Low-dose valganciclovir as preemptive therapy for cytomegalovirus infection occurring in allogeneic stem cell transplant recipients

Few data are available to date on the dose of oral valganciclovir as cytomegalovirus (CMV) preemptive therapy in stem cell transplantation patients. This study aimed to evaluate the efficacy and safety of low-dose valganciclovir (900 mg/day) as preemptive treatment in allotransplanted recipients. Valganciclovir was used in 34 patients who underwent allogeneic stem cell transplantation for hematological malignancies at the dose of 900 mg oral administration/day (12 patients, group 1) or 1,800 mg oral administration/day (22 patients, group 2). Thirty-two out of 34 patients (94%) obtained negativization of polymerase chain reaction for CMV at a median of 12.5 days from the beginning of valganciclovir administration (10/12 patients of group 1, 22/22 patients of group 2). We conclude that oral administration of valganciclovir can induce clearance of CMV viral load in about 2 weeks; moreover, lower-dose oral valganciclovir (900 mg/day) has a comparable efficacy to the proposed standard dose (1,800 mg/day).

The proliferative response to CpG-ODN stimulation predicts PFS, TTT and OS in patients with chronic lymphocytic leukemia

We recently reported that leukemic cells from IgVH-unmutated/progressive CLL more frequently proliferate in response to CpG-ODN stimulation than their corresponding counterparts. Here we evaluated the prognostic impact of this proliferative response in 91 CLL patients. The proliferative response was highly predictive of PFS, TTT and OS in the whole series and refined prognosis in patients with M-CLL. BCR stimulation modulated the response to CpG-ODN, suggesting that the proliferative capacity of the leukemic cells is related to antigen-encounter history. These data support the hypothesis that the capacity of the leukemic cells to respond to external stimuli influences disease progression in CLL.

Expression of mutated IGHV3-23 genes in chronic lymphocytic leukemia identifies a disease subset with peculiar clinical and biological features

PURPOSE

B-cell chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease whose outcome can be foreseen by investigating the mutational status of immunoglobulin heavy chain variable (IGHV) genes. Moreover, a different prognosis was reported for CLL expressing specific IGHV genes in the context or not of stereotyped B-cell receptors. Here we investigated novel associations between usage of specific IGHV genes and clinical features in CLL.

EXPERIMENTAL DESIGN

Among 1,426 CLL-specific IG-rearrangements, stereotyped B-cell receptor clusters never utilized the IGHV3-23 gene. Given this notion, this study was aimed at characterizing the IGHV3-23 gene in CLL, and identifying the properties of IGHV3-23-expressing CLL.

RESULTS

IGHV3-23 was the second most frequently used (134 of 1,426) and usually mutated (M; 109 of 134) IGHV gene in our CLL series. In the vast majority of M IGHV3-23 sequences, the configuration of the 13 amino acids involved in superantigen recognition was consistent with superantigen binding. Clinically, M IGHV3-23 CLL had shorter time-to-treatment than other M non-IGHV3-23 CLL, and multivariate analyses selected IGHV3-23 gene usage, Rai staging, and chromosomal abnormalities as independent prognosticators for M CLL. Compared with M non-IGHV3-23 CLL, the gene expression profile of M IGHV3-23 CLL was deprived in genes, including the growth/tumor suppressor genes PDCD4, TIA1, and RASSF5, whose downregulation is under control of miR-15a and miR-16-1. Accordingly, relatively higher levels of miR-15a and miR-16-1 were found in M IGHV3-23 compared with M non-IGHV3-23 CLL.

CONCLUSIONS

Altogether, expression of the IGHV3-23 gene characterizes a CLL subset with distinct clinical and biological features.

Intrinsic and extrinsic factors influencing the clinical course of B-cell chronic lymphocytic leukemia: prognostic markers with pathogenetic relevance

B-cell chronic lymphocytic leukemia (CLL), the most frequent leukemia in the Western world, is characterized by extremely variable clinical courses with survivals ranging from 1 to more than 15 years. The pathogenetic factors playing a key role in defining the biological features of CLL cells, hence eventually influencing the clinical aggressiveness of the disease, are here divided into "intrinsic factors", mainly genomic alterations of CLL cells, and "extrinsic factors", responsible for direct microenvironmental interactions of CLL cells; the latter group includes interactions of CLL cells occurring via the surface B cell receptor (BCR) and dependent to specific molecular features of the BCR itself and/or to the presence of the BCR-associated molecule ZAP-70, or via other non-BCR-dependent interactions, e.g. specific receptor/ligand interactions, such as CD38/CD31 or CD49d/VCAM-1. A putative final model, discussing the pathogenesis and the clinicobiological features of CLL in relationship of these factors, is also provided.

Immune Recovery of Lymphocyte Subsets 6 Years after Autologous Peripheral Blood Stem Cell Transplantation (PBSCT) for Lymphoproliferative Diseases. A Comparison between NHL, HD and MM in Group of 149 Patients

To evaluate the normalization of lymphocyte subsets several years after autologous peripheral blood stem cell transplantation (aPBSCT) and to detect any differences based on the underlying lymphoproliferative diseases, we analyzed the immunological recovery of 149 patients with Non Hodgkin's Lymphoma (NHL), Hodgkin's Disease (HD), Multiple Myeloma (MM). Lymphocyte recovery was assessed before the transplant, on days 15, 30, 60, 90, 120 and on years 1, 2, 4, 6. Analysis of a total of 709 lymphocytes, including total lymphocyte count, CD3 +, CD4 +, CD8 +, CD4 +/CD8 + ratio, CD19 +, CD3 + HLA-DR +, CD16 + 56 +, was performed. The normalization of total lymphocyte counts was achieved between days 14 to 22 following PBSCT. CD3 + cells count showed a normalization after 2 years in the HD and NHL groups and after 4 years in MM group. CD4 + subset achieved normalization during the sixth year in the 3 groups. The CD8 + and CD19 + lymphocytes subsets achieved normal values in the 3 groups at day 60 and at day 120 respectively. CD16 + 56 + and CD3 +/HLA-DR + lymphocytes showed median values above the normal range starting from day 30. Immunological recovery was similar in all 3 groups. Moreover, the recovery of all subsets evaluated was similarly demonstrated within 6 years after aPBSCT.

Stereotyped B-cell receptor is an independent risk factor of chronic lymphocytic leukemia transformation to Richter syndrome

PURPOSE

Few biological prognosticators are useful for prediction of Richter syndrome (RS), representing the transformation of chronic lymphocytic leukemia (CLL) to aggressive lymphoma. Stereotyped B-cell receptors (BCR) may have prognostic effect in CLL progression. We tested the prognostic effect of stereotyped BCR for predicting RS transformation.

EXPERIMENTAL DESIGN

The prevalence of stereotyped BCR was compared in RS (n = 69) versus nontransformed CLL (n = 714) by a case-control analysis. Subsequently, the effect of stereotyped BCR at CLL diagnosis on risk of RS transformation was actuarially assessed in a consecutive CLL series (n = 753).

RESULTS

RS (n = 69) displayed a higher prevalence of stereotyped BCR (P < 0.001) compared with nontransformed CLL. The actuarial risk of RS transformation was significantly higher in CLL carrying stereotyped BCR (P < 0.001). Among BCR subsets most represented in CLL, subset 8 using IGHV4-39/IGHD6-13/IGHJ5 carried the highest risk of RS transformation [hazard ratio (HR), 24.50; P < 0.001]. Multivariate analysis selected stereotyped BCR (HR, 3.33; P = 0.001) and IGHV4-39 usage (HR, 4.03; P = 0.004) as independent predictors of RS transformation. The combination of IGHV4-39 usage and stereotyped BCR in the same patient identified CLL with a very high risk of RS transformation (5-year risk, 68.7%). The risk carried by stereotyped BCR and IGHV4-39 usage was specific for RS transformation and had no effect on CLL progression without transformation.

CONCLUSIONS

Analysis of BCR features may help identify CLL patients at risk of RS. A close monitoring and a careful biopsy policy may help early recognition of RS in CLL patients using stereotyped BCR, particularly if combined with IGHV4-39.

Factors associated with mortality in bacteremic patients with hematologic malignancies

We conducted a retrospective cohort study to identify risk factors for mortality in a large cohort of hematologic patients with bacteremia. From 2000 through 2005, bacteremia was diagnosed in 217 patients with hematologic malignancies. The infections were caused only by Gram-positive organisms in 57.1% (124/217) cases and only by Gram-negative bacteria in 37.8% (82/217); the remaining 5.1% (11/217) were polymicrobial. The overall 30-day mortality rate was 20.3% (44/217). In multivariate analysis, significant predictors of mortality were prolonged neutropenia (P < 0.001), acute renal failure (P = 0.002), nosocomial bacteremia (P = 0.009), age >55 years (P = 0.007), and monomicrobial bacteremia due to antibiotic-resistant Gram-negative bacteria (P = 0.009). Reducing fatal outcomes associated with bacteremia in patients with hematologic malignancies is a challenge, and the emergence of resistance to the antimicrobials widely used in this setting is of great concern. Future infection trends must be carefully monitored and treatment guidelines adjusted accordingly.

Phosphorylation of the activation loop tyrosines is required for sustained Syk signaling and growth factor-independent B-cell proliferation

The Syk kinase is regarded as a promising target for the treatment of antigen-driven B-cell malignancies, considering its essential role in propagating antigenic stimuli through the B-cell receptor (BCR). In certain common B-cell malignancies Syk is activated even in the absence of BCR engagement, suggesting a wider role for this kinase in lymphomagenesis. In this paper, we have profiled molecular differences between BCR-induced and constitutive Syk activation in terms of phosphorylation of regulatory tyrosine residues, downstream signaling properties and capacity to sustain B-cell proliferation. Analysis of primary chronic lymphocytic leukemia B-cells and diffuse large B-cell lymphoma cell lines revealed that constitutive and BCR-induced Syk activation differ with respect to the phosphorylation status of the regulatory tyrosines at positions 352 and 525/526, with only the first site being phosphorylated in the case of constitutive and both sites in the case of BCR-induced Syk activation. Syk phosphorylated only on Y352 is capable of downstream signaling, as evidenced by experiments with a phosphomimetic mutant in which the activation loop tyrosines (YY525/526) were replaced with phenylalanines. However, phosphorylation at YY525/526 was shown to significantly increase the enzymatic activity of Syk and to be required for sustained PLCgamma2, Akt and ERK signaling as well as B-cell transformation. These data demonstrate that constitutively active Syk and Syk activated by BCR crosslinking represent separate stages of Syk activation with distinct signaling properties and transforming capacities.

Molecular and clinical features of chronic lymphocytic leukaemia with stereotyped B cell receptors: results from an Italian multicentre study

A fraction of chronic lymphocytic leukaemia (CLL) cases carry highly homologous B-cell receptors (BCR), i.e. characterized by non-random combinations of immunoglobulin heavy-chain variable (IGHV) genes and heavy-chain complementarity determining region-3 (HCDR3), often associated with a restricted selection of IGVK/L light chains. Such 'stereotyped' BCR occur more frequently in CLL with unmutated (UM) than mutated (M) IGHV genes. We analysed 1426 IG rearrangements (from 1398 CLL cases) by a clustering driven by HCDR3 similarities. Molecular findings were correlated to time-to-treatment (TTT) and presence of known prognosticators. Sixty-nine clusters (319 IG-rearrangements, 22.4%) with stereotyped BCR were identified. Among 30 confirmed clusters (>or=3 IG-rearrangements/cluster), we found 14 novel clusters, of which 11 had M IG rearrangements (M clusters) and predominantly (8/11) used IGHV3 subgroup genes. Recurrent cluster-biased amino acid changes were found throughout IGHV sequences of these 'M clusters'. Regarding clinical outcome: (i) UM CLL from the IGHV1-2/1-3/1-18/1-46/7-4-1/IGKV1-39 cluster had poorer prognosis than UM/M cases, or UM cases using the same IGHV genes but not in clusters; (ii) M CLL from the IGHV3-21/IGLV3-21 cluster had TTT similar to UM CLL, and shorter than M CLL expressing IGHV3-21 but not in cluster. Altogether, our analysis identified additional molecular and clinical features for CLL expressing stereotyped BCR.

Severe veno-occlusive disease after autologous peripheral blood stem cell transplantation for high-grade non-Hodgkin lymphoma: report of a successfully managed case and a literature review of veno-occlusive disease

Veno-occlusive disease (VOD) of the liver is a severe complication of high-dose chemotherapy and allogeneic or autologous stem cell transplantation with potential fatal outcome. We report a case of severe VOD in a patient with a high-grade B-cell lymphoma. Liver-venule occlusion was confirmed by liver biopsy. Supportive care, fibrinolytic treatment with recombinant tissue plasminogen activator and defibrotide maintenance therapy led to complete resolution of VOD demonstrated at liver biopsy and with a follow-up of 44 months after autologous peripheral blood stem cell transplantation. The literature on VOD has been reviewed.

Oral fludarabine and cyclophosphamide as front-line chemotherapy in patients with chronic lymphocytic leukemia. The impact of biological parameters in the response duration

We tested the efficacy and safety of oral fludarabine and cyclophosphamide as front-line therapy in chronic lymphocytic leukemia (CLL) and assessed the influence of immunoglobulin variable region heavy chain (IgVH) gene mutation status, interphase cytogenetic abnormalities, and expression of ZAP-70 and CD38 on clinical outcome. Thirty-seven patients with previously untreated CLL received oral fludarabine (30 mg m(2)) and oral cyclophosphamide (250 mg m(2)) for three consecutive days every 4 weeks for six cycles. Eighteen patients had unmutated and 15 had mutated IgVH genes. Nine patients had the 'high risk' cytogenetic abnormality del(11q22.3) or del(17p13.1). Fifteen patients were ZAP-70-positive and eight patients were CD38-positive. Among the 35 valuable patients, 14 patients (40%) obtained a complete response and 13 (37%) a partial response. The median progression-free survival (PFS) was 23 months and median time to re-treatment (TTR) was 38 months. A significantly lower overall response rate (43% vs. 85%, p = 0.011), a shorter PFS (22 vs. 27 months, p = 0.015), and a shorter TTR (22 vs. 40 months, p = 0.031) were noticed in the 'high risk' cytogenetic abnormalities group; TTR was also shorter in IgVH-unmutated than in IgVH-mutated patients (26 vs. 41 months, p = 0.035). Hematologic toxicity included grade IV neutropenia (ten patients) and grade III/IV anemia (three patients). Gastrointestinal toxicity was mild and no patient required hospitalization. The oral combination of fludarabine and cyclophosphamide is an effective, safe, and well-tolerated regimen that, if confirmed with larger series, will be appropriate especially in patients with low risk biological parameters.

Influence of specific CD4+ T cells and antibodies on evolution of hypervariable region 1 during acute HCV infection

BACKGROUND/AIMS

Several studies suggest that the evolutionary rate of HVR1 sequence in acute HCV hepatitis derives from the action of a continuous immune-driven positive selection. However, these studies have not been performed examining the relationship between HVR1 evolution and the development of specific immunity to autologous HVR1 sequences.

METHODS

We performed a longitudinal analysis of HVR1 sequences and specific antibodies and CD4+ T cells in ten HCV acutely infected patients with different clinical outcomes (recovery versus persistence).

RESULTS

We showed that although both recovered and chronically evolving individuals developed IFN-gamma+ T cells specific for Core and NS sequences, HVR1-specific CD4+ T cells were detected only in patients clearing the virus. On the contrary, all patients displayed anti-HVR1 antibodies that recognized sequences exclusively carried by autologous viruses. Measurements of genetic diversity and the number of non-synonymous per synonymous substitutions within HVR1 sequences before and after antibody appearance showed an increase of these parameters only in concomitance with the appearance of anti-HVR1 antibodies.

CONCLUSIONS

The evidence that anti-HVR1 antibodies favor HVR1 variant selection suggests that viral complexity in chronically infected patients could represent a virus adaptive strategy to escape the continuous selective process mediated by anti-HVR1 antibodies.

MTHFR polymorphisms’ influence on outcome and toxicity in acute lymphoblastic leukemia patients

Recently the influence of polymorphisms of different genes involved in metabolism of chemoterapic agents have been studied especially in childhood acute lymphoblastic leukemia (ALL). We evaluated the influence of C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) polymorphisms on time to relapse and survival and on methotrexate (MTX) toxicity in 82 ALL adult patients. Relapse free survival and event free survival between homozygous wild-type and variant patients in both polymorphisms were not significantly different. However, we observed an association between 677TT variant and survival in a subset of ALL patients homogenously treated with MTX-based maintenance (p=0.02). In the same subgroup we confirmed the role of 677TT variant on toxicity during MTX treatment (p=0.003).

Prognostic significance of combined analysis of ZAP-70 and CD38 in chronic lymphocytic leukemia

The clinical heterogeneity that characterizes chronic lymphocytic leukemia (CLL) poses critical questions concerning the identification of high risk patients. Unmutated IgV(H) genes, CD38 and ZAP-70 expression have emerged as the most useful tools in identifying aggressive CLL. The simultaneous expression of ZAP-70 and CD38 in 157 patients with CLL has been evaluated. Fifty-seven patients (36%) were positive for ZAP-70 and 46 patients (29%) were positive for CD38. Both molecules were highly correlated and predictive of the clinical course of the disease. According to the simultaneous evaluation of ZAP-70 and CD38, patients were divided into three groups. In 81 patients (52%), there was a negative concordance of both molecules (ZAP-70(-)/CD38(-)); in 27 patients (17%) there was a positive concordance (ZAP-70(+)/CD38(+)); in 49 patients (31%) there was a discordant expression (ZAP-70(+)/CD38(-) and ZAP-70(-)/CD38(+)). A comparison of the clinical and laboratory data showed in ZAP-70(+)/CD38(+) patients a significantly higher bone marrow and peripheral blood lymphocytosis, lower hemoglobin levels, more advanced clinical stage, and higher number of unmutated IgV(H) status with respect to the other two groups. Furthermore, ZAP-70(+)/CD38(+) patients displayed a much shorter treatment-free interval (median 12 months vs 42 months in discordant patients and not reached in ZAP-70(-)CD38(-) patients). These results prove that the concomitant evaluation of ZAP-70 and CD38 expression allows the separation of CLL patients in prognostic subgroups and suggest that their simultaneous assessment should become an integral component of the CLL diagnostic grid.

Unrelated cord blood transplant in children with high-risk acute lymphoblastic leukemia: a long-term follow-up

BACKGROUND AND OBJECTIVES

The aim of this single center study was to assess the impact of pre-transplant factors on long-term follow-up in young patients affected by high-risk acute lymphoblastic leukemia (ALL) who underwent an unrelated cord blood transplant (CBT). The conditioning regimens, graft-versus-host disease (GVHD) prophylaxis and supportive policies were uniform for all patients.

DESIGN AND METHODS

We analyzed the results of CBT performed in 30 patients, aged <18 years, affected by high risk ALL. As conditioning regimen, all patients received 12 Gy fractionated total body irradiation, etoposide, cyclophosphamide and horse anti-lymphocyte globulin. GVHD prophylaxis consisted of 6-methylprednisolone and cyclosporine A. RESULTS The cumulative incidence of engraftment was 93% (95% CI:0.85-0.93). The cumulative incidence of grade III-IV acute and chronic GVHD was 7% (95% CI:0.01-0.19) and 33% (95% CI: 0.17-0.64), respectively. The 9-year cumulative incidence of transplant-related mortality and relapse was 34% (95% CI:0.13-0.45) and 31% (95% CI:0.16-0.61), respectively. The 9-year overall survival, leukemia-free survival and event-free survival were 42% (95% CI:0.52-0.93), 47% (95% CI:0.25-0.61) and 46% (95% CI:0.33-0.61), respectively. A number of CFU-GM <1 x 10(4)/Kg of recipient body weight was the only factor that negatively affected all outcome parameters both in univariate and multivariate analyses.

INTERPRETATION AND CONCLUSIONS

The infused cell dose expressed as in vitro progenitor cell growth represents the most important pre-transplant factor affecting the long-term outcome after an unrelated CBT in young patients with high risk ALL. The number of CFU-GM should thus be considered in the selection process of cord blood units for transplant.

Non-tunneled central venous catheters in adult stem cell transplantation recipients: An effective option

Stem cell transplantation (SCT) recipients require central venous catheter (CVC) insertion for the administration of chemotherapy, antibiotics and total parenteral nutrition. Traditionally, tunneled CVC have been considered as the golden standard although they require surgery for both insertion and removal. We prospectively evaluated the use of a non-tunneled CVC in 182 consecutive patients who had undergone allogenic or autologous SCT. The median duration of CVC was 4 weeks (range 1-24) with a significant difference between allogenic (8 weeks, range 2-24) and autologous SCT (4 weeks, range 1-24) (p<0.0001). The life expectancy of the CVC was significantly influenced by spontaneous removal, which occurred in 26 patients (13.8%). There was a significant increase of this complication in allogenic SCT (p=0.039). The overall incidence of sepsis was 24.5%, although catheter-related sepsis was microbiologically documented by positive culture of the tip only in 17 cases (9%). Non-tunneled CVC in adult SCT recipients allowed (a) bedside insertion and removal, (b) guidewire replacement for diagnostic or therapeutic purposes (dialysis or pheresis procedures) thus reducing the need for repeated venipunctures. (The Journal of Vascular Access 2001; 2: 168-174).

Kinetics of peg-filgrastim after high-dose chemotherapy and autologous peripheral blood stem cell transplantation

Peg-filgrastim is a form of G-CSF with a sustained duration of action due to self-limited clearance. We administered 6 mg peg-filgrastim to 18 autograft recipients on day +1 after transplantation for hematologic malignancies. Plasma samples were collected at baseline and during transplantation. Hematopoietic recovery and clinical outcomes were compared to the historical data of 54 patients not receiving G-CSF. Patients receiving peg-filgrastim achieved a serum level of 115 000 pg/ml on day +2, 24 h after drug administration. Drug level maintained a plateau until day +8 and, after day +10, declined concomitantly with myeloid recovery. Patients experienced prompt neutrophil recovery: days +9 and +10 to 500 and 1000 neutrophils per microliter, and 4 days with an absolute neutrophil count <100 cells per microliter. Duration of antibiotic therapy was significantly shortened, but we did not observe significant differences in other end points. In conclusion, peg-filgrastim was well tolerated and efficacious, and hastened myeloid recovery.

All-trans Retinoic Acid in Association with Low Dose Cytosine Arabinoside in the Treatment of Acute Myeoid Leukemia in Elderly Patients

All-trans retinoic acid (ATRA) has shown a synergistic activity in combination with cytosine arabinoside in vitro in the treatment of acute myeloid leukaemia (AML). In this paper we report the results of treatment with low dose cytosine arabinoside (LDAC) with or without ATRA in 28 patients with acute myeloid leukaemia aged over 60 years: 14 patients received only LDAC and the other 14 LDAC + ATRA. The patients of the 2 groups showed similar clinical features: in 10 patients AML developed after a myelodysplastic form and 4 patients presented a previous malignancy. All the patients received subcutaneous (sc) LDAC (15 mg twice a day for 14 days) and in 14 patients oral ATRA (45 mg/sqm in the same days) was added to LDAC; the courses were repeated every 4 weeks from diagnosis to relapse. The treatment was well tolerated and the patients could self-administer sc LDAC and oral ATRA at home. No statistically significant differences were observed in complete remission rate (21% vs. 50%, respectively) and resistant rate (57% vs. 29%), but the patients treated with the combination of the 2 drugs had a better time to treatment failure (15 weeks vs. 30 weeks, respectively) (P = 0.045) and a longer survival (37 weeks vs. 66 weeks) (P = 0.019). Our experience, although with a low number of patients, confirms the efficacy of ATRA in combination with sc LDAC in the treatment of AML in elderly patients.

Comprehensive characterization of IGHV3-21-expressing B-cell chronic lymphocytic leukemia: an Italian multicenter study

IGHV3-21-using chronic lymphocytic leukemia (CLL) is a distinct entity with restricted immunoglobulin gene features and poor prognosis and is more frequently encountered in Northern than Southern Europe. To further investigate this subset and its geographic distribution in the context of a country (Italy) with both continental and Mediterranean areas, 37 IGHV3-21 CLLs were collected out of 1076 cases enrolled by different institutions from Northern or Central Southern Italy. Of the 37 cases, 18 were identified as homologous (hom)HCDR3-IGHV3-21 CLLs and were found almost exclusively (16 of 18) in Northern Italy; in contrast, 19 nonhomHCDR3-IGHV3-21 cases were evenly distributed throughout Italy. Clinically, poor survivals were documented for IGHV3-21 CLLs as well as for subgroups of mutated and homHCDR3-IGHV3-21 CLLs. Negative prognosticators CD38, ZAP-70, CD49d, and CD79b were expressed at higher levels in homHCDR3 than nonhomHCDR3-IGHV3-21 cases. Differential gene expression profiling (GEP) of 13 IGHV3-21 versus 52 non-IGHV3-21 CLLs identified, among 122 best-correlated genes, TGFB2 and VIPR1 as down- and up-regulated in IGHV3-21 CLL cases, respectively. Moreover, GEP of 7 homHCDR3 versus 6 nonhomHCDR3-IGHV3-21 CLLs yielded 20 differentially expressed genes, with WNT-16 being that expressed at the highest levels in homHCDR3-IGHV3-21 CLLs. Altogether, IGHV3-21 CLLs, including those with homHCDR3, had a peculiar global phenotype in part explaining their worse clinical outcome.

Low-dose thalidomide in combination with oral fludarabine and cyclophosphamide is ineffective in heavily pre-treated patients with chronic lymphocytic leukemia

Elevated levels of TNF-alpha have been associated with progressive disease in patients with chronic lymphocytic leukemia (CLL). Thalidomide has been shown to inhibit production of TNF-alpha. We investigated the effects of thalidomide on clinical outcome and TNF-alpha serum levels in five pre-treated CLL patients. The schedule consisted on daily thalidomide (Thal), oral fludarabine (Flu) and oral cyclophosphamide (CTX). Median duration of treatment was 60 days; four patients stopped treatment for disease progression and one patient for neurological toxicity. Serum TNF-alpha levels did not show any decrease during treatment. Low-dose thalidomide is not effective in CLL patients with refractory disease.

Relationship between autoimmune phenomena and disease stage and therapy in B-cell chronic lymphocytic leukemia

The aim of this multicenter GIMEMA study was to correlate autoimmune complications (AIC) in B-cell chronic lymphocytic leukemia (B-CLL) with stage and therapy. Autoimmune hemolytic anemia (129/194 cases) and autoimmune thrombocytopenia (35/194 cases) were typically present in advanced and multi-treated disease. Age over the median, stage C and first and second line therapy were identified as independent risk factors by multivariate analysis. In contrast, non-hematologic AIC (30/194 cases) and the presence of serological markers of autoimmunity were mostly observed in early B-CLL, suggesting different pathogenic mechanisms underlying hematologic and non-hematologic autoimmune phenomena in B-CLL.

ZAP-70 enhances B-cell-receptor signaling despite absent or inefficient tyrosine kinase activation in chronic lymphocytic leukemia and lymphoma B cells

Expression of ZAP-70 is an important negative prognostic factor in chronic lymphocytic leukemia (CLL). This protein tyrosine kinase is a key mediator of T-cell receptor (TCR) signaling and is structurally homologous to Syk, which plays an analogous role in B-cell receptor (BCR) signaling. Recent studies indicate that ZAP-70 may participate in BCR signaling as well, but the mechanism of action is not completely understood. We have now compared antigen receptor-induced activation of ZAP-70 in B cells and T cells by analyzing phosphorylation of critical regulatory tyrosine residues. We show that BCR-mediated activation of ZAP-70 is very inefficient in CLL and lymphoma B cells and is negligible when compared to activation of Syk. Despite the inefficient catalytic activation, the ability of ZAP-70 to recruit downstream signaling molecules in response to antigen receptor stimulation appeared relatively preserved. Moreover, ectopic expression of ZAP-70 enhanced and prolonged activation of several key mediators of BCR signaling, such as the Syk, ERK, and Akt kinases, and decreased the rate of ligand-mediated BCR internalization. We conclude that the role of ZAP-70 in BCR signaling is quite distinct from its role in TCR signaling and is likely mediated by inhibition of events that terminate the signaling response.

The Akt signaling pathway determines the different proliferative capacity of chronic lymphocytic leukemia B-cells from patients with progressive and stable disease

Chronic lymphocytic leukemia (CLL) B-cells are hyporesponsive to many proliferative signals that induce activation of normal B-lymphocytes. However, a heterogeneous response has recently been observed with immunostimulatory CpG-oligodeoxynucleotides (CpG ODN). We now show that CpG ODN induce proliferation mainly in CLL B-cells from patients with progressive disease and unmutated immunoglobulin V(H) genes, whereas G(1)/S cell cycle arrest and apoptosis are induced in leukemic B-cells from stable/V(H) mutated CLL. Examination of early signaling events demonstrated that all CLL B-cells respond to CpG ODN stimulation by degradation of the NF-kappaB inhibitor IkappaB and activation of the Akt, ERK, JNK and p38 MAPK kinases, but the magnitude and duration of the signaling response was greater in the proliferating cases. Pharmacological inhibition of these pathways showed that simultaneous activation of Akt, ERK and JNK is required for cell cycle progression and proliferation. Conversely, introduction of constitutively active Akt in nonproliferating CLL B-cells resulted in induction of cyclin A following CpG ODN stimulation, indicating that increased Akt activation is sufficient to overcome the hyporesponsiveness of these cells to proliferative signals. Thus, the magnitude of Akt signaling may determine the distinct responses observed in leukemic B-cells belonging to the different prognostic subgroups.

Immunophenotypic characterization of IgVH3-72 B-cell chronic lymphocytic leukaemia (B-CLL)

The frequent expression of the otherwise rare IgVH3-72 gene was demonstrated in highly stable B-cell chronic lymphocytic leukaemias (B-CLLs). Here we describe the immunophenotypic profiles of eleven IgVH3-72 B-CLLs, by investigating expression of ZAP-70 and of a set of surface antigens previously demonstrated to represent the signature of distinct B-CLL prognostic groups. All IgVH3-72 B-CLLs revealed a homogeneous immunophenotypic profile, expressing all the markers associated with good prognosis, but not those representing the signature of bad prognosis B-CLLs, including ZAP-70. Our results corroborate the notion that IgVH3-72 B-CLLs represent a molecularly and immunophenotypically homogeneous disease group with a good prognosis.

Rituximab therapy for chronic lymphocytic leukemia-associated autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AIHA) is a well-known complication of chronic lymphocytic leukemia (CLL). In recent years the anti-CD20 monoclonal antibody rituximab has been used for the therapy of steroid-refractory AIHA and autoimmune thrombocytopenia, either idiopathic or in association with CLL. We report the results of rituximab treatment for 14 patients suffering from CLL-associated AIHA. They developed a direct antiglobulin test positive AIHA at a mean time of 47 months (range 0-135 months) from the diagnosis of CLL. In 3 cases AIHA was diagnosed at the same time as CLL. Only 1 patient had fludarabine-related AIHA. All patients received steroids as first-line treatment. At a mean time of 46 days (range 1-210 days) from the diagnosis of AIHA all patients received rituximab at a dosage of 375 mg/m(2)/weekly for 4 weeks. All patients except 3 (2 died of cardiac failure or sepsis soon after the third cycle and 1 HCV-positive patient experienced a rise in serum amino transferases) completed the scheduled four programmed cycles. First injection side effects of rituximab were minimal. All but 2 patients showed an increase in hemoglobin levels in response to rituximab (mean value 3.6 g/dl; range 0.7-10 g/dl) and a reduction in the absolute lymphocyte count and lymph nodes and spleen volume. Nine patients required packed red cell transfusions before starting rituximab; 5 no longer needed transfusions just after the second cycle and another patient after the fourth cycle. Three patients (22%) were considered to fully respond and 7 (50%) only responded partially. At a mean follow-up of 17 months, 8 patients were still alive, 6 of them transfusion-free. Our results prove that the anti-CD20 monoclonal antibody is an effective and well-tolerated alternative treatment for CLL-associated AIHA.

Mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone followed by autologous peripheral blood stem cell transplantation

BACKGROUND

The objective of the current study was to evaluate a salvage chemotherapy regimen consisting of mitoxantrone, carboplatin, cytosine arabinoside, and methylprednisolone (MiCMA) for the treatment of patients with primary refractory or recurrent non-Hodgkin lymphoma (NHL).

METHODS

From September 1991 to August 2002, 94 consecutive patients ages 16-60 years who had either recurrent or refractory NHL (mainly diffuse large-cell lymphomas) were treated on the MiCMA protocol. Patients had peripheral blood stem cells collected successfully for autologous stem cell transplantation after two or three cycles of MiCMA.

RESULTS

Sixty-four of 85 evaluable patients achieved a response to the MiCMA regimen: 24 patients (26%) achieved a complete response and 40 patients (44%) achieved a partial response, for a total response rate of 70%. Sixty-two patients underwent autologous stem cell transplantation. After a median follow-up of 58 months, 47 patients (55%) remained alive; among these patients, 32 were free of disease (37%). No toxic deaths related to MiCMA were observed. Three patients died of infectious complications after transplantation.

CONCLUSIONS

The current results suggested that MiCMA chemotherapy is an effective therapeutic alternative salvage regimen for patients with primary refractory or recurrent NHL. Response rates, overall survival, and freedom from disease progression were found to be associated significantly with response to MiCMA. Peripheral blood stem cell transplantation was feasible in virtually all patients, and its outcome was influenced strongly by chemosensitivity.

Comparison of ZAP-70/Syk mRNA levels with immunoglobulin heavy-chain gene mutation status and disease progression in chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVES

The protein tyrosine kinase ZAP-70 has recently emerged as a major prognostic indicator in chronic lymphocytic leukemia (CLL). ZAP-70 is structurally and functionally homologous to Syk, a key mediator of B-cell receptor signaling. We therefore evaluated ZAP-70 expression in CLL B cells using Syk as an intracellular standard.

DESIGN AND METHODS

The relative amounts of ZAP-70 and Syk were determined in purified B cells from 92 CLL patients using a novel reverse transcriptase/polymerase chain reaction (RT-PCR) procedure that co-amplifies both transcripts with equal efficiency. The ZAP-70/Syk mRNA ratio was correlated with VH gene mutation status, median treatment-free survival and FACS analysis of ZAP-70 expression.

RESULTS

ZAP-70 was expressed in the majority of cases with unmutated VH genes (88%), but also at lower levels in a substantial fraction of cases with mutated VH genes (44%). High levels of ZAP-70, defined as ZAP-70/Syk mRNA ratios above 0.25, were observed mainly in cases with unmutated VH genes and correlated with short treatment-free survival. In contrast, no difference was observed in the median treatment-free survival between patients with low ZAP-70/Syk ratios (0.05-0.25) and patients with no or negligible ZAP-70 expression (ZAP-70/Syk<0.05). In 73 cases ZAP-70 expression was investigated by RT/PCR and FACS analysis; concordance with VH gene mutation status was 86% and 71%, respectively.

INTERPRETATION AND CONCLUSIONS

ZAP-70 is frequently expressed in CLL B cells, but only high levels correlate with unmutated VH gene status and progressive disease. Expression of ZAP-70 can be accurately assessed by analysis of the ZAP-70/Syk mRNA ratio, thus providing an alternative to FACS analysis.

Positive selection of cytotoxic T lymphocyte escape variants during acute hepatitis C virus infection

Cellular immune responses are induced during hepatitis C virus (HCV) infection and acute-phase CD8+ T cells are supposed to play an important role in controlling viral replication. In chimpanzees, failure of CD8+ T cells to control HCV replication has been associated with acquisition of mutations in MHC class I-restricted epitopes. In humans, although selection of escape mutations in an immunodominant CTL epitope has been recently described, the overall impact of immune escape during acute HCV infection is unclear. Here, by performing an in depth analysis of the relationship between early cellular immune responses and viral evolution in a chronically evolving HCV acutely infected individual, we demonstrate: (i) the presence of a potent and focused CD8(+ T cell response against a novel epitope in the NS3 protein, (ii) the elimination of the quasi-species harboring the original amino acid sequence within this epitope, and (iii) the selection for a virus population bearing amino acid changes at a single residue within the cytotoxic T cell epitope that strongly diminished T cell recognition. These results support the view that acute-phase CD8+ T cell responses exert a biologically relevant pressure on HCV replication and that viruses escaping this host response could have a significant survival advantage.