Update on transcobalamin deficiency: clinical presentation, treatment and outcome

Transcobalamin (TC) transports cobalamin from blood into cells. TC deficiency is a rare autosomal recessive disorder usually presenting in early infancy with failure to thrive, weakness, diarrhoea, pallor, anemia, and pancytopenia or agammaglobulinemia. It can sometimes resemble neonatal leukemia or severe combined immunodeficiency disease. Diagnosis of TC deficiency is suspected based on megaloblastic anemia, elevation of total plasma homocysteine, and blood or urine methylmalonic acid. It is confirmed by studying the synthesis of TC in cultured fibroblasts, or by molecular analysis of the TCN2 gene. TC deficiency is treatable with supplemental cobalamin, but the optimal type, route and frequency of cobalamin administration and long term patient outcomes are unknown. Here we present a series of 30 patients with TC deficiency, including an update on multiple previously published patients, in order to evaluate the different treatment strategies and provide information about long term outcome. Based on the data presented, current practice appears to favour treatment of individuals with TC deficiency by intramuscular injections of hydroxy- or cyanocobalamin. In most cases presented, at least weekly injections (1 mg IM) were necessary to ensure optimal treatment. Most centres adjusted the treatment regimen based on monitoring CBC, total plasma homocysteine, plasma and urine methylmalonic acid, as well as, clinical status. Finally, continuing IM treatment into adulthood appears to be beneficial.

Autoimmune manifestations in acquired idiopathic splenic atrophy: A puzzling association

Splenic atrophy is an uncommon diagnosis associated with celiac sprue or other well-characterized connective tissue diseases, drepanocytosis, or amyloidosis. We report two patients with splenic atrophy revealed by thrombocytosis. Both patients had anti-nuclear antibodies. Patient 1 also had a grade III Chisholm lymphocytic sialadenitis with a rheumatoid factor, anti-extractable nuclear antibodies, and a polyclonal hypergammaglobulinemia consistent with the diagnosis of Sjögren's syndrome. Patient 2 displayed a previous history of idiopathic pericarditis. An anti-pneumococcal vaccination was given to both patients and neither experienced infectious complications. Splenic atrophy should be suspected in patients with thrombocytosis of unexplained origin and a blood smear consistent with asplenia. Such patients must be checked for clinical and biological symptoms of autoimmune disorders.

High efficacy and safety profile of fractionated doses of Mylotarg as induction therapy in patients with relapsed acute myeloblastic leukemia: a prospective study of the alfa group

Pivotal phase II studies in acute myeloblastic leukemia (AML) patients in first relapse have used gemtuzumab ozogamicin (GO) (Mylotarg) at a dose of 9 mg/m(2) on days 1 and 14. These studies showed a 26% response rate (13% complete remission (CR) and 13% CRp (complete remission with incomplete platelet recovery)) but with high degree of hematological and liver toxicities. Based on in vitro studies showing a re-expression of CD33 antigenic sites on the cell surface of blasts cells after exposure to GO, we hypothesized that fractionated doses of GO may be efficient and better tolerated. Fifty-seven patients with AML in first relapse received GO at a dose of 3 mg/m(2) on days 1, 4 and 7 for one course. Fifteen patients (26%) achieved CR and four (7%) CRp. Remission rate correlated strongly with P-glycoprotein and MRP1 activities. The median relapse-free survival was 11 months, similar for CR or CRp patients. Median duration of neutropenia < 500/microl and thrombocytopenia < 50,000/microl were, respectively, 23 and 21 days. No grade 3 or 4 liver toxicity was observed. No veno-occlusive disease occurred after GO or after hematopoietic stem cell transplantation given after GO in seven patients. Mylotarg administered in fractionated doses demonstrated an excellent efficacy/safety profile.

Design and first interim analysis of a randomized phase III trial comparing imatinib versus imatinib (IM) based combination therapies in newly diagnosed chronic myelogenous leukemia patients in chronic phase

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Background: Despite impressive results achieved with IM 400 mg/day alone, only a minority of pts reached a complete molecular remission at 12-month. Higher dose of IM or its combination with other therapies might improve molecular remission. Design of the trial: the 3 experimental arms are IM 400mg daily in combination with Peg-IFN-α2a (Peg-IFNα2a, 90 μg weekly) or with Ara-C (20 mg/m2/day, days 15–28 of 28-day cycles) or IM 600mg daily. The reference arm is IM 400mg daily. All pts (over 18 years of age with Bcr-Abl positive CML) receive IM 400 mg/day as monotherapy days 1–14 and then start the assigned regimen for at least 12 months. The endpoints are overall survival (primary), rate and duration of hematologic, cytogenetic and molecular responses and tolerability. An interim analysis of the first 636 pts at 1 year from randomization will allow evaluation of molecular response rates, one of the experimental arm being selected for further comparison with IM 400. An experimental arm would be selected if it increased the 4 log reduction response rate at 12-month by at least 20 percentage points, (15% to 35%), with an acceptable tolerability. Results: This evaluation is based on a cohort of 370 pts with a median time of observation of 16 months, recruited between 9/2003 and 9/2005. [median age 53 yrs (18–81); Sokal distribution: 38% of pts low, 38% intermediate, and 24% high]. At 1 month 80% of pts achieved complete hematologic response. At 12 months, 138 pts (72%) achieved a major cytogenetic response, being complete in 120 pts (63%). Grade 3/4 hematologic toxicity occurred in 8% of IM400 pts, 9% of IM600 pts, 41% of IM+IFN pts and 33% of IM+Ara-c pts respectively. Dose of Peg IFN was reduced in 16% of pts, 45 μg per week being well tolerated. Grade 3/4 non hematological toxicity occurred in 11% of IM400 pts, 16% of IM600 pts, 10% of IM+IFN pts (maily skin rash) and 11% of IM+Ara-c pts. Discontinuation of experimental treatment occurred in 17% of IM600 pts, 36% of IM+IFN pts and 16% of IM+Ara-c pts. Conclusion: This first analysis confirmed both feasibility of IM combinations and high response rates. However a substantial hematological toxicity requires a careful assessment of pts.

[Table: see text]

Prediction of relapse by day 100 BCR-ABL quantification after allogeneic stem cell transplantation for chronic myeloid leukemia

Chronic myeloid leukemia (CML) relapse after allogeneic stem cell transplantation (SCT) is a relatively frequent situation, which is correlated to disease status, time from diagnosis to transplant and T-cell depletion. We evaluated the potential for early minimal residual disease (MRD) BCR-ABL quantification to predict relapse of CML patients receiving allogeneic SCT. Minimal residual disease was analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction (RQ-PCR) at day 100 (d100) in 38 patients with >1 year follow-up after conventional non-T-cell-depleted SCT. Normal ABL control values from 1724 follow-up blood samples were used to define an RQ-PCR amplifiability index and the limits of reliable use of BCR-ABL ratios. We then compared the 14 patients with a high-level d100 BCR-ABL/ABL ratio (> or = 10(-4)) to that of the 24 patients with a negative/low-level ratio (<10(-4)). Despite being comparable for all classical parameters, the incidence of relapse was significantly higher in the high MRD group (11/14 (79%)) compared to that of the low/negative MRD group (7/24 (29%)) (P = 0.009), with d100 MRD values representing an independent risk factor of relapse and disease-free survival, but not of overall survival, in multivariate analysis. These data should facilitate risk-adapted post-transplant immunosuppression and/or tyrosine kinase inhibitor therapy based on an early evaluation of MRD.

The VAD chemotherapy regimen plus a G-CSF dose of 10 μg/kg is as effective and less toxic than high-dose cyclophosphamide plus a G-CSF dose of 5 μg/kg for progenitor cell mobilization: results from a monocentric study of 82 patients

A study was conducted to compare the efficiency and toxicity of two peripheral blood stem cell (PBSC) mobilization procedures for newly diagnosed patients with multiple myeloma. Patients from group 1 (n=51) were treated by high-dose cyclophosphamide (HD-CY) plus G-CSF (5 microg/kg/day), and the second group (n=31) by VAD regimen plus G-CSF administration (10 microg/kg/day). Successful mobilization, defined by a minimal count of 2.5 x 10(6) CD34(+) cells/kg collected, was achieved in 96 and 90% of patients in groups 1 and 2, respectively (P=0.15). The mean peripheral blood CD34(+) cells concentration and the mean CD34(+) cells/kg collected were higher in group 2 than in the group 1 (P=0.05). The mean number of leukaphereses necessary to collect a count of 2.5 x 10(6) CD34(+) cells/kg was reduced in group 2 compared to group 1. Adverse events, blood products consumption and time spent in the hospital were significantly greater after HD-CY. In conclusion, VAD plus a G-CSF dose of 10 microg/kg administration seems preferential to HD-CY plus a G-CSF dose of 5 microg/kg for PBSC collection because of equivalent or better efficiency in stem cell mobilization, strong favorable toxicity profile and reduced cost.

Plasmocytome cutané EBV+ isolé chez une malade transplantée rénale : efficacité d’un traitement par rituximab

INTRODUCTION

Postransplant lymphoproliferative disorders are well known complications of solid organ transplant, usually associated with Epstein-Barr virus (EBV).

OBSERVATION

A 25 year old renal transplant patient presented with two subcutaneous nodules on the lower limb that appeared 3 years after a second renal transplantation. Biopsy of one nodule showed an EBV associated plasmocytoma located in the subcutaneous tissue. A complete systemic evaluation showed no evidence of extracutaneous involvement. The patient was treated with anti CD20 therapy (rituximab), and complete remission was achieved.

DISCUSSION

Extranodular localisations of postransplant lymphoproliferative disorders are usually reported, but cutaneous localizations are rarely described. Histological presentation are various, but plasmocytoma-type is infrequent. Initial therapy of cutaneous EBV-associated postransplant lymphoproliferative disorders without extracutaneous involvement consists in reduction of the immunosuppression therapy and/or an antiviral treatment and prolonged surveillance. Treatment with monoclonal anti-CD20 antibodies (rituximab) is proposed.

T-cell prolymphocytic leukemia with autoimmune manifestations in Nijmegen breakage syndrome

Nijmegen breakage syndrome (NBS) is characterized by growth retardation, microcephaly, mental retardation, immunodeficiency, and predisposition to malignancies, especially B-cell lymphomas. In contrast, leukemia is rare. A 23-year-old NBS patient presented with anemia, thrombocytopenia, and hyperlymphocytosis. The diagnosis of T-cell prolymphocytic leukemia (T-PLL) was confirmed by cytological and immunological assays (TdT(-), CD2(+), CD5(+), CD3m, and CD7(+)). Biological assays also showed a hemolytic anemia and a clotting factor V decrease. The patient was first treated by methylprednisone for 3 weeks. During this period the lymphocyte count decreased. The simultaneous normalization of the hemolysis and of factor V suggested that both could be related to T-PLL. Since T-PLL is refractory to conventional therapies with a poor prognosis, an intensive chemotherapy such as 2'-deoxycoformycin with anti-CDw52 monoclonal antibodies is usually favored. In the present case, however, because of the specific context (i.e., NBS-induced immunodepression, severe hemolytic anemia, and acquired factor V deficiency), he received pentostatin weekly during 1 month and in maintenance during 6 months. At last follow-up (7 months) he showed a persistent control of the lymphocytosis with no side effect.

Primary follicular lymphoma of the gastrointestinal tract: a study of 25 cases and a literature review

BACKGROUND

To describe better the clinical, biological, endoscopic and pathological presentations, as well as the outcome, of primary follicular lymphoma (FL) of the gastrointestinal (GI) tract.

PATIENTS AND METHODS

From November 1983 to February 2001, 25 eligible patients with primary FL of the GI tract were retrieved from several French Departments of Pathology departments based on histological diagnosis and immunophenotype. Median age was 56 years (range 44-71) with a sex ratio female/male of 2 (17/8).

RESULTS

Abdominal pain was the main presenting symptom followed by intestinal obstruction. The small intestine was the most common site of involvement. Lesions were unifocal in the majority of patients (15/25). A pattern similar to lymphomatous polyposis was observed in 50% (7/14) of patients. Twelve patients had stage I, 10 patients stage II and three patients stage IV disease, and there was minimal extra intestinal involvement. Lymphoma tissues were composed of neoplastic follicles, most of which were grade 1 according to the World Health Organization (WHO) classification. The immunophenotype of the lymphoma cells was CD20+, CD10+, bcl2+ and CD5-. In tissue samples, IgH/bcl2 rearrangement at the MBR locus was present in 11 of 14 patients tested. Seven patients did not receive any treatment; four of them progressed after a median follow-up of 37.5 months. Treatment was otherwise heterogeneous, and complete remission was obtained in 15 patients which lasted for a median of 31 months. Relapses were either in the GI tract (n = 3) or outside the GI tract (n = 3). After a median follow-up of 34 months (range 5-203), 22 patients were still alive (complete remission, 11; partial remission, three; stable disease, six; progressive disease, two).

CONCLUSIONS

Primary FL of the GI tract is a predominantly female lymphoma that most frequently involves the small intestine. Since the endoscopic and clinical presentation may not be different from lymphomatous polyposis, which is often associated with mantle cell origin of tumor cells, it is mandatory to perform an immunohistological and, if possible, a molecular analysis of GI lymphoma. The course of the disease is indolent and does not differ from nodal FL. Thus, therapy may not be required unless significant clinical symptoms are present or until disease progression.

The stem cell mobilizing capacity of patients with acute myeloid leukemia in complete remission correlates with relapse risk: results of the EORTC-GIMEMA AML-10 trial

Variable numbers of CD34+ cells can be harvested from the blood of AML patients in CR after G-CSF supported mobilization following consolidation chemotherapy. We hypothesized that a decreased ability to mobilize stem cells reflects a chemotherapy-induced reduction in the number of normal and leukemic stem cells. We therefore analyzed whether the mobilizing capacity of these patients was of prognostic significance. 342 AML-patients in first CR received daily G-CSF from day 20 of the consolidation course and underwent 1-6 aphereses to obtain a minimum dose of 2 x 10(6) CD34+ cells/kg. Afterwards they were randomized for autologous bone marrow (BM) or blood SCT. As a surrogate marker for the mobilizing capacity, the highest yield of CD34+ cells of a single apheresis was adopted. Patients could be categorized into four groups: no harvest (n = 76), low yield (<1 x 10(6) CD34+/kg; n = 50), intermediate yield (1-6.9 x 10(6) CD34+ cells/kg; n = 128) and high yield (> or = 7 x 10(6) CD34+ cells/kg; n = 88). The median follow-up was 3.4 years; 163 relapses and 16 deaths in CR were reported. Autologous blood or BM SCT was performed in 36%, 64%, 81% and 88%, respectively, of the patients assigned to the no harvest, low, intermediate and high CD34+ yield group. The 3-year disease-free survival rate was 46.7%, 65.0%, 50.4% and 26.9% (P = 0.0002) and the relapse incidence was 47.5%, 30.1%, 43.1% and 71.9% (P < 0.0001). Multivariate Cox's proportional hazards model showed that the CD34+ yield was the most important independent prognostic variable (P = 0.005) after cytogenetics. Patients with the highest mobilizing capacity have a poor prognosis due to an increased relapse incidence.

Hypereosinophilia as a presenting sign of acute graft-versus-host disease after allogeneic bone marrow transplantation

The authors report two cases of hypereosinophilia as the major presenting sign of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT). Tissue biopsies of the skin, salivary gland, gut, and liver showed evidence of acute GVHD (aGVHD). In one case, further investigations have been performed. Elevated levels of interleukin (IL)-5 and soluble IL-2 receptor were found in the blood, and skin biopsy specimens demonstrated high levels of IL-5 messenger ribonucleic acid (mRNA). In contrast, skin biopsy specimens from other patients with aGVHD but without eosinophilia were negative for IL-5 mRNA. The authors also demonstrated the presence of IL-4 and interferon(IFN)-gamma mRNA within the same skin biopsy specimen, suggesting that this case of aGVHD was mediated by both Th1 and Th2 cell type. These two patients were treated by glucocorticoids with resolution of the hypereosinophilia and the symptoms of GVHD. The authors briefly discuss the possible mechanisms of this hypereosinophilia with respect to aGVHD.

Remission of transformed myelodysplastic syndrome with fibrosis after danazol therapy

Danazol has been used with success in some hematological diseases, but there is no report of this treatment in acute leukemia. We report here a case of remission of myelodysplastic syndrome with myelofibrosis in transformation after danazol therapy in a 72-yr-old man. The role of danazol in remission induction is briefly discussed.

Sequential chemotherapy by CHOP and DHAP regimens followed by high-dose therapy with stem cell transplantation induces a high rate of complete response and improves event-free survival in mantle cell lymphoma: a prospective study

Mantle cell lymphoma (MCL) is a distinct clinico-pathological entity with a poor prognosis. We have conducted a prospective study in patients with MCL to evaluate a therapeutic strategy in which CHOP polychemotherapy was followed by DHAP if CHOP failed to induce complete remission. Responding patients then proceeded to an intensification therapy with autologous peripheral blood stem cell transplantation (APBSCT). Twenty-eight consecutive patients with newly diagnosed aggressive MCL were included. After four cycles of CHOP regimen, two complete responses (CR) were obtained (7%) and 14 (50%), five (18%) and seven (25%) patients achieved partial (PR), minor (MR) and no response, respectively (one patient died from septic complications during CHOP induction). The two patients in CR after CHOP underwent intensification with TBI, high-dose cyclophosphamide-etoposide and APBSCT. The other twenty-five patients received DHAP and in this group a response rate of 92% (21 CR (84%), two PR (8%)) was observed. Two patients had progressive disease. The twenty-three responding patients received high-dose therapy (TAM8 regimen: TBI-cytarabine-melphalan) followed by APBSCT. One of the two partial responding patients achieved CR after TAM8. After a median follow-up of 47.6 months (range, 14-70), seven patients have relapsed. Our data confirm that: (1) CHOP regimen induces a low CR rate in MCL; (2) CHOP plus DHAP appears to be much more efficient and allows a large proportion of patients to proceed to high-dose therapy in CR; (3) consolidation therapy including TBI and high-dose Arac-C followed by APBSCT may improve event-free survival.

Typical essential thrombocythaemia does not express bcr-abelson fusion transcript

Essential thrombocythaemia (ET) is a chronic myeloproliferative disorder (MPD) characterized by an elevated platelet count and no identifiable underlying primary cause. According to the diagnostic criteria of the Polycythemia Vera Study Group (PVSG), ET lacks features diagnostic for other MPDs, including the Philadelphia chromosome (Ph) or bcr-abl rearrangement. Recently, some authors have reported bcr-abl transcript positivity in ET patients, but these findings remain controversial. The aim of this study was to investigate whether the bcr-abl transcript could be found in ET patients and to verify the hypothesis of a new ET variant. ET patients (n = 121) with a median age at diagnosis of 55 years were enrolled. The bcr-abl transcript status was examined by multiplex reverse transcription-polymerase chain reaction. Only two cases were positive for bcr-abl, one of which had the Ph at diagnosis. The positive bcr-abl transcript was associated, in both cases, with mild basophilia at diagnosis. After a median follow-up of 43 months (0-309 months), two patients in the bcr-abl-negative group developed Ph and bcr-abl-negative acute myeloid leukaemia (AML). In contrast, one of the two patients in the bcr-abl-positive group died from AML 13 years after diagnosis. In conclusion, our data on a large group of patients shows the rarity of the bcr-abl transcript in well-established ET. However, a subset of patients with apparent ET and basophilia may express the transcript and may constitute a novel entity intermediate between chronic myeloid leukaemia (CML) and typical ET. A prospective study is warranted in order to define better the clinical and biological characteristics of bcr-abl-expressing ET.

Multiple herpes simplex virus infections with various resistance patterns in a matched unrelated donor transplant recipient

A 45-year-old matched unrelated BMT recipient had sequential mucocutaneous herpes simplex virus (HSV) type 2 infections. Five months after BMT, a penile lesion occurred and was cured using acyclovir, as expected from in vitro susceptibility results. The same lesion recurred 1 month later but worsened with acyclovir. The HSV isolate was resistant to acyclovir (IC(50) = 105 microM), and a nucleotide (G) was added to the thymidine kinase gene leading to a premature stop codon. The lesion improved markedly with foscarnet. During this treatment a second HSV infection occurred on the buttocks 2 weeks after the first one and healed completely with acyclovir. This course correlated with in vitro results of the buttock HSV isolate which was foscarnet-resistant (IC(50) = 300 microg/ml) and acyclovir-sensitive. Surprisingly, no mutation gene of the foscarnet-resistant isolate was detected in the DNA polymerase gene. This case shows that an HSV acyclovir-resistant infection may be followed by an acyclovir-sensitive one. Determination of antiviral susceptibility is needed to monitor the treatment of various HSV infections in immunocompromised BMT recipients.

BCR-ABL fails to inhibit apoptosis in U937 myelomonocytic cells expressing a carboxyl-terminal truncated STAT5

Recent experimental data suggest that one of the major effects of BCR-ABL gene expression in hematopoietic cells is the inhibition of apoptosis. Although the exact mechanisms of this phenomenon are not clear, it is thought to be related to the fact that BCR-ABL induces several signalling pathways also activated by growth factors. In order to determine the anti-apoptotic role of BCR-ABL in a hematopoietic cell line and to by-pass the influence of cytokine-dependence, BCR-ABL gene was expressed in the autonomously growing myelomonocytic U937 cell line using retroviral vectors. There was no resistance to apoptosis induced by either serum deprivation or different doses of etoposide in any U937 clones expressing BCR-ABL protein. In addition to serum deprivation and etoposide, BCR-ABL-expressing clones were not protected from apoptosis induced by TNF, ceramide-C2 and FAS-cross-linking. BCL2 expression was absent in U937 cells and BAX levels were identical between Neo and BCR-ABL clones. To further investigate the mechanisms of this phenomenon, band-shift assays were performed to detect activation of STAT molecules. No constitutive activation of STATs was detected in either NeoR or BCR-ABL-U937 cells, although both IFN-gamma and GM-CSF activated STAT1 and STAT5, respectively, with similar kinetics in both NeoR and BCR-ABL-U937 cells. In addition, the GM-CSF-induced-STAT5 activation was found to be weakened in all clones expressing BCR-ABL. In both control NeoR and BCR-ABL-transfected clones, band-shift assays revealed the presence of an abnormal truncated STAT5 recognized only by an anti-N-terminal but not by an anti-C-Terminal STAT5 antibody. These findings suggest a possible link between the absence of anti-apoptotic potential of BCR-ABL and abnormalities of the STAT5 pathway, including, absence of constitutive activation of STAT5, inhibition of GM-CSF-induced STAT5 activation and expression of a carboxyl-terminal-truncated STAT5.

Lack of efficacy of 2-chlorodeoxyadenoside in the treatment of splenic lymphoma with villous lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is a B-cell chronic lymphoproliferative disorder. Splenectomy and/or chlorambucil (CLB) are usually regarded as the most effective treatment in SLVL patients. However, a few patients relapse and the second line therapy remains questionable. Although 2-Cda has been evaluated in patients with chronic lymphoid leukemia (CLL) and hairy cell leukemia (HCL), it has been reported as the treatment of SLVL in only one case report. Therefore, we have evaluated its efficacy and toxicity in 7 SLVL patients. The median duration between diagnosis and treatment was 18 months (range, 1 to 59). The patients received 2-CdA (0.1 mg/kg/d) by venous infusion for 7 days with a median number of 1 cycle (range, 1 to 2) either as a first line therapy (one patient) or after a failure of other therapies (splenectomy, chemotherapy). Two patients achieved a complete response. The first one maintained his CR during a follow-up of 9 months and then relapsed; the second patient remained in CR after a follow-up of 20 months. Four patients achieved a partial response and relapsed after a median follow-up of 3.5 months (range, 1 to 4). One patient had no response. The treatment was not well tolerated with many infectious events. In the limits of our study, 2-Cda does not appear to be efficient therapy for SLVL and is not well tolerated for patients in relapse after splenectomy or resistant to CLB.

Pleiotropic syndrome of dehydrated hereditary stomatocytosis, pseudohyperkalemia, and perinatal edema maps to 16q23-q24

Dehydrated hereditary stomatocytosis (DHS) is a rare genetic disorder of red cell permeability to cations, leading to a well-compensated hemolytic anemia. DHS was shown previously to be associated in some families with a particular form of perinatal edema, which resolves in the weeks following birth and, in addition, with pseudohyperkalemia in one kindred. The latter condition was hitherto regarded as the separate entity, "familial pseudohyperkalemia." DHS and familial pseudohyperkalemia are thought to stem from the same gene, mapping to 16q23-q24. This study screened 8 French and 2 American families with DHS. DHS appeared to be part of a pleiotropic syndrome in some families: DHS + perinatal edema, DHS + pseudohyperkalemia, or DHS + perinatal edema + pseudohyperkalemia. If adequately attended to, the perinatal edema resolved spontaneously after birth. Logistic regression showed that increased mean corpuscular volume and mean corpuscular hemoglobin concentration were the parameters best related to DHS. In patients in whom cation fluxes were investigated, the temperature dependence of the monovalent cation leak exhibited comparable curves. Specific recombination events consistently suggested that the responsible gene lies between markers D16S402 and D16S3037 (16q23-q24). The 95% confidence limits (Z(max) >/= 3.02) spanned almost the complete 9-cM interval between these 2 markers.

Transforming growth factor inhibits erythropoiesis by blocking proliferation and accelerating differentiation of erythroid progenitors

Erythropoiesis is positively regulated by stem cell factor, interleukin 3, and erythropoietin, which synergize to allow the production of hemoglobinized red blood cells from erythroid progenitors. In contrast, interferon gamma, tumor necrosis factor alpha, and transforming growth factor B(1), (TGF-beta(1)) are powerful inhibitors of erythropoiesis. Interferon gamma and alpha act principally by inducing apoptosis. The aim of this study was to elucidate the mechanisms by which TGF-beta(1) inhibits erythropoiesis. We used an in vitro serum-free system of human red blood cell production. From a virtually pure population of CD36(+) erythroid progenitors, stem cell factor, interleukin 3, and erythropoietin allowed massive proliferation (x300) and promoted terminal red blood cell differentiation. We show here that TGF-beta(1) (2 ng/mL) inhibited the growth of CD36(+) cells by 15-fold. TGF-beta(1) markedly accelerated and increased erythroid differentiation as assessed by hemoglobin and glycophorin expression. Furthermore, May-Grünwald-Giemsa staining and ultrastructural analysis revealed that TGF-beta(1) induced full differentiation toward normal enucleated red cells even in the absence of macrophages. This acceleration of erythroid differentiation did not modify the pattern of hemoglobin chains expression from adult or fetal erythroid progenitors. Analysis of apoptosis, cell cycle and Ki-67 expression showed that TGF-beta(1) inhibited cell proliferation by decreasing the cycle of immature erythroid cells and accelerating maturation toward orthochromatic normoblasts that are not in cycle. We showed that TGF-beta(1) is a paradoxical inhibitor of erythropoiesis that acts by blocking proliferation and accelerating differentiation of erythroid progenitors.

Acquired delta-storage pool deficiency associated with idiopathic myelofibrosis

A 73-year-old woman complained of easy bruising, as a consequence of prolonged bleeding time despite normal platelet counts. Platelet aggregation profile, mepacrine fluorescence test, flow cytometry and transmission electron microscopy studies led to the diagnosis of delta-storage pool deficiency (SPD) A few months later, she developed hyperleucocytosis with immature granulocytes and erythroblasts. The presence of bone marrow fibrosis and clonal cytogenetic abnormalities led to the diagnosis of idiopathic myelofibrosis (IM). Association between SPD and IM has never been reported. The pathogenesis of this unusual association remains unclear and may involve proliferation of abnormal monoclonal stem cells with differentiation into activated megakaryocytes associated with impaired dense granule development and increased cytokines release which may be. involved in myelofibrosis.

Biological effects induced by variable levels of BCR-ABL protein in the pluripotent hematopoietic cell line UT-7

There is currently no satisfactory model allowing analysis of dose-effect relationships of BCR-ABL proteins in human hematopoietic cells. To study comparatively the proliferative, differentiative and anti-apoptotic actions of different levels of BCR-ABL proteins in the context of the same cellular background, we have introduced the BCR-ABL gene into the GM-CSF-dependent pluripotent human cell line UT-7. Individual clones expressing BCR-ABL were analyzed by Western blots. After normalization to equivalent levels of endogenous ABL protein, 14 clones always grown in GM-CSF were found to express low but variable levels of BCR-ABL whereas two clones selected in the absence of GM-CSF expressed very high levels of BCR-ABL. All low-level BCR-ABL expressing clones exhibited a behavior similar to that of the GM-CSF-dependent parental cells as they ceased to proliferate upon growth factor deprivation and showed a strong proliferative response upon GM-CSF addition. One out of 14 clones showed progressive GM-CSF independence during culture over several weeks and was found to have a significant increase of BCR-ABL expression at that time. The resistance of this clone (E8-2) to different apoptotic stimuli was found to be increased as compared to its low BCR-ABL-expressing counterpart (E8-1) and similar to that observed in clones with very high levels of BCR-ABL (UT-7/9 and UT-7/11) which were totally resistant to apoptotic stimuli. When injected into nude mice, parental UT-7 cells and clones with low-level of BCR-ABL were not tumorigenic over 10 weeks of observation whereas UT-7 clones with high levels of BCR-ABL (UT-7/9, UT-7/11 and UT-7/E8-2) induced aggressive tumors in 2-4 weeks with a significant correlation between the amount of BCR-ABL protein and the rate of tumor growth. In conclusion, the establishment of an in vitro and in vivo CML model using UT-7 cells suggests for the first time in human cells, that the fully transformed phenotype induced by BCR-ABL requires high levels of BCR-ABL expression. These findings suggest that variable levels of BCR-ABL in primary patient cells could also be responsible for the different phenotypic features seen in chronic and acute phases of CML, such as the differentiation ability induced by growth factors.

Fludarabine: an effective treatment in patients with splenic lymphoma with villous lymphocytes

Splenic lymphoma with villous lymphocytes (SLVL) is a B cell chronic lymphoproliferative disorder. Splenectomy and/or chlorambucil are usually regarded as the most effective treatment in SLVL patients. However, a few patients relapse and the second-line treatment remains questionable. In a retrospective study, we evaluated the efficacy and toxicity of fludarabine (FDR) in 10 SLVL patients. The median duration between diagnosis and treatment was 17 months (range, 1-30). Two patients were previously untreated. The patients received FDR 25 mg/m2/day by venous infusion for 5 days with a median of four cycles of chemotherapy (range, 2-6). All patients were assessable: five patients achieved a good and persistent response after a median follow-up of 14 months (5-31), two achieved a good response but relapsed after a follow-up of 15 and 36 months. One out of the three partial responders have a persistent response. The treatment was well tolerated. FDR appears to be an efficient therapy with a favorable toxicity profile for patients in relapse after splenectomy or resistant to CLB. Furthermore it could constitute an alternative to splenectomy in older patients. A longer follow-up and the study of a larger group of patients are warranted to confirm our findings.

TGF-beta1 drives and accelerates erythroid differentiation in the epo-dependent UT-7 cell line even in the absence of erythropoietin

OBJECTIVE

TGF-beta1 is a powerful inhibitor of erythropoiesis. However, its mechanisms of action are not fully elucidated yet at the cellular level. In this work we have studied the effects of TGF-beta on UT-7 cell survival, proliferation and differentiation.

MATERIALS AND METHODS

UT-7 cell line is strictly dependent on growth factors for cell survival, growth, and differentiation. Epo (2 U/mL) induces erythroid differentiation as assessed by up regulation of glycophorin A and the presence of 5%-10% benzidine positive cells (BPC). In contrast, even in the presence of Epo (2 U/mL), GM-CSF (1 ng/mL) inhibits erythroid differentiation.

RESULTS

When UT-7 cells were switched from GM-CSF to Epo, TGF-beta1 (2 ng/mL) induced a rapid (3 days [Epo+TGF-beta1] vs 8 days [Epo]) and marked erythroid differentiation (80% [Epo+TGF-beta1] vs 10% [Epo] BPC) including Hemoglobin A synthesis (HbA/HbF ratio of 1 [Epo] vs 4 [Epo+TGF-beta1]). In the presence of GM-CSF, although to a lesser extent, TGF-beta1 induced erythroid differentiation (40% BPC). This effect was not a consequence of TGF-beta1-induced apoptosis because, in the presence of Epo or GM-CSF, apoptosis occurred only at day 8 or 10, respectively. Moreover, although SCF inhibited apoptotic effect of TGF-beta1, SCF+TGF-beta1+Epo was the best combination to give rise to the highest number of hemoglobinized cells. We further demonstrated that induction of erythroid differentiation by TGF-beta1 was not due to an autocrine loop involving Epo/Epo-R or to a prolongation of the G1 phase of the cell cycle.

CONCLUSION

Taken together, these data suggest that TGF-beta1 is an inducer of erythroid differentiation, even stronger than Epo at the cellular level.

Membrane-bound Fas (Apo-1/CD95) ligand on leukemic cells: A mechanism of tumor immune escape in leukemia patients

There is evidence from bone marrow transplantation that T cells may be involved in the immunologic control of leukemia. But many patients relapse despite a potent graft-versus-leukemia effect mediated by allogeneic T cells. The expression of the FasL protein has been suggested as a mechanism of tumor immune escape. We, therefore, evaluated the capacity of leukemic cells from patients with acute or chronic myelogenous leukemia to escape the allogeneic or autologous immune response by bearing the FasL molecule. Although almost all leukemic cells express the 37-kD form of FasL, only 54% of acute myeloblastic leukemia and 27% of chronic myeloid leukemia (CML) cells bore a FasL with killing properties, as assessed by the ability of leukemic cells to cause the apoptosis of a Fas-sensitive target cell line or autologous activated T cells in 3 tested leukemic cases. Experiments with a recombinant Fas-Fc molecule confirmed the role of Fas/FasL in leukemic-mediated cell death. Only CML leukemic cells from certain individuals contained the 26-kD truncated form of FasL. Thus, myeloid leukemic cells from some, but not all patients can set up a mechanism of immune escape involving the Fas/FasL pathway. This leukemic escape may have implications for patients eligible for adoptive cellular immunotherapy.

The dose of granulocyte-colony-stimulating factor after chemopriming treatment does not influence apheresis yield of progenitor cells: a retrospective study of 91 cases

BACKGROUND

The optimal dose of post-chemotherapy granulocyte-colony-stimulating factor (G-CSF) administration before peripheral blood progenitor cell (PBPC) collection has not been determined as yet, although 5 microg per kg per day has been recommended as the standard dose. This study retrospectively analyzed the effect of G-CSF dose on peripheral blood CD34+ cell collection from 91 patients with hematologic malignancies.

STUDY DESIGN AND METHODS

Various doses of G-CSF were administered after several chemotherapeutic PBPC mobilization regimens. According to the dose of G-CSF administered, patients were assigned to two groups. Group 1 included 46 patients who received a low dose of G-CSF (median, 3.6 [range, 2.8-4.6] microg/kg/day). Group 2 included 45 patients who received a standard G-CSF dose of 6.0 (5.5-8. 1) microg per kg per day. Patients in the two groups were matched for age, diagnosis, previous therapy, and chemotherapeutic PBPC mobilization regimens.

RESULTS

No difference was observed in the median number of CD34+ cells harvested from each group. The number of leukapheresis procedures necessary to obtain a minimum of 3 x 10(6) CD34+ cells per kg was the same in both groups, and the percentage of patients who failed to achieve adequate PBPC collections was similar in the two groups.

CONCLUSION

The administration of low-dose G-CSF after chemotherapy appears equivalent to administration of the standard dose in achieving satisfactory PBPC collection. This approach could allow significant savings in medical cost. A randomized and prospective study is necessary, however, to assess the validity of these conclusions.

Comparison of lenograstim vs filgrastim administration following chemotherapy for peripheral blood stem cell (PBSC) collection: a retrospective study of 126 patients

Mobilization techniques for peripheral blood stem cell (PBSC) collection include the administration of chemotherapy followed by hematopoietic growth factors or growth factors alone. Two forms of recombinant human granulocyte colony-stimulating factor (rhG-CSF) are available for PBSC mobilization: lenograstim and filgrastim which are the glycosylated and non-glycosylated forms respectively. In order to determine the influence of the two forms of G-CSF following chemotherapy on PBSC collection, we conducted a retrospective study in 126 patients with various hematological malignancies: 65 and 61 for the lenograstim and filgrastim groups respectively. No significant differences between the two groups were observed in terms of sex, age and diagnosis. Prior therapies and PBSC mobilization regimen were also equivalent. No significant difference was observed between the groups for the median CD34+ cells harvested. The number of leukapheresis necessary to obtain a minimal number of 3 x 10(6) CD34+ cells/kg was equivalent for the two groups. The proportion of patients affected by a failure in PBSC collection was similar in the two groups. Our data suggest that lenograstim and filgrastim are equivalent for PBSC mobilization after chemotherapy.

A phase II trial of induction and consolidation therapy of acute myeloid leukemia with weekly oral idarubicin alone in poor risk elderly patients

We have conducted a phase II outpatient trial testing weekly oral administration of idarubicin (ZAVEDOS-ZVD) alone to determine the rate of objective response and toxicity in poor risk acute myeloid leukemia (AML) patients over 60 years of age. The treatment consisted of three phases: induction, with 20 mg/m2 of ZVD on days 1, 8, 15 and 22; consolidation with 20 mg/m2 of ZVD for 4 weeks; and maintenance with six cycles lasting 3 months and consisting of oral 6 mercapto-purine 2 mg/kg/day, 4 days a week for 2 months; subcutaneous cytarabine 1 mg/kg, once a week for 2 months; and oral ZVD 20 mg/m2 on day 1 and day 8 of the third month. In case of failure after induction course, patients received salvage treatment with 4 weekly oral doses of 40 mg/m2 ZVD. Fifty-one patients with a median age of 76 years were enrolled and could receive induction course. Of these 51 patients, 37 could receive subsequent courses, which consisted either of consolidation, or salvage. Only 11 patients underwent maintenance treatment. Sixty-three percent of patients had to be hospitalized during induction, for a median duration of 14.5 days, and 87% required hospitalization during salvage for a median duration of 17.5 days. Only five patients (38%) required hospitalization during consolidation. There were three toxic deaths (6%), two from hemorrhage and one from pulmonary embolism. The overall response rate was 29%, with 12 patients in complete response (25%) and two in partial response (4%). The median overall survival rate is 4 months for the whole population, and the median DFS is 9.6 months among the 14 responding patients. The results of this trial show that this new weekly schedule of oral ZVD chemotherapy is feasible and effective in poor risk elderly patients with AML. This regimen may be helpful for patients unable to tolerate intensive intravenous regimens, and is a real alternative to palliative treatments.

The timing of granulocyte-colony-stimulating factor administration after chemotherapy does not affect stem and progenitor cell apheresis yield: a retrospective study of 65 cases

BACKGROUND

The optimal time for postchemotherapy granulocyte-colony stimulating factor (G-CSF) administration before peripheral blood stem and progenitor cell (PBPC) collection is not well defined. The impact of G-CSF scheduling on the number of CD34+ cells collected by leukapheresis from 65 patients with malignant disease was studied retrospectively.

STUDY DESIGN AND METHODS

Chemotherapy was performed on Days 1 and 2 and was followed by G-CSF to mobilize PBPCs. In Group 1, 30 patients received the first dose of G-CSF immediately after the end of chemotherapy, as commonly recommended. In Group 2, 35 patients received the first G-CSF dose after the end of chemotherapy (Days 7 or 8).

RESULTS

No difference was observed between the two groups in white cell recovery and the median number of CD34+ cells harvested. The number of leukapheresis procedures necessary to obtain the minimal number of 3 x 10(6) CD34+ cells per kg was the same. The proportion of patients with a failure of PBPC collection was similar, and G-CSF consumption was reduced in Group 2 without increasing infectious risks.

CONCLUSION

Early administration of G-CSF after chemotherapy appears not to be a prerequisite for satisfactory PBPC collection. This approach could allow significant savings in terms of medical cost. A randomized and prospective study would be necessary, however, to assess the validity of these conclusions.

Retinoic acid, but not arsenic trioxide, degrades the PLZF/RARalpha fusion protein, without inducing terminal differentiation or apoptosis, in a RA-therapy resistant t(11;17)(q23;q21) APL patient

Primary blasts of a t(11;17)(q23;q21) acute promyelocytic leukaemia (APL) patient were analysed with respect to retinoic acid (RA) and arsenic trioxide (As2O3) sensitivity as well as PLZF/RARalpha status. Although RA induced partial monocytic differentiation ex vivo, but not in vivo, As203 failed to induce apoptosis in culture, contrasting with t(15;17) APL and arguing against the clinical use of As203 in t(11;17)(q23;q21) APL. Prior to cell culture, PLZF/RARalpha was found to exactly co-localize with PML onto PML nuclear bodies. However upon cell culture, it quickly shifted towards microspeckles, its localization found in transfection experiments. Arsenic trioxide, known to induce aggregation of PML nuclear bodies, left the microspeckled PLZF/RARalpha localization completely unaffected. RA treatment led to PLZF/RARalpha degradation. However, this complete PLZF/RARalpha degradation was not accompanied by differentiation or apoptosis, which could suggest a contribution of the reciprocal RARalpha/PLZF fusion product in leukaemogenesis or the existence of irreversible changes induced by the chimera.

Homing receptor alpha4beta7 integrin expression predicts digestive tract involvement in mantle cell lymphoma

Appropriate staging and evaluation of residual disease is critical to improving the treatment of patients with lymphoma. The specific expression of homing receptors may determine the preferential dissemination pattern of tumoral cells. We investigated the expression of the mucosal homing receptor alpha4beta7 on tumoral cells from peripheral lymph node in patients with newly diagnosed mantle cell lymphoma (MCL) to check whether it is associated with gastrointestinal involvement. Expression of the alpha4beta1 integrin and the peripheral lymph node addressin CD62L were also examined. Thirteen MCL patients presenting with peripheral lymphadenopathy were studied. Expression of the mucosal homing receptor integrin alpha4beta7 by peripheral lymph node lymphoma cells was found to be frequent (5/13) and associated with gastrointestinal involvement (5/7). In contrast, lymphoma cells from patients without gastrointestinal involvement did not express alpha4beta7 (6/6) (P = 0.03). These data suggest that alpha4beta7 integrin is expressed by a subset of MCLs and that its expression may predict digestive tract involvement in MCL, furnishing a basis for recognizing two distinct clinical and phenotypic forms, ie, "digestive homing (or digestive primitive)" versus "peripheral" MCL. Further studies on more patients will be needed to understand the impact of biological differences on the prognosis of these two clinical forms.

The feasibility of peripheral blood stem cell collection for autograft following failure in bone marrow aspiration

High doses of cytotoxic drugs may impair stem cell collection. Failure in stem cell collection by bone marrow aspiration can be rescued by harvesting Peripheral Blood Stem Cell (PBSC) after a combination of chemotherapy and hematopoietic growth factor. We, therefore, retrospectively evaluated the possibility of collecting PBSC after chemotherapy and/or G-CSF administration in 12 patients with insufficient Granulocyte-macrophage colony-forming unit (CFU-GM) counts after bone marrow aspiration (all patients had previously received heavy chemotherapy for hematologic malignancies); median collection of CFU-GM/kg count was 2,9 x 10(4)/kg (range 0,4 to 8 x 10(4)/kg) whereas the minimal count required for autografting is 10 x 10(4)/kg. Median collections of CFU-GM from PBSC were 5,8 x 10(4)/kg. While the CFU-GM collected in PBSC was higher than after bone marrow aspiration, only 5 patients had enough PBSC for autografting. In another case, addition of cells collected from both PBSC and bone marrow aspiration yielded a sufficient number of CFU-GM to allow autografting. Therefore in this selected and small group of patients, failure in bone marrow aspiration does not seem to be predictive of a low PBSC collection but a long therapy free interval and use of G-CSF alone for PBSC mobilization could constitute a valuable alternative. Three patients had a successful short term hematologic reconstitution out of the four patients having had an autograft.