Results of the vincristine, doxorubicin, and dexamethasone regimen in adults with standard- and high-risk acute lymphocytic leukemia.

One hundred five untreated adult patients with acute lymphocytic leukemia (ALL) were entered on the vincristine, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and Decadron (dexamethasone; Merck Sharp and Dohme, West Point, PA) (VAD) regimen. Induction therapy with VAD and VAD plus cyclophosphamide (CVAD) was followed by a 2-year rotating maintenance program with multiple antileukemic combinations, and included early intensifications with Adriamycin and high-dose cytarabine (ara-C) and a late intensification with cyclophosphamide, carmustine (BCNU), and etoposide (VP-16) (CBV) followed by autologous bone marrow transplantation (BMT). Duration of therapy was 24 to 30 months. Eight-eight patients (84%) achieved complete remission (CR) with VAD-CVAD, and 94 (90%) ultimately had CR with continuation of the maintenance as planned. Induction mortality was 3%; only half of the patients required prolonged hospitalization of 1 week or longer, or intravenous antibiotics. Maintenance therapy was given to 79 patients, while nine with histocompatibility locus antigen (HLA)-matched related donors underwent allogeneic BMT. The median remission duration was 22 months, and the median survival was 19 months. Factors associated with significantly worse CR rates were older age, the presence of hypoalbuminemia or hyperbilirubinemia, L2 or L3 morphology, and myeloid markers on leukemic cells. Those associated with significantly worse remission durations were the presence of elevated leukocyte or absolute peripheral blast counts, Philadelphia chromosome (Ph)-positive or B-cell ALL, L2 morphology, and more than one course to achieve CR. Patients could be divided into standard-risk ALL (28% of patients) and high-risk ALL (72% of patients) with long-term remission rates of 70% versus less than 30%. The 26 patients who underwent CBV autologous BMT had similar long-term outcome compared with 21 patients who did not (older age, medical contraindications, or socioeconomic problems). The presence or absence of myeloid markers on leukemic cells did not affect long-term prognosis. We conclude that VAD therapy is a well-tolerated effective induction regimen. High-risk ALL patients require alternative maintenance investigational approaches.

Autologous and allogeneic bone marrow transplantation for chronic lymphocytic leukemia: preliminary results.

PURPOSE: This study was undertaken to evaluate the feasibility and therapeutic effect of high-dose chemoradiotherapy with autologous or allogeneic bone marrow transplantation (BMT) in patients with advanced chronic lymphocytic leukemia (CLL) who relapse after fludarabine treatment. PATIENTS AND METHODS: Twenty-two patients with advanced CLL received high-dose cyclophosphamide, total-body irradiation, and BMT. Eleven patients with relapsed CLL received autologous BMT with marrow collected during a prior fludarabine-induced remission; leukemia cells were depleted from the autologous marrow in seven patients using an anti-CD19 monoclonal antibody and immunomagnetic separation. Eleven patients received allogeneic or syngeneic BMT, seven of whom had refractory Rai stage III or IV disease. RESULTS: Six autologous transplant recipients achieved a complete remission (CR), four a nodular CR (nCR), and one a partial remission (PR). Two recurred with CLL, and three developed Richter's transformation. Two patients had recurrence of immune cytopenias while in morphologic remission; one of these patients died of cytomegalovirus pneumonia. Six of 11 patients survive in remission 2 to 29 months following BMT. Of the 11 patients who received allogeneic or syngeneic BMT, seven achieved a CR, two a nCR, and one a PR; 10 survive 2 to 36 months following BMT. CONCLUSION: These data indicate that high-dose chemotherapy with allogeneic BMT is effective at producing CRs in patients with CLL. Autologous transplantation in CLL is feasible and is capable of producing remissions in patients with advanced CLL. Further studies are warranted to assess the role of BMT in the treatment of CLL.

Analysis of CD7 expression in acute myelogenous leukemia: martingale residual plots combined with 'optimal' cutpoint analysis reveals absence of prognostic significance.

Conflicting results exist regarding the prognostic importance of CD7 expression in acute myelogenous leukemia (AML). Differences in the method of determining CD7 positivity, the antibody used, the therapy administered, and the CD7 level used as a cutoff point to reduce it to a binary variable have all been postulated to account for the discordant findings. We determined the level of CD7 expression by flow cytometric analysis using the Leu9 monoclonal antibody in 331 patients with newly diagnosed AML and attempted to determine the impact of CD7 on AML prognosis. This study used the same methodology and antibody as three of the four studies that reported a positive association between CD7 expression and prognosis in AML. Optimal cutpoint analysis was used to divide the population into CD7-positive (CD7+) (>10.5% expression) and CD7-negative (CD7-) (< 10.5% expression) groups with the largest survival difference. At the optimal cutpoint, the difference in survival was not statistically significantly different (P = 0.068 uncorrected, P = 0.244 corrected for optimal cutpoint search). There was a marked imbalance in the distribution of favorable cytogenetic abnormalities [t(8;21), inversion 16, t(15;17)], with 95% segregating to the CD7- group. Analysis excluding patients with favorable cytogenetic abnormalities revealed no prognostic importance for CD7 expression (P = 0.24 uncorrected). The response rate (CR) and survival experiences of CD7+ and CD7- patients were similar with six different regimens. CD7 expression was not a significant independent prognostic factor in a Cox regression model that included cytogenetics as a predictive variable, but it was marginally significant when cytogenetics was excluded. We conclude that regardless of the antibody used, the therapy received, or the cutoff point selected to determine CD7 expression, CD7 is not associated with response rate, prognosis, or survival in AML. The 'optimal cutoff point analysis' utilized in this study has applicability to other biologic parameters as well.

More cell death in refractory anemia with excess blasts in transformation than in acute myeloid leukemia.

Refractory anemia with excess blasts in transformation (RAEB-T) is a subgroup of myelodysplastic syndrome (MDS) in which the bone marrow blast count ranges from 20% to 30%. The recently proposed World Health Organization Classification of Hematologic Malignancies eliminated this category from MDS by lowering the blast count cutoff for acute myeloid leukemia (AML) from 30% to 20%. However, MDS is distinguished from AML by a significant increase in apoptosis. To investigate the difference in apoptosis between RAEB-T, AML, and other categories of MDS, we prospectively analyzed fresh bone marrow samples using the Annexin V and mitochondrial potential assays. There was a significantly higher level of apoptosis in RAEB-T than in AML according to both assays, while no significant differences between RAEB-T and other categories of MDS were noted. The data suggest that RAEB-T is more likely to be an advanced stage of MDS and biologically different from AML.

Increased CD38 expression is associated with favorable prognosis in adult acute leukemia.

CD38 is expressed in acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) blasts and its prognostic significance is unknown. We investigated CD38 expression in 304 AML and 138 ALL patients. CD38 was lower in AML-M3 compared to other FAB subtypes (5% vs. 41%; P < 0.001), but was similar among ALL subtypes (56.6%; P = 0.69). Ph + ALL and AML with t(15; 17) patients showed lower CD38 expression than the other cytogenetic groups. Overall survival favored AML and ALL patients with higher CD38 levels. Multivariate analysis revealed CD38 expression to be an independent outcome predictor in AML, but not in ALL.

Prevention of graft-versus-host disease with anti-CD5 ricin A chain immunotoxin after CD3-depleted HLA-nonidentical marrow transplantation in pediatric leukemia patients.

To determine if partial T cell depletion and intensive post-transplant immunosuppression is effective for the prevention of graft-versus-host disease (GVHD) in pediatric recipients of HLA-non-identical marrow transplants, 10 children with leukemia received high-dose thiotepa, cyclophosphamide and total body irradiation followed by transplantation of CD3-depleted marrow from matched unrelated or one-antigen mismatched related adult donors. To maximize the number of stem cells infused, a large volume (1-1.51) of marrow was harvested from the donors. After immunopurging, the marrow infused contained a median of 3.7 x 10(6) CD34+ cells/kg, 1.4 x 10(6) CD3+ cells/kg, and 1.6 x 10(6) CD5+ cells/kg as assessed by flow cytometry. Cyclosporine, methylprednisolone and anti-CD4 ricin A chain immunotoxin (XZ-CD5) were used for prevention of GVHD post-transplant. All patients achieved an ANC > 0.5 x 10(9)/l. No patient developed capillary leak syndrome or renal failure from XZ-CD5. Five developed grade 2-4 acute GVHD, and all responded to treatment with steroids. Five of nine evaluable patients developed chronic GVHD. Two patients relapsed, but the most common cause of death was infection with or without chronic GVHD. Four patients survive 10+ to 27+ months post-transplant. XZ-CD5 is well-tolerated in T cell-depleted marrow transplant recipients. However, partial T cell depletion and intensive post-transplant immunosuppression did not prevent moderate acute GVHD or chronic GVHD. This may have been due to the high number of T cells infused with the marrow.

Successful treatment of progressive multifocal leukoencephalopathy with low-dose interleukin-2.

A patient with low-grade lymphoma presented 8 months after autologous marrow transplantation with dizziness, aphasia and hemiparesis. Magnetic resonance imaging (MRI) showed an abnormal T2 signal in the frontoparietal region unilaterally. Biopsy of the area demonstrated progressive multifocal leukoencephalopathy positive for JC virus and p53. Treatment with interleukin-2 at 0.5 MU/m2/day i.v. continuous infusion resulted in near complete resolution of symptoms and MRI abnormalities. The absolute number of CD3+CD4+ and CD3-CD56+ cells in the peripheral blood also increased, and the CD4/CD8 ratio normalized. She remains free of evidence of progressive multifocal leukoencephalopathy 1 year off therapy.

Transfusion reactions in patients with cancer.

In general, the true incidence of transfusion reactions is difficult to determine with certainty. In patients with cancer, it becomes even more complex to define. During a four-year study period in which 100,177 units of red blood cell transfusions were given to 25,744 cancer patients, 245 episodes of transfusion reactions were reported. The incidence of overall reaction was 0.3% of all transfused units, which is significantly lower than other studies. Febrile nonhemolytic reactions and allergic urticarial reactions were the most frequently noted, constituting 51.3% and 36.7%, respectively, of total reactions. There were only 17 hemolytic reactions (four immediate and 13 delayed-type). The incidence of delayed hemolytic reactions in cancer patients is significantly lower than that reported for patients in non-oncology hospital settings. This could result from the inability of cancer patients to produce alloantibodies against blood group antigens as frequently and efficiently as can those with non-neoplastic conditions.

Evaluation of a positive autologous control in pretransfusion testing.

The clinical usefulness of autologous control (AC) in pretransfusion testing was evaluated. The records of 515 blood samples with positive direct antiglobulin tests detected by positive AC were reviewed. This represents 3.5% of 14,548 pretransfusion samples tested during a one-year period. One hundred ninety-four of 515 samples required further elution studies, and the results were 114 nonreactive, 18 autoantibodies, 52 ABO isoagglutinins, 5 transfusion-induced alloantibodies, and 5 unidentifiable antibodies. All alloantibodies also were detected in the serum. Therefore, AC and the elution results provided no further information in selecting blood for compatibility testing. By reviewing the patients' records, the authors determined that, only in five cases, the report of positive AC and elution results changed diagnosis or therapeutic course. The information of positive AC rarely was used in either assuring compatibility of blood or management of the patients clinically.

Positive direct antiglobulin test and high serum immunoglobulin G values.

To investigate the association between the positive direct antiglobulin test (DAT) and hypergammaglobulinemia, the authors prospectively studied 154 patients, classified into three groups: Group 1, 52 patients with a positive DAT result in pretransfusion samples; Group 2, 52 patients with a negative DAT result; and Group 3, 50 patients initially found to have an elevated serum immunoglobulin G (IgG) level. Serum protein electrophoreses and IgG quantifications were performed for all three groups. Serum haptoglobin and lactate dehydrogenase (LD) isoenzyme electrophoreses were also assayed for Group 1. Of 52 patients in Group 1, 17 (33%) had an elevated serum IgG level and nonreactive eluates. Clinical history, haptoglobin, and LD isoenzyme studies did not suggest increased red blood cell destruction. Only 2 (4%) of 52 patients in Group 2 had an elevated serum IgG level. Of 50 in Group 3, 25 (50%) had a positive DAT result with nonreactive eluates and did not have hemolytic diseases. Two of 10 patients (20%) with serum IgG levels ranging from 18 to 20 g/L (1.8-2.0 g/dL), 13 of 29 (45%) with serum IgG levels from 20 to 40 g/L (2.0-4.0 g/dL), 4 of 6 (67%) with serum IgG levels from 40 to 60 g/L (4.0-6.0 g/dL), and 6 of 6 (100%) with serum IgG levels from 60 to 80 g/L (6.0-8.0 g/dL) had a positive DAT result. The authors concluded there is a significant correlation between a positive DAT result and serum IgG concentrations and that the higher the elevated serum IgG, the more frequently the positive DAT result is observed. Elevated serum IgG levels may explain many positive DAT results in pretransfusion blood samples.

Higher levels of surface CD20 expression on circulating lymphocytes compared with bone marrow and lymph nodes in B-cell chronic lymphocytic leukemia.

Differential expression of CD20 surface antigen in B-cell neoplasms at different sites is largely unknown. The number of CD20 antibodies bound per cell (CD20 ABC) in bone marrow (BM), peripheral blood (PB), and lymph node aspirate (LNA) samples from patients with B-cell chronic lymphocytic leukemia (B-CLL) or other B-cell disease was studied using quantitative flow cytometry. CD20 ABC differed significantly with the specimen type in B-CLL, being highest in PB (mean, 9,051) and lower in BM (mean, 4,067) and LNA (mean, 3,951). No difference in CD20 ABC between BM and PB samples was found in splenic lymphoma, mantle cell lymphoma, or follicular lymphoma. Also, we found a significant difference of CD20 ABC by type of disease: lowest in B-CLL; higher in splenic, follicular, and mantle cell lymphoma; and highest in hairy cell leukemia. The lower CD20 surface antigen levels in BM and LNA than in PB in B-CLL may have clinical relevance with regard to the efficacy of rituximab therapy.

Cell kinetic analysis of interleukin-2 receptor-tested chronic lymphocytic leukemia using the AgNOR silver stain.

B-cell chronic lymphocytic leukemia (B-CLL) is typically a low-grade neoplasm with a diploid DNA index and low proliferative activity. Interleukin-2 receptor (IL-2R/CD25) positivity often indicates increased proliferative activity and activation in both T and B lymphocytes. The argyrophilic nucleolar organizer regions (AgNORs) are loops of DNA identified by a silver staining technique and have been correlated with ploidy and proliferative activity. Two distinct AgNOR counting methods have been previously shown to correlate with DNA ploidy and proliferative activity, respectively: the mean AgNOR count (mAgNOR) correlates more with ploidy, and the percentage of nuclei with > or = 5 AgNORs/nucleus (pAgNOR) reflects proliferative activity. We studied bone marrow specimens from 32 patients with B-CLL using both anti-IL-2R on the marrow aspirates and the AgNOR silver stain on marrow biopsy specimens, applying both AgNOR counts. All tumors were CD5+, CD19+, and CD19/CD20+. Sixteen tumors were IL-2R- (< 20% IL-2+ B cells), and 16 were IL-2R+ (> or = 20% IL-2R+ B-cells). No significant difference in morphology of bone marrow involvement was noted in the two groups. A male predominance was noted in the IL-2R+ group of patients (3:1). There was also a preponderance of lambda light chain expression in the IL-2R+ tumors (11/16) compared with the IL-2R- cases (5/16). Except for two cases, all tumors had mAgNOR counts within the diploid range (< 2.4). The 16 IL-2R- tumors had pAgNOR in the range of 0% to 7% (mean, 2.31 +/- 2.18 standard deviation), whereas the IL-2R+ tumors had pAgNOR ranging from 6% to 15% (mean, 10.20 +/- 2.70 standard deviation; P < .0001). This finding suggests that IL-2R+ B-CLL might represent a subgroup of tumors with higher proliferative activity.

Absence of CD26 expression is a useful marker for diagnosis of T-cell lymphoma in peripheral blood.

We report flow cytometric characterization of surface CD26 expression in 271 peripheral blood samples from 154 patients evaluated for the presence of a T-cell lymphoproliferative disorder, primarily mycosis fungoides/Sézary syndrome (MF/SS). The presence of morphologically identifiable tumor cells on peripheral blood smears was the criterion for lymphomatous involvement. In 66 of 69 samples from 28 patients, we identified an abnormal CD26-/dim T-cell population that was distinct from the variable CD26 expression seen in normal peripheral blood T cells. This population was CD26- in 23 patients and weakly CD26+ in 5 patients. CD7 was more variably expressed in MF/SS tumor cells, allowing recognition of a distinct, quantifiable abnormal T-cell population in only 34 of 69 involved samples. An increased CD4/CD8 ratio and lower surface expression of CD4 in tumor cells also helped separate the CD26-/dim atypical population for quantification. In 35 blood samples from other types of T-cell tumors, tumor cells in 10 of 11 morphologically involved cases showed absent/dim CD26. Although capable of detecting abnormalities in most cases of MF/SS, CD7 expression does not provide as clear a separation of the neoplastic population and can be replaced by CD26 staining in routine peripheral blood flow cytometric screening of MF/SS patients.

De novo CD5+ Burkitt lymphoma/leukemia.

CD5 is a T-cell marker aberrantly expressed in B-cell chronic lymphocytic leukemia and mantle cell lymphoma. Other B-cell neoplasms, including Burkitt lymphoma, are usually CD5-. We report 4 cases of de novo CD5+ Burkitt lymphoma/leukemia in elderly patients, all of whom were in a leukemic phase and had variable lymph node and splenic involvement. The blasts were typically medium sized, with folded nuclei, distinct but not prominent nucleoli, and moderate amounts of somewhat vacuolated basophilic cytoplasm; they were terminal deoxynucleotidyl transferase--negative and surface immunoglobulin--positive. All 4 cases demonstrated c-myc rearrangement, but none had t(14;18), t(11;14), or cyclin D1 overexpression or rearrangement. Only 1 patient achieved complete remission after hyper-CVAD (hyperfractionated cyclophosphamide, vincristine, doxorubicin, dexamethasone) therapy. One patient responded poorly to hyper-CVAD, and 2 patients died during induction chemotherapy. These rare cases of aggressive lymphoid malignancy with CD5 positivity and molecular features associated with Burkitt lymphoma/leukemia are best classified as Burkitt leukemia. However, the morphologic and immunophenotypic similarity to the blastoid variant of mantle cell lymphoma are diagnostically challenging. The diseases can be distinguished at the genetic level, since Burkitt lymphoma involves the rearrangement of c-myc, and mantle cell lymphoma usually the overexpression or rearrangement of cyclin D1.

Detection of subgroups of chronic B-cell leukemias by FMC7 monoclonal antibody.

Monoclonal antibody FMC7 detects subgroups of B-cell leukemias that have arisen from cells in late stages of B-cell maturation. FMC7 was studied by flow cytometry on cell samples from 192 patients with a diagnosis of chronic lymphocytic leukemia (CLL) or lymphoma. The leukemic cells from 16 patients were reactive with this antibody. These 16 cases were evaluated for other surface markers, morphology of cells, and clinical characteristics. Of the 16 patients, 14 had cells that strongly expressed surface immunoglobulin (SIg). This is atypical of CLL cells, which characteristically show weak expression of SIg. Eleven cases had kappa and five had lambda light chain. All patients' cells had consistently brighter CD20 expression than that of CD19. Fourteen patients had expression of CD5 on their leukemic cells. One patient had more than 55% prolymphocytes, meeting the criteria of prolymphocytic leukemia (PLL), two patients had CLL in prolymphocytic transformation (CLL/PL), and two other patients were classified as having a paraimmunoblastic variant of small lymphocytic lymphoma based on a high number of paraimmunoblasts and on the histologic features. Another nine patients had immature lymphoid cells distinct from prolymphocytes or paraimmunoblasts on morphologic study. The immature cells were variable in size, and the nuclear chromatin was less clumped than that of prolymphocytes. The histologic diagnoses in four of these cases were consistent with mantle cell lymphoma. Splenomegaly was observed in 11 patients (69%), and 11 patients had advanced Rai 3 or 4 disease. Among 10 patients treated with fludarabine, five responded to therapy. Monoclonal antibody FMC7 is useful for identifying a group of atypical variants of CLL, PLL, and other B-cell lymphomas in leukemic phase that can be easily confused with CLL. Careful attention to the cell morphology and histologic features is important for the differential diagnosis of FMC7-positive, B-cell lymphoproliferative diseases.

Immunotyping of lymphoma by fine-needle aspiration. A comparative study of cytospin preparations and flow cytometry.

Immunotyping is an essential adjunct to cytomorphology for the diagnosis of lymphoma by fine-needle aspiration (FNA). Two independent techniques, cytospin preparations and flow cytometry, were used for immunotyping studies on 71 patients with histologically confirmed non-Hodgkin's lymphoma (63 B-cell lymphomas and 8 T-cell lymphomas). Diagnostic concordance between the two methods was obtained in 69 patients (97%). kappa, lambda, and CD3 (Leu-4) markers were routinely measured on all cytospins, and additional markers were requested when indicated. The standard panel measured by flow cytometry included 14 markers. In general, mean values of light-chain (kappa and lambda) immunoglobulins were consistently slightly higher by cytospin analysis than by flow cytometry. Light-chain immunoglobulin ratios (kappa/lambda or lambda/kappa) obtained by both methods proved to be reliable independent predictors of polyclonality or monoclonality. Correlation studies using the Spearman rank coefficient revealed good concordance among values of kappa, alpha, CD3, and CD5 obtained by the two techniques, suggesting that subjective quantitation by cytospins yields similar results to objective quantitation by flow cytometry. Cytospin analysis and flow cytometry appear equally capable of immunotyping aspirated lymphoid samples reliably. The advantages of each method are discussed.

Use of peripheral blood blasts vs bone marrow blasts for diagnosis of acute leukemia.

Acute leukemia can be diagnosed when blasts constitute 30% or more of the nucleated cells in a patient's peripheral blood (PB) sample. To determine whether in such cases bone marrow (BM) aspirates are still necessary, we compared the results of diagnostic studies performed on PB samples with blast counts of 30% or more with those performed on the same patients' BM samples. We found no differences in morphologic features, cytochemistry, or immunophenotype between the blasts in PB and BM samples in any of 30 cases studied. However, in 10 (23%) of 44 cases in which cytogenetic analysis was performed, PB but not BM samples were insufficient for analysis. The converse never occurred. Five of the 10 cases had acute lymphoblastic leukemia and 5 had acute myeloid leukemia (41% of the patients with acute lymphoblastic leukemia and 17% of the patients with acute myeloid leukemia). In cases with adequate metaphases, there was strong correlation between the cytogenetic results for PB and BM samples. Some PB samples with blast counts of 30% or more are adequate for diagnosis of acute leukemia, especially when therapy can be delayed until it is known that an adequate number of analyzable metaphases are recovered from the PB samples.

Translocation (X;10)(p10;p10): A rare but nonrandom chromosomal abnormality in acute leukemia of myeloid differentiation.

Structural abnormality of chromosome X is uncommonly seen in patients with acute leukemia, and translocation between chromosome X and 10 is an exceedingly rare event. In this report, we describe the occurrence of t(X;10)(p10;p10) in two patients with acute leukemia, one with acute monocytic leukemia and the other with myeloblastic relapse arising from bilineage leukemia. To our knowledge, similar chromosomal abnormality has been reported only twice in the literature.

Natural killer cell activity in chronic lymphocytic leukemia patients treated with fludarabine.

Fludarabine, the 5'-monophosphate of 9-beta-D-arabinofuranosyl-2- fluoroadenine (FaraAMP), is effective in the treatment of chronic lymphocytic leukemia (CLL) and has been demonstrated to increase natural killer (NK) cell lytic activity (NKa) in humans and mice. To determine the effect of FaraAMP on NK cells in CLL, we analyzed NKa toward K562 targets after in vitro incubation with FaraAMP and after in vivo exposure to fludarabine. Pretreatment analysis of peripheral blood from 12 CLL patients (9 untreated) revealed: median number of NK cells 500/microliter (range 290-1160); median NKa lytic unit30/10(6) cells (range 5-80). These results were similar to those from healthy adult donors. After exposure to 3, 30 or 300 microM FaraAMP, the median maximum stimulation index (NKa FaraAMP/NKa) was 1.2 (range 0.9-1.5), within the range observed in normal adults. FaraA also stimulated NKa in vitro toward autologous CLL cells in two of five patients as measured by a dye-exclusion assay. In three patients following three or more treatment courses of fludarabine (30 mg/m2 per day for 5 days) the NK cell number and NKa were maintained near pretreatment values. Phenotypic analysis of the peripheral mononuclear cells in 34 consecutive CLL patients revealed a marked reduction in CD5/CD20 and CD4 cell numbers after three courses of fludarabine with less effect on CD8 and CD56 cells. These results indicate that fludarabine spares NK cells and may stimulate NKa in some CLL patients.

Immunophenotypes in adult acute lymphocytic leukemia. Role of flow cytometry in diagnosis and monitoring of disease.

Flow cytometry has revolutionized the study of hematopoietic cells. Immunophenotyping by multiparameter flow cytometry supplements conventional morphologic diagnosis by providing information on cell lineage and differentiation in ALL and helps monitor disease by improving sensitivity in detecting minimal residual disease. The use of multiple MoAbs and multicolor study by flow cytometry has revealed heterogeneity among ALL and mixed-lineage acute leukemia, which are assigned to the same diagnostic categories by morphology. As technology has improved, clinical and research applications of flow cytometry have expanded to include evaluation of nuclear markers, oncogene proteins, apoptosis, cytokine receptors, and drug resistance. Expanded identification of MoAbs against leukemia-specific markers and the use of QFCM be a significant in managing patients with ALL in the future. In addition, flow cytometry and flow cytometric sorting will be combined more and more with other technologies, such as molecular probing or fluorescence in situ hybridization (FISH). The sorting of rare malignant cells based on immunophenotype and subsequent confirmation by PCR or FISH has already been proven feasible. Ultimately, it is hoped that further definition of subgroups of ALL by immunophenotyping using prognostically significant markers and the use of hybrid technologies of flow cytometry and molecular analysis or cytogenetics will improve treatment strategies for patients with ALL.