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Results for “Immunophenotyping”

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PubMed1991

Immunophenotyping of 515 cases of acute lymphoblastic leukemia in China.

Using cell surface markers and a panel of monoclonal antibodies, 515 cases of acute lymphoblastic leukemia (ALL) were immunophenotyped. T cell type ALL (T-ALL), non-T cell type ALL (Non-T-ALL) including common ALL (C-ALL), Null-ALL and B cell type ALL (B-ALL) were found. These major subtypes of ALL were further divided according to their phenotypes in detail. It was noticed that the phenotypes of these subtypes of ALL reflected basically the phenotypes of normal T or B cells at various differentiation stages or certain population of lymphocytes. The diagnosis of cell lineage was more precise when based on immunophenotyping than morphological description. The combination of morphological and immunological classification can improve the diagnosis of acute leukemias. In addition, it was observed that the immunophenotyping was relevant to clinicopathologic features, responses to therapy and prognosis of ALL patients. The incidences of major subtypes of ALL, the age distribution of ALL subsets and male sex bias with T-ALL in Chinese are discussed.

Adolescent↗

PubMed1991

Multiparameter analysis of acute mixed lineage leukemia: correlation of a B/myeloid immunophenotype and immunoglobulin and T-cell receptor gene rearrangements with the presence of the Philadelphia chromosome translocation in acute leukemias with myeloid morphology.

Morphological, immunological, cytogenetic, and molecular features of 28 cases of acute mixed lineage leukemia (AMLL), defined by the co-expression of lymphoid and myeloid cell surface antigens, were correlated in a multiparameter study. These 28 cases were identified in a series of 260 consecutive acute leukemia cases occurring predominantly in adults and were subdivided into 18 cases of AMLL with myeloid morphology and cytochemistry (AMLL-AML) and 10 cases of AMLL with lymphoid morphology and cytochemistry (AMLL-ALL). A lack of correlation was observed between the expression of B- or T-cell associated antigens with the presence of the expected immunoglobulin (Ig) or T-cell receptor (TCR) gene rearrangements in the AMLL cases with myeloid morphology. Only three of the 18 total AMLL-AML cases, each co-expressing B- and myeloid-associated cell surface antigens (B/My), had Ig heavy chain gene rearrangements with or without rearrangements of TCR genes. Ig light chain genes remained in the germline configuration. Strikingly, these three cases were the only AMLL-AML cases in our series to have the Philadelphia (Ph) chromosome translocation t(9;22)(q34;q11), suggesting that a significant percentage of acute leukemias with myeloid morphology and gene rearrangements may be Ph+ AMLL. The fact that three of the 10 B/My AMLL-AML cases in our series were Ph+ suggests that there may be an increased frequency of Ph chromosome, a translocation associated with a poor prognostic outcome, in B/My AMLL-AML occurring in the adult population. Although most AMLL cases with lymphoid morphology had Ig and TCR gene rearrangements associated with a variety of immunophenotypes and karyotypes, two Ph+ AMLL-ALL cases had many similar features (B/My immunophenotype; IgH with or without TCR rearrangements; Ig light chain genes germline) to their Ph+ AMLL-AML counterparts. However, the Ph+ AMLL-ALL cases differed from the Ph+ AMLL-AML cases by the expression of a more mature B-cell lineage immunophenotype and by their additional cytogenetic changes.

Acute Disease↗

PubMed1990

Characterization of common variable immunodeficiency: identification of a subset of patients with distinctive immunophenotypic and clinical features.

The peripheral blood lymphocyte surface markers and clinical features of 38 patients with common variable immunodeficiency (CVID) were assessed. These studies identified a subset of CVID consisting of 14 of the 38 patients with a distinctive T-cell immunophenotype and clinical findings. The phenotypic changes were characterized by an abnormally low CD4/CD8 ratio (less than or equal to 0.9) due primarily to a significant increase in CD8 T cells. In addition, there was an expansion in CD8 T cells coexpressing CD57 and increased expression of the activation markers HLA-DR and interleukin-2 receptor (IL-2R) by these cells. This group of immunophenotypically abnormal CVID patients also had characteristic clinical features, including splenomegaly (P less than .02) and in vivo T-cell dysfunction based on the evaluation of delayed-type hypersensitivity (P less than .05). Approximately 71% of these patients had splenomegaly and 42% were anergic in contrast to the remaining group of CVID patients, in which 29% had splenomegaly and 7% were anergic. These findings define a subgroup of CVID patients that have specific immunophenotypic features and functional T-cell abnormalities.

Adult↗

PubMed1990

Alterations in immunoglobulin or T cell receptor gene rearrangement at relapse: involvement of 11q23 and changes in immunophenotype.

We studied the organization of immunoglobulin (Ig) genes and the beta-chain gene of the T cell receptor (TCR) along with the clinical features, immunophenotypes, and karyotypes of 14 children with acute leukemia at diagnosis and relapse. The median time to relapse was 23 months. Eleven children had identical gene rearrangement patterns at diagnosis and relapse. All three patients whose blast cells showed variations in gene rearrangement patterns between diagnosis and relapase also demonstrated a change in the immunophenotype: one from cALLA+ to cALLA- B precursor cell ALL; one from T-ALL to AML; and one showed a marked increase in myeloid characteristics at relapse. Blast cells from these three patients at relapse showed the presence of chromosomal translocations involving 11q23; for two patients, this involved replacement of the original karyotype. We conclude that while most relapses are the result of reemergence of the original clone, new clones that differ in immunophenotype, karyotype, and gene rearrangement are occasionally present at relapse. Relapses may also occur in which the original clone has undergone major changes in gene expression and arrangement of the Ig heavy chain genes in the absence of karyotypic replacement.

Acute Disease↗

PubMed1995

Detection and monitoring of a concomitant atypical myeloproliferative disorder and chronic lymphocytic leukemia by flow-cytometric immunophenotyping.

OBJECTIVE: To illustrate the utility of a broad panel of monoclonal antibodies to detect secondary processes or unexpected characteristics of the primary blood dyscrasia. DESIGN: Case report and discussion. SETTING: Regional academic medical center. PATIENT: A 64-year-old man presenting with an apparent acute myeloid leukemia. INTERVENTIONS: Sequential immunophenotyping with a broad panel of monoclonal antibodies to monitor progression of disease and response to therapy. MAIN OUTCOME MEASURE: Identification and monitoring of the two atypical populations in this patient with correlation to the clinical status of the patient. RESULTS: Identification of an unsuspected mature lymphoid clone and characterization of the evolution of the myelomonocytic clone. CONCLUSION: The evolving mature lymphoid clone may have been overlooked in the context of a predominant atypical myeloproliferative process, particularly if a limited panel of monoclonal antibodies had been used for immunophenotyping. Sequential immunophenotyping was useful in monitoring the progression of each atypical process.

Antigens, CD↗

PubMed1995

Immunophenotypic and immunoelectron microscopic characterization of major constituent cells in malignant fibrous histiocytoma using human cell lines and their transplanted tumors in immunodeficient mice.

BACKGROUND: Malignant fibrous histiocytoma (MFH) is the most common soft tissue sarcoma of adult life. Its histogenesis, however, is still a matter of debate because of its various cellular components. EXPERIMENTAL DESIGN: To elucidate the nature of tumor cells of MFH, six human MFH cell lines were compared immunohistochemically and immunoelectron microscopically with fibrosarcoma and fibroblast cell lines. In vitro differentiation of tumor cells was evaluated after the treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA), IL-3, macrophage CSF, and granulocyte-macrophage CSF. Heterotransplantation of MFH tumor cells into nude mice and severe combined immunodeficient mice was performed to examine whether the tumor cells differentiate toward histiocytes or not. Gene expression of monocyte chemoattractant protein-1 in cultured tumor cells and transplanted tumors was also evaluated. RESULTS: All MFH cell lines examined were positive for collagen type I and prolyl hydroxylase. They failed to react with most anti-myeloid mAb such as CD11c, CD14, CD15, CD33, CD35, CD45, anti-HLA-DR, and PM-2K. Several Ab, including CD13, CD32, CD68, CD71, and HAM56, were reactive with MFH cells. However, all of these Ab were also reactive with fibrosarcoma and/or fibroblastic cell lines. These data indicate that MFH cell lines possess immunophenotypic characteristics very similar to those of fibrosarcoma and fibroblastic cell lines. In vitro treatment of tumor cells with TPA, IL-3, macrophage CSF, granulocyte-macrophage CSF, or their combination did not change their immunophenotypic characteristics and did not induce differentiation toward histiocytes (macrophages). Transplantation of tumor cells into nude mice and severe combined immunodeficient mice produced tumors similar in histology to human MFH. Tumor cells in the transplanted tumors revealed the same immunophenotypic characterization that they did in vitro. No in vivo differentiation of tumor cells toward histiocytes was observed. Immunohistochemical staining with anti-mouse macrophage mAb revealed marked infiltration of macrophages of mouse origin. Quantitative immunoelectron microscopy disclosed that these cells coincided with histiocyte-like cells. Gene expression of monocyte chemoattractant protein-1 was detected in all MFH cell lines as well as in transplanted tumors. CONCLUSIONS: The histiocyte-like cells in malignant fibrous histiocytoma are not a neoplastic component but rather infiltrated macrophages attracted by tumor-derived monocyte chemoattractant(s), and the tumor cells belong to a fibroblastic lineage differentiated from mesenchymal cells.

Adult↗

PubMed1994

[The immunophenotypic lymphocyte analysis of orbital lymphadenosis and its significance].

An immunophenotypic lymphocyte analysis of 56 cases of orbital lymphadenosis was performed with a panel of 10 monoclonal antibodies against the lymphocyte differentiation antigen by the streptavidin-peroxidase conjugate method to reveal that (1) all 15 cases of inflammatory pseudotumor and 32 of 33 cases of reactive lymphocyte hyperplasia manifested polyclonality of the constituent cells; (2) the immunophenotype of cells was monoclonal in 2 of 3 cases of atypical lymphocyte hyperplasia and diagnosis of malignant lymphoma (ML) were established; and (3) among 5 cases of ML, the cells were shown to be B-cells in 4 cases and T-cells in 1 case. These results suggested that immunophenotyping could be useful in differentiating the benign from the malignant orbital lymphadenosis and the histologic types of ML. The relationship between pathologic and immunologic classifications of orbital lymphadenosis was also discussed.

Diagnosis, Differential↗

PubMed1994

[Immunophenotyping of leukemia: overview].

Leukaemias that cannot be classified properly by morphological/cytochemical parameters may be diagnosed clearly by immunophenotyping. In this way, the neoplastic cells can be designated to either the myeloid or the lymphatic line of blood cells. Furthermore, myeloid leukaemias can be subtyped immunophenotypically in cases of type M0, M6, and M7, leukaemias, as well as in cases of mixed lineage or undifferentiated leukaemias. In patients with non-Hodgkin-lymphomas the cells can be characterized as being of B- or T-cell origin, and their activational or proliferative state can be assessed. Notably with acute lymphatic leukaemias, the prodigious therapeutical progress over the past years must be attributed to the refined definition of subtypes by immunophenotyping.

Antibodies, Monoclonal↗

PubMed1994

[Immunophenotyping of acute lymphatic leukemia: diagnostic aspects and clinical relevance].

During the past two decades immunophenotyping has yielded significant new information regarding the biological heterogeneity of ALL and has provided a solid basis for a biologically oriented and reliable classification of this disease. At present, lineage commitment of acute leukaemias can be achieved in more than 98% of cases by applying a standardized panel of mAbs to pan-B-cell (CD19, cyCD22), pan-T-cell (cyCD3, CD7) and pan-myeloid antigens (CD13, CD33, MPO) that are expressed either on the surface or in the cytoplasm of the earliest progenitors of the respective cell lineage. Further subclassification of ALL based on the analysis of antigens more closely associated with different maturational stages of B- and T-cell lineage has proven useful for the identification of biologically and clinically distinct entities in both B-cell precursor and T-lineage ALL. Immunophenotyping in about 2800 patients recruited for the German multicentre trials has shown that children and adults differ markedly in frequency distribution of immunological subgroups, with a higher adult incidence of immature B-cell precursor (i.e., pre-pre-B ALL) and T-lineage ALL immunophenotypes (i.e., pre-T ALL). Detailed immunological analyses using a broad panel of mAbs have recently documented typical ALL cases inappropriately expressing myeloid antigens (My+ ALL) as well as morphologically/cytochemically defined acute myeloid leukaemia (AML) with lymphoid-associated markers (Ly+ AML). Based on our own results and a critical review of published data, leukaemic blasts in 5-20% of ALL patients disclose My+ ALL, whereas a coexpression, mostly of T-cell-associated antigens, can be identified in 10-25% of AML cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1996

Immunophenotype of intraductal carcinoma.

OBJECTIVE: Mammography and breast-conserving therapy have focused attention on the classification of intraductal carcinoma (IDC) and emphasized the prognostic importance of comedo versus noncomedo variants. We used histochemical markers to define the immunophenotype of 43 IDCs with respect to comedo versus noncomedo status and patterns of angiogenesis. RESULTS: Reactions in comedo carcinomas were significantly negative for estrogen receptor and progesterone receptor, and positive for p53 and HER-2/neu more often than the noncomedo variant. All seven IDCs associated with Paget's disease showed positive reactions for HER-2/neu. Basement membrane immunoreactivity for type IV collagen and laminin was discontinuous in most examples of IDC regardless of type, with a trend toward more intense staining in comedo than in noncomedo carcinomas. Periductal angiogenesis was not significantly related to the type of IDC but was more pronounced with comedo carcinomas. CONCLUSIONS: These observations indicate that there are immunophenotypic correlates to the current structural classification of IDC. The immunophenotype of IDC is helpful in subclassifying an IDC and could prove useful as a prognostic indicator for local control in patients treated by breast-conserving therapy.

Adult↗

PubMed1996

CD30 (Ki-1)-positive malignant lymphomas: clinical, immunophenotypic, histologic, and genetic characteristics and differences with Hodgkin's disease.

This study compares the histologic and immunophenotypic features of 71 cases of primary CD30+ diffuse large-cell lymphomas (DLCL) and 128 cases of Hodgkin's disease (HD) and discusses the clinical features of 52 patients with CD30+ DLCL. It includes analysis of sites of involvement, staging, response to treatment, sites and treatment of recurrences, and disease-free and overall survival. Diagnostic immunophenotypic differences were found between CD30+ DLCL and HD. All cases of CD30+ DLCL were positive for one or more common or lineage-specific lymphocyte antigens or for EMA. In contrast, 96.9% of HD cases were negative for CD45, CD45-RO, CD43, and CD20. The four exceptions are discussed. All cases of HD were negative for EMA. In patients with CD30+ DLCL, a T-cell phenotype was found in 60%, a null-cell type in 22%, and a B-cell type in 18% of the cases. The median age of patients with T- and null-cell phenotype was 22 years (range, 4 to 72). Fifty-two percent of them had high-stage (III and IV) disease and 61% had extranodal involvement at presentation, including 25% with skin lesions. Lymph nodes draining the skin lesions became involved in seven of 11 patients. No patient had initial bone marrow involvement. Most patients were treated with chemotherapy, and 83% had a complete remission. Fifty-four percent remain free of disease with a median follow-up of 47 months. Thirteen patients (29%) had one or more recurrences and five of them remain free of disease after salvage therapy, with a median follow-up period of 79 months. The clinical stage did not affect survival, probably as a result of different therapy. The t(2;5) translocation was found in five of 15 patients who had cytogenetic abnormalities. Of the other 10 cases, the translocation was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) in four of five cases studied. All nine cases were of T- or null-cell phenotype. The cases of B-cell CD30+ DLCL had a characteristic immunophenotype. All were negative for EMA. These patients were older and had frequent bone marrow involvement but no skin infiltration by lymphoma. All three patients who were human immunodeficiency virus-positive (HIV+) had lymphomas of B-cell lineage. Detection of the t(2;5) translocation by molecular genetics is a useful and highly specific marker in the differential diagnosis between HD and CD30+ DLCL.

Adolescent↗

PubMed1997

Evaluation of the Revised European-American Lymphoma classification confirms the clinical relevance of immunophenotype in 560 cases of aggressive non-Hodgkin's lymphoma.

The Revised European-American Lymphoma (REAL) classification has been criticized for its emphasis on the unproven clinical relevance of immunophenotype. A worse prognosis for peripheral T-cell non-Hodgkin's lymphomas (PTCLs) has been inconsistently reported in part because the definition of PTCL has been imprecise (eg, T-cell-rich B-cell non-Hodgkin's lymphomas [TCRBCLs] have been misdiagnosed as PTCLs in the past) and because its correlation with other known prognostic factors has not been studied by multivariate analysis. We analyzed six protocols from 1984 to 1995 with Working Formulation intermediate grade and immunoblastic lymphomas (exclusive of mantle cell) and selected only those cases in which immunophenotyping was performed and was conclusive. Of a total of 560 evaluable patients, 68 were PTCLs (12%) and the remaining 492 (88%) were B-cell non-Hodgkin's lymphomas, including 16 TCRBCLs (3% of total). The 5-year failure-free survival (FFS) for PTCLs and B-cell large-cell lymphomas (BCLCLs) is 38% and 55%, respectively (P < .0001) and the 5-year overall survival (OS) is 39% and 262%, respectively (P < .001). The M.D. Anderson prognostic tumor score (MDATS) and International Prognostic Index (IPI) for all patients was calculated. With MDATS of less than 3 (good prognosis), the 5-year FFS for PTCL and BCLCL is 56% and 69%, respectively (P = .01), and the 5-year OS is 64% and 77%, respectively (P = .06). With MDATS of greater than 2 (poor prognosis), 5-year FFS for PTCL and BCLCL is 26% and 38%, respectively (P = .03), and the 5-year OS is 24% and 41%, respectively (P = .02). With an IPI of less than 3 (good prognosis), the 5-year FFS for PTCL and BCLCL is 49% and 64%, respectively (P = .001), and the 5-year OS is 55% and 71%, respectively (P = .013). With an IPI greater than 2 (poor prognosis), the 5-year FFS for PTCL and BCLCL is 11% and 35%, respectively (P = .044), and the 5-year OS is 10% and 40%, respectively (P = .011). Multivariate analysis shows that MDATS, IPI, and T-cell phenotype are totally independent and are the most significant predictors of FFS and OS. The 68 PTCLs include 45 PTCLs unspecified, 10 Ki-1 anaplastic (ALCL), 8 angioimmunoblastic, and 5 angiocentric lymphomas. Angiocentrics were usually refractory (1 of 5 remissions only). ALCL rarely relapsed late. We conclude that the immunophenotypic basis of the REAL classification is clinically relevant and that, although other prognostic features also influence outcome, the T-cell phenotype still remains an independent and significant prognostic factor.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1997

Immunophenotyping investigation of minimal residual disease is a useful approach for predicting relapse in acute myeloid leukemia patients.

A high complete remission rate is currently achieved in patients with acute myeloid leukemia (AML). However, many patients eventually relapse due to the persistence of low numbers of residual leukemic cells that are undetectable by conventional cytomorphologic criteria (minimal residual disease [MRD]). Using immunophenotypic multiparametric flow cytometry, we have investigated in sequential studies (diagnosis and follow-up) the impact of MRD detection on the outcome of 53 AML patients that had achieved morphologic remission with standard AML protocols and displayed at diagnosis an aberrant phenotype. Patients were studied at diagnosis with a panel of 35 monoclonal antibodies in triple staining combinations for detection of aberrant or uncommon phenotypic features. According to these features, a patient's probe was custom-built at diagnosis for the identification of possible residual leukemic cells during follow-up. The level of MRD at the end of induction and intensification therapy correlated with the number of relapses and relapse-free survival (RFS). Thus, patients with more than 5 x 10(-3) residual cells (5 residual cells among 1,000 normal bone marrow [BM] cells) identified as leukemic by immunophenotyping in the first remission BM showed a significant higher rate of relapse (67% v 20% for patients with less than 5 x 10(-3) residual cells; P = .002) and a lower median RFS (17 months v not reached; P = .01). At the end of intensification, with a cut-off value of 2 x 10(-3) leukemic cells, AML patients also separated into two distinct groups with relapse rates of 69% versus 32% (P = .02), respectively, and median RFS of 16 months versus not reached (P = .04). In addition, overall survival was also significantly related to the level of residual cells in the marrow obtained at the end of induction and particularly after intensification therapy (P = .008). Furthermore, we have explored whether residual disease was related with the functional expression of multidrug resistance (MDR-1) at diagnosis as assessed by the rhodamine123 assay. Patients with > or =5 x 10(-3) residual leukemic cells at the end of induction therapy had a significantly higher rhodamine-123 efflux (mean, 56% +/- 24%) than those with less than 5 x 10(-3) residual cells (mean, 32% +/- 31%; P = .04). Finally, multivariate analysis showed that the number of residual cells at the end of induction or intensification therapy was the most important prognostic factor for prediction of RFS. Overall, our results show that immunophenotypical investigation of MRD strongly predicts outcome in patients with AML and that the number of residual leukemic cells correlates with multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Five-color immunophenotyping plus DNA content analysis by laser scanning cytometry.

Laser scanning cytometry is a new laboratory technology similar to flow cytometry but with advantages for certain clinical and research applications. To date, laser scanning cytometry has been successfully used to perform three-color immunophenotypic analysis of hematologic specimens, single-color immunophenotyping plus DNA content analysis of numerous specimen types, and automated analysis of fluorescence in situ hybridization specimens. Several other interesting applications are also in development. In general, advantages of laser scanning cytometry include reduced specimen size requirements, simplified methodologies, and the ability to microscopically examine individual cells-allowing for the direct correlation of cytologic morphology with objective fluorescence measurements. In this report, we describe a method which more fully takes advantage of the laser scanning cytometer's capabilities for immunophenotypic analysis of hematologic specimens. Specifically, we have devised a method to increase the number of fluorescent parameters from three to a total of six, five representing binding of immunofluorescent antibodies and one for stoichiometric measurements of DNA content. As with most laser scanning cytometric applications, this technique can be utilized on extremely small specimens and enables direct correlation of all of the measured fluorescent parameters with light microscopic cytologic morphology.

DNA↗

PubMed1998

Flow cytometric characterization of human umbilical cord blood lymphocytes: immunophenotypic features.

BACKGROUND AND OBJECTIVE: One of the most important potential advantages in the use of human umbilical cord blood (HUCB) for hematopoietic reconstitution after myeloablative therapy seems to be the lower occurrence of acute graft-versus-host-disease (GvHD) in recipients after allogeneic transplantation. Since mature T cells play an important role in GvHD pathogenesis, we tried to verify whether a different immunophenotypic pattern exists between HUCB and peripheral blood (PB) T cells. DESIGN AND METHODS: An immunophenotypic study on 40 HUCB and 40 PB samples from healthy adult volunteers was performed, by means of flow cytometry using a large panel of monoclonal antibodies in double labeling. RESULTS: The absolute lymphocyte count was greater in HUCB (5233 +/- 1808 microL) than in adult PB (1941 +/- 378 microL). Significant differences in percentage were found between cord and adult T-cells, respectively (CD3+: 59.9 +/- 12 vs 74.9 +/- 4.6%), CD3- CD16+ and/or CD56+ natural killer (NK) cells (23.8 +/- 10.1 vs 10.8 +/- 5.3%) and CD3+CD16+ and/or CD56+ cytotoxic T lymphocyte subset (0.3 +/- 0.3 vs 10.7 +/- 4.1%). There was no difference in CD4/CD8 ratio (1.7 +/- 0.5 vs 1.6 +/- 0.2%) between the two groups. In absolute terms, HUCB contained an higher number of all lymphocyte subsets, with the exception of CD3+CD16+ and/or CD56+ T lymphocyte subpopulation, CD3+CD25+ and CD3+HLADR+ activated T-cells. CD38, a marker of activation and immaturity, was present on virtually all cord T cells and on approximately half of the adult T cells. The large majority of HUCB T cells co-expressed CD45RA naive antigen (CD4+CD45RA+: 87.6 +/- 5.2%, CD8+ CD45RA+: 93.5 +/- 7.8%; CD4+CD45RO+: 12.3 +/- 5.2%; CD8+CD45RO+: 6.4 +/- 7.8%) whereas in adult PB T cells an higher number of CD45RO+ memory cells was detected (CD4+CD45RA+: 44.8 +/- 9.6%; CD8+CD45RA: 71.5% +/- 8.1%; CD4+CD45RO+: 55.2 +/- 9.6%; CD8+ CD45RO+: 28.5 +/- 8.1%). Finally, less than 14% of lymphocytes were shown to belong to B lineage in both sources, while, in absolute terms, they were more represented in HUCB with respect to adult PB. INTERPRETATION AND CONCLUSIONS: In the present study we found significant difference between HUCB and adult PB lymphocytes in their immunophenotypic profile. In particular HUCB showed T lymphocytes that appeared to be phenotypically immature. Indeed, as a likely consequence of poor antigenic experience during pregnancy, the majority of HUCB cells were naive, expressing the RA isoform of the CD45 molecule. These findings could justify the previously reported reduced cord blood lymphocyte alloreactivity when allogeneic transplantation is performed and require further functional studies in order to confirm the impairment of HUCB immune system response to alloantigens.

Adult↗

PubMed1997

The relationship between argyrophilic proteins and some immunophenotypic markers in acute leukemia cells.

This study reports the immunophenotypic features of a series of 62 selected acute leukemia patients with increased incidence of argyrophilic proteins (AgNORs) at the time of initial diagnosis. Peripheral blood and bone marrow cells of patients with T-ALL, B-precursor ALL and AML were studied. The method of silver staining was used to determine the number of AgNORs per cell. Cell surface markers were detected by a standard immunofluorescence assay. To demonstrate the relationship between AgNOR quantity and cell proliferation, the expression of activation and proliferation antigens CD38 and CD71 was investigated. To characterize the immunophenotype and the discrete stages of differentiation, the wide panel of antibodies against lymphoid, myeloid and non-lineage specific antigens was used. The number of AgNORs at diagnosis ranged from 3.05 to 6.70. Immunophenotypic analysis showed a variation in CD38 and CD71 expression among different leukemia subtypes. CD71 antigen was more expressed in T-ALL than in B-precursor ALL or in AML. Notable was the relationship between increased AgNOR quantity and antigens that characterize the immaturity of leukemic cells. The association with CD7, CD2, CD5 (without CD3 membrane expression) and CD34 in T blasts was evident. High positivity of CD19, CD10, CD34 and HLA-DR in relation to the increased amount of AgNORs in B-lineage ALL was observed. The vast majority of AML patients with high numbers of AgNORs simultaneously expressed CD13, CD33, CD34 and HLA-DR. One third of AML cases coexpressed T cell marker CD7. In conclusion, the presence of increased numbers of AgNORs at diagnosis might reflect the dependence on an early stage of leukemia cell differentiation.

Acute Disease↗

PubMed1998

Light scatter and immunophenotypic characteristics of blast cells in typical acute promyelocytic leukemia and its variant.

Acute promyelocytic leukemia (APL), defined by the French-American-British (FAB) classification as the M3 subtype of acute myeloblastic leukemia (AML), is readily diagnosed by direct cytomorphologic examination. The potential difficulty in recognizing the microgranular variant of APL (M3v) stems from the morphological characteristics of APL leukemic cells, which resemble monocytes. From 109 newly diagnosed acute leukemic patients, 48 were classified as AML and 16 of these patients (33%) had APL Mononuclear cells (MNC) of all APL patients were analyzed by flow cytometry for immunophenotypic features and forward and right angle scatter (FW-SC/RT-SC) light characteristics. Two clearly different FW-SC/RT-SC distribution patterns were recognized and defined as hypergranular (mature cells) and hypogranular (immature cells). Correlation between FW-SC/RT-SC patterns and the FAB system was poor: from eight patients classified as M3, six had the hypergranular pattern and two had the hypogranular pattern; from eight cases with M3, five and three patients had hypogranular and hypergranular patterns, respectively. The most relevant cellular immunophenotypic feature was the high frequency of CD34+ cases (5/7) recorded exclusively in patients with the hypogranular pattern. An interesting finding was that MNCs of all APL patients changed color from beige to green in the course of 3-4 h, whereas none of the 93 specimens of non-M3 acute leukemia cases showed this phenomenon. Summarizing, the FW-SC/RT-SC characteristics of APL blast cells along with the immunophenotype may represent an objective and reproducible measurement system to distinguish microgranular (M3v) from typical (M3) APL In addition, the present study has identified another unique feature of APL based on the green color of their blast cells imparted by the high content in myeloperoxidase.

Adolescent↗

PubMed1998

Immunophenotypic characteristics of T-acute lymphoblastic leukemia cells in relation to DPP IV enzyme expression.

In the present study we have examined immunophenotypic characteristics ofT-acute lymphoblastic leukemia (T-ALL) cells in relation to the expression of enzyme dipeptidyl peptidase IV (DPP IV). Peripheral blood and bone marrow cells of T-ALL patients at diagnosis were estimated. Cell surface markers were detected by a standard immunofluorescence assay and FACStar flow cytometry using a broad panel of monoclonal antibodies to define T-cell immunophenotype. DPP IV activity was investigated in phenotypically defined T-lymphoblasts. Association between DPP IV expression and proliferation was monitored by the expression of CD71 and CD38, which could be considered as markers of activation and proliferation, and by the silver-staining of nucleolar organizer regions-related proteins (argyrophilic proteins). Lymphoblasts, divided according to the presence or absence of DPP IV activity revealed remarkable heterogeneity in the immunophenotypic features. The vast majority of DPP IV positive T-ALL cases expressed CD4, CD8, CD7, CD5, CD2 along with CD71 and CD38 antigens, but the cells were surface membrane CD3 antigen negative. The phenotype of DPP IV negative cases displayed membrane CD3 antigen and variable expression of CD4 and CD8. CD71 and CD38 were frequently negative. It appears, that DPP IV active cells form the population with immature phenotype, as evidenced by mCD3 antigen absence. Relation between DPP IV positive cells and proliferation activity of T-blasts was observed, given by the presence of CD71 and CD38 positivity and overexpression of argyrophilic proteins (AgNORs). In conclusion, our study indicates a close relationship between DPP IV activity and the features ofT-cell immaturity. Association among DPP IV, CD71, CD38 and AgNORs might reflect possible relationship between immature phenotype and proliferative ability of blast cells in T-ALL patients.

ADP-ribosyl Cyclase↗