The 2017 WHO update on mature T- and natural killer (NK) cell neoplasms

Over the last decade, there has been a significant body of information regarding the biology of the lymphoid neoplasms. This clearly supports the need for updating the 2008 WHO (World Health Organization) classification of haematopoietic and lymphoid tumours. The 2017 WHO classification is not a new edition but an update and revision of the 4th edition. New provisional entities but not new definitive entities are included, and novel molecular data in most of the entities and changes in the nomenclature in few of them have been incorporated. In the context of the mature T- and NK-cell neoplasms, the most relevant updates concern to: 1-dysregulation of the JAK/STAT pathway due to gene mutations which are common to various aggressive and indolent neoplasms; 2-incorporation of new molecular players that are relevant to the pathogenesis of these neoplasms and/or have prognostic implications; 3-inclusion of new provisional entities within the subgroups of anaplastic, primarily intestinal and cutaneous lymphomas such as breast implant-associated anaplastic large cell lymphoma, indolent T-cell lymphoproliferative disorder of the gastrointestinal tract and primary cutaneous acral CD8⁺ T-cell lymphoma; 4-identification of poor prognostic subtypes of peripheral T-cell lymphomas not otherwise specified (PTCL, NOS) characterized by overexpression of certain genes and of a subgroup PTCL, NOS with a T follicular phenotype that now is included together with angioimmunoblastic T-cell lymphoma under the umbrella of lymphomas with a T follicular helper phenotype; and 5-refinement on the designation and definition of already established entities. A review of the major changes will be outlined.

Over 30% of patients with splenic marginal zone lymphoma express the same immunoglobulin heavy variable gene: ontogenetic implications

We performed an immunogenetic analysis of 345 IGHV-IGHD-IGHJ rearrangements from 337 cases with primary splenic small B-cell lymphomas of marginal-zone origin. Three immunoglobulin (IG) heavy variable (IGHV) genes accounted for 45.8% of the cases (IGHV1-2, 24.9%; IGHV4-34, 12.8%; IGHV3-23, 8.1%). Particularly for the IGHV1-2 gene, strong biases were evident regarding utilization of different alleles, with 79/86 rearrangements (92%) using allele (*)04. Among cases more stringently classified as splenic marginal-zone lymphoma (SMZL) thanks to the availability of splenic histopathological specimens, the frequency of IGHV1-2(*)04 peaked at 31%. The IGHV1-2(*)04 rearrangements carried significantly longer complementarity-determining region-3 (CDR3) than all other cases and showed biased IGHD gene usage, leading to CDR3s with common motifs. The great majority of analyzed rearrangements (299/345, 86.7%) carried IGHV genes with some impact of somatic hypermutation, from minimal to pronounced. Noticeably, 75/79 (95%) IGHV1-2(*)04 rearrangements were mutated; however, they mostly (56/75 cases; 74.6%) carried few mutations (97-99.9% germline identity) of conservative nature and restricted distribution. These distinctive features of the IG receptors indicate selection by (super)antigenic element(s) in the pathogenesis of SMZL. Furthermore, they raise the possibility that certain SMZL subtypes could derive from progenitor populations adapted to particular antigenic challenges through selection of VH domain specificities, in particular the IGHV1-2(*)04 allele.

CD52 expression in T-cell large granular lymphocyte leukemia – Implications for treatment with alemtuzumab

Few reports on the successful treatment of T-cell large granular lymphocyte (LGL) leukemia with the humanized anti-CD52 monoclonal antibody alemtuzumab are emerging in the literature. The expression of CD52 by LGLs has not been previously investigated. Using semi-quantitative 2- and 3-color flow cytometry, we documented the expression of CD52 in 100% of abnormal cells in T-cell LGL leukemia (n = 11) and natural killer (NK) cell LGL leukemia (n = 2), and showed no significant difference in CD52 expression between T-cell prolymphocytic leukemia (PLL) and T-cell LGL leukemia. Higher CD52 expression has been noted in responders to alemtuzumab in T-cell PLL and in chronic lymphocytic leukemia (CLL), a B-cell disorder. The strong and consistent expression of CD52 shown here highlights the potential role of alemtuzumab in the treatment of refractory T-cell LGL leukemia and possibly aggressive NK cell leukemia.

Fludarabine, Cyclophosphamide and Mitoxantrone in Relapsed or Refractory Chronic Lymphocytic Leukemia and Low Grade Non-Hodgkin's Lymphoma

A regimen combining fludarabine, cyclophosphamide and mitoxantrone (FCM) was used to treat 29 patients with relapsed or refractory chronic lymphocytic leukemia (CLL, N = 24) and low-grade non-Hodgkin's lymphoma (NHL, N = 5) based on evidence suggesting synergism between the 3 drugs. Patients were treated with mitoxantrone 5mg/m2 i.v. day 1 only, fludarabine 25 mg/m2 i.v. for 3 days or 24 mg/m2 orally for 5 days, cyclophosphamide 250 mg/m2 i.v. for 3 days or 150 mg/m2 orally for 5 days inclusive. Eighteen patients had previously received fludarabine and most were heavily pretreated with 40% having >2 prior treatments. A median number of 4 FCM courses (range of 1-9) were given. The response rate was 78.5%: 32% complete remission, 25% nodular partial remission, 21.5%, partial remission. Median duration of response was 19 months and median survival was 42 months. Sixteen patients (57%) developed neutropenia to < 0.5 x 10(9)/l and 12 (43%) infectious complications. Four patients developed large cell lymphoma (Richter's syndrome) and 2 acute myeloid leukemia. FCM is a useful combination for relapsed or refractory CLL and low grade NHL with high response rates and long duration of response. The role of FCM as first line therapy deserves study as well as its combination with the monoclonal antibody Rituximab.

The Leukemic Presentation of Mantle-cell Lymphoma: Disease Features and Prognostic Factors in 58 Patients

Mantle-cell lymphoma (MCL) is a B-cell malignancy with distinct molecular genetics and pathological features. Peripheral blood involvement has been reported with variable frequency, but information on the natural history of cases presenting with leukemia is lacking. This study aimed to determine the clinical and prognostic features of such cases. We studied clinical features, tumor characteristics, prognostic factors and outcome in 58 patients with leukemic presentation of MCL. Diagnosis was based on morphology, immunophenotype, presence of t(11;14), histology and cyclin D1 expression. The median age was 62 years and male:female 2.4:1. Presenting features included splenomegaly (74%), lymphadenopathy (45%), hepatomegaly (17%) and, in a minority, gastro-intestinal involvement or involvement of Waldeyer's ring; 10% had lymphocytosis alone. Six patients developed central nervous system disease. Median lymphocyte count was 58 x 10(9)/l, 55% had anemia and 17% had thrombocytopenia. Morphology of peripheral blood showed small-cell MCL in 15% of cases, typical MCL in 46% and blastoid MCL in 39%. Immunological markers showed a typical phenotype (CD5+ CD23 -) in 68%, and atypical phenotypes, CD5- CD23- in 17% or CD5+ CD23+ in 15%. CLL scores were 0, 1 or 2 in 96%. Median overall survival was 36 months. Good response to first-line treatment (P = 0.0008) and splenomegaly (P = 0.03) were favorable prognostic factors, while other features including morphology and CD38 expression had no impact on survival or treatment response. This analysis demonstrates that except for splenomegaly, survival of MCL patients presenting with leukemia is not significantly influenced by clinical or tumor characteristics. Splenectomy is a useful treatment option in this group of patients.

Splenic marginal zone lymphoma proposals for a revision of diagnostic, staging and therapeutic criteria

Since the initial description of splenic marginal zone lymphoma (SMZL) in 1992, an increasing number of publications have dealt with multiple aspects of SMZL diagnosis, molecular pathogenesis and treatment. This process has identified multiple inconsistencies in the diagnostic criteria and lack of clear guidelines for the staging and treatment. The authors of this review have held several meetings and exchanged series of cases with the objective of agreeing on the main diagnostic, staging and therapeutic guidelines for patients with this condition. Specific working groups were created for diagnostic criteria, immunophenotype, staging and treatment. As results of this work, guidelines are proposed for diagnosis, differential diagnosis, staging, prognostic factors, treatment and response criteria. The guidelines proposed here are intended to contribute to the standardization of the diagnosis and treatment of these patients, and should facilitate the future development of clinical trials that could define more precisely predictive markers for histological progression or lack of response, and evaluate new drugs or treatments.

Adult T-cell leukaemia/lymphoma

Adult T-cell leukaemia/lymphoma (ATLL) is a mature T-cell neoplasm of post-thymic lymphocytes aetiologically linked to the human T-cell lymphotropic virus, HTLV-I, and with a distinct geographical distribution. The disease manifests with leukaemia in greater than two thirds of patients, while the remaining patients have a lymphomatous form. According to the disease manifestations, various forms which differ in clinical course and prognosis have been recognised: acute, chronic, smouldering and lymphoma. Organomegaly, skin involvement, circulating atypical lymphocytes ("flower" cells) with a CD4+ CD25+ phenotype and hypercalcaemia are the most common disease features. The diagnosis should be based on a constellation of clinical features and laboratory investigations. The latter comprise: lymphocyte morphology, immunophenotype, histology of the tissues affected in the pure lymphoma forms and serology or DNA analysis for HTLV-I. The differential diagnosis of ATLL includes other mature T-cell neoplasms such as T-cell prolymphocytic leukaemia (T-PLL), Sézary syndrome (SS), peripheral T-cell lymphomas and occasionally healthy carriers of the virus or Hodgkin disease. The clinical course is aggressive with a median survival of less than 12 months in the acute and lymphoma forms. Despite major advances in understanding the pathogenesis of the disease, management of these patients remains a challenge for clinicians as they do not respond or achieve only transient responses to therapies used in high-grade lymphomas. The use of antiretroviral agents such as zidovudine in combination with interferon-alpha, with or without concomitant chemotherapy, has shown activity in this disease with improvement in survival and response rate. Consolidation with high dose therapy and autologous or allogeneic stem-cell transplantation should be considered in young patients.

Assessment of fludarabine plus cyclophosphamide for patients with chronic lymphocytic leukaemia (the LRF CLL4 Trial): a randomised controlled trial

BACKGROUND

Previous studies of patients with chronic lymphocytic leukaemia reported high response rates to fludarabine combined with cyclophosphamide. We aimed to establish whether this treatment combination provided greater survival benefit than did chlorambucil or fludarabine.

METHODS

777 patients with chronic lymphocytic leukaemia requiring treatment were randomly assigned to fludarabine (n=194) or fludarabine plus cyclophosphamide (196) for six courses, or chlorambucil (387) for 12 courses. The primary endpoint was overall survival, with secondary endpoints of response rates, progression-free survival, toxic effects, and quality of life. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number NCT 58585610.

FINDINGS

There was no significant difference in overall survival between patients given fludarabine plus cyclophosphamide, fludarabine, or chlorambucil. Complete and overall response rates were better with fludarabine plus cyclophosphamide than with fludarabine (complete response rate 38%vs 15%, respectively; overall response rate 94%vs 80%, respectively; p<0.0001 for both comparisons), which were in turn better than with chlorambucil (complete response rate 7%, overall response rate 72%; p=0.006 and 0.04, respectively). Progression-free survival at 5 years was significantly better with fludarabine plus cyclophosphamide (36%) than with fludarabine (10%) or chlorambucil (10%; p<0.00005). Fludarabine plus cyclophosphamide was the best combination for all ages, including patients older than 70 years, and in prognostic groups defined by immunoglobulin heavy chain gene (V(H)) mutation status and cytogenetics, which were tested in 533 and 579 cases, respectively. Patients had more neutropenia and days in hospital with fludarabine plus cyclophosphamide, or fludarabine, than with chlorambucil. There was less haemolytic anaemia with fludarabine plus cyclophosphamide (5%) than with fludarabine (11%) or chlorambucil (12%). Quality of life was better for responders, but preliminary analyses showed no significant difference between treatments. A meta-analysis of these data and those of two published phase III trials showed a consistent benefit for the fludarabine plus cyclophosphamide regimen in terms of progression-free survival.

INTERPRETATION

Fludarabine plus cyclophosphamide should now become the standard treatment for chronic lymphocytic leukaemia and the basis for new protocols that incorporate monoclonal antibodies.

Microsatellite instability indicative of defects in the major mismatch repair genes is rare in patients with B-cell chronic lymphocytic leukemia: Evaluation with disease stage and family history

A possible role for DNA mismatch repair defects and microsatellite instability (MSI) in the pathogenesis of a number of B-cell lymphoproliferative disorders has recently been debated. To gain further insight into the impact of MSI on B-CLL, we evaluated samples from a series of 982 patients using the mono-satellite markers BAT25 and BAT26, which are highly sensitive in demonstrating classical mismatch repair (MMR) deficiency. Only 1% of cases displayed MSI and this was not correlated with stage of disease or family history of B-CLL. A sub-polymorphic germline variant of BAT25 was identified in one familial case, which was also detected in the patient's affected brother. In conclusion, our study demonstrates that MSI does not have a prominent role in the pathogenesis of B-CLL.

Characteristic appearances of the bone marrow in T-cell large granular lymphocyte leukaemia

AIMS

To augment the limited literature on bone marrow (BM) appearances in T-cell large granular lymphocyte (LGL) leukaemia and to identify a histological signature to aid in diagnosis of this condition.

METHODS AND RESULTS

A descriptive analysis of the histology of the BM in T-cell LGL leukaemia was performed (n = 38). Antibodies against CD3, CD4, CD5, CD8, CD16, CD56, CD57 and CD20 or CD79a were employed. Antibodies against CD68 (macrophages) and CD34 (sinusoids) were also included. BM was normocellular or hypercellular in the majority of cases, with interstitial lymphoid infiltration in 97%. Lymphoid nodules were present in 55% and intrasinusoidal permeation in 58%. Apoptotic figures and haemosiderin deposition were common. All cases showed trilinear haematopoiesis with normal or increased megakaryopoiesis and erythropoiesis, but normal/reduced myelopoiesis. Reticulin was increased (Grade II-III). Immunohistochemistry revealed interstitial infiltration in all cases and helped to identify lymphoid nodules in two-thirds of cases. Preferential localization of CD8+ T lymphocytes to the interstitium and CD4+ T lymphocytes to the periphery of CD20+ B-cell nodules was seen in almost 90% of cases.

CONCLUSIONS

Nodules with non-clonal B-cell centres surrounded by CD4+ cells, with interstitial CD8+ cells, are a characteristic finding in T-cell LGL leukaemia and may represent a histological signature for this condition.

Cytogenetic abnormalities additional to t(11;14) correlate with clinical features in leukaemic presentation of mantle cell lymphoma, and may influence prognosis: a study of 60 cases by FISH

Mantle cell lymphoma (MCL), characterised by t(11;14)(q13;q32), has a poor prognosis. Many cases have additional cytogenetic abnormalities, and often have a complex karyotype. Fluorescence in situ hybridisation (FISH) was used to study 60 cases with leukaemic presentation of MCL, to determine the frequency, clinical correlations and prognostic impact of a panel of molecular cytogenetic abnormalities: 17p13 (TP53 locus), 13q14, 12 p11.1-q11 (centromere), 6q21 and 11q23. CD38 expression, of prognostic value in chronic lymphocytic leukaemia (CLL), was also studied, and correlations with clinical and cytogenetic abnormalities sought. Eighty per cent of cases had at least one abnormality in addition to t(11;14). Deletions at 17p13 (TP53) and 13q14 were most frequent and involved the majority of the leukaemic clone. Cases with TP53 deletion were more likely to have splenomegaly and marked leucocytosis (>30 x 10(9)/l), and less likely to have lymphadenopathy than those without deletion. Deletions at 11q23 and 6q21 were associated with extranodal disease. 13q14 and 11q23 deletions showed a trend towards worse prognosis by univariate analysis. In multivariate analysis, deletions at 13q14 and 6q21 were independent predictors of poor outcome. Deletion at 17p13 did not show prognostic impact in this series. CD38, positive in two-thirds of cases, was associated with male gender and nodal disease but not with any cytogenetic abnormality, or with survival.

Gemcitabine, cisplatin and methylprednisolone (GEM-P) in patients with T-cell lymphoma: Results from The Royal Marsden Hospital

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Background: There is a need for novel, effective therapies for T-cell non-Hodgkin’s lymphoma (NHL). The combination of gemcitabine, cisplatin and methylprednisolone (GEM-P) has shown activity in patients (pts) with relapsed Hodgkin’s disease and NHL (Chau I et al. Br J Haematol 2003, Baetz T et al. Ann Oncol 2003). We report a single institution retrospective analysis of GEM-P for pts with T-cell NHL. Methods: Sixteen pts with T-cell NHL treated at the Royal Marsden Hospital between June 2001 and March 2005 with GEM-P (gemcitabine 1 g/m2 D1, 8, 15; cisplatin 100 mg/m2 D15; methylprednisolone 1 g D1–5, repeated every 28D) were identified. Results: 16 pts (9 males and 7 females) were analysed. Histological subtypes were: angioimmunoblastic (n = 5), T-cell enteropathy (n = 2), NK/T cell nasal-type (n = 2), T-cell anaplastic (n = 3) and peripheral T-cell unspecified (n = 3). Median age was 55 years (range: 18–71 years), 69% had IPI-score ≥ 2 and 69% had stage III/IV disease. 15 /16 pts were pre-treated: median number of prior treatments: 1 (range: 0–4). At the start of GEM-P treatment pts presented with: primary refractory disease (n = 3), 1st relapse (n = 6), 1st relapse refractory (n = 3), 2nd relapse (n = 2) and 4th relapse (n = 1). Median time from diagnosis of T-cell NHL to start of GEM-P was 8.9 months(m) and median number of cycles given was 3 (range: 1–6). Of 16 evaluable patients, 3 pts (19 %) achieved complete remission (CR), 8 pts (50 %) achieved partial remission (PR), (ORR= 69%; CI-95% 41.4–89.0) and 5 pts (31%) progressed while on GEM-P. One pt received high dose chemotherapy (melphalan/etoposide) after CR to GEM-P. After a median follow up of 17.4m the mean progression free survival (PFS) was 9m (range 1.15–37.5). The median overall survival (OS) has not been reached and the survival probability at 1 year was 68.2% (95% CI: 40–85). The main grade 3/4 toxicities were myelosuppression (leucopenia 62%, neutropenia 62% and anaemia 12%) and required granulocyte colony stimulating factor (GCSF) in 3 pts with neutropenic sepsis and in 1 pt with neutropenia. Conclusion: GEM-P has encouraging efficacy with an acceptable toxicity profile in pts with previously treated T-cell NHL.

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IgVH genes mutation and usage, ZAP-70 and CD38 expression provide new insights on B-cell prolymphocytic leukemia (B-PLL)

B-prolymphocytic leukemia (B-PLL) is a rare disease with poor prognosis. To further characterize the biological features of this disease, we analyzed immunoglobulin heavy chain (IgVH) mutations, ZAP-70 and CD38 in 19 cases with de novo B-PLL. Immunoglobulin heavy chain genes analysis showed an unmutated pattern (>98% homology to germ line) in 9/17 cases (53%), with 100% homology in eight. In the remaining, it ranged from 90 to 97.4%, with three cases slightly mutated (98-95%) and five heavily mutated (<95%). All B-PLL utilized members of VH3 (11/17) and VH4 (6/17) families, with V3-23, V4-59 and V4-34 gene accounting for more than half of them, regardless of mutational status. ZAP-70, assessed by flow cytometry, ranged from 1 to 91% cells, being > or =20% in 57% of cases. CD38 ranged from 1 to 99% (median 21%). There was no correlation between IgVH status and ZAP-70 or CD38 expression, but male gender and del(17p) were more common in the unmutated group. Neither IgVH mutations, CD38 expression nor del(17p) influenced patients' outcome. Unexpectedly, ZAP-70+ B-PLL patients survived longer (40 months) than ZAP-70- B-PLL (8 months). B-PLL appears biologically heterogeneous regarding IgVH mutations, ZAP-70 and CD38 expression, showing a pattern distinct from that of other lymphoproliferative disorders.

Isolated central nervous system involvement in adult T-cell lymphoma/leukaemia

Central nervous system (CNS) presentation of adult T-cell lymphoma/leukaemia is rare, and almost invariably associated with systemic disease. We report an unusual manifestation of adult T-cell lymphoma/leukaemia, with isolated CNS involvement and unusual imaging findings. We also describe objective response to antiviral therapy. To our knowledge, this is the first report of such presentation and response.

Prolonged treatment response in aggressive natural killer cell leukemia

We describe a case of natural killer (NK) cell leukemia with acute presentation, systemic symptoms and hepatosplenomegaly. The uniform and aberrant phenotype of NK cells with infiltration of bone marrow and spleen was in keeping with a malignant diagnosis. Aggressive presentation was demonstrated by marked constitutional symptoms and significant tumor burden (liver, spleen, blood, bone marrow). The subsequent clinical course has been indolent, but this may have been influenced by treatment. Treatment consisted sequentially of splenectomy, intravenous pentostatin and the combination of cyclosporine A and recombinant human erythropoietin and has resulted in survival of over 48 months. We discuss the difficulties in the diagnosis of this condition, explore possible causes of cytopenia(s), and highlight the role of immunosuppression in controlling disease manifestations in large granular lymphocyte proliferative disorders.

Richter's transformation of chronic lymphocytic leukemia

Transformation of CLL into a large cell lymphoma has an incidence of 3-5%. We have studied 101 cases of CLL treated with fludarabine over a 10-year period (1990-2000) and observed a 12% incidence of transformation. In six of 12 patients, transformation was documented within 4 months following treatment with fludarabine. Pathological material, available in nine cases, was investigated for latent EBV by staining for LMP-1 by immunohistochemistry and EBERs-1 and 2 by in situ hybridisation. LMP-1 and EBERs were demonstrated in three of the nine samples. In two cases there was a different pattern of immunoglobulin gene rearrangement in the transformed cells assessed by PCR (FR3 fragment) compared to the original CLL clone. One of these two cases showed evidence of latent EBV. The other seven cases, of which two were EBV positive, showed identical pattern of Ig gene rearrangement in both the CLL and the transformed cells. We suggest that the relatively high incidence of transformation in this series may be due to immunosuppression mainly related to fludarabine, although other agents and prior therapies may have also contributed.

Cutaneous findings in chronic lymphocytic leukaemia

BACKGROUND

Chronic lymphocytic leukaemia (CLL) is a malignancy characterized by clonal expansion of B lymphocytes with distinct morphology and immunophenotype. The dermatological literature relating to CLL is sparse. A global descriptive survey of a large number of CLL patients has not previously been published.

OBJECTIVES

To report the spectrum of dermatological conditions seen in a large series of CLL patients.

METHODS

Skin complications in patients with established CLL were identified retrospectively from clinical and photographic records, principally a database of over 750 consecutive cases. These events were classified, enumerated and compared.

RESULTS

Forty patients with 125 skin manifestations were identified and studied. Forty-one manifestations had documented clinical or histological atypia. In 21 of these 41 complications there had been no prior immunosuppressive therapy. We observed that cutaneous malignancies frequently presented atypically both clinically and histologically. There were 18 patients with 56 instances of basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), and clinical atypia was more common with SCC than with BCC. Other cutaneous findings included varicella zoster (n = 6), leukaemia cutis (n = 3), acute graft-versus-host disease (n = 5), cutaneous drug eruptions (n = 9), multiple warts (n = 3), herpes simplex (n = 3), cutaneous T-cell lymphoma (n = 2), eosinophilic folliculitis (n = 2), malignant melanoma (n = 2) and Merkel cell tumour (n = 2).

CONCLUSIONS

We have identified a range of dermatological conditions in CLL patients, with a tendency to atypical presentations. The atypia was independent of prior chemotherapy.

CD87 (urokinase-type plasminogen activator receptor), function and pathology in hematological disorders: a review

The analysis of CD87 (urokinase-type plasminogen activator receptor - uPAR) expression has a potential role in the diagnostic or prognostic work-up of several hematological malignancies, particularly acute leukemia and multiple myeloma. The distribution of CD87 in acute myeloid leukemia (AML) varies according to the FAB subtype (highest expression in M5 and lowest in M0). Functionally, it is conceivable that the expression of CD87 could contribute to the invasive properties of the leukemic cells towards the skin and mucosal tissues as reflected by the clinical behavior of CD87 high cases. The lack of or weaker expression of CD87 on blast cells from ALL patients supports the concept that CD87 investigation might help in the distinction of AMLs from lymphoid malignancies. Among lymphoproliferative disorders, the expression of CD87 is exclusively found in pathological plasma cells. Since plasma cells also coexpress some adhesion molecules such as CD138 and CD56, this observation is consistent with the capacity of these cells to home in the bone compartment. High levels of soluble uPAR appear to represent an independent factor predicting worse prognosis and extramedullary involvement in multiple myeloma.

The variant form of hairy-cell leukaemia

Hairy-cell leukaemia-variant (HCL-variant) is a rare B-cell disorder which accounts for 10% of HCL cases. It affects elderly or middle-aged males. The main features are splenomegaly, lymphocytosis and cytopenias without monocytopenia. The circulating cells have a morphology intermediate between prolymphocytes and hairy cells. The immunophenotype shows a mature B-cell phenotype with expression of the B-cell antigens CD11c and CD103-but unlike typical HCL the cells are CD25- and HC2-negative. The histology of bone marrow and spleen shows a pattern of infiltration similar to that in HCL. There is no recurrent chromosomal abnormality but complex karyotypes and monoallelic p53 deletion by fluorescence in situ hybridization are common. Patients are resistant to alkylating agents and interferon-alpha (IFN-alpha) and only half achieve partial responses to pentostatin and/or cladribine. Splenectomy results in long-lasting partial responses in over two-thirds of the patients and is a good palliative treatment. Despite the lack of response to most therapies, the clinical course of HCL-variant is chronic. The median survival is 9 years and 42% of patients die of unrelated causes. Transformation to large cell is seen in 6% of patients. The inferior survival in HCL-variant compared with typical HCL cases may reflect the chemotherapy resistance.

A comparison of flow cytometry, bone marrow biopsy, and bone marrow aspirates in the detection of lymphoid infiltration in B cell disorders

AIMS

To evaluate the diagnostic value of bone marrow aspirates, trephine biopsies (BMB), and flow cytometry (FC) in the assessment of bone marrow infiltration in chronic lymphoid disorders.

METHODS

Investigations were carried out in 110 diagnostic and follow up specimens from B cell disorders, namely: chronic lymphocytic leukaemia (CLL; 65), non-Hodgkin's lymphoma (NHL; 39), and hairy cell leukaemia (HCL; 6). A selected panel of monoclonal antibodies was used both for FC and immunohistochemistry.

RESULTS

In CLL there was agreement between the three investigations in 71% of samples and in 88% when only FC and BMB were compared. In nine of 65 samples, FC and BMB were positive, although the aspirate was reported as negative. Four BMB negative samples had minimal residual disease (MRD) detected by FC, whereas two samples were positive both on BMB and aspirate but showed no evidence of disease on FC. In NHL, there was agreement between the three investigations in 22 of 39 cases, and in 27 of 39 cases there was agreement between FC and BMB. In eight of 39 NHL cases, FC was negative but the BMB was either positive (five) or uncertain (three), whereas in three of 39, FC was positive but BMB was either negative (one) or uncertain (two). In three of five uncertain BMB, no clonal population was detected by the polymerase chain reaction, whereas in the remaining two cases the nodular aggregates disappeared on further sectioning.

CONCLUSIONS

Both BMB and FC are better than bone marrow aspirates for the detection of infiltration in B cell disorders. FC might be slightly more sensitive than BMB to detect MRD in CLL, whereas BMB may be slightly better than FC in NHL.

Detection of cyclin D1 in B cell lymphoproliferative disorders by flow cytometry

AIMS

To describe and revise a flow cytometric assay for evaluating cyclin D1 overexpression in B cell lymphoproliferative disorders (B-LPDs).

METHODS

Cyclin D1 expression was evaluated in 11 healthy controls and 51 patients with B-LPD by flow cytometry using the 5D4 monoclonal antibody. In 25 cases, experiments were repeated up to four times with mononuclear cells (MNC) fixed in ethanol for 1-120 days to evaluate the consistency of cyclin D1 expression. Flow cytometry results were compared with fluorescence in situ hybridisation (FISH) for the t(11;14) translocation in 19 patients and with immunohistochemistry (IHC) using the DCS-6 monoclonal antibody in nine patients.

RESULTS

A mean fluorescence intensity ratio (MFIR) of 4.8 was defined as the cut off point for positivity based on cyclin D1 expression in healthy controls (mean + 3 SD). Ten patients overexpressed cyclin D1 by flow cytometry. These included five of eight patients with mantle cell lymphoma, four of 19 with chronic lymphocytic leukaemia, and one with follicular lymphoma. MFIR in the repeat experiments differed less than 25% in 20 of 25 patients and in no cases did it cross the cut off point. There was a good correlation between cyclin D1 expression by flow cytometry and FISH for t(11;14) in 15 of 19 patients and six of nine had concordant results with flow cytometry, FISH, and IHC.

CONCLUSION

Cyclin D1 expression remains fairly stable once MNC are fixed in ethanol and the flow cytometric assay can be used for the routine screening of B-LPD. Further comparisons between flow cytometry, IHC, and FISH may be needed to ascertain the diagnostic value of the flow cytometric assay.

Chromosomal imbalances in familial chronic lymphocytic leukaemia: a comparative genomic hybridisation analysis

A subset of B cell chronic lymphocytic leukaemia (CLL) is familial. Lack of large families makes it attractive to exploit methods in addition to genetic linkage analysis for the identification of a susceptibility locus. One strategy that can localise regions of the genome that may harbour tumour suppressor genes is to identify regions of chromosomal imbalance using comparative genomic hybridisation (CGH) analysis. We examined 24 familial CLL cases by CGH analysis. Losses that are documented as arising frequently in sporadic CLL were observed at a comparable frequency in familial CLL. However, gains and losses in two regions of the X chromosome - Xp11.2-p21 and Xq21-qter - appear more common in familial CLL than in sporadic CLL. This suggests these regions may harbour a susceptibility locus for CLL. There is also some evidence that chromosome regions 2p12-p14 and 4q11-q21 may harbour predisposition genes.

Cd8(+)/V beta 5.1(+) large granular lymphocyte leukemia associated with autoimmune cytopenias, rheumatoid arthritis and vascular mammary skin lesions: successful response to 2-deoxycoformycin

We report a case of CD8(+)/V beta 5.1(+) T-cell large granular lymphocyte leukemia (T-LGL leukemia) presenting with mild lymphocytosis, severe autoimmune neutropenia, thrombocytopenia, polyarthritis and recurrent infections with a chronic disease course. Immunophenotyping showed an expansion of CD3(+)/TCR alpha beta(+)/CD8(+bright)/CD11c(+)/CD57(-)/CD56(-) large granular lymphocytes with expression of the TCR-V beta 5.1 family. Southern blot analysis revealed a clonal rearrangement of the TCR beta-chain gene. Hematopoietic growth factors, high dose intravenous immunoglobulin and corticosteroids were of limited therapeutic benefit to correct the cytopenias. During the disease course, the patient developed a severe cutaneous leg ulcer and bilateral vascular mammary skin lesions. Treatment with 2-deoxycoformycin resulted in both clinical and hematological complete responses, including the resolution of vascular skin lesions. Combined immuno-staining with relevant T-cell associated and anti-TCR-V beta monoclonal antibodies proved to be a sensitive method to assess the therapeutic effect of 2-deoxycoformicin and to evaluate the residual disease.

New additions to antibody panels in the characterisation of chronic lymphoproliferative disorders

Advances in flow cytometry techniques and the availability of monoclonal antibodies that detect key functional molecules on lymphocytes have contributed greatly to a more precise diagnosis of the chronic lymphoproliferative disorders. In addition to the diagnostic value, the expression of certain markers such as p53 or CD38 provides relevant prognostic information to the clinician. Beyond their diagnostic and prognostic value, immunological markers play a major role in the detection of minimal residual disease, enabling the clinician to estimate more accurately the response to chemotherapy. Those monoclonal antibodies that are relevant to the characterisation of the chronic lymphoproliferative disorders and that could be incorporated in a routine practice are discussed.

Transformation of T-cell large granular lymphocyte leukaemia into a high-grade large T-cell lymphoma

We describe a case of T-cell large granular lymphocyte (LGL) leukaemia that transformed into a large-cell T-cell lymphoma 11 years from diagnosis. A 29-year-old asymptomatic female presented in 1989 with lymphocytosis, neutropenia and mild bone marrow infiltration. The circulating cells were LGL with a CD2+, CD3+, CD8+, CD4-, CD16+, CD56+, CD57- phenotype. In August 2000, she developed fever, a large submandibular mass and hepatosplenomegaly. Biochemistry showed abnormal liver function tests and raised lactate dehydrogenase (LDH) levels. A serological screen for Epstein-Barr virus, cytomegalovirus, human T-lymphotropic virus-I, human herpes virus (HHV)-6 and HHV-7 was negative. Histology of the mass was consistent with the diagnosis of peripheral T-cell lymphoma composed of large cells, and immunohistochemistry showed that the lymphoma cells had a phenotype identical to the mature LGL. Molecular analysis with the polymerase chain reaction (PCR) demonstrated rearrangement of the T-cell receptor (TCR) gamma-chain gene with a band of identical size in both bone marrow mature LGL and lymph node cells. The patient was treated with CHOP (cyclophosphamide, vincristine, doxorubicin and prednisolone), resulting in the disappearance of the mass and improvement of the hepatosplenomegaly, LDH and liver abnormalities. She underwent splenectomy, and spleen histology showed involvement by T-cell LGL leukaemia with no evidence of transformation. This case illustrates that transformation or Richter syndrome may occur in a minority of patients with T-cell LGL leukaemia, a disease that has a benign clinical course in most cases. This is the first case documented by molecular methods of the transformation of the pre-existing clone.

Immunophenotype changes and loss of CD52 expression in two patients with relapsed T-cell prolymphocytic leukaemia

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive disease often resistant to conventional chemotherapy. Long lasting remissions with the monoclonal antibody CAMPATH-1H (anti-CD52) have been documented. We describe two unusual T-PLL patients treated successfully first with CAMPATH-1H in whom, at the time of relapse, the cells underwent a phenotypic switch with loss of CD52 expression. In one of them, cytogenetic analysis demonstrated the same chromosome abnormalities in the cells at diagnosis and relapse. The reasons for the immunophenotypic changes are unknown but it is likely that loss of CD52 antigen expression contributed to the resistance to CAMPATH-1H in one of the patients when re-treated.

Comparative genomic hybridization and amplotyping by arbitrarily primed PCR in stage A B-CLL

Cytogenetic analysis is useful in the diagnosis and to assess prognosis of B-cell chronic lymphocytic leukemia (B-CLL). However, successful cytogenetics by standard techniques has been hindered by the low in vitro mitotic activity of the malignant B-cell population. Fluorescence in situ hybridization (FISH) has become a useful tool, but it does not provide an overall view of the aberrations. To overcome this hurdle, two DNA-based techniques have been tested in the present study: comparative genomic hybridization (CGH) and amplotyping by arbitrarily primed PCR (AP-PCR). Comparative genomic hybridization resolution depends upon the 400-bands of the human standard karyotype. AP-PCR allows detection of allelic losses and gains in tumor cells by PCR fingerprinting, thus its resolution is at the molecular level. Both techniques were performed in 23 patients with stage A B-CLL at diagnosis. The results were compared with FISH. The sensitivity of AP-PCR was greater than CGH (62% vs. 43%). The use of CGH combined with AP-PCR allowed to detect genetic abnormalities in 79% (15/19) of patients in whom G-banding was not informative, providing a global view of the aberrations in a sole experiment. This study shows that combining these two methods with FISH, makes possible a more precise genetic characterization of patients with B-CLL.

High remission rate in T-cell prolymphocytic leukemia with CAMPATH-1H

T-cell prolymphocytic leukemia (T-PLL) is a chemotherapy-resistant malignancy with a median survival of 7.5 months. Preliminary results indicated a high remission induction rate with the human CD52 antibody, CAMPATH-1H. This study reports results in 39 patients with T-PLL treated with CAMPATH-1H between March 1993 and May 2000. All but 2 patients had received prior therapy with a variety of agents, including 30 with pentostatin; none achieved complete remission (CR). CAMPATH-1H (30 mg) was administered intravenously 3 times weekly until maximal response. The overall response rate was 76% with 60% CR and 16% partial remission (PR). These responses were durable with a median disease-free interval of 7 months (range, 4-45 months). Survival was significantly prolonged in patients achieving CR compared to PR or no response (NR), including one patient who survived 54 months. Nine patients remain alive up to 29 months after completing therapy. Seven patients received high-dose therapy with autologous stem cell support, 3 of whom remain alive in CR 5, 7, and 15 months after autograft. Stem cell harvests in these patients were uncontaminated with T-PLL cells as demonstrated by dual-color flow cytometry and polymerase chain reaction. Four patients had allogeneic stem cell transplants, 3 from siblings and 1 from a matched unrelated donor. Two had nonmyeloablative conditioning. Three are alive in CR up to 24 months after allograft. The conclusion is that CAMPATH-1H is an effective therapy in T-PLL, producing remissions in more than two thirds of patients. The use of stem cell transplantation to consolidate responses merits further study.

Deletions of D13S25, D13S319 and RB-1 mapping to 13q14.3 in T-cell prolymphocytic leukaemia

Deletions of 13q14.3 are well known in several malignancies and are thought to be associated with tumour suppressor function. The RB-1 gene is a tumour suppressor gene, but other loci including D13S319 and D13S25 telomeric to this within 13q14.3 are deleted in B-cell chronic lymphocytic leukaemia (B-CLL), multiple myeloma and non-Hodgkin's lymphoma, with varying clinical significance. The fluorescence in situ hybridization screening of 22 patients with T-prolymphocytic leukaemia (T-PLL) for deletions of 13q14.3 revealed loss of D13S25 in 17 cases (mean 40% range 13-98%), with 11 patients having at least a 20% deletion. Mapping the deletions for the RB-1, D13S319,and D13S25 loci revealed D13S25 as the most frequently deleted marker. However, patients with only the D13S25 deletion had low percentages of cells with the deletion (12-13%), suggesting that loss of D13S25 on its own may not provide sufficient growth advantage. The use of the YAC 954c12, which maps immediately adjacent to D13S25, defined the telomeric border of the deletion in some of the cases. Inv(14)(q11q32) and t(14;14)(q11;q32) are characteristic of T-PLL, but are also observed in premalignant T-cell clones in patients with ataxia telangiectasia. Transition to overt leukaemia may result from loss of suppressor function. Thus, 13q14.3 deletions could contribute to the development of overt leukaemia in T-PLL, but the involvement of more than one gene in the region cannot be excluded.

p53 abnormalities in splenic lymphoma with villous lymphocytes

The incidence and role of p53 abnormalities have not been reported in splenic lymphoma with villous lymphocytes (SLVL), the leukemic counterpart of splenic marginal zone lymphoma. Because p53 abnormalities correlate with progressive and refractory disease in cancer and isochromosome 17q has been described in SLVL, a low-grade lymphoma that behaves aggressively in a minority of patients, this study investigated p53 changes by molecular and immunophenotypic methods in samples from 59 patients. The p53 deletion was analyzed by fluorescence in situ hybridization, and p53 protein expression was assessed by immunocytochemistry in 35 of 59 cases and by flow cytometry in 20 of 35 patients. Ten patients (17%) had a monoallelic p53 loss, 3 (9%) of 35 nuclear protein expression by immunocytochemistry, and 2 (10%) of 20 by flow cytometry. Two patients had both deletion and protein expression. Direct sequencing of all p53 exons was used to delineate mutations in 9 of 11 patients with an identified abnormality. Mutations, both compromising p53 DNA binding, were identified in the 2 patients with deletion and protein accumulation. Kaplan-Meier analysis revealed a significantly worse survival for patients with p53 abnormalities. Although p53 abnormalities are infrequent in SLVL, they underlie a more aggressive disease course and poor prognosis. (Blood. 2001;97:3552-3558)