Large granular lymphocytic leukaemia with a mixed T-cell/B-cell phenotype

We report a case of large granular lymphocytic leukaemia (LGLL) with mixed T-cell/B-cell phenotypes. The LGLL cells expressed T-cell markers such as CD1, CD2, CD3, CD5, CD7, CD8 and CD57. The CD8⁺ LGLL cells coexpressed B-cell markers including CD20 and PCA-1, and a fraction of purified CD8⁺ LGLL cells secreted double isotypes of immunoglobulins (IgG-κ and IgA-κ). Both TCRB and IGH genes were clonally rearranged. The LGLL cells could be divided into at least three subpopulations that were cytogenetically distinct, and all subpopulations involved the 11q23. The expression of both T- and B-cell markers on the LGLL cells suggests the involvement of a putative common lymphoid progenitor in leukaemic transformation.     

Large granular lymphocyte leukaemia occurring after renal transplantation

Post-transplantation lymphoproliferative disorders (PTLD) are a clinicopathologically heterogenous group of lymphoid proliferations. The majority are of B-cell origin and associated with Epstein-Barr virus (EBV) infection. In contrast, the development of T-cell PTLD is much less common and EBV does not appear to be involved in pathogenesis. In this report we describe three patients who developed large granular lymphocyte (LGL) leukaemia after renal transplantation. These patients had clonal expansion of CD3⁺, CD8⁺, CD57⁺, CD56⁻ LGL. We were unable to detect CMV antigen or find evidence for EBV or human T-cell leukaemia/lymphoma virus genome in the LGL from these patients. These data show that LGL leukaemia should be included as one of the types of T-cell proliferations which can occur post transplant.     

Large granular lymphocytic leukaemia pathogenesis and management

The WHO classification recognises three distinct disorders of large granular lymphocytes: T-cell large granular lymphocytic leukaemia (T-LGL), chronic lymphoproliferative disorders of NK-cells (CLPD-NK) and agressive NK-cell leukaemia. Despite the different cell of origin, there is considerable overlap between T-LGL and CLPD-NK in terms of clinical presentation and therapy. Many patients are asymptomatic and do not require treatment. Therapy, with immunosuppressant agents such as low dose methotrexate or ciclosporin, is usually indicated to correct cytopenias. In contrast, aggressive NK-cell leukaemia and the rare CD56(+) aggressive T-LGL leukaemia follow a fulminant clinical course, affect younger individuals and require more intensive combination chemotherapy followed by allogeneic stem cell transplant in eligible patients. The relative rarity of these disorders means that there have been few clinical trials to inform management. However, there is now considerable interest in the pathogenesis of the chronic LGL leukaemias and this has stimulated early trials to evaluate novel agents which target the dysregulated apoptotic pathways characteristic of this disease.     

Stem cell transplantation for chronic lymphocytic leukaemia

Early results of autologous stem cell transplantation (ASCT) in chronic lymphocytic leukaemia (CLL) suggested a significant proportion of patients remained disease-free for years, raising the possibility of cure. More recent studies have shown no evidence of a plateau in the survival curves indicating that, at best, ASCT may only prolong disease-free survival. Problems remain over progenitor cell mobilization and one study has raised anxieties about post-transplant myelodysplasia. The impact of ASCT in CLL will only be properly ascertained in a randomized clinical trial and this in underway in Europe. Initial results of conventional allogeneic transplantation (allo-SCT) were very disappointing, with an unacceptably high mortality, but did show that cure was possible in some patients. The introduction of reduced intensity conditioning has limited the early transplant-related mortality but it remains too early to determine what proportion of patients will be cured. In view of these uncertainties, is important that reduced intensity allo-SCT for CLL is conducted in the context of a clinical trial. Finally, CLL is very heterogeneous condition and great deal more is becoming understood about the prognostic factors. These will become important in allowing patients and their physicians a choice in balancing the risks of various treatment options.     

Allogeneic haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: outcome in a 20-year cohort

The curative potential of allogeneic haematopoietic stem cell transplant (allo HSCT) in chronic lymphocytic leukaemia CLL is established, with a demonstrated role for graft-versus-leukaemia and less certainty for other factors in determining outcome. The first two decades of CLL patients proceeding to allo HSCT at the Leukaemia/Bone Marrow Transplant Program of British Columbia (n = 49 consecutive, 1991-2009) were studied to clarify factors predicting outcome. The donor was related in 29 (59%) and unrelated in 20 (41%). Conditioning was reduced-intensity in 27 (55%) and myeloablative in 22 (45%). Thirty-one of 49 patients survive with median follow-up of 5 years (0·2-15). Cumulative incidence of non-relapse mortality; complete remission (CR); clearance of fluorescence in situ hybridization (FISH) abnormality and progression at 10 years was 36%; 69%; 55% and 22%. Overall survival (OS) was 63% at 2 years; 55% at 5 years and beyond. Factors predicting OS (P value by log rank <0·05) were: comorbidity index <3, FISH rank (Dohner) and 17p deletion, alemtuzumab pre-HSCT, achievement of CR post-HSCT, donor chimerism >90%, clearance of FISH abnormality post-HSCT and absence of high-grade (3-4) graft-versus-host disease. Results from this province-wide, two-decade cohort demonstrated that a substantial proportion of patients with high-risk CLL become long term disease-free survivors.     

Graft-versus-leukaemia effect after non-myeloablative haematopoietic transplantation can overcome the unfavourable expression of ZAP-70 in refractory chronic lymphocytic leukaemia

ZAP-70 (zeta-chain-associated protein 70 kDa) expression is associated with poor prognosis in patients with chronic lymphocytic leukaemia (CLL). This study evaluated the efficacy of non-myeloablative allogeneic stem cell transplantation in patients with advanced CLL and assessed the impact of ZAP-70 expression on the outcome. Thirty-nine sequential patients were included. All had previously been treated with fludarabine. All patients received a preparative regimen of fludarabine (30 mg/m(2)/d for 3 d), intravenous cyclophosphamide (750 mg/m(2)/d for 3 d), and high-dose rituximab. Immunohistochemical techniques on marrow biopsy samples were used to determine that ZAP-70 was expressed in 25 patients, whereas 13 other patients were ZAP-70 negative, and one was of indeterminate status. With a median follow-up time of 27 months, the estimated overall survival and current progression-free survival (CPFS) rates at 4 years were 48% and 44% respectively. Patients who were ZAP-70 positive had 56% survival, and their CPFS rate increased from 30% to 53% after a donor lymphocyte infusion. Multivariate analysis indicated that chemorefractory disease and mixed T cell chimerism at day 90, but not ZAP-70 positivity, were associated with the risk of disease progression after transplantation. These results demonstrate a potent graft-versus-leukaemia effect that can overcome the adverse prognostic effect of ZAP-70 expression.     

Autologous stem cell transplantation and purging in adult acute lymphoblastic leukaemia

The prognosis for adult acute lymphoblastic leukaemia (ALL) is poor. Only 20-30% of patients will be cured with conventional chemotherapy. Haematopoietic progenitor transplantation is thus an attractive option in these patients. Even if allogeneic transplantation allows a better control of the disease, autologous transplantation remains an important alternative for patients lacking a suitable donor or when allogeneic transplants imply excessive risk. Relapse is the main drawback of autologous transplants, but many strategies are being explored to overcome this problem.We focus here on transplant modality, the source of haematopoietic progenitors, and the best timing to apply the procedure. Also reviewed are the current situation and future strategies for improving results in this setting, such as ex vivo purging; immunotherapy and maintenance chemotherapy.     

Evaluation of schistocyte monitoring after haematopoietic stem cell transplantation

Introduction: Observation of schistocytes on the peripheral blood following haematopoietic stem cell transplantation (SCT) is a common finding. As their presence is not specific to the onset of SCT‐related thrombotic microangiopathy, we evaluated the interest of schistocyte measurement twice a week during the entire follow‐up of 195 patients undergoing SCT, particularly focussing on the 125 allogeneic SCT. Methods: Schistocytes were strickly defined as triangular‐, crescent‐ or helmet‐shaped red blood cells according to consensus standards and were checked blindly under the microscope and with computer image analysis. Results: Mean schistocyte percentage was 0.7% (±0.5%, reference value ≤0.5). High schistocyte percentage was observed after allografts (0.79%) when compared to autologous SCT (0.47, P < 0.001). All but one patients undergoing allogenic SCT had schistocytes ≥0.6%. Conversely, significant schistocytosis was observed in 20% of the autologous SCT. Initial diagnosis [chronic myelocytic leukaemia, acute lymphoblastic leukaemia (ALL)], high‐risk status, unrelated transplant and conditioning regimen including total body irradiation influenced higher schistocyte percentage (≈0.9%). Significant rise in the schistocyte percentage was observed during acute/chronic graft‐versus‐host disease, veno‐occlusive disease (VOD), cholestatic hepatitis, haemorrhagic cystitis (HC) and pulmonary complications. Multivariate analysis showed a significant association between thrombotic microangiopathy (TM), renal impairment and delayed thrombopaenia after day 50, and schistocyte >1.2%. SCT‐TM grade ≥2 occurred in nine patients. A marked rise in schistocyte >4.5% was observed, which was not reached during the other SCT‐related complications. Children with ALL, undergoing unrelated allogeneic SCT, with early acute graft‐versus‐host disease refractory to steroids were prone to present SCT‐TM, associated with VOD, interstitial pneumopathy and HC, resulting in a high mortality rate (six of seven patients). Our data confirmed that schistocytosis was common after SCT. Mild percentages were likely concomitant with extensive endothelial damage but higher percentage should have prompted to a close monitoring with SCT‐TM investigation. Conclusion: In our experience, systematic schistocyte count after HSCT proved to be useful: the occurrence of an increased percentage was a surrogate marker for complications even if unspecific for TM.     

Cyclosporine A alleviates severe anaemia associated with refractory large granular lymphocytic leukaemia and chronic natural killer cell lymphocytosis

Large granular lymphocytic (LGL) leukaemia and chronic natural killer cell lymphocytosis (CNKL) are chronic indolent disorders often associated with neutropenia and constitutional symptoms. Severe anaemia occurs in about 20% of patients and is currently treated with corticosteroids followed by oral cyclophosphamide in non-responders. 30% of patients fail initial measures, and salvage therapy is inadequate. We describe three transfusion-dependent patients (two with T-LGL leukaemia, one with CNKL) refractory to corticosteroids, cyclophosphamide, and in one case fludarabine. Cyclosporine A (CSA) initiation resulted in prompt transfusion-independence and was well tolerated in all patients, making it an attractive alternative therapy for this disorder.     

Bioethical considerations of monoclonal B-cell lymphocytosis: donor transfer after haematopoietic stem cell transplantation

Monoclonal B-cell lymphocytosis (MBL) is a recently described laboratory finding in otherwise healthy individuals. In MBL, a light chain-restricted, clonal B-cell population, often with a chronic lymphocytic leukaemia (CLL) phenotype, is identified by flow cytometry. Although the prognostic significance remains unclear, there is an increased incidence in ageing populations and those with a family history of CLL. During the past decade of MBL study, three families have come to our attention in which prospective sibling haematopoietic stem cell donors were found to have an MBL. These families raise complex bioethical issues with regard to disclosure of research data, eligibility for clinical trials and potential donor transfer of MBL. These issues are explored in this report. Identification of MBL among prospective sibling transplant donors will become a common occurrence in transplant practice as transplantation is increasingly offered to older individuals and those with CLL.     

Continuous complete remission in adult patients with acute lymphocytic leukaemia at a median observation of 12 years after autologous bone marrow transplantation

We report our long-term experience with autologous bone marrow transplantation (ABMT) for 32 adult patients with acute lymphocytic leukaemia (ALL) in second or later remission (CR), or in first CR but with high-risk. Bone marrow was purged with mafosfamide (n = 25) or with immunomagnetic beads and monoclonal antibodies (n = 7). Retrospective analysis showed that 12 out of 32 patients were in continuous complete remission (CCR) at a median of 143 months (range 66-181 months). A plateau was reached at 50 months and the disease-free and overall survival rates were both 37.5%. It was notable that durable CCR could be achieved for patients in second (three out of nine) or third (one out of six) CR. ABMT could produce durable CCR and the long-term outcome compared favourably with those reported for allogeneic transplantation.     

Impact of human herpesvirus-6 after haematopoietic stem cell transplantation

We studied 228 consecutive stem cell transplant recipients, screened for reactivation of human herpesvirus-6 (HHV-6) in peripheral blood and other specimens as clinically indicated by means of qualitative polymerase chain reaction. Among them, 197 received an allograft and 31 autograft. Ninety-six of 228 patients (42.1%) showed HHV-6 reactivation in peripheral blood and 129 of 228 (56.6%) demonstrated HHV-6 in at least one of the specimens tested. 41.9% of patients were asymptomatic when HHV-6 was identified. Clinical features, noted when HHV-6 was detected, included interstitial or alveolar pneumonia, gastroduodenal and colorectal disease, bone marrow suppression and liver disease. However, based on clinical and histopathological criteria, HHV-6 was considered a causal agent in only a minority of patients, in particular, those suffering from bone marrow suppression (n = 11), gastroduodenitis (five), colitis (three), interstitial/alveolar pneumonia (five), skin rash (one), pericarditis (two) and encephalitis (one). HHV-6 reactivation was significantly associated with the occurrence of graft-versus-host disease [odds ratio (OR) 5.31], Epstein-Barr virus coinfection (OR 8.89) and unrelated donor transplantation (OR 5.67) indicating an increased stage of immunosuppression.     

Preventing relapse after haematopoietic stem cell transplantation for acute leukaemia: the role of post‐transplantation minimal residual disease (MRD) monitoring and MRD‐directed intervention

Relapse is the main cause of treatment failure after allogeneic haematopoietic stem cell transplantation (allo‐HSCT) for acute leukaemia (AL). Post‐transplantation minimal residual disease (MRD) monitoring enables risk stratification and identifies AL patients at higher risk of relapse. MRD assessment primarily involves the determination of leukaemia‐associated immunophenotypic patterns using multiparameter flow cytometry, and the polymerase chain reaction (PCR)‐based evaluation of expression levels of leukaemia‐related genes (specific reciprocal gene rearrangements and other mutation types). In addition, next generation sequencing and digital PCR may further enrich current MRD detection. Several MRD‐directed interventions have demonstrated the ability to reduce the risk of relapse with acceptable treatment‐related toxicities. Donor lymphocyte infusion (DLI) is the most important intervention for MRD‐positive patients, while several modified strategies, such as granulocyte colony‐stimulating factor–mobilized peripheral blood cells followed by short term immune suppression and escalating dose regimen, further improve the safety and efficacy of DLI. Interferon therapy, targeted drugs, and hypomethylating agents have also been introduced for MRD‐directed interventions. Referring to the issues of whether and who would benefit from pre‐emptive intervention according to MRD, in this review, we summarized this rapidly evolving area of MRD monitoring and MRD‐directed interventions in AL patients after allo‐HSCT.     

Haemopoietic stem cell autografts for leukaemia

Conclusions The technology for collecting and cryopreserving haemopoietic stem cells has improved greatly in recent years. Two major problems remain: we need to develop methods for removing residual leukaemic cells from marrow harvested from patients with acute leukaemia in remission and we need to define further the optimal approach to chemo-radiotherapy of patients, both those in relapse and those in remission, before autografting. If progress can be made in these areas, and the problems are no more daunting than those that face the specialist in allogeneic transplantation, the possibility that autografting will contribute to the cure of patients with acute leukaemia and to important prolongation of life for those with CGL can become a reality.     

Sequential changes in the bone marrow trephine biopsy in B-cell chronic lymphocytic leukaemia

Background: Trephine biopsy of the bone marrow is integral to both diagnosis and prognosis in B-cell lymphocytic leukaemia (B-CLL), but its usefulness would be enhanced by more information on the type, degree and rate of change that occur over time in histologic pattern and lymphocytic infiltration.
Aims: To investigate these changes by serial trephine biopsy in totally untreated patients, in treatment-free intervals in treated patients and during intervals of treatment.
Methods: In 82 patients with predominantly early B-CLL observed for a median of 65 months (13–331), 309 trephine biopsies were carried out, a median of three (two to eight) per patient. The biopsies were classified into nodular, interstitial, mixed and diffuse patterns. Lymphocytic infiltration was subjectively graded into minimal (< 20%), intermediate (20–50%) and majority (> 50%) categories and all changes were compared.
Results : Intensity of infiltration increased through this histologic range, as did the relative risk of death. Survival of patients with > 50% involvement was significantly poorer than those with < 50%. Changes in both lymphocyte numbers and pattern occurred slowly in early disease but quickened as the leukaemia advanced. Under treatment, lymphocytes decreased but the histology did not alter significantly. Examining the marrow for disease progression should be part of regular follow-up. It may help identify the minority of patients with early disease which will run a more active course and in whom early therapy may yet be indicated. We recommend biopsy at two-yearly intervals in early disease, more frequently as the leukaemia advances. The minimal, intermediate and majority classification in addition to the histologic pattern is a useful grading. (Aust NZ J Med 1993; 23: 470–476.)