PubMed HealthSearch

SEARCH · PubMed Health

Results for “Lymphoma, T-Cell, Peripheral”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The N6-methyladenosine reader IGF2BP2 in T-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) represents a highly heterogeneous and aggressive lymphoid neoplasm that lacks pathogenic biomarkers of RNA modification with therapeutic potential. IGF2BP2 is recognized as an N6-methyladenosine reader critically involved in oncogenesis. In this study, we observed consistently high expression of IGF2BP2 across common nodal PTCL subtypes in 3 independent external cohorts, which was further confirmed in our RNA-sequencing (RNA-seq) data set of 196 patients with newly diagnosed PTCL. Both in vitro and in vivo, IGF2BP2 promoted tumor cell growth and inhibited CD8+ T-cell infiltration within the tumor microenvironment. Mechanistically, IGF2BP2 bound to endosome-related genes (RAB4, VPS35, RAB9, and STAM) to maintain their stability, which resulted in enhanced endocytic activity and increased internalization of membrane proteins, and ultimately induced tumor cell proliferation and inhibition of CD8+ T-cell-mediated tumor cytotoxicity. The relationship between IGF2BP2 and endocytosis-associated genes was confirmed using RNA-seq data from patients with PTCL. IGF2BP2 as an upstream regulator of both tumor growth and immune suppression was further demonstrated in patient-derived xenograft models and a coculture system established using tumor samples from patients with PTCL and peripheral blood mononuclear cells. Notably, therapeutic targeting of IGF2BP2 with CWI1-2 suppressed endocytosis and impeded tumor growth in both cell lines and patient-derived xenograft models. Collectively, our findings highlight IGF2BP2 as a clinically relevant oncogenic driver in PTCL that integrates tumor-intrinsic growth signals with immune evasion through endocytosis-centered regulation, providing a novel therapeutic rationale for RNA modification-based strategies that concurrently target tumor cells and the tumor microenvironment.

Humans

Integrative pooled transcriptomic analysis reveals shared and distinct molecular signatures in adult T-cell leukemia/lymphoma and peripheral T-cell lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) and peripheral T-cell lymphomas (PTCLs) are aggressive neoplasms of mature T cells with poor prognosis and limited therapies. ATLL originates from HTLV-1 infection, while PTCL comprises heterogeneous subtypes without a defined etiologic factor. Comparative molecular profiling of these malignancies remains limited. We conducted an integrative pooled transcriptomic analysis of publicly available Gene Expression Omnibus (GEO) microarray datasets to compare ATLL, PTCL, and normal T-cell samples. Differential expression, functional enrichment, and protein-protein interaction (PPI) network analyses were performed using STRING, Cytoscape, and Gephi. Key hub genes and functional modules were further analyzed through KEGG and Enrichr databases. Comparative analyses revealed upregulation of extracellular matrix (ECM) components (COL1A1, COL3A1, FN1, SPARC, THBS1) and immune-regulatory molecules (CD163, CXCL12-CXCR4, complement subunits). Shared pathways included ECM-receptor interaction, focal adhesion, and PI3K-Akt signaling. PTCL showed enrichment in coagulation and angiogenesis, while ATLL displayed distinct enrichment of cytoskeletal, chemokine, immune-regulatory, and signaling-associated pathways. PPI networks identified ECM and chemokine signaling as key hubs, with subtype-specific modules related to immune regulation, proliferation, and metabolism. This integrative approach uncovers common and distinct oncogenic programs in ATLL and PTCL, emphasizing ECM remodeling and immune modulation as shared hallmarks. Hub genes such as COL1A1, FN1, and CXCL12-CXCR4 may represent candidate molecular signatures that warrant validation in independent patient cohorts and functional studies before their clinical utility can be established.

Humans

Herpesvirus saimiri-induced lymphoproliferative disease in howler monkeys.

Four of 5 howler monkeys (Alouatta caraya) experimentally infected with Herpesvirus saimiri (HVS) developed a rapidly fatal malignant lymphoma accompanied by peripheral T-cell lymphocytosis. HVS was isolated from fresh and tissue cultured blood and tissue lymphocytes and from cell cultures derived from nonlymphoid organs. Humoral antibodies against HVS-induced antigens were detected in the sera of the animals. The in vitro response of the peripheral blood lymphocytes to mitogenic stimulants was depressed following HVS infection.

Alouatta

A case of T-cell lymphoma with Sézary cells in the blood and bone marrow accompanied by peripheral T and B lymphocytosis.

A case of T-cell lymphoma occurred in a man, aged 66, whose symptoms started as itching and the appearance of 1-2 cm indurated plaques with central pustules on the skin of the trunk and face. A few months later generalized lymphomas and splenomegaly were present. Investigations of the lymphocytic subpopulations in situ in fresh frozen sections of lymphomas and skin showed only T cells. Samples of blood and bone marrow disclosed lymphocytosis and Sézary cells. Both T and B lymphocytes were definitely increased in the blood. The value of tissue studies in analyzing lymphocytic subpopulations is emphasized as a differential diagnostic aid in classifying lymphomas. A relationship between the T-cell neoplasia and the T and B lymphocytosis to mycosis fungoides and the Sézary syndrome is discussed.

Aged

[Malignant mediastinal lymphoblastic lymphoma with t-cell ALL (author's transl)].

29 cases of T-cell derived lymphoblastic lymphoma and T-ALL have been analyzed. There is a striking prevalence of the male sex. In the peripheral blood we often find initially an excessive number of white blood cells combined with normal values for the other constituents in about half of the patients; This may be an expression for the rapid occurrence of leukaemia in T-cell lymphosarcoma. In addition to systemic ALL-therapy we performed X-ray irradiation of the mediastinum in 8 of our patients. This yielded to significantly longer first complete remissions. All patients with T-cell LSA/ALL with or without mediastinal mass should be treated in this manner. Cytochemically a strong focal acid phosphatase reaction was found to be acharacteristic of these cells. It has proved to be a screening method for this disease. The cells are T-cell derived and their pattern of surface markers is similar to that found in fetal thymocytes.

Acid Phosphatase

B-lymphocytes and T-lymphocytes in three types of bovine lymphosarcoma.

Lymphoid cells of peripheral blood, lymph nodes, and thymus from clinically normal cattle, cattle infected with bovine leukemia virus (BLV), and cattle with lymphosarcoma were characterized for T- and B-cell surface markers. B-cells were detected by the erythrocyte-antibody-complement (EAC) rosette test and the surface immunoglobulin (sig) immunofluorescence assay. Peripheral blood from BLV-infected cattle had a higher than normal percentage of B-cells by both EAC rosette and sig immunofluorescence assays. Lymphoid cells from tumorous lymph nodes of cattle with the adult type of lymphosarcoma had a higher than normal percentage of sig-bearing cells, but in the same cell preparation the EAC rosette-positive cells were fewer than sig-positive cells. T-cells were detected by the erythrocyte rosette test. The percentage of T-cells by this test in lymph nodes of adult type lymphosarcoma was lower than that in normal cattle. A distinctly lower than normal percentage of lymphocytes could be characterized as either B- or T-cells in lymph nodes thymus, and peripheral blood from the calf type and thymic type of lymphosarcoma.

Animals

Morphologic and cytochemical comparison of human lymphoblastoid T-cell and B-cell lines: light and electron microscopy.

Human lymphoblastoid cell lines characterized as T- or B-cells by various markers were compared morphologically and cytochemically by light and electron microscopy. Distinct differences in nuclear morphology, amount of cytoplasm, pyroninophilia, and periodic acid-Schiff (PAS) staining enabled us to discriminate between T- and B-cell lines. T-cells had nuclei with an irregular configuration, stippled heterochromatin, and small or absent nucleoli. The scanty cytoplasm of T-cells contained intensely stained, PAS-positive globules and was less pyroninophilic than the cytoplasm of B-cells. B-cells had more rounded, uniform, vesicular nuclei with prominent nucleoli and peripheral heterochromatin. The cytoplasm of B-cells was abundant and strongly pyroninophilic. Transmission electron microscopy generally confirmed these morphologic differences. These findings supported our contention that consistent cytologic features concordant with immunologic markers make it possible to identify certain lymphomas as being of B- or T-cell origin on purely morphologic grounds.

B-Lymphocytes

Suppression and enhancement of mitogen response in chickens infected with Marek's disease virus and the herpesvirus of turkeys.

The kinetics of phytohemagglutinin (PHA) response of peripheral blood lymphocytes from chickens infected with oncogenic Marek's disease (MD) virus (MDV) or nononcogenic herpesvirus of turkeys (HVT) was studied with a whole blood microassay. At about 7 days after inoculation, a depression in PHA response was observed in MDV-inoculated resistant line N or susceptible line 7(2) chickens and in HVT-inoculated line 7(2) chickens. All chickens initially regained their PHA responsiveness. Susceptible chickens that died of MD or developed MD lymphoma in later stages of virus infection showed a second severe depression in PHA response. No depression was observed in HVT-vaccinated chickens when challenged with MDV. The PHA response of MDV-inoculated chickens that survived MD, HVT-inoculated chickens, and HVT-vaccinated MDV-challenged chickens showed evidence of enhancement. The depression of PHA response was studied and was attributed to the suppressive effect of macrophages on T-cell response, a finding consistent with our previous studies on MDV suppression of PHA response.

Animals

Lymphocyte mitogen reactivity and enumeration of circulating B- and T-cells during feline leukemia virus infection in the cat.

Mitogen-induced blast transformation of peripheral blood lymphocytes and quantitative changes in circulating T- and B-cells were studied serially in cats inoculated with feline leukemia virus (FeLV). Concanavalin A-induced blast transformation sharply declined beginning at 5 weeks post inoculation (Pl) in FeLV-infected cats when compared to age-matched uninfected control cats. Similar but less consistent changes were seen in responses to pokeweed mitogen-induced stimulation. In most infected kittens this defect persisted until they died from thymic lymphosarcoma, 15-24 weeks Pl. An early lymphopenia, due primarily to a decrease in circulating B-cells, occurred in infected cats 5-8 weeks Pl. Following a return of total and B-lymphocytes to control values, infected cats developed increased numbers of T-cells at 16 or more weeks Pl, which correlated with circulating lymphoblastic lymphocytes bearing T-cell markers. These results correlated neoplasia arising in a thymus-derived lymphocyte population with mitogenic hyporeactivity in the preneoplastic period and suggested that FeLV-induced immune alterations may be a necessary antecedent of leukemogenesis in the cat.

Animals

Multiomic study of cutaneous T-cell lymphoma reveals single-cell clonal evolution in progression and therapy resistance.

Cutaneous T-cell lymphoma (CTCL) remains a challenging disease due to its significant heterogeneity, therapy resistance, and relentless progression. Multiomics technologies offer the potential to provide uniquely precise views of disease progression and response to therapy. Here, we present a comprehensive multiomics view of CTCL clonal evolution, incorporating exome, whole-genome, epigenome, bulk, single-cell T-cell receptor, and single-cell RNA sequencing of 99 clinically annotated serial skin, peripheral blood, and lymph node samples from 34 patients with CTCL. We leveraged this extensive data set to define the molecular underpinnings of CTCL progression in individual patients at single-cell resolution with the goal of identifying clinically useful biomarkers and therapeutic targets. Our studies identified recurrent progression-associated clonal genomic alterations; we highlight mutation of CCR4, phosphoinositide 3-kinase inhibitor signaling, and programmed cell death protein 1 (PD-1) checkpoint pathways as evasion tactics deployed by malignant T cells. We identified a gain-of-function mutation in STAT3 (D661Y) and demonstrated, using cleavage under targets and release using nuclease (CUT&RUN) and RNA sequencing, that it enhances binding to and transcription of genes in Rho GTPase pathways. With our previous work implicating this pathway in histone deacetylase inhibitor-resistant CTCL, these data provide further support for a previously unrecognized role for Rho GTPase pathway dysregulation in CTCL progression. Recurrent progression-associated mutations were common in the epigenetic modifier EZH2, suggesting that EZH2 inhibition may benefit patients with CTCL. Our findings support an approach in which genomic analysis is widely used for improved disease monitoring, biomarker-informed clinical trial design, and genome-guided therapeutic decision-making. Moreover, these molecular changes present new opportunities for therapeutic targeting in this challenging and incurable cancer.

Multiomics

Role of the CTCF binding site in Human T-Cell Leukemia Virus-1 pathogenesis.

During HTLV-1 infection, the virus integrates into the host cell genome as a provirus with a single CCCTC binding protein (CTCF) binding site (vCTCF-BS), which acts as an insulator between transcriptionally active and inactive regions. Previous studies have shown that the vCTCF-BS is important for maintenance of chromatin structure, regulation of viral expression, and DNA and histone methylation. Here, we show that the vCTCF-BS also regulates viral infection and pathogenesis in vivo in a humanized (Hu) mouse model of adult T-cell leukemia/lymphoma. Three cell lines were used to initiate infection of the Hu-mice, i) HTLV-1-WT which carries an intact HTLV-1 provirus genome, ii) HTLV-1-CTCF, which contains a provirus with a mutated vCTCF-BS which abolishes CTCF binding, and a stop codon immediately upstream of the mutated vCTCF-BS which deletes the last 23 amino acids of the p12 gene, and iii) HTLV-1-p12stop that contains the intact vCTCF-BS, but retains the same stop codon in p12 as in the HTLV-1-CTCF cell line. Hu-mice were infected with mitomycin-treated or irradiated HTLV-1 producing cell lines. There was a delay in pathogenicity when Hu-mice were infected with the HTLV-1-CTCF virus compared to mice infected with either HTLV-1-p12 stop or HTLV-1-WT virus. Proviral load (PVL), spleen weights, and CD4 T cell counts were significantly lower in HTLV-1-CTCF infected mice compared to HTLV-1-p12stop infected mice. Furthermore, we found a direct correlation between the PVL in peripheral blood and death of HTLV-1-CTCF infected mice. In cell lines, we found that the vCTCF-BS regulates Tax expression in a time-dependent manner. The scRNAseq analysis of splenocytes from infected mice suggests that the vCTCF-BS plays an important role in activation and expansion of T lymphocytes in vivo. Overall, these findings indicate that the vCTCF-BS regulates Tax expression, proviral load, and HTLV pathogenicity in vivo.

Human T-lymphotropic virus 1

A viral clonality evenness score to predict progression to adult T-cell leukaemia in asymptomatic carriers of human T-lymphotropic virus type 1 in Japan: a retrospective longitudinal cohort study.

BACKGROUND: Adult T-cell leukaemia/lymphoma (ATL) is a highly aggressive T-cell malignancy that occurs in approximately 2-7% of individuals with human T-lymphotropic virus type 1 (HTLV-1), after decades of asymptomatic infection. To address the urgent need for predictive biomarkers to identify asymptomatic carriers of HTLV-1 at high risk of progression to ATL, we aimed to evaluate viral clonality sequencing as a potential tool for risk stratification. METHODS: This retrospective longitudinal cohort study involved HTLV-1 carriers enrolled in the Joint Study on Predisposing Factors of ATL Development, a nationwide cohort study initiated in Japan in 2002. Participants were selected from this cohort on the basis of their baseline proviral load at the time of enrolment as an asymptomatic carrier, length of follow-up, and clinical outcome. The cohort was subdivided into three subgroups: the first comprising HTLV-1 carriers who developed ATL, the second comprising carriers with high proviral load (&#x2265;4%) who did not progress to ATL, and the third comprising carriers with low proviral load (<4%) who did not progress to ATL. DNA extracted from peripheral blood mononuclear cells collected at enrolment and at least one follow-up visit was analysed by HTLV-1 clonality sequencing and the proviral load was quantified. We calculated a viral clonality evenness (VCE) score, based on the Shannon Evenness Index, to quantify the uniformity of the clonal distribution of samples, for which 0 represents a perfectly monoclonal architecture and 1 indicates a completely polyclonal landscape. We then estimated the performance of proviral load thresholds and VCE scoring to classify the risk of progression to ATL using the area under the receiver operating characteristic curve (AUC), the accuracy, and Matthews correlation coefficient. VCEs were compared between participant subgroups with the Wilcoxon rank sum test. FINDINGS: 56 participants followed up by JSPFAD between Feb 6, 2003, and July 19, 2022, were included in this study: 17 who progressed to ATL (mean follow-up 8&#xb7;3 years [SD 4&#xb7;0]), 18 who had a high proviral load and did not progress to ATL (9&#xb7;7 years [3&#xb7;4]), and 21 who had a low proviral load and did not progress to ATL (7&#xb7;5 years [3&#xb7;0]). Clonality sequencing of samples from 39 participants who did not progress to ATL revealed hundreds to thousands of HTLV-1 integration sites at both timepoints, corresponding to multiple clones of low and uniform abundance, and these participants had high VCE scores (&#x2265;0&#xb7;694) at baseline. By contrast, most participants (14 of 17) who progressed to ATL had a single predominant clone or two to four predominant clones at both timepoints, and lower VCE scores (<0&#xb7;694) at baseline than those who did not progress (p<0&#xb7;0001). AUCs were very similar for proviral load thresholds (91 [95% CI 80-98]) and VCE scoring (91 [78-100]), although when using methods that give equal weight to every individual, VCE scoring outperformed proviral load thresholds in predicting progression to ATL (accuracy: proviral load 0&#xb7;76 [95% CI 0&#xb7;76-0&#xb7;77], VCE scoring 1&#xb7;00 [0&#xb7;99-1&#xb7;00]; Matthews correlation coefficient: proviral load 0&#xb7;23 [95% CI 0&#xb7;19-0&#xb7;24], VCE scoring 0&#xb7;91 [0&#xb7;80-1&#xb7;00]). Prediction based on VCE scoring indicated no false positives, compared with 20% when using proviral load, although VCE scoring yields a greater number of false negatives (0&#xb7;3% vs 0&#xb7;1%). INTERPRETATION: The implementation of VCE scoring in clinical practice could inform early pre-emptive therapeutic interventions, exclusively targeting individuals with HTLV-1 at high risk and aiming to prevent progression to aggressive, treatment-refractory disease. Further validation, including independent confirmation of the performance of VCE scoring in multiple populations and the characterisation of its temporal dynamics, will be crucial to determine its clinical utility and potential integration into care pathways. FUNDING: Association Jules Bordet, FNRS-T&#xe9;l&#xe9;vie, FCC, WALInnov, FLF, JSPS-KAKENHI, and CoBiA.

Humans

Secondary cell-mediated cytotoxic response to challenge of rats with syngeneic Gross virus-induced lymphoma.

Secondary cell-mediated cytotoxicity generated in vivo against a syngeneic Gross virus-induced lymphoma [(C58NT)D] in WF rats was detected by the 4-hour 51Cr release assay. At 30 days or more following primary tumor cell inoculation, after the tumors had regressed, lymphoid cells had little or no detectable direct cytotoxic reactivity. At rechallenge with tumor cells, high levels of cytotoxicity were detected in the peritoneal exudate, peripheral blood, mesenteric lymph node, and spleen cells. The secondary cellular immune response after challenge developed earlier, reached higher levels, and lasted longer than the primary immune response. The secondary cytotoxic reactivity was shown to be immunologically specific by the use of various tumor cells both as target and inhibitor cells. Treatment of immune spleen cells with specific antiserum to rat T-cells and complement abolished their cytotoxic reactivity, whereas removal of complement receptor-bearing cells or phagocytic cells did not reduct the cytotoxicity. These data demonstrated that specific-memory T-cells persisted for long periods in the lymphoid organs of immune rats and could rapidly become cytotoxic from rechallenge with the tumor.

AKR murine leukemia virus

The mitogenic effect of the lymphocytosis promoting factor from Bordetella pertussis on human lymphocytes.

The purified lymphocytosis promoting factor (LPF) from Bordetella pertussis was found to be a potent mitogen for peripheral blood lymphocytes (PBL) from normal adults as well as for cord blood lymphocytes. Proliferation occurred in autologous plasma or fetal calf serum, regardless of previous exposure to pertussis infection or immunization. Only one adult human serum, from a physician constantly working with B. pertussis, inhibited the mitogenic response to LPF and this serum was shown to contain precipitating antibody against LPF. The proliferative effect of LPF was characteristic of a "nonspecific" mitogen and not of antigen stimulation of sensitized cells.LPF, phytohemagglutinin, and concanavalin A were approximately equal in potency although variation occurred depending upon the cell donor. Experiments with lymphocyte subpopulations obtained by rosetting techniques employing sheep erythrocytes, mouse erythrocytes, and sheep erythrocytes coated with antibody and complement suggested the requirement of a multicellular system for LPF mitogencity.PBL from most patients with chronic lymphatic leukemia and lymphosarcoma cell leukemia were even less responsive to LPF than to phytohemagglutinin, whereas PBL from patients with lymphosarcoma usually responded to both mitogens. It can be inferred from the results of experiments with both normal and leukemic cells that LPF, which is a murine thymus-derived (T)-cell mitogen, is also a T-cell mitogen for human PBL. The exact cell requirement and mode of action, however, are as yet unknown.

Adult

Pre-treatment T cell features and immune-milieu characteristics shape treatment-induced exhaustion and resistance to Blinatumomab in B-cell acute lymphoblastic leukemia.

BACKGROUND: Blinatumomab (Blina), a CD19&#xd7;CD3 bispecific T cell engager, is approved for the treatment of B-cell precursor acute lymphoblastic leukemia (BCP-ALL), yet resistance remains a major challenge and the mechanisms driving treatment failure remain poorly understood. METHODS: To define the immunological determinants of resistance, we performed longitudinal profiling of peripheral blood T cells and the immune milieu of 34 patients receiving Blina using flow cytometry (n=19), single-cell CITE-seq (n=13), ex vivo Blina-induced cytotoxicity (n=26) and serum proteomics (n=17). RESULTS: At baseline, Responders (R) were enriched for CD8+ effector memory T cells (TEM) expressing higher levels of cytotoxic genes and their transcriptional regulator ZNF683. Conversely, CD8+ TEM from Non-Responders (NR) displayed transcriptional features of activation without proportionate cytotoxic commitment. Over the course of the first treatment cycle, NR exhibited a progressive expansion of TIM3+CD8+ T cells that correlated with a rapid loss of ex vivo cytotoxic function. Linking baseline state to post-treatment T-cell exhaustion, the magnitude of TIM3+CD8+ expansion correlated inversely with baseline ZNF683 expression in CD8+TEM. Beyond T-cell-intrinsic features, NR harbored an immunosuppressive milieu characterized by higher circulating levels of M2-polarizing factors (CSF-1, HGF) and the TIM-3 ligand Galectin-9, which correlated positively with the magnitude of TIM3+CD8+ T-cell expansion. CONCLUSIONS: These findings indicate that post-Blina CD8+ T-cell exhaustion is associated with resistance and it is shaped by both reduced ZNF683-dependent cytotoxic programming in CD8+ TEM and an immunosuppressive milieu. This provides a rationale for risk stratification based on baseline transcriptional profiling of CD8+ TEM and for combinatorial strategies targeting the suppressive microenvironment.

Humans

Rabbit anti-EL4 serum. A reagent with specificity for a population of murine suppressor cells.

Antisera against the C57B1 (H-2b) mouse lymphoma, EL4 were prepared in rabbits. After absorption with mouse liver, red cells and thymocytes the antisera appeared to be cytotoxic for a subpopulation of peripheral T cells. The absorbed antisera blocked the immunosuppressor function of Con A-stimulated splenic lymphocytes, but was unreactive against Con A-stimulated and allogeneically primed cytotoxic cells, or helper T cells. Consequently, heteroantiserum against EL4 may provide a useful reagent for the differentiation of cytotoxic from suppressor T-cell subsets.

Animals

Evidence for suppressor cell activity associated with induction of Herpesvirus saimiri-induced lymphoma.

Peripheral blood lymphocytes (PBL) from Herpesvirus saimiri (HVS) infected owl monkeys lose their ability to respond to PHA during the development of lymphoma. In this study, five HVS-infected owl monkeys were examined for their ability to respond to PHA and to confer this loss of PHA reactivity to normal lymphocytes. Four of the monkeys developed HVS-induced disease and lost their ability to respond to PHA. Although less affected, reduced responses were also found with PWM. The animals which developed disease and suppressed PHA responses were found to be able to confer this loss of PHA reactivity to normal lymphocytes. One HVS-infected monkey did not develop disease or loss of PHA reactivity and did not confer a loss of PHA reactivity to normal lymphocytes. In the four affected monkeys, the conference of suppression to PHA was not accompanied by a concomitant reduction in response to PWM by the normal lymphocytes, demonstrating some specificity in the suppressor cell activity. Thus, the presence of suppressor cell activity appears to be associated with the inhibition of T-cell function and possibly the eventual development of lymphoma.

Animals

Childhood leukemia-lymphoma. Heterogeneity of phenotypes and prognoses.

Results are reported on 724 children and adolescents with acute leukemia-lymphoma. One hundred patients had immunologic marker analysis that defined the major phenotypic groups, i.e., T-cell, B-cell (Burkitt), myeloid, and the most frequent form, non-T, non-T "common" or "undifferentiated" acute leukemia. Pre-T, pre-B, and "null" leukemias are included in the latter group. Response to therapy and survival was best in non-T, non-B acute lymphocytic leukemia, intermediate in T-cell disease, and worst in B-cell (Burkitt) disease. Additional factors resulting in decreased survival include elevated peripheral leukocyte count, presence of enlarged nodes, less depression of hemoglobin and platelets, and age greater than 7 years (all associated with 'lymphomatous" disease). Other factors resulting in decreased survival include age under 3 years and depression of serum immunoglobulins. Definition of the heterogeneity of childhood leukemia-lymphoma dictates differing forms of therapy for the various types of these diseases.

Adolescent