Case Of Prolymphocytic Leukemia Research Articles

Successful Result of 113 Patients for Refractory/Recurrent Leukemia By Allogeneic Hematopoietic Cell Transplantation and Prophylactic Immunotherapy

Objective:To retrospectively evaluate the results of allogeneic hematopoietic stem cell transplantation for Refractory/Recurrent leukemia.Methods:From July 2012 to May 2016, total 113 patients with Refractory/Recurrent leukemia were enrolled, including 31 cases of ALL, 73 cases of AML and 8 cases of CML-BP, 1 case of Prolymphocytic leukemia. The average leukemia burden was 51% (10-99) in bone marrow before conditioning. Myeloablative conditioning regimens consisted of 13 cases of BuCy, 47 cases of TBI/FLAG, 28 cases of TBI/Cy, and 16 cases of FLAG that followed by reduced-intensified BUCY, 9 cases of CLAG/BuCy. Transplant types included sibling HLA-identical allo-HSCT (n=22) and relative HLA-haploidentical HSCT (n=91). All patients received cyclosporine A, MMF and methotrexate for GVHD prophylaxis. Analyzed outcomes were hematological engraftment, incidence of acute and chronic GVHD, incidence of CMV/EBV infecton, incidence of relapse, and nonrelapse mortality (NRM), Overall survival (OS) and Disease-free survival (DFS).Results:The median mononuclear cells and CD34+ for transfusion were 8.83 (7.02-11.64) ×108/Kg and 2.91 (0.8-8.32) ×106/Kg. 111 patients achieved stable engraftment, 2 patients died of infection before engraftment. The median time of ANC≥0.5×109/L was 16 days(8-29) and the median time of platelet ≥20×109/L was 22 days (8-150). On day 28postallogeneic transplant, 110 patients were in complete remission of bone marrow, 1 patient was in hematologic relapse. Immunity residue were negative in 107 patients and positive in 4 patients. 62 patients developed acute GVHD, the accumulative incidence of aGVHD was (57.6±4.8)%, the accumulative incidence of II-IV grade aGVHD was (47.2±4.8)%, and the accumulative incidence of III-IV grade aGVHD was (25.2±4.1)%. 62 patients developed cGVHD (43 patients extensive, 19 patients limited), the accumulative incidence of cGVHD was (70.2±6.6)% and for extensive type, the accumulative incidence was (43.6±5.2)%. The accumulative incidence of CMV infection was (42.3±4.7)%, and the accumulative incidence of EBV infection was (4.5±2)%. 10 patients developed virus cystitis, and the accumulative incidence was (9.1±2.1)%. The median follow-up time post transplantation was 10 months (1-46), 35 patients occurred hematologic relapsed and the accumulative incidence of relapse was (39.7±5.9)%. For AML, ALL and CML-BP patients, the accumulative incidence of relapse were (33.8±6.9)%, (56.6±11.7)% and (25±15.3)%respectively (p>0.05). On median follow up (10 months), 49 patients died and 64 patients survived. The cause of death included relapse (28 cases), infection (6 cases), GVHD (11 cases) diffuse alveolar hemorrhage (2cases), radiation enteritis (1 case), and TMA (1 case).Among 64 survirors, two-year accumulative incidences of OS were (49.3±5.7)%, and two-year accumulative incidences of LFS were (45.1±5.4). The two-year accumulative incidences of OS for AML, ALL and CML-BP patients were ( 52.4±7.1)%, (28.1±9.7)%,and (87.5±11.7)%respectively (p>0.05). The two-year accumulative incidence of LFS for AML, ALL and CML-BP patients were (49.8±6.5)%, (24.7±9.1)%, and (70±18.2)%respectively (p>0.05). Incidence of relapse, OS and LFS were similar in different conditioning cohorts (p>0.05). There was no significant difference in the incidence of relapse, OS and LFS over two years among patients with C-Kit, FLT3, MLL and without such genes(p>0.05). There is significant difference in incidence of relapse, OS and LFS among patients with different leukemia burdens(p<0.01). Patients with leukemia burden at 10-19% has lower relapse rate but higher OS and LFS compared to patients with leukemia burden at 80%. Incidence of relapse, OS and LFS for the prophylactic immunotherapy cohort were 32.9%, 61.1% and 57.6% respectively, compared to 45.2%, 35.8% and 35% for non prophylactic immunotherapy cohort (p<0.01). Incidence of relapse , OS and LFS for the cGVHD cohort were 12.9%, 68.4% and 66.2% respectively, compared to 78.7%, 13.9% and 12.8% for non cGVHD(p<0.01). Incidence of relapse , OS and LFS for extensive cGVHD cohort were 12.3%, 62.1% and 61.8% respectively, compared to 58.8%, 31.4% and 31.2% for non extensive cGVHD(p<0.01)Conclusion:Our clinical results have shown that the salvaged HSCT is a promising modality for treatment of Refractory/Recurrent leukemia. Especially for Refractory/Recurrent AML and CML-BP. DisclosuresNo relevant conflicts of interest to declare.

Chronic lymphoproliferative disorders at an Indian tertiary cancer centre - the panel sufficiency in the diagnosis of chronic lymphocytic leukaemia.

Flow cytometry has come to occupy the vanguard of the high through put diagnostic techniques that have been used to differentiate between various chronic lymphoproliferative disorders (CLPD). However, economic considerations have created the need for minimal consensus panels that can yield maximum information at reasonable costs. To collect, analyse and correlate the morphologic, immunophenotypic, and the cytogenetic data from the cases of chronic lymphoproliferative disorders, which were diagnosed at an Indian speciality cancer centre. The morphology was recorded after staining the samples with the Leishman or the MGG stains. The lineage assignment was done by using three colour flow cytometry with a primary panel of antibodies. For the cytogenetic studies, the short term culture of the sample cells were arrested by using colcemid and they were G-banded by using trypsin and Giemsa stain. FISH studies were conducted by using a CLL-specific diagnostic kit. A total of 66 cases were evaluated, which had a median age of 64.5 years and a sex ratio of 2.3:1. Of these 66 cases, 40 cases were of CLL and 9 cases were of atypical CLL. 17 cases were classified as CLPD and these included 13 cases of Non-Hodgkin's Lymphoma, two cases of Hairy Cell Leukaemia, one case of Follicular Lymphoma and one case of Prolymphocytic Leukaemia. In immunophenotyping, the lack of expression of CD22 had the highest correlation with a definitive diagnosis of CLL. Cytogenetics demonstrated a classical follicular lymphoma abnormality, t (14; 18) (q32; q21), in one case. A basic minimal panel is sufficient for the routine diagnosis of CLL. However, the stratification of CLPD requires the use of more extensive panels.

Rituximab-induced severe acute thrombocytopenia: A case report and review of literature

19528 Background: Rituximab, an anti-CD20 monoclonal antibody, is a generally safe and well-tolerated drug. Severe acute thrombocytopenia following administration is a rare phenomenon. Case Report: An 84-year old male with a recent diagnosis of aggressive mantle cell lymphoma was admitted with a mild urinary tract infection. His condition gradually improved and inpatient chemotherapy was begun with R-CHOP. He received a 660 mg rituximab infusion without initial complication. The next day his platelet count had fallen from a pre-infusion level of 121,000/mm3 to 15,000/mm3. There were no signs of hemorrhage and over the course of the next three days the platelet count increased to 24,000. He did not require platelet transfusion and had a marked decrease in his white blood count and lymphadenopathy. The patient was discharged in good condition. Results: A MEDLINE/OVID database search revealed only five previous reported cases of rituximab-induced thrombocytopenia in adults. These included two cases of hairy cell leukemia, two cases of mantle cell lymphoma and one case of prolymphocytic leukemia. Pre-treatment platelet counts ranged from 31,000 to 151,000, and post-treatment counts from 6,000 to 10,000 (mean recorded drop 82,200). Four patients received platelet transfusions. Discussion: Rituximab-induced thrombocytopenia is likely underdiagnosed because most patients do not have blood counts performed the day after treatment. Proposed theories include; (i) CD20 antigen causing antigen-antibody immune-mediated cell lysis by compliment activation, (ii) CD20 antigen on the platelet surface, (iii) platelet binding of a soluble anti-CD20/rituximab complex, and (iv) intravascular fibrinolysis. Interestingly our case and all previously reported cases involved massive bone marrow involvement by neoplastic B-lymphocytes. A large number of patients treated with rituximab will have routine blood counts checked 1 to 2 weeks following therapy and physicians may wrongly attribute thrombocytopenia to the effects of other chemotherapy and make unnecessary dose reductions. Rituximab should therefore be used with caution, especially in those patients with bone marrow involvement. Routine blood counts should be considered soon after therapy to document this potential adverse effect. No significant financial relationships to disclose.

5′ Region and Exon 7 Mutations of the TP53 Gene in Two Cases of B-Cell Prolymphocytic Leukemia

We previously found that cases of typical B-chronic lymphocytic leukemia (CLL), atypical B-CLL with t(11;14) and mantle cell lymphomas characterized by rapid progression of the disease and resistance to therapy, had mutations of the TP53 gene. In this paper, abnormalities of the TP53 gene were investigated in two cases of prolymphocytic leukemia, one with t(11;14)(q13;q32), evolving from atypical CLL (patient 1), and one presenting as a de novo condition (patient 2). TP53 DNA was investigated by Southern blot and PCR-SSCP analysis, and TP53 expression was investigated by Northern blot analysis and immunocytochemistry. C-MYC and BCL-1/PRAD1 gene expression were also investigated. Restriction enzyme analysis of TP53 DNA in patient 1 showed alteration of fragments including exon I and intron I, and, in both patients, a specific loss of TP53 DNA. In patient 2, PCR direct sequencing showed in exon VII a 9 bp deletion including codons 252–254. In patient 1, TP53 RNA and protein were not found, indicating that the unusual 5′ rearrangement has affected TP53 gene expression. By contrast, patient 2 exhibited detectable TP53 RNA and protein. Detectable but weak BCL-1/PRAD1 RNA was present in both patients, whereas C-MYC RNA expression was clearly present only in case 1. The presence of TP53 hemizygous mutations in both patients suggests that TP53 abnormalities may be important in the pathogenesis of prolymphocytic leukemia (PLL), and may possibly account for the frequent resistance to therapy observed in this disease.

Similar patterns of V kappa gene usage but different degrees of somatic mutation in hairy cell leukemia, prolymphocytic leukemia, Waldenstrom's macroglobulinemia, and myeloma

To compare V kappa gene usage and the amount of somatic mutation in rearranged Ig genes from patients with lymphoproliferative disorders, we have polymerase chain reaction-amplified and sequenced a total of 26 V kappa genes from a total of 55 cases. Six sequences were obtained both from six cases of prolymphocytic leukemia (PLL) and from nine cases of hairy cell leukemia (HCL). Seven sequences were obtained both from 11 cases of Waldenstrom's macroglobulinemia (WM) and 29 cases of multiple myeloma (MM). Eleven different germline genes have been used in this series, indicating a wide but nonrandom usage of germline Ig gene rearrangements in these disorders. Comparison of the nucleotide sequences of V kappa genes obtained from B-cell malignancies with germline V kappa genes shows that somatic mutation is rare in PLL and HCL and common in WM and MM. Analysis of the pattern of mutations suggests that WM and MM are derived from B cells that have been selected by antigen at a relatively late stage of differentiation.

Similar Patterns of Vκ Gene Usage But Different Degrees of Somatic Mutation in Hairy Cell Leukemia, Prolymphocytic Leukemia, Waldenstrom's Macroglobulinemia, and Myeloma

To compare V kappa gene usage and the amount of somatic mutation in rearranged Ig genes from patients with lymphoproliferative disorders, we have polymerase chain reaction-amplified and sequenced a total of 26 V kappa genes from a total of 55 cases. Six sequences were obtained both from six cases of prolymphocytic leukemia (PLL) and from nine cases of hairy cell leukemia (HCL). Seven sequences were obtained both from 11 cases of Waldenström's macroglobulinemia (WM) and 29 cases of multiple myeloma (MM). Eleven different germline genes have been used in this series, indicating a wide but nonrandom usage of germline Ig gene rearrangements in these disorders. Comparison of the nucleotide sequences of V kappa genes obtained from B-cell malignancies with germline V kappa genes shows that somatic mutation is rare in PLL and HCL and common in WM and MM. Analysis of the pattern of mutations suggests that WM and MM are derived from B cells that have been selected by antigen at a relatively late stage of differentiation.

Interleukin 1 (IL-1α and IL-1β) induces differentiation/activation of B cell chronic lymphoid leukemia cells

The effect of interleukin 1 (IL-1) was studied on leukemic cells from 12 patients with B cell chronic lymphoid leukemias including two cases of hairy cell leukemia (HCL), two cases of HCL-variant (HCL-V), one case of prolymphocytic leukemia (PLL), and seven cases of chronic lymphocytic leukemia (CLL). In most cases, IL-1 induced differentiation characterized by increments of sIgγ +, sIgμ + and PCA-1 + cells, and a decrement of CD5 + cells, and activation characterized by increments of CD23 + and HC2 + cells, but induced the proliferation of leukemic cells only in two HCL-V cases. Among these effects, increment of sIg + cells was observed more frequently in non-CLL ( 4 5 cases) than in CLL ( 2 7 cases), and increments of sIgγ +, CD23 + and PCA-1 + cells were induced more frequently by IL-1β than by IL-1α. These results suggest that IL-1, especially IL-1β, plays a significant role in the differentiation and activation of leukemic cells, but has only a minor role as an extrinsic/autocrine growth factor. IL-1 may be useful for studying the differentiation pathway of leukemic cells in B cell chronic lymphoid leukemias, particularly those with more mature cells such as PLL and HCL.

Electron microscopic morphometry of chronic type lymphoid leukemias

Malignant cells from 1 case of chronic lymphocytic leukemia of the T-cell type (T-CLL), 5 cases of chronic lymphocytic leukemia of the B-cell type (B-CLL), 1 case of prolymphocytic leukemia of the B-cell type (B-PLL), 1 case of lymphocytic lymphoma of intermediate differentiation of the B-cell type (B-ILL), 1 case of splenic B-cell lymphoma with circulating villous lymphocytes (SLVL), and 2 cases of hairy cell leukemia (HCL) were measured on electron micrographs. The area of the cytoplasm, nucleus, nucleoli, and the perimeters of nuclei were measured and the nucleo-cytoplasmic ratio, nucleolo-nuclear ratio, and nuclear contour index (NCI) were calculated. Malignant cells from B-PLL had the largest cytoplasmic, nuclear, and nucleolar areas. The NCI was largest (4.74) in T-CLL. B-ILL, B-PLL, and SLVL had an intermediate (4.5) NCI. HCL and B-CLL had the smallest (4.1) NCI. Lymphoid cells in SLVL were smaller in size than HCL cells and had a higher NCI than that of HCL. Thus, electron microscopic morphometry can provide further information to aid in distinguishing chronic type lymphoid leukemias.

T-Cell Membrane CD45RA (2H4) and CD45RO (UCHL1) Determinants: I, Diverse Patterns of Expression in Mature (Post-Thymic) T-Cell Proliferations.

By simultaneous two- and three-colour flow cytometry, this study analysed the expression of membrane CD45RA (2H4) and CD45RO (UCHL1) determinants by normal thymocytes (n = 5) and peripheral blood lymphocyte subpopulations (CD4(+), n = 21; CD8(+), n = 12; CD8(dim+), n = 12) and compared these patterns with those of T-cells from representative CD4(+)CD8(-) (n = 8), CD4(+)CD8(+) (n = 2), CD4(-)CD8(+) (n = 10) and CD4(-)CD8(-) (n = 1) proliferations. These comprised cases of prolymphocytic leukaemia (T-PLL, n = 5), adult T-cell leukaemia-lymphoma (ATLL, n = 2), Sezary Syndrome (SS, n = 4), chronic lymphocytic leukaemia (T-CLL, n = 4), and lymphoproliferative disease of granular lymphocytes (LDGL, n = 5). Normal thymocyte fractions, of which a mean of 85% cells co-expressed membrane CD4 and CD8, were predominantly (mean 89%) 2H4(-)UCHL1(+) with the remaining cells consisting of 2H4(int)UCHL1(+) and 2H4(+)UCHL1(-) components. Further analysis showed that virtually all CDla(+) thymocytes were UCHL1(+) whereas the CD1a(-) fraction comprised similar proportions of both UCHL1(-) and UCHL1(+) subpopulations. Similarly, normal blood CD4(+), CD8(+) and CD8(dim+) lymphocytes showed reciprocal CD45RA/CD45RO expression and could be phenotypically grouped into 2H4(+)UCHL1(-) 2H4(int)UCHL1(+) and 2H4(-)UCHL1(+) subpopulations. Mean proportions of 48% and 68%, for CD4(+) and CD8(+) lymphocytes respectively, showed a composite 2H4(+)UCHL1(-) phenotype, whereas the percentage of NK-associated CD8(dim+) cells with this phenotypic pattern was considerably higher (mean, 85%). Normal lymphocyte subpopulations lacking both determinants (2H4(-)UCHL1(-)) were only rarely noted. Comparing normal patterns of CD45RA/CD45RO expression with those of the T-cell proliferations revealed diverse and abnormal patterns of staining for 3/6 of the CD4(+)CD8(-) SS and ATLL, and for 5/5 of the T-PLL (CD4(+)CD8(-), n = 2; CD4(+)CD8(+), n = 2; and CD4(-)CD8(+), n = 1) cases studied. In contrast, the nine cases of CD4(-)CD8(+) T-CLL and LDGL all showed CD45RA/CD45RO staining patterns similar to that of normal CD8(+)/CD8(dim+) blood lymphocytes (i.e. a predominance of 2H4(+)UCHL1(-) cells). Although the variant CD45RA/CD45RO pattern types of the CD4(+) proliferations did not appear to be related to either the diagnostic category or other phenotypic characteristics, the high proportion of abnormal patterns within this case group suggests that recognition of these abnormalities may be potentially relevant to the differentiation of benign and malignant CD4(+) proliferations and, in addition, may be of aetiological importance with respect to the diverse acquired defects in immunity commonly seen in patients with such disorders.

A new antigen identified by the monoclonal antibody UCHB 1 delivers a costimulatory signal to a subset of human B cells.

A novel anti-B cell monoclonal antibody UCHB1 is described which detects an antigen present on a selected subpopulation of both normal and leukemic B cells. Approximately 20% of normal tonsil and peripheral blood (PB) B cells are UCHB 1+ and the majority of B cells from all cases of prolymphocytic leukemia (PLL) tested, together with a low, variable percentage of PB B cells from non-Hodgkin's lymphoma patients with centroblastic centrocytic leukemia also express this antigen. Chronic lymphocytic leukemia and hairy cell leukemia B cells, pre-B acute lymphoblastic leukemia and Epstein-Barr virus transformed cell lines all lack UCHB 1 positivity as do all non-B lineage leukocytes and cell lines so far tested. In tonsil sections UCHB 1 staining is almost completely confined to surface IgM+ mantle zone lymphocytes and follicular dendritic cells, but not B cells, within the germinal centers. UCHB 1 can induce a rise in the level of intracellular free calcium ([Ca2+]i) in PLL B cells and low concentrations of monoclonal antibody can result in the entry of these cells into cell cycle in the absence of additional factors. The proliferative effect of UCHB 1 is greatly enhanced in the presence of Staphylococcus aureus Cowan and, to a lesser extent, phorbol ester. A similar costimulatory effect is exerted on a proportion of normal tonsil B cells although here, despite inducing a rise in [Ca2+]i, UCHB 1 alone does not cause cells to proliferate. UCHB 1 may well prove to be a useful antibody both to distinguish between different B cell leukemias and to study the phenotype and function of leukemic and normal B cell subpopulations.

A new anthracycline regimen for prolymphocytic leukemia? Study of a case report with flow cytometric implications

A case of prolymphocytic leukemia (PL) is reported, which showed a good response to a new antiblastic schedule (4-epidoxorubicin-asparaginase-dexamethasone) in spite of the resistance to other chemotherapy regimens. However during the course of the disease it was possible to observe the terminal appearance of a small aneuploid cell population in the peripheral blood of the patient and, in the same time, the clinical condition deteriorated considerably. The significance of this neoplastic progression and the pros and cons of aggressive chemotherapy regimens remain to be carefully evaluated in PL and related disorders.

Six new cases of prolymphocytic leukemia with heterogeneous prognosis. Clinical and immunologic features, light microscopy, and ultrastructural findings.

The clinical features and diagnostic evaluation of six patients affected by prolymphocytic leukemia (PLL), are described. Some of the cases deviate from a relatively uniform and aggressive clinical course of the disease entity. An actuarial survival analysis of 60 cases gathered from the literature and the authors' experience indicate that the cases showing the most prolongated evolution may reach 30% of the total. The different aggressiveness in the clinical course of these patients does not depend on the efficiency of the therapies applied. The percentage of prolymphocytes (PL) in peripheral blood throughout the clinical course was variable and not depending on the treatments used. This fact, in conjunction with (1) the presence of cellular types deviated from the typical PL and detected both at optical and ultrastructural levels and (2) the existence of cases of PL with minimal splenomegaly and leukocyte counts of less than 50 X 10(9)/liter, could lead to an underdiagnosis of PLL and hinder the actual cognition of the natural medical history of the disease.

Prolymphocytic leukemia: Histologic findings in atypical cases

Significant enlargement of peripheral lymph nodes is not characteristic of prolymphocytic leukemia. The absence of this physical feature of the disease has been so consistent in previous reports that it has come to have considerable importance in the differential diagnosis of prolymphocytic leukemia. We describe two cases of prolymphocytic leukemia, in which, in sharp contrast to other published cases, striking lymphadenopathy was present throughout the clinical course. In one case, the disease responded dramatically, but briefly, to L-asparaginase. The immunologic characteristics of cells from lymph nodes suggested that in both cases, the leukemic process was B-cell type. The features of the prolymphocytic proliferation in lymph nodes and the utility of Wright-Giemsa stained touch preparations have been emphasized.

Stereologic analysis of the ultrastructure of isolated human T and non-T lymphoid cells. III. Studies in chronic lymphoid leukemias, hairy cell leukemia and some malignant lymphomas.

Malignant cells from 9 cases of chronic lymphocytic leukemia (CLL), 4 cases of prolymphocytic leukemia (PLL), 4 cases of hairy cell leukemia (HCL), 4 cases of malignant lymphoma of centrocytic type and 3 cases of malignant lymphoma of lymphoblastic type (Kiel classification), all examined for T and B markers, were analysed by electron microscopy. Stereological methods were applied to assess relative and absolute values concerning the whole cell and nuclear and cytoplasmic components of the average cell in each population, and comparisons were made between the morphologically and immunologically defined subsets. The CLL-lymphocyte possessed the smallest cell volume, a high nucleo-cytoplasmic volume ratio, densely packed heterochromatin, a small nucleolar volume and a sparse Golgi complex. The 7 B-derived cases were characterized by a larger volume of rough ER and a more irregular plasma membrane than the two T-derived cases, which typically displayed dense granules in paranuclear aggregations. The prolymphocyte could be distinguished from the CLL-cell by its larger cell volume, lower nucleo-cytoplasmic volume ratio, proportionally lesser heterochromatin, typically condensed at the periphery and around a prominent nucleolus. All 4 cases of PLL were of B-nature and shared the features of B-CLL regarding increased rough ER and low content of granules. The hairy cell exhibited the largest cell volume, the lowest nucleo-cytoplasmic volume ratio, an indented nucleus and a remarkable irregular cellular surface with long "hairy" processes. The cytoplasmic inclusions of ribosome-lamella complexes were recorded exclusively in hairy cells, in half of the patients. The centrocyte was characterized by a cell volume of intermediate size, a high nucleo-cytoplasmic volume ratio and the highest degree of nuclear irregularity recorded. The amount of rough ER was considerably less than in B-CLL and B-PLL. Finally, the blast from the cases of lymphoblastic lymphoma, all of T-nature, displayed a smooth plasma membrane, a high euchromatin-heterochromatin volume ratio and dense granules, characteristically clustered in the vicinity of the Golgi complex. Stereology on the ultrastructure of malignant lymphoid cells provides a more accurate characterization and may be helpful in classification.

A Case of prolymphocytic Leukemia with Selective IgM Hypogammaglobulinemia

A Case of prolymphocytic Leukemia with Selective IgM Hypogammaglobulinemia

Similarities in mitochondrial ultrastructure of leukemic cells and ethidium-bromide-treated normal cells

Electron micrographs of blastic human lymphocytes from phytohemagglutinin (PHA) cultures showed normal mitochondria with round, oval, and elongated shapes, containing well-defined cristae and electron-dense matrix. Micrographs of blastic lymphocytes from PHA cultures with ethidium bromide (EB) at 1 to 3 μg/ml, however, showed swollen mitochondria with fewer cristae and vacuolated matrix. Similarly damaged mitochondria were observed in micrographs of blast cells from patients with acute lymphoblastic (ALL) and acute myeloblastic leukemia (AML) and also in lymphocytes from cases of prolymphocytic leukemia (PLL). This study shows specific structural damage to mitochondrial cristae in normal proliferating lymphocytes when their mitochondrial DNA transcription, hence protein synthesis, is selectively inhibited by EB. It confirms that damaged cristae give structural evidence of inhibited mitochondrial protein synthesis. The structural damage of mitochondrial cristae observed in a variety of leukemic cells suggests that mitochondrial protein synthesis may be disturbed or abnormal in leukemic cells.

A hemalog D analysis of chronic lymphocytic leukaemia and other lymphoproliferative disorders affecting the blood.

A correlative clinical and Hemalog D study of 80 cases of chronic lymphocytic leukaemia (CLL) was performed and the results compared with those in other lymphoproliferative disorders affecting the blood (eight cases of hairy-cell leukaemia, HCL; three cases of prolymphocytic leukaemia, PLL: two cases of lymphoplasmacytoid proliferation, LPP; and one case of Sézary's syndrome, SS). In CLL the mean percentage and absolute counts of large unstained cells (LUC) were 8.7% and 6.2 x 109/1 (6200/mm3), and the percentage of LUCs was not substantially affected by treatment; there was no correlation between LUCs and Rai clinical stage. SS and LPP were characterised by a similar percentage of LUCs, but both HCL and PLL were distinguished by a higher mean percentage of LUCs. Stage IV CLL was associated with monocytopenia, but other stages of CLL, PLL, LPP, and SS showed no consistent reduction of absolute numbers of non-lymphoid cell types. In contrast, HCL was characterised by a consistent absolute neutropenia and monocytopenia which distinguished its Hemalog D profile from that of PLL.

Prolymphocytic leukaemia: an ultrastructural study of 22 cases.

Twenty-two cases of prolymphocytic leukaemia (PLL) have been studied by transmission electron microscopy (TEM); 17 had B-cell surface markers (B-PLL) and five had T-cell characteristics (T-PLL). The predominant cell, the prolymphocyte, has distinct features which were common to all cases: it is a relatively large lymphoid cell with a prominent nucleolus, well condensed peripheral nuclear chromatin and a variable amount of heterochromatin in intranuclear clumps. Eight cases of PLL (seven B-PLL, one T-PLL) showed minor morphological deviations from typical PLL which may present diagnostic difficulties when studied only at light microscopy: the cells in four of these had some features in common with those of chronic lymphocytic leukaemia (CLL), namely round regular nuclei and heavy chromatin condensation, but the nucleoli were larger in the PLL cases. In four other cases nuclear clefting was a prominent feature at TEM. B-PLL can be distinguished by ultrastructural features from other B-cell malignancies, e.g. follicular lymphoma, B-CLL and B-acute lymphoblastic leukaemia.

Cell Studies in Prolymphocytic Leukaemia

A case of prolymphocytic leukaemia, showing several features not yet reported in this disease, is reported. The majority of lymphocytes in the peripheral blood and bone marrow had markers of both B- and T-lymphocytes. The simultaneous presence of receptors for sheep RBC and surface immunoglobulins on individual cells was demonstrated and the endogenous origin of these markers was established. The lymphocytes had some of the functional characteristics seen in chronic lymphocytic leukaemia (CCL). In vitro cell death in the presence of colchicine (colchicine ultrasensitivity) and polystyrene bead column retention were of the same order as seen in CLL. In contrast with the findings in CLL, these cells were markedly radioresistant in vitro. The dominant clinical features--anaemia and constitutional symptoms--appeared to be related to hypersplenism associated with massive splenomegaly. The relevance of these findings is discussed.

Prolymphocyte Leukaemia of T‐Cell Type: Immunological, Enzymatic and Ultrastructural Morphometric Characteristics

A case of prolymphocytic leukaemia with immunological characteristics of T-cell type is reported. Three noteworthy findings can be emphasized: the presence of C3 receptors on the T-prolymphocytes, the study of the acid-phosphatase isoenzymatic pattern, which showed an increased band 3 with absence of band 3b, and the morphometric ultrastructural investigation. Cytochemistry and ultrastructural morphometry may be useful for a more precise characterization of prolymphocytic leukaemia and help to distinguish it from other lymphoproliferative disorders.