes (CLL/PL) and more progressive disease; 17p abnormalities, chiefly mutations and deletions of p53, although rare, seem to be associated with transformation such as Richter syndrome, with CLL/PL and poor response to therapy. Abnormalities at 13q, though not correlated with particular clinical syndromes, are the subject of intense interest due to the possibility that one or more tumour suppressor genes relevant to the pathogenesis of CLL may be identified. Two areas in which work is being focused are 13q14 and 13q12. Finally, the incidence of familial cases of CLL, which has been known for a number of years, will lead to an international effort to collect familial cases, which ultimately will allow a genetic linkage study to discover a CLL "susceptibility gene". The presentations at the IWCLL were up-to-date, stimulating and pointed the way forward to further rapid progress in this exciting field.

Chromosome Aberrations↗

PubMed1997

Quantification of P-glycoprotein in chronic lymphocytic leukemia by flow cytometry.

The P-glycoprotein (P-gp) was investigated in 40 patients with chronic lymphocytic leukemia by immunological, functional and quantitative assays. The proportion of positive cases with the anti-Pgp McAb UIC2 was 30% and increased to 64% after neuraminidase treatment (p = 0.002). Fifty-six per cent of cases were positive with the functional test with rhodamine 123 and verapamil. A negative correlation was found between the number of cells stained with the McAb and the functional test (p = 0.006). The mean of P-gp molecules was 2509 +/- 2805 molecules per cell; these values were higher than in the control K562 cell line in the majority of cases. The number of positive cases and P-gp molecules were higher in treated than in untreated patients (p = 0.01 and 0.07). There were no significant differences with respect to response to treatment, but a higher number of P-gp molecules was found in non-responders. When the results of the functional test were put together with the quantification assay this allowed the detection of 71% non-responders. Our findings suggest that quantification of the P-gp could be of value in the assessment of possible drug resistance in CLL.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1997

Two unbalanced translocations, t(12;22)(p13;q11) and t(12;?)(p13;?), in an aggressive chronic B-cell leukemia: TEL gene analysis using FISH.

The translocation t(12;22)(p13;q11) has been consistently described in myeloid malignancies and shown to result from a fusion between the TEL and MN1 genes. Previously described deletions of 12p in acute lymphoblastic leukemias have been recently shown to harbor undetected translocations involving the TEL gene at 12p13. We document a case of an aggressive chronic B-cell leukemia whose cells had trisomy 12 and two unbalanced translocations involving 12p13, including a t(12;22)(p13;q11) as shown by conventional cytogenetics and fluorescence in situ hybridization (FISH). The 12p13 breakpoint of the t(12;22)(p13;q11) was telomeric to the TEL gene, and the second unbalanced translocation with breakpoint 12p13 resulted in the deletion of TEL. This case demonstrates that TEL gene deletions may be relevant in cases of mature B-lymphoproliferative diseases.

Chromosomes, Human, Pair 12↗

PubMed1997

Interphase cytogenetics in chronic lymphocytic leukemia.

The incidence of trisomy 12 and 13q12-q14 abnormalities in patients with chronic lymphocytic leukemia (CLL) was determined by conventional cytogenetics and interphase fluorescence in situ hybridization (FISH). In the analysis of 580 consecutive patients, trisomy 12 was detected by conventional cytogenetics in 39 cases (9%) and 117 cases (20%) by FISH. Trisomy 12 was shown to be associated with advanced clinical stage, atypical morphology, and higher proliferative activity. Combined immunophenotyping and FISH showed that trisomy 12 was present only in a proportion of the clonal B-cells. These data suggest that trisomy 12 is a secondary event associated with features of disease progression. Sequential FISH showed clonal progression of the trisomic clone over time. Three hundred patients also were investigated for 13q deletions using FISH analysis of the RB1 locus (13q14). Monoallelic RB1 deletion was seen in 104 (34%) of cases. One case had a homozygous deletion in 90% of the cells. Dual-color FISH detected the presence of trisomy 12 and RB1 in 17 (5%) cases. DNA probes for 13q12.3 (BRCA2) and 13q14 (RB1 and DBM locus) were used in 35 cases. Twenty-eight (80%) cases showed deletion of a 1Mb 13q12.3 encompassing the BRCA2 locus, whereas 22/35 (63%) were deleted at 13q14. Our data suggest that abnormalities of 13q are more frequent than trisomy 12 in CLL and provide evidence for the presence of a new candidate gene at 13q12.3 that may be involved in the pathogenesis of CLL.

Chromosome Deletion↗

PubMed1997

Clustering of missense mutations in the ataxia-telangiectasia gene in a sporadic T-cell leukaemia.

Ataxia-telangiectasia (A-T) is a recessive multi-system disorder caused by mutations in the ATM gene at 11q22-q23 (ref. 3). The risk of cancer, especially lymphoid neoplasias, is substantially elevated in A-T patients and has long been associated with chromosomal instability. By analysing tumour DNA from patients with sporadic T-cell prolymphocytic leukaemia (T-PLL), a rare clonal malignancy with similarities to a mature T-cell leukaemia seen in A-T, we demonstrate a high frequency of ATM mutations in T-PLL. In marked contrast to the ATM mutation pattern in A-T, the most frequent nucleotide changes in this leukaemia were missense mutations. These clustered in the region corresponding to the kinase domain, which is highly conserved in ATM-related proteins in mouse, yeast and Drosophila. The resulting amino-acid substitutions are predicted to interfere with ATP binding or substrate recognition. Two of seventeen mutated T-PLL samples had a previously reported A-T allele. In contrast, no mutations were detected in the p53 gene, suggesting that this tumour suppressor is not frequently altered in this leukaemia. Occasional missense mutations in ATM were also found in tumour DNA from patients with B-cell non-Hodgkin's lymphomas (B-NHL) and a B-NHL cell line. The evidence of a significant proportion of loss-of-function mutations and a complete absence of the normal copy of ATM in the majority of mutated tumours establishes somatic inactivation of this gene in the pathogenesis of sporadic T-PLL and suggests that ATM acts as a tumour suppressor. As constitutional DNA was not available, a putative hereditary predisposition to T-PLL will require further investigation.

Amino Acid Sequence↗

PubMed1997

G-CSF mobilization of haemopoietic cell populations in SCID mice engrafted with human leukaemia.

We have studied granulocyte colony-stimulating factor (G-CSF)-induced mobilization of haemopoietic cells in severe combined immune-deficient (SCID) mice engrafted with human leukaemia. Three leukaemia cell lines were investigated: the HL60 myeloblastic cell line, a chronic myeloid leukaemia (CML) xenograft cell line and an acute myeloid leukaemia (AML) xenograft line. Engraftment was detected using immunofluorescent staining of class I human leukocyte antigens and flow cytometry. All the tumours grew as disseminated disease with engraftment of bone marrow preceding involvement of peripheral blood (PB). After treatment with G-CSF (250 microg/kg/day) for 5 days, mobilization of haemopoietic progenitor cells (HPCs) was observed in non-engrafted SCID mice (40-fold) and in mice engrafted with human leukaemia (20-fold). G-CSF stimulated increases in PB HPCs and total numbers of host nucleated cells in leukaemia-bearing mice but did not induce rises in numbers of circulating HL60 colony-forming cells. Similarly, in mice engrafted with human CML or AML, G-CSF did not increase the number of malignant cells in the PB. These results provided evidence that the migration of normal and malignant haemopoietic cells into the PB are controlled by different mechanisms, and that contamination of PBSC harvests with leukaemic cells in SCID-human chimaeric mice is not enhanced by G-CSF-stimulated mobilization.

Animals↗

PubMed1997

Potential role for concurrent abnormalities of the cyclin D1, p16CDKN2 and p15CDKN2B genes in certain B cell non-Hodgkin's lymphomas. Functional studies in a cell line (Granta 519).

Abnormalities of several cell-cycle regulatory genes including cyclin D1, p16CDKN2 and p15CDKN2B have been described in B cell non-Hodgkin's lymphoma (B-NHL). We describe a new B-NHL cell line (Granta 519), with concurrent abnormalities of the cyclin D1, pl6CDKN2 and pl5CDKN2B genes. An independent clinical case of mantle cell NHL (Mc-NHL) with concomitant overexpression of cyclin D1, and deletion of the p16CDKN2 gene was also identified, suggesting that this combination of oncogenic aberration is a pathophysiologic contribution to a subset of NHL cases. More in-depth functional studies of this concept were facilitated by the availability of the cell line Granta 519 which was derived from a case of high-grade NHL and has a mature B cell immunophenotype. Cytogenetic analysis identified translocation t(11;14)(q13;q32) and complex rearrangements involving chromosomes 9p22, 13p21, 17pl1, and 18q21. Molecular analysis identified overexpression of cyclin D1 mRNA and biallelic deletion of the p16CDKN2 and p15CDKN2B genes. To elucidate the effect of these genetic abnormalities on the G1 control of Granta 519 cells, the level and function of the major components of the cyclinD/retinoblastoma (RB) pathway were investigated. Cyclin D1 was dominant among the D-type cyclins, formed abundant complexes with cyclin-dependent kinase (Cdk) Cdk4 rather than Cdk6, and the immunoprecipitated cyclin D1/Cdk4 holoenzyme was active as a pRB kinase. Electroporation of wild-type pl6CDKN2 arrested the Granta 519 cells in G1, consistent with the p16CDKN2 loss as a biologically relevant event during multistep evolution of the tumor, and with the expression of functional pRB. Direct cooperation of these distinct abnormalities to cell-cycle, deregulation in NHL cells was suggested by G1 acceleration upon inducible overexpression of cyclin D1 in a control breast cancer cell line lacking p16CDKN2, an effect which could be prevented by ectopic expression of p16CDKN2. Taken together, these data suggest that concurrent overexpression of cyclin D1 and functional elimination of p16CDKN2 and p15CDKN2B may characterize certain cases of mantle cell NHL, and that cooperation of the abnormalities is likely to provide a growth advantage of the tumour cells through more efficient inactivation of the RB tumor suppressor. Further clinicopathologic studies of this possibility are warranted.

Aged↗

PubMed1997

Adhesion receptors on peripheral blood leukemic B cells. A comparative study on B cell chronic lymphocytic leukemia and related lymphoma/leukemias.

The expression of a series of adhesion receptors: L-selectins (CD62L): Leu-8, several integrins (LFA-1: CD11a/CD18, VLA-4: CD49d/CD29 and VLA-5: CD49e/CD29), ICAM-1(CD54) and the 'homing receptor' (CD44) were investigated by a dual color flow cytometry in 56 cases of B cell disorders namely, 39 chronic lymphocytic leukemias (CLL), four hairy cell leukemia (HCL), seven splenic lymphoma with villous lymphocytes (SLVL) and six other non-Hodgkin's lymphoma (NHL). The functional activity of L-selectins was assessed with L-selectin ligand analogs (polyphosphomonester core polysaccharide: PPME and fucoidin). Leukemic B cells were identified with phycoerythrin-conjugated monoclonal antibodies (McAbs) anti-CD19, anti-kappa/lambda investigated simultaneously for the expression of adhesion receptors estimated with fluorescein-isothiocyanate (FITC) conjugated McAbs. The percentage of leukemic cells expressing L-selectins (Leu-8) was high in CLL (52% of positive cases) and integrin expression (LFA-1, VLA-4, 5) was low (19 and 33%, respectively), while a reverse pattern, low Leu-8 (17%), and a high VLA-4 (77%), was observed in non-CLL cases. The expression of LFA-1 alpha-chain was variable in non-CLL cases, and the LFA-1 heterodimer was expressed on most clonal B cell in NHLs (92%). LFA-1 alpha-chain was detected on cells from only one HCL case, while beta2 integrin was regularly expressed on hairy cells. VLA-5 integrin was found on a relatively small number (26%) of mature B cell leukemias. A remarkable finding was the detection of ICAM-1 in all CLL cases albeit the number of positive cells was significantly lower (P < 0.05) compared to non-CLL cases. CD44 was expressed on a high number of neoplastic cells in all the investigated categories. There was no correlation between the expression of the adhesion molecules and clinical and laboratory parameters except for CD18 which was expressed on a significantly (P < 0.05) higher number of leukemic cells in CLL with more advanced stages. This study demonstrates that even closely related B cell leukemia/lymphomas have a certain well defined and strictly variable adhesion profile which is characteristic of the disease entity and therefore, the adhesion profile may offer additional information useful for differential diagnosis and study of disease pathogenesis.

Adult↗

PubMed1997

Sezary cell leukaemia: a distinct T cell disorder or a variant form of T prolymphocytic leukaemia?

We report the clinical, ultrastructural, immunophenotypic and virological features of nine cases of a rare type of mature T cell disorder formerly designated Sezary cell leukaemia. All patients presented with lymphocytosis ranging from 12.7 to 133 x 10(9)/l, bone marrow infiltration, splenomegaly and lymphadenopathy. Skin involvement was absent at presentation but developed as a terminal event in two patients, one of whom showed a pattern of dermal infiltration different from that characteristic of Sezary syndrome. Cells from eight cases bore a mature T cell phenotype and electronmicroscopy revealed lymphocytes with cerebriform nuclei resembling Sezary cells. All cases except one were HTLV-I negative. Patients were treated with various chemotherapy regimens but with poor outcome, the median survival being 13 months. Laboratory and clinical data suggest great similarity between Sezary cell leukaemia and T prolymphocytic leukaemia (T-PLL), namely coexpression of CD4 and CD8 (3/9 cases), identical chromosomal abnormalities in the three cases studied (isochromosome 8q plus inversion 14 or t(X;14)(q28;q11)) and a remarkable sensitivity to CAMPATH-1H (complete remission of 21 months' duration in one patient), suggesting that this entity could be considered a variant form of T-PLL. The alternative diagnosis of adult T cell leukaemia/lymphoma could not be excluded in one patient in whom positive HTLV-I serology was documented.

Adult↗

PubMed1997

The human T-cell lymphotropic viruses types I/II are not involved in T prolymphocytic leukemia and large granular lymphocytic leukemia.

The possible involvement of the human T lymphotropic viruses type I and II (HTLV-I and -II) in lymphoproliferative disorders of mature T cells other than adult T cell leukemia/lymphoma (ATLL) has been controversial. Most studies have focused primarily on the cutaneous T cell lymphomas. However, skin involvement is a frequent feature of T prolymphocytic leukemia (T-PLL) and antibodies against HTLV-I and -II have been reported in individuals with large granular lymphocytic (LGL) leukemia. We examined 36 patients with T-PLL and 28 with LGL leukemia for evidence of HTLV-I and -II. Polymerase chain reaction (PCR) was performed on DNA from fresh peripheral blood mononuclear cells (PBMCs) and PBMCs after short-term culture (STC) using primers against all parts of the HTLV-I genome (LTR, gag, env, pol, tax/rex) and against HTLV-II pol and gag. Reverse transcriptase (RT) activity was measured on supernatants from STCs using a sensitive PCR-based technique. No HTLV-I or -II sequences were found by PCR nor RT activity detected in the 64 cases. Our findings do not provide evidence of HTLV-I or -II infection in T-PLL and LGL leukemia patients from an HTLV-I nonendemic area. Previous positive reports on these disorders may represent technical artefacts, detection of endogenous HTLV-like sequences or reflect patients from endemic areas and a variable etiology of T cell diseases.

Human T-lymphotropic virus 1↗

PubMed1997

Analysis of residual disease in chronic lymphocytic leukemia by flow cytometry.

We have investigated the value of both conventional and quantitative flow cytometry to detect minimal residual disease in 21 CLL patients in remission including bone marrow histology: eight in complete remission (CR), 11 in nodular partial remission (nPR) and two in PR. The techniques used were double immunostaining with CD5 and CD19 and quantitative estimation of the number of both antigens with standard microbeads. Reference values were established on normal peripheral blood and bone marrow controls. Patients were considered in 'immunological' remission when the percentage of CD5+ CD19+/total CD19+ cells was <25% in PB and <15% in BM. In six of the eight patients in CR, CLL cells were still detectable by flow cytometry. Only two patients, that underwent allogeneic bone marrow transplant, achieved immunological remission. CLL samples showed significantly higher CD5 and lower CD19 antigen density than normal controls (P < 0.001). Persistence of residual disease was a predictor of time to progression. None of the two patients in immunological remission relapsed within a period of 13 and 33 months, whilst two of the six patients in CR with positive flow cytometry relapsed 3 and 6 months after achieving CR. This study demonstrates that flow cytometry contributes to increase the sensitivity of the clinicohematological criteria to detect residual malignant cells in CLL patients and may be useful to monitor disease status following treatment.

Adult↗

PubMed1997

In vivo 'purging' of residual disease in CLL with Campath-1H.

We assessed the role of human CD52 antibody (Campath-1H) in six patients with chronic lymphocytic leukaemia (CLL) treated to maximal response with purine analogues (fludarabine/deoxycoformycin) in whom persistent leukaemic infiltration of blood and bone marrow had precluded autologous stem cell transplantation. Five patients achieved haematological and histological complete remission following Campath-1H and one had minimal focal residual CLL in a trephine biopsy. Autologous transplantation was performed in two patients without complications and with rapid haemopoietic engraftment. Treatment with Campath-1H may be of value in eradicating residual disease in CLL and may facilitate high-dose therapy in young patients.

Adult↗

PubMed1997

Interferon-gamma+ and interleukin-2+ T cells in peripheral blood from multiple myeloma patients in relation to disease status and maintenance therapy with interferon-alpha2b (intron A).

Peripheral blood T cells from 83 patients with multiple myeloma (MM) were examined for the production of interferon-gamma (INF-gamma) and interleukin-2 (IL-2) using three-colour flow cytometry. Comparisons were made between the percentage of cytokine-positive lymphocytes in normal donors and in patients during remission or relapse. Patients were divided into those who were on maintenance therapy with interferon-alpha2b (intron A) and those who had no further treatment after high-dose melphalan (HDM) with or without autologous bone marrow (ABMR) or peripheral blood stem cell rescue (PBSCR). The percentage of INF gamma+/CD3+, INF gamma+/CD45RO+/CD3+ and IL-2+/CD8+ was higher in patients on INF alpha2b during remission and relapse compared with normal donors (P<0.005). During remission INF gamma+/CD45RO+/CD3+ and IL-2+/CD8+ lymphocytes were higher in patients not on INF alpha2b (P<0.05 and P<0.005, respectively). In relapsed patients INF gamma+/CD3+ and INF gamma+/CD45RO+/CD3+ were increased in patients not taking INF alpha2b (P<0.005). There was no significant difference between the percentages of cytokine-positive lymphocytes in patients taking or not taking INF alpha2b either during remission or relapse. Plasma IL-6 levels were similar in both groups of patients during remission. The data suggest that if maintenance therapy with INF alpha2b induces the synthesis of INF gamma and IL-2 in vivo, the magnitude of the effect is small and may be unimportant in providing an anti-tumour effect in the majority of patients.

Antineoplastic Agents↗

PubMed1997

The significance of minimal residual disease in hairy cell leukaemia treated with deoxycoformycin: a long-term follow-up study.

We investigated the clinical significance and long-term follow-up of detecting minimal residual disease (MRD) in hairy cell leukaemia (HCL) in complete remission (CR) after treatment with deoxycoformycin (DCF). MRD was assessed in 23 patients by immunophenotyping peripheral blood and bone marrow frozen sections using a panel of antibodies, CD11c, CD25, CD103 and HC2, which detect hairy cells. 31 cases with active HCL were used as controls. 10/23 patients (43%) had MRD in bone marrow (seven), blood (one) or both sites (two) which was not detected on haematoxylin-eosin bone marrow sections nor by immunohistochemistry on paraffin sections in six cases tested. Sequential studies in four cases did not show changes in the amount of MRD. At a median follow-up of 72 months (range 15-108), 5/23 (22%) patients have relapsed with a median time of 59 months (range 15-105). MRD was detected in three of the five patients who relapsed. In the two patients with negative MRD, one relapsed with an abdominal mass and the other was a late relapse at 84 months. MRD was also documented in 7/18 patients who continued in clinical CR for a median of 80 months (range 63-98). There were no statistical differences in disease-free survival between MRD+ and MRD- patients (P = 0.8). Our findings indicate that relapse after long-term remission achieved with DCF cannot be predicted when MRD is detected by sensitive methods. A search for other parameters such as proliferative rate of the residual cells or chest and abdominal CT scan might identify patients with a higher probability of disease recurrence.

Adult↗

PubMed1997

A randomized comparison of liposomal versus conventional amphotericin B for the treatment of pyrexia of unknown origin in neutropenic patients.

One hundred and thirty-four adults and 204 children were randomized in two prospective, parallel comparative multicentre trials to receive either conventional amphotericin B 1 mg/kg/d (c-AMB), liposomal amphotericin B 1 mg/kg/d(L-AMB1) or liposomal amphotericin B 3 mg/ kg/d (L-AMB3). Patients were entered if they had a pyrexia of unknown origin (PUO) defined as temperature of 38 degrees C or more, not responding to 96 h of systemic broad-spectrum antibiotic treatment, and neutropenia (< 0.5 x 10(9)/l). The safety and toxicity of liposomal amphotericin B was compared with that of conventional amphotericin B. Efficacy of treatment was assessed, with success defined as resolution of fever for 3 consecutive days (< 38 degrees C) without the development of any new fungal infection. Clinical and laboratory parameters were collected for safety analysis. In both the paediatric and adult populations, L-AMB treated patients had a 2-6-fold decrease in the incidence (P < or = 0.01) of test-drug-related side-effects, compared to c-AMB. Severe trial-drug-related side-effects were seen in 1% of L-AMB treated patients, in contrast to 12% of patients on c-AMB (P < 0.01). Nephrotoxicity, in the patient subset not receiving concomitant nephrotoxic agents, defined as a doubling from the patients baseline serum creatinine level, was not observed in the L-AMB1 arm whereas the incidence was 3% in patients on L-AMB3 and 23% in those on c-AMB (P < 0.01). Moreover, time to develop nephrotoxicity was longer in both L-AMB arms than c-AMB (P < 0.01). Severe hypokalaemia was observed less frequently in both L-AMB arms (P < 0.01). Analysis was by intention-to-treat and included all patients randomized. Success was defined by a minimum of 3 consecutive days with fever (< 38 degrees C) continuing to study end indicated by recovery of neutrophils to 0.5 x 10(9)/l. Addition of systemic antifungal therapy or development of systemic fungal infection were failures as was persistent fever to study end. Efficacy assessments indicated success in 49% of the total group treated with c-AMB, 58% of patients responded to L-AMB1 and 64% to L-AMB3. A statistically significant difference was found between c-AMB and L-AMB3 (P = 0.03) but a Kaplan-Meier analysis of time to differvescence of fever showed there was no significant difference between the arms. It was concluded that liposomal amphotericin at either 1 or 3 mg/kg/d was significantly safer than conventional amphotericin B in children and adults. The main aim of this open-label study was to compare safety between the three trial arms. However, we provide evidence for an equivalent or possibly superior efficacy of liposomal amphotericin with regard to resolution of fever of unknown origin. Subsequent trials should compare amphotericin preparations in defined fungal infections.

Adult↗