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PubMed2006

Phylogeographic structuring of Plasmodium lineages across the North American range of the house finch (Carpodacus Mexicanus).

The determinants of the geographic distribution of avian hematozoa are poorly understood. Sampling parasites from one avian host species across a wide geographic range is an accepted approach to separate the potential influence of host species distribution from geographic effects not directly related to host species biology. We used polymerase chain reaction to screen samples for hematozoan infection from 490 house finches (Carpodacus mexicanus) collected at 8 sites spanning continental North America. To explore geographic patterns of parasite lineage distributions, we sequenced a portion of the mitochondrial cytochrome b gene of Plasmodium species infecting 77 house finches. We identified 5 distinct Plasmodium haplotypes representing 3 lineages that likely represent 3 species. One lineage was common at all sites where we detected Plasmodium species. The second lineage contained 3 haplotypes that showed phylogeographic structuring on a continent-wide scale, with 1 haplotype common in eastern North America and 2 common in western North America. The third divergent lineage was recovered from 1 individual host. Considered together, the partial phylogeographic structuring of Plasmodium cytochrome b lineages over the range of the house finch suggests that parasite lineage distribution is not solely dependent on host species distribution, and other factors such as arthropod vector competence and distribution may be important.

Animals↗

PubMed2003

Biphenotypic acute leukemia with coexpression of CD79a and markers of myeloid lineage.

Acute leukemias demonstrating immunophenotypic features of more than 1 cell lineage are referred to as acute leukemias of ambiguous lineage in the new World Health Organization classification system. A subtype of leukemia of ambiguous lineage is biphenotypic acute leukemia in which the malignant cell population expresses markers of 2 different lineages, most commonly myeloid and either B- or T-lymphoid lineages. This entity has been defined by a scoring system proposed by the European Group for the Immunological Characterization of Acute Leukemias (EGIL), with various markers assigned a score of 2, 1, or 0.5 depending on their specificity for myeloid or lymphoid lineage. Those cases having a score greater than 2 for the myeloid and either the B- or T-lymphoid lineages are biphenotypic acute leukemia in this system. One marker, CD79a, has been so clearly associated with acute lymphoblastic leukemia (ALL) by some researchers that its expression in the presence of blast markers is considered indicative of B-ALL. We describe an unusual case of acute leukemia meeting the criteria for biphenotypic acute leukemia in which CD79a expression was observed in the blast population.

Aged↗

PubMed2000

Hemopoietic lineage commitment decisions: in vivo evidence from a transgenic mouse model harboring micro LCR-betapro-LacZ as a transgene.

A substantial body of published data suggests activation of lineage-specific genes in multipotential hemopoietic cells before their unilineage commitment. Because the behavior and plasticity of cells isolated in vitro away from microenvironmental constraints exercised in vivo may be altered, one wonders whether similar findings can be observed in a physiologic setting in vivo. We used a transgenic mouse model harboring human micro LCR together with beta promoter sequences as a transgene to examine activation of lineage-specific programs in vivo. By using LacZ as a reporter, we had the ability to detect, quantitate, and select live cells with different levels of LacZ activation. We found strong expression of LacZ by X-gal staining in 2 lineages-erythroid and megakaryocytic. Activation in the latter was a novel finding not previously observed when similar transgenes were used. We also found activation of muLCR-betapro at low levels in progenitor cells of granulocytic-macrophagic, erythroid, or megakaryocytic lineage detected by in vitro assays, suggesting activation before commitment to a specific lineage pathway. In particular, the expression of LacZ was graded among progenitors, so that in a proportion of them activation occurred only after commitment to erythroid or megakaryocytic lineage. In addition, we found quantitative reduction in LacZ expression between fetal liver and bone marrow-derived cells, the basis of which is unclear. Collectively our data provide in vivo evidence supporting the view that lineage-specific genes are expressed in a graded fashion in pluripotential cells before their irreversible unilineage commitment. (Blood. 2000;95:1274-1282)

Animals↗

PubMed1992

[Phenotypic and genotypic analysis of acute leukemia--current status of lineage specific classification].

More detailed identification and understanding of the heterogeneity of leukemias using a broad panel of markers seems to be essential for the successful design of more sophisticated and effective treatments. Based on the FAB system, immunological phenotypes using a panel of monoclonal antibodies, and rearrangements of immunoglobulin and T-cell receptor genes, acute leukemia can be divided into six subtypes such as B-lineage, T-lineage, AML, NK-lineage, AUL and mixed lineage leukemia. The definition of B-lineage and T-lineage cells, a new classification for mixed lineage leukemia, incidence of dual rearrangements and their clinical significance are discussed.

Acute Disease↗

PubMed1992

Autologous bone marrow transplantation in high-risk remission B-lineage acute lymphoblastic leukemia using a cocktail of three monoclonal antibodies (BA-1/CD24, BA-2/CD9, and BA-3/CD10) plus complement and 4-hydroperoxycyclophosphamide for ex vivo bone marrow purging.

Fourteen patients with high-risk B-lineage acute lymphoblastic leukemia (ALL) in complete remission underwent autologous bone marrow transplantation (BMT) using a combined immunochemopurging protocol. A monoclonal antibody (MoAb) cocktail of BA-1, BA-2, and BA-3 plus rabbit complement (C') plus 4-hydroperoxycyclophosphamide (4-HC) was used to eliminate residual occult leukemia cells from autografts. All patients were conditioned with single-dose total body irradiation (TBI) followed by high-dose Ara-C. All 14 patients engrafted at a median of 24 days (range, 12 to 36 days). Three patients are alive and disease free at 3.5 years, 3.9 years, and 4.1 years post-BMT. The Kaplan-Meiser estimate and standard error of the probability of sustained remission was 23% +/- 12% at 3.5 years post-BMT with a mean relapse-free interval of 1.4 +/- 0.4 years. The disease-free survival (DFS) at 3.5 years was 21% +/- 11%, with a mean DFS time of 1.3 +/- 0.4 years. A novel and quantitative minimal residual disease (MRD) detection assay, which combines fluorescence-activated multiparameter flow cytometry and cell sorting with leukemic progenitor cell (LPC) colony assays, was used to analyze remission BM samples from B-lineage ALL patients for residual LPC, and to evaluate the efficacy of ex vivo BM purging. Notably, the minimal residual leukemia burden before BMT, as measured by the percentage of B-lineage LPC in the pre-BMT remission BM samples, indicated the outcome of the BMT. The median value for the minimal residual leukemia burden before BMT was 0.0035% (35 LPC/10(6) mononuclear cells). The Kaplan-Meier estimates and standard errors of the probability of remaining in remission after BMT were 43% +/- 19% for patients whose BM samples contained less than or equal to 0.0035% LPC and 0% +/- 0% for patients whose BM samples contained greater than 0.0035% B-lineage LPC (P less than .05). In contrast to the minimal residual leukemia burden measured by the described MRD assay system, the percentage of blasts or TdT+ cells in the remission BM samples did not correlate with the probability of relapse. The applied purging protocol showed variable success in destroying target B-lineage LPC populations contaminating the autografts. While in some cases purging was highly effective, eliminating up to greater than or equal to 4 logs of residual B-lineage LPC, in other cases only 0.1 to 0.2 logs of B-lineage LPC were purged.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed2005

[Sensitivity and specificity analysis of the lineage related antibodies in acute leukemia immunophenotyping by flow cytometry].

To evaluate the sensitivity and specificity analysis of the lineage related antibodies in acute leukemia immunophenotyping by flow cytometry (FCM), immunophenotyping in 184 patients with acute leukemia was performed by FCM analysis. The results showed that in the lineage-related antibodies of acute myelocytic leukemia (AML), the sensitivity of CD13 and CD33 was higher (95.5% and 91.2%, respectively), the specificity of them was deficient (72.5% and 62.2%, respectively); the sensitivity of MPO was low (69.1%), but the specificity was high (100%); the sensitivity and specificity of CD117 were high (88.2% and 100%, respectively); the sensitivity of CD14 and CD15 was low (18.4% and 27.2%, respectively); the specificity of CD14 with monocytes was high. As the lineage-related antibodies of B-lineage ALL were concerned, CD19 showed high sensitivity and low specificity (100% vs 83.4%); the sensitivity and specificity of CD79a (96.4% vs 100%) and CD22 (100% vs 100%) were high; the sensitivity and specificity of CD10 (53.6% vs 82.5%) and CD20 (70.4% vs 87.5%) were low. In T-lineage ALL, the specificity of CD3 was high (97.5%), but the sensitivity was below the mark (80.0%); the sensitivity of CD7 was high (100%), but the specificity was low (77.9%); while the sensitivity and specificity of CD5, CD2 and CD1a were all deficient. In conclusion, the sensitivity and specificity analysis of the lineage-related antibodies in acute leukemia immunophenotyping are coincident with St Jude immunophenotyping project. It seems only that CD117 is superior to MPO in defining AML, but the sensitivity and specificity analysis of CD22 and CD79 are similar in defining B-lineage ALL, therefore, anyone of them may be selected as your need.

Acute Disease↗

PubMed1991

The regulation of transmitter expression in postembryonic lineages in the moth Manduca sexta. I. Transmitter identification and developmental acquisition of expression.

The majority of the neurons in the adult nervous system of Manduca sexta are born postembryonically, during larval life. Stereotypic arrays of identifiable neuroblasts generate their clonal families or lineages commencing at the end of the second larval instar through pupal day 2, when the neuroblasts die (Booker and Truman, 1987a). We have used immunohistochemical techniques to follow the neurochemical differentiation of GABA and a peptide similar to molluscan small cardioactive peptide B (SCPB) in identified lineages. We report here the distribution and developmental acquisition of the expression of these putative transmitters. There are 24 postembryonic lineages in the second thoracic ganglion of the larvae (Booker and Truman, 1987a). Immunoreactivity against GABA and SCPB is seen only in a subset of these 24 clonal families. GABA immunoreactivity is confined to the progeny of the E, K, M, N, T, and X neuroblasts and is expressed by most or all of the neurons in these lineages. The SCPB-like immunoreactivity is found in a subset of the neurons in only two clonal groups, the K and M groups, and is colocalized with GABA. These results show that, though heterogeneity in transmitter type exists (GABA, GABA/SCPB), members of a given lineage share at least some features (GABA) in common. The onset of transmitter expression was followed in detail for the K- and M-lineage neurons. During the larval stages, the postembryonic lineage cells are developmentally arrested in a partially differentiated state (Booker and Truman, 1987a) and do not express transmitter immunoreactivity at this time. Their maturation resumes with the onset of metamorphosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Significance of lineage specific differentiation markers for complex classification of acute leukemias. II. Acute lymphoblastic leukemias.

Acute lymphoblastic leukemias originate from cells committed either to the T-lineage (T-ALL) or B-lineage (nonT-ALL). Leukemic cells are allocated to these lineages according to the expression of lineage specific differentiation markers (LSDM), which are T-cell antigen receptors for the T-cell lineage and immunoglobulins for the B-cell lineage. T-ALL seem to be one type of disease, among nonT-ALL it is possible to distinguish several types of diseases according to the immunoglobulin expression and clinical findings. The specificity of monoclonal antibodies and other markers is discussed with regard to the classification of ALL and "hybrid acute leukemias" (hAL), the latter with cells differentiating into myeloid and lymphoid lineages. The existence of a single hAL has not yet been reliably proved with the use of LSDM. Short-term cultures of leukemic cells represent useful diagnostic tools particularly for acute unclassifiable leukemias. Present knowledge of karyotype findings in acute leukemias classified according to LSDM is reviewed and the necessity to introduce a complex classification on this basis stressed.

Cell Differentiation↗

PubMed1990

Mixed-lineage leukemia and asynchronous antigen expression.

Considerable confusion exists regarding the definition of acute mixed-lineage leukemia. We have proposed a list of strict criteria, limiting the term acute mixed-lineage leukemia to those patients whose blast cells co-express lymphoid and myeloid characteristics. This system includes cytochemical, immunologic, molecular, and cytogenetic characteristics that are strongly associated with either lymphoid or myeloid lineages. As more information becomes available, the criteria for mixed-lineage leukemia will undoubtedly change. Identification of patients with mixed-lineage leukemia and metachronous leukemia (lineage switch) is important for determining the prognostic implications of these findings. Care must be taken in identifying cases of metachronous leukemia because of the increased incidence of second malignancies following aggressive therapy. Evidence of a recurrence of the original clone must be obtained before metachronous leukemia can be diagnosed. As with mixed-lineage and metachronous leukemias, the potential clinical and prognostic implications of lymphoid leukemias with antigenic asynchrony should be identified. The asynchronous antigen expression in leukemic lymphoblasts may provide a means for detecting minimal residual disease. Detection of minimal residual leukemia is possible because these blasts differ from the predominant population of normal lymphoid cells in their expression of cell surface markers. Study of the mechanisms that lead to these unusual leukemias may result in better understanding of the processes that underlie both normal hematopoietic differentiation and leukemogenesis. An understanding of these leukemias may also permit identification of cases that are destined to fail current therapies so that more intensive or selective therapy can be instituted for such children. Curing the 30% of children with ALL that relapse despite our best efforts should be one of the top priorities for pediatric oncologists.

Antigens, Neoplasm↗

PubMed1990

Primary treatment of childhood acute lymphoblastic leukemia of non-T cell lineage (including infants).

About 85% of children with ALL have leukemic blasts that express cell membrane antigens associated with B-cell lineage, although few are surface immunoglobulin positive. Patients differ from children with ALL of T-cell lineage in that they tend to be younger, less predominantly male, and less likely to have a mediastinal mass or CNS leukemia at diagnosis, and they have a lower leukocyte count. Leukemic blasts from these children are more likely to be hyperdiploid. However, B cell-lineage ALL is not homogeneous either. It includes infants, children, and adolescents; it includes patients with leukemic blasts that either express or fail to express CD10, CD24, and cytoplasmic immunoglobulin. B cell-lineage ALL includes patients with blasts showing hyperdiploidy and patients with blasts with translocations such as t(4;11), t(1;19), and t(9;22). In general, outcome for patients with B cell-lineage ALL is superior to the outcome of those with T cell-lineage ALL in univariate analysis. However, when comparisons are stratified by age and leukocyte count, any apparent prognostic advantage for children with B cell-lineage ALL is diminished. The addition of effective CNS prophylaxis to effective systemic chemotherapy made cure a reality for about one half of children with ALL. Subsequent work has made it possible to omit cranial irradiation and its sequelae for most children with ALL. At least three regimens have offered an unambiguous improvement over the original St. Jude prophylactic CNS therapy regimen. These regimens are the BFM 76/79 regimen, the New York regimen, and the Dana-Farber regimen. Cure appears possible for 70% of children. These regimens differ markedly in detail, but appear to benefit similar subsets of patients. Identification of their critical therapeutic elements is one challenge for the future. A second challenge is the early identification of patients likely to do poorly on these effective regimens, whether by age under 1 year, specific blast morphology, cytochemical findings, immunophenotype, cytogenetic findings, drug pharmacokinetic features, or early response to antileukemic therapy. The third challenge is continued awareness of the acute morbidity of therapy and its impact on the lives of children and their families, together with a heightened vigilance for likely long-term sequelae. Most children with lymphoblastic leukemia in the United States are referred to cancer treatment centers for the initiation of therapy. Over one half of the children who are diagnosed participate in formal clinical trials.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

PubMed1986

Differentiation of K562 leukemia cells along erythroid, macrophage, and megakaryocyte lineages.

K562 is a human leukemic cell line used as model of hematopoietic differentiation. A variety of differentiation-inducing agents was used in this study, and the expression of surface membrane antigens associated with specific lineages of differentiation and changes in the cytochemistry of the induced cells were monitored. Sodium butyrate, hemin, retinoic acid, dimethyl sulfoxide (DMSO), phorbol myristate acetate (PMA), and interferon induced unique alterations in the binding of monoclonal antibodies specific for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Hemoglobinization, Sudan Black B, glycogen content, nonspecific esterase, alkaline phosphatase, and 5'-nucleotidase staining were also altered. K562 cells were terminally differentiated with PMA to nitroblue tetrazolium-(NBT) positive macrophages. Expression of 3-fucosyl-N-acetyl lactosamine, previously thought to be myeloid specific but found on all early hematopoietic progenitors, was modulated during differentiation to nonmyeloid lineages. Lineage infidelity was noted during functional differentiation along all hematopoietic lineages. The presence of multiple lineage surface markers and cytoplasmic characteristics in leukemic cells is not indicative of lack of potential to differentiate. K562 cells cannot be compared to any normal stage of hematopoietic differentiation, but they do have the capacity to differentiate along erythroid, macrophage, and megakaryocytic lineages.

Antibodies, Monoclonal↗

PubMed1987

T-cell receptor gamma chain gene rearrangement in acute myelogenous leukemia--evidence for lymphoid lineage prematurity.

The T-cell receptor gamma chain (TcR gamma) gene is rearranged in early T-cell differentiation. However, rearrangement of the TcR gamma gene is not specific for T lineage since it has also been noted in B-cell neoplasia. TcR beta gene rearrangement and heavy chain immunoglobulin gene rearrangement have also been reported in acute myelogenous leukemia (AML). Because of the previous reports of lineage heterogeneity at the molecular level, we analyzed seven patients who met the standard criteria for AML by Southern blot hybridization with a TcR gamma gene probe, a TcR beta gene probe, and an immunoglobulin heavy chain JH gene probe. In two samples, the TcR gamma gene was rearranged. One of these two samples also had rearrangement of the immunoglobulin JH gene. None of the seven samples showed TcR beta gene rearrangement. The two samples with TcR gamma gene rearrangement also showed 25% and 80% of terminal deoxynucleotidyl transferase (TdT) positivity, respectively. Both samples expressed myeloid lineage-associated antigens without any lymphoid lineage-associated antigens. Our studies indicate that TcR gamma gene rearrangement is not specific for lymphoid lineage and the presence of TcR gamma and immunoglobulin JH gene rearrangements without expression of lymphoid lineage-associated markers supports the concept that there is lymphoid lineage prematurity in AML.

Gene Rearrangement, gamma-Chain T-Cell Antigen Rec↗

PubMed1984

Lineage switch in acute leukemia.

Conversions of leukemic cell lineage (lymphoid or myeloid) have been reported only rarely. Our review of the cytochemical and immunophenotypic features of 89 cases of childhood leukemia in marrow relapse indicated lineage switch (lymphoid to myeloid or the reverse) in six patients (6.7%). Five patients with acute lymphoblastic leukemia (ALL) at diagnosis had converted to acute nonlymphoblastic leukemia (ANLL), and one had converted from ANLL to ALL. Each child received lineage-specific multiagent chemotherapy when initially diagnosed, and all achieved a complete remission. After conversion, four patients readily achieved second remissions with treatment for the phenotype evident at lineage switch. Two patients with ANLL at conversion failed ALL-directed reinduction, while one of the two responded to high-dose cytarabine but died during bone marrow hypoplasia, emphasizing the importance of prompt recognition of lineage switch and selection of an appropriate plan of retreatment. Cytogenetic studies disclosed evidence of clonal selection in one patient and clonal stability in two. These findings indicate an unexpectedly high frequency of lineage switch in patients who relapse in the bone marrow after intensive chemotherapy. Although specific causative factors could not be identified, our observations suggest at least two general mechanisms for lineage switch in acute leukemia. In one, chemotherapy appears to eradicate the dominant clone present at diagnosis, permitting expansion of a secondary clone with a different phenotype. In the second, drug-induced changes in the original clone may either amplify or suppress differentiation programs so that phenotypic shift is possible.

Acute Disease↗

PubMed1983

Quantal and proliferative cell cycles: how lineages generate cell diversity and maintain fidelity.

There are no known differences between the mechanisms that generate diverse differentiation programs in a mosaic embryo such as Caenorhabdites elegans or in a regulative embryo such as a chick. Transit through an invariant sequence of compartments in a lineage is obligatory for a given precursor cell 1) to inherit its differentiation program from its mother, and 2) to transmit to its daughters, by way of a predetermined binary decision, a new differentiation program. The inheritability of a differentiation program must be encoded in a structural molecule. We postulate that during an S period of a quantal cell cycle, chromosomal structures are so altered that a network of genes that could not be transcribed in the mother becomes available for transcription in the daughters. We do not view as a likely possibility the traditional notion that cell-cell or cell-matrix interactions instruct or commit blank, naive cells to transform into cells with unique differentiation programs. From this perspective, we have initiated experiments to determine the minimal rounds of DNA synthesis, following fertilization, that are required to generate founder cells for several major lineages in the chick. Somewhere between the 15th and 18th generations after fertilization erythrogenic hematocytoblasts that are cytokeratin-positive and vimentin- and hemoglobin-negative undergo a quantal cell cycle. Their daughters are cytokeratin-negative and vimentin- and hemoglobin-positive. DNA synthesis, but not cytokinesis, is an obligatory requirement for this switch in differentiation programs. Essentially similar findings are presented for cells in the cardiogenic, neurogenic, melanogenic, and endothelial lineages. There is no evidence that cell-cell or cell-matrix interactions are required for this diversification. Such interactions, however, may be required for the large number of proliferative cell cycles within particular compartments of particular lineages that are characteristic of all growing or expanding systems. With respect to classical "CFU cells" it is of interest that definitive white blood cells have not yet been identified in these cultures. Lastly, the high ratio of primitive red blood cells to non-red blood cells in the first 40 hours of culture is consistent with the notion that the majority of all cells present in the blastodisc at these early stages are in fact already committed to a unipotent erythrogenic lineage [5, 18, 23, 44, 45]. The issue of changing ratios of cells within compartments of a lineage, as well as of cells in different lineages, is much neglected in consideration of (a) normal embryogenesis, (b) cell-renewal in mature organisms and, particularly,

Animals↗

PubMed1994

Polynesian mitochondrial DNAs reveal three deep maternal lineage clusters.

The 4000-year-old human population expansion into Remote Oceania has been studied from a variety of genetic perspectives. Here, we report the discovery that Polynesians, traditionally considered to be a single cohesive linguistic and cultural unit, exhibit at least three distinct mitochondrial DNA (mtDNA) groups that probably shared a common maternal ancestor more than 85,000 years ago. The major lineage groups were first identified by PCR amplification of the mitochondrial region V deletion marker, known to be present at high frequency in Polynesian populations. Sequence analysis of mtDNA hypervariable control regions reveals a surprising number of lineages in Polynesia. We also note high sequence divergence between lineage groups deleted and not deleted in region V. Major group I lineages are common in Remote Oceania and include about 95% of the Native Hawaiian, 90% of the Samoan, and 100% of the Tongan donors in our sample. They contain the region V deletion and generally share three control region transition substitutions. This group also contains non-Polynesian individuals, such as Indonesians, Native Americans, Micronesians, Malaysians, Japanese, and Chinese. The group I Polynesians differ by 4.4% in sequence identity from major lineage group II Polynesians, who do not have the region V deletion and who share among themselves four distinct single-base substitutions. Group II individuals are seen at low frequency (< 10%) in Hawaii, Samoa, and the Cook Islands and may represent the predominant maternal lineage group of Papuan Melanesia. Major lineage group III, not found in Hawaii, tentatively links Samoa to Indonesia. Our observation of deep maternal genetic branches in Polynesia today confirms the notion that during the colonization of the Pacific, mainland Asian immigrants mixed with Melanesian peoples already inhabiting Near Oceania and carried a complex assortment of maternal genotypes derived from two distinct geographic sources to isolated island archipelagoes.

Base Sequence↗

PubMed1993

Studies on relationships between metastatic and non-metastatic tumor cell populations using lineages labeled with dominant selectable genetic markers.

The relationships between metastatic and non-metastatic cell populations co-existing in composite neoplasms have been studied using cell lineages marked with a dominant selectable marker (neomycin resistance), by transfection. The experimental circumstances were arranged so that the lineages were known to be genotypically distinct (i.e. not merely phenotypic variants of the same lineage) and so that a single metastatic clone was each time combined with a mixed polyclonal non-metastatic population and both partners were distinctly and recognizably marked. This made it possible to ascertain the fates of clones with different metastatic capabilities during tumor progression and metastasis and evaluate their relative contributions to the clinical extent of disease. It was found that metastatic and non-metastatic cell lineages co-existed in most of the late-stage primary tumors examined and that a cell lineage that is invariably non-metastatic, when growing on its own, can with surprising frequency be found thriving in distant metastatic deposits, when it grows to form a primary tumor in combination with a metastatic partner. In fact, occasional metastases from such tumors contained no detectable cells of the metastatic lineage. The endowment of a tumor cell lineage with a new, clinically significant, capability which it convincingly and reproducibly did not manifest before, by another coexisting cell population raises several new questions about the contribution of such phenomena to the overall debilitating properties of the neoplasm and the geometric progression of its impact on the host.

Animals↗

PubMed1996

CD2 antigen expression on leukemic cells as a predictor of event-free survival after chemotherapy for T-lineage acute lymphoblastic leukemia: a Children's Cancer Group study.

We examined the prognostic impact of CD2 antigen expression for 651 patients with T-lineage acute lymphoblastic leukemia (ALL), who were enrolled in front-line Childrens Cancer Group treatment studies between 1983 and 1994. There was a statistically significant correlation between the CD2 antigen positive leukemic cell content of bone marrow and probability of remaining in bone marrow remission, as well as overall event-free survival (EFS) (P = .0003 and P = .002, log-rank tests for linear trend). When compared with patients with the highest CD2 expression level (> 75% positivity), the life table relative event rate (RER) was 1.22 for patients with intermediate range CD2 expression level (30% to 75% positivity) and 1.81 for "CD2-negative" patients (< 30% positivity). At 6 years postdiagnosis, the EFS estimates for the three CD2 expression groups (low positivity to high positivity) were 52.8%, 65.5%, and 71.9%, respectively. CD2 expression remained a significant predictor of EFS after adjustment for the effects of other covariates by multivariate regression, with a RER of 1.47 for CD2-negative patients (P = .04). Analysis of T-lineage ALL patients shows a significant separation in EFS after adjustment for the National Cancer Institute (NCI) age and white blood cell (WBC) criteria for standard and high-risk ALL (P = .002, RER = 1.67). The determination of CD2 expression on leukemic cells helped identify patients with the better and poorer prognoses in both of these risk group subsets. For standard risk T-lineage ALL, CD2-negative patients had a worse outcome (P = .0007, RER = 2.92) with an estimated 5-year EFS of 55.9% as compared with 78.3% for the CD2-positive patients. Thus, CD2 negativity in standard risk T-lineage ALL identified a group of patients who had a worse outcome than high-risk T-lineage ALL patients who were CD2 positive. The percentage of CD2 antigen positive leukemic cells from T-lineage ALL patients is a powerful predictor of EFS after chemotherapy. This prognostic relationship is the first instance in which a biological marker in T-lineage ALL has been unequivocally linked to treatment outcome.

Adolescent↗

PubMed1998

Lineage-negative human leukocyte antigen-DR+ cells with the phenotype of undifferentiated dendritic cells in patients with carcinoma of the abdomen and pelvis.

The characteristics of antigen-presenting cells in carcinomas that involve the abdominopelvic cavity are unknown. Dendritic cells, a population of antigen-presenting cells, have been identified as lineage-negative human leukocyte antigen (HLA)-DR+ cells by two-color flow cytometry. We used this criterion to study the putative dendritic cells in ascites from 25 patients with peritoneal carcinomatosis. The mean proportion +/- SD of lineage-negative HLA-DR+ cells in ascites was 3.1 +/- 4.6% (range, 0.05-17.3%). Most lineage-negative HLA-DR+ cells expressed CD45RA or CD4 antigens. Dendritic cells had low proportions of CD80, CD11c, CD45RO, and CD58, suggesting that they were of low maturity. The proportion of lineage-negative HLA-DR+ cells in ascites of seven patients was significantly higher than the proportion in peripheral blood from the identical patients (4.5 +/- 5.7 versus 0.5 +/- 0.4; P < 0.05). In paired specimens of ascites and peripheral blood, the proportion of lineage-negative HLA-DR+ cells that coexpressed CD86 or CD58 was significantly lower in ascites than in peripheral blood, whereas a higher proportion of lineage-negative HLA-DR+ cells in ascites expressed CD4. Relative fluorescence intensity of HLA-DR+ was also lower in dendritic cells from ascites and blood from patients with carcinomatosis than it was in blood from normal donors. As an indicator of macrophage activation, the concentration of neopterin in ascitic fluid correlated negatively with the numbers of lineage-negative HLA-DR+ cells in ascites (Spearman correlation coefficient, -0.44; P = 0.05) correlated positively with the concentration of interleukin 10 in ascitic fluid (Spearman correlation coefficient, -0.40; P = 0.05). IFN-gamma and tumor necrosis factor alpha were also not detected. These findings suggest that certain factors associated with the tumor microenvironment might influence the number of these dendritic cells and their expression of function-associated markers.

Abdominal Neoplasms↗