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Biomedical subjects

C H Pui

Publications and source records attributed to C H Pui.

At least 235 records · Page 13Linked to original sources

Serum CD4, CD8, and interleukin-2 receptor levels in childhood acute myeloid leukemia.

Leukemic cell expression and serum levels of CD4, CD8, and interleukin-2 receptor (IL-2R) were determined at diagnosis for children or adolescents with acute myeloid leukemia (AML). Cellular expression of CD4 was detected in 18 of 62 cases, CD8 in none of 60 cases, and IL-2R in one of 33 cases tested. Myeloblasts of the M4 and M5 subtypes expressed CD4 significantly more frequently than other FAB subtypes (p = 0.0001). Serum levels of the three soluble factors (tested for 91 patients) were positively correlated with each other. Increased serum CD4 levels were significantly associated with cellular CD4 expression, high leukocyte count, M5 leukemia, spleen enlargement, and age less than 1 year. High serum CD8 levels correlated significantly with splenomegaly, extramedullary disease, absence of Auer rods, and high leukocyte count. Cases with high serum IL-2R levels were less likely to have Auer rods and more likely to have splenomegaly and M5 leukemia; serum levels greater than 750 U/ml were associated with a higher probability of treatment failure (p = 0.05), even after adjustment for other potential prognostic factors. Further studies of serum CD4, CD8, and IL-2R levels may help to clarify the immunoregulatory role of T-cells in patients with AML.

Antigens, Differentiation, T-Lymphocyte↗

Secondary non-Hodgkin's lymphoma after treatment for childhood cancer.

To determine the risk and pertinent features of non-Hodgkin's lymphoma (NHL) as a second malignancy, medical records were searched of 5484 consecutive children treated for various malignancies at a single institution during a 27 year period. Of these, three have developed secondary NHL. The probability of secondary NHL in this cohort at 5 and 10 years after the diagnosis of the first malignancy was 0.05% (95% confidence interval, 0.01%, 0.2%) and at 15 years 0.16% (0.04%, 0.63%). With 30710 person-years observed, the risk in this cohort was 9.8 per 100,000 person-years. A literature search disclosed variously detailed descriptions of 21 cases of secondary NHL in patients whose primary malignancy had been diagnosed when they were less than 20 years old. Of 18 cases with documented secondary NHL histology, the most common subtypes were large cell (n = 7) and small non-cleaved cell (n = 6); mixed histology was found in three and lymphoblastic in two cases. Twenty-three of 24 children with secondary NHL had initial lymphohematopoietic neoplasms: Hodgkin's disease (n = 18), acute lymphoblastic leukemia (n = 4) and acute myelogenous leukemia (n = 1); the remaining child had astrocytoma. Of 18 patients (including three cases from this institution) with known outcome, only four were reported to be alive at 5+, 6+, 12+ and 96+ months, respectively. Secondary NHL occurs most often after therapy for Hodgkin's disease and confers a dismal prognosis.

Adolescent↗

Raised plasma methotrexate concentrations following intrathecal administration in children with renal dysfunction.

Plasma methotrexate (MTX) concentrations were measured following intrathecal (IT) MTX treatment in four patients with acute lymphocytic leukemia and acute renal dysfunction. All four patients had raised serum MTX concentrations to potentially cytotoxic concentrations for a prolonged period of time, (96-120 h). In contrast, serum MTX concentrations after the same dosage of IT treatment ranged from undetectable to 0.11 microM by 15-24 h in seven control patients with normal renal function, and were undetectable by 48 h in all controls. The terminal MTX T1/2 was 19-44 h in the patients with renal dysfunction. Decreased renal clearance or a rapid efflux of MTX from cerebrospinal fluid, or both, could account for the high and sustained concentrations. Plasma MTX concentrations after IT treatment were normal in two patients treated after their renal function returned to normal. Patients with renal dysfunction should be carefully monitored for plasma MTX concentrations and may require leucovorin to prevent systemic side-effects after IT MTX treatment.

Antineoplastic Combined Chemotherapy Protocols↗

Pleural effusion is associated with a poor treatment outcome in stage III small non-cleaved cell lymphoma.

The clinical significance of pleural effusion was assessed in 24 children with unresectable abdominal small non-cleaved cell lymphoma (St. Jude Stage III). Patients were consecutively enrolled and treated on a regimen including high dose fractionated cyclophosphamide and co-ordinated high dose methotrexate and cytarabine. The overall results were excellent, with 20 of 24 patients alive and event-free at a median follow-up of 4 years. Only one of the patients who lacked pleural effusion has relapsed (testicular), even though many had massive disease. In contrast, three of seven patients with pleural effusion have failed treatment (p = 0.02) and subsequently died. Two measures of tumor burden, serum lactic dehydrogenase and, in a subset of patients, interleukin-2-receptor levels, were significantly higher in patients with pleural effusion (p = 0.002 and p = 0.05, respectively). These findings suggest that unresectable abdominal small non-cleaved cell lymphoma associated with pleural effusion should be up-staged and that these patients should receive more intensive chemotherapy.

Abdominal Neoplasms↗

Extranodal primary tumor site indicates poor prognosis in childhood head and neck non-Hodgkin's lymphomas.

As a result of the diversity of lymphoid structures in the head and neck, we analyzed clinical characteristics and outcomes of 87 consecutive children with non-Hodgkin's lymphoma (NHL) arising in this region to determine if the nodal versus extranodal primary site influences prognosis. Thirty-one children had primary nodal NHL whereas 56 had extranodal NHL. The two groups were similar in the distribution of age, gender, race, serum lactic dehydrogenase levels, and disease stage. However, extranodal tumors were slightly more likely to have small non-cleaved cell histology (32/56 versus 11/31, p = 0.07) than nodal tumors. In a multivariate analysis, extranodal involvement (p = 0.017), advanced stage disease (p = 0.054) and treatment era (p = 0.056) were each significantly associated with a shorter time of event-free survival. Children with extranodal and extralymphatic NHL had an even worse treatment outcome than did others (p = 0.006). The poor prognosis of extranodal involvement was also evident among children with stage I or II NHL. We conclude that extranodal involvement has an adverse influence on treatment outcome in children with NHL arising in the head and neck region.

Adolescent↗

Testicular relapse in children with acute nonlymphoblastic leukemia.

The clinical course and other distinctive features of five children who developed a testicular relapse 4 months to 25 months after the diagnosis of acute nonlymphoblastic leukemia (ANLL) are described. The chief presenting feature at relapse was painless testicular enlargement, as is also seen in children with acute lymphoblastic leukemia who relapse in the testes. By French-American-British convention, the malignant cells were classified as M4 (myelomonoblastic) in four cases and M2 (myeloblastic) in one. All children received a course of multiagent reinduction chemotherapy and all but one received local irradiation to the testes. Only one of these children, whose relapse was a late event after elective cessation of therapy, is a long-term survivor. A comparison with six previously published cases shows similar clinical characteristics and outcome. Given the poor responses of such patients to conventional treatment, it seems worthwhile to consider the use of intensive reinduction chemotherapy with concomitant bilateral testicular irradiation followed by remission intensification and an autologous or allogenic marrow transplant.

Adolescent↗

Biology and clinical significance of cytogenetic abnormalities in childhood acute lymphoblastic leukemia.

Virtually all cases of childhood ALL have chromosomal abnormalities and half contain translocations, which are nearly equally divided between random and nonrandom rearrangements. Nonrandom chromosomal abnormalities have been correlated with leukemic cell lineage, the degree of cell differentiation, and the specific gene involved at the molecular level. Many cytogenetic findings have prognostic significance; however, the adverse influence of certain changes, including most chromosomal translocations, may in fact be offset by the greater cytoreductive effects of intensified therapy. Table 4 summarizes the relation of selected karyotypic findings to treatment outcome in patients treated on contemporary protocols. Among all of the chromosomal abnormalities identified in childhood ALL, hyperdiploidy greater than 50 has been associated with the most favorable prognosis. At the opposite end of the spectrum, the treatment outcome for patients with classical Ph+ or hypodiploid ALL is very poor even in programs of intensive chemotherapy; alternative treatment such as bone marrow transplantation should be considered for such patients. Cases with the t(4;11)(q21;q23) also have a very poor clinical outcome, but the adverse prognosis may be limited to the infant or adolescent age groups. The prognostic significance of other nonrandom translocations, such as t(1;19)(q23;p13) and several other abnormalities, needs to be further assessed in larger numbers of patients. Finally, as more is learned about the molecular pathology underlying these rearrangements, it may be possible to develop new therapeutic agents that are specifically targeted to interfere with the aberrant gene products expressed by human leukemic cells.

Child↗

Abnormalities of the long arm of chromosome 6 in childhood acute lymphoblastic leukemia.

To determine the biologic significance of the structural rearrangements of the long arm of chromosome 6(6q) in acute lymphoblastic leukemia (ALL) at diagnosis, we studied 412 consecutive children whose leukemic cell chromosomes had been completely banded and identified 45 (11%) children with this abnormality. The 45 cases were divided into del(6q) only (n = 11), del(6q) and numerical abnormalities (n = 4), del(6q) and structural abnormalities (n = 23), and 6q translocations (n = 7). The breakpoints of del(6q) were subgrouped: del(6)(q15q21) in 11 cases, del(6) (q13q21) in six, del(6)(q21q23) in four, del(6)(q15) in four, del(6)(q15q23) in three, and other deletions in 10 cases. Notably, all these deletions encompassed the 6q21 band, suggesting that this might be the locus of a recessive tumor suppressor gene, the absence of which contributes to malignant transformation or proliferation. Among the seven children with 6q translocations, a previously unidentified nonrandom translocation, t(6;12)(q21;p13) was noted in two cases with an early pre-B immunophenotype. Clinical features and event-free survival were similar among children with or without 6q abnormalities. Overall, children with 6q abnormalities were less likely than those without the abnormality to have a pre-B immunophenotype (P = .03). T-cell immunophenotypes were equally represented in cases with or without 6q abnormalities. However, all four children with del(6q) and a 12p abnormality had early pre-B ALL and all three children with del(6q) and a 9p abnormality had a T-cell immunophenotype. The lack of specificity for a particular immunophenotype may imply that the gene or genes affected by 6q abnormalities are broadly active in the multistep process of lymphoid leukemogenesis. The relatively high frequency of microscopically visible del(6q) indicates the need for molecular studies to identify cases with submicroscopic deletions.

Child↗

Myeloid neoplasia in children treated for solid tumours.

Therapy-related myeloid neoplasia developed 14 to 189 months after diagnosis of the primary malignancy in 12 out of 3365 children treated for malignant solid tumours; 6 of the 12 were in their first complete remission. The 10-year cumulative incidence of myeloid neoplasia was 1.3% (95% Cl 0.5-3.6) for the 447 patients with Hodgkin's disease, 1.3% (0.4-4.3) for the 420 with non-Hodgkin lymphoma, and 1.2% (0.3-5.2) for the 440 with neuroblastoma. This complication appeared in 1 of 180 children with brain tumours and in none of the 1878 with other malignancies. Risk of therapy-related myeloid neoplasia in patients with Hodgkin's disease was associated with recurrence of the primary malignancy, a combination of radiotherapy and chemotherapy with alkylating agents, and age greater than or equal to 12 years at diagnosis of Hodgkin's disease. Of the 8 patients who underwent chromosomal analysis of neoplastic myeloid cells, 2 showed complete loss of chromosome 7 and 4 showed t(9;11) or t(8;21) with or without del(16)(q22). The 2 patients who had received an epipodophyllotoxin had an 11q23 abnormality. The risk of therapy-related myeloid neoplasia is low in children with malignant solid tumours.

Adolescent↗

Near-triploid and near-tetraploid acute lymphoblastic leukemia of childhood.

Cytogenetic and DNA flow cytometric analyses of leukemic cells from 1,971 children with newly diagnosed acute lymphoblastic leukemia (ALL) identified stem lines with modal chromosome numbers greater than 65 in 26 patients (1.3%). Near-triploidy (66 to 73 chromosomes) was found in six cases and near-tetraploidy (82 to 94 chromosomes) in 20. A striking morphologic finding was the presence of clumped chromatin with grooved nuclei or Rieder cell formation in 20 cases. Other than a slight excess of the pre-B immunophenotype, the near-triploid cases did not appear to differ substantially from the general ALL population in clinical features. In contrast, near-tetraploid cases were more often associated with a T-cell immunophenotype (47% v 14%, P less than .001) and L2 morphology (30% v 22%, P less than .01), and were older at diagnosis (median age, 8.6 v 4.8 years, P = .01) than cases with other ploidies. Moreover, an unusually high proportion of near-tetraploid cases tested (6 of 15) expressed one or more of the myeloid-associated antigens CD13, CD15, and CD33. Despite the use of contemporary intensive chemotherapy and short follow-up for most patients, 6 of the 20 near-tetraploid cases have relapsed or died. This study suggests that the near-tetraploid subtype differs from other cases of hyperdiploid greater than 50 ALL, which have been associated with a favorable prognosis.

Adolescent↗

14q32 translocations are associated with mixed-lineage expression in childhood acute leukemia.

The frequency and characteristics of childhood acute leukemia with a 14q32 translocation [other than the t(8;14)(q24;q32)] were determined in 335 cases of newly diagnosed acute lymphoblastic leukemia (ALL) and 105 cases of acute nonlymphoblastic leukemia (ANLL). Ten children, representing 2.3% of the entire cohort, had this abnormality (1.5% of ALL patients and 4.8% of ANLL patients). By French-American-British (FAB) criteria, 4 cases were classified as L1, 1 as L2, 2 as M1, 1 as M2, and 2 as M5. Remarkably, mixed-lineage expression was found in 6 of these 10 cases, but in only 21 of the other 430 cases without a 14q32 translocation (P less than .001). Leukemic cells from 5 of these 6 cases (4 ANLL, and 1 ALL) coexpressed CD13, a myeloid-associated antigen, and CD2, a T-cell-associated antigen; blasts from the sixth case (ALL) coexpressed CD13 and CD19, a B-lineage-associated antigen. Thus, in addition to the well-described 11q23 translocations and t(9;22), 14q32 translocations also appear to be associated with mixed lineage antigen expression. Break-points of the reciprocal chromosomes from chromosome 14 were identified in five of these cases: 1q23, 6q23-q25, 7p15, 8q11, and 12q13. Of the four mixed-lineage cases that were tested, none showed rearrangement of the immunoglobulin heavy chain (IgH) gene. This suggests that the 14q32 breakpoint does not involve the IgH gene and that an unidentified important gene may reside on 14q32.

Adolescent↗

Methotrexate plus L-asparaginase. An active combination for children with acute nonlymphocytic leukemia.

Forty-one children with refractory acute nonlymphocytic leukemia (ANLL) were treated from March 1975 to February 1979 with a schedule-dependent combination of methotrexate (MTX) and L-asparaginase. Intravenous (IV) MTX was followed 24 hours later by IV L-asparaginase (10,000 units [U]/m2). The MTX dose was started at 60 to 100 mg/m2 and was escalated by 20 to 40 mg/m2 as tolerated. This sequence was repeated every 7 to 10 days. Eight patients (20%) achieved a complete remission (CR) and six others had a partial response (PR), with clearance of blasts from the peripheral blood and reduction of bone marrow blasts to less than 25% of nucleated marrow cells. Responding patients received a median maximum MTX dose of 120 mg/m2 (range, 60 to 220 mg/m2). The median number of courses required to achieve a CR was 6 (range, 2 to 13 courses). Toxicity consisted of allergic reactions to L-asparaginase (n = 12), stomatitis (n = 6), minimal elevation of hepatic enzymes (n = 2), and hyperglycemia (n = 1). Treatment was given on an outpatient basis in 95% of all courses. The data indicate that this combination therapy has antileukemic activity and is relatively nontoxic in childhood ANLL.

Adolescent↗

Clinical presentation, karyotypic characterization, and treatment outcome of childhood acute lymphoblastic leukemia with a near-haploid or hypodiploid less than 45 line.

Cytogenetic and DNA flow cytometric analyses of leukemic cells from 2,184 children with newly diagnosed acute lymphoblastic leukemia (ALL) identified 27 cases (1.2%) that had a hypodiploid line with fewer than 45 chromosomes per cell. Had cytogenetic techniques been used alone, seven cases would have been missed, compared with five if only flow cytometry had been used. For comparative purposes, the 27 cases were divided into three groups: near-haploid (n = 10), hypodiploid 30-40 (n = 9), and hypodiploid 41-44 (n = 8). Blast cells from patients with near-haploid ALL lacked structural chromosomal abnormalities; showed nonrandom retention of two copies of chromosomes 8, 10, 14, 18, 21, and the sex chromosomes; and had a second leukemic line with exactly twice the number of chromosomes or DNA content. Karyotypic analysis of the hypodiploid 30-40 and hypodiploid 41-44 groups disclosed structural abnormalities in the stemline or sideline of most of the well-banded cases; those in the latter group were similar to findings in cases with 45 chromosomes. As in the near-haploid group, chromosome 21 and the sex chromosomes were preferentially retained in the hypodiploid 30-40 and 41-44 cases. Except for a slight excess of female patients in the near-haploid group and an older age at diagnosis in the hypodiploid 30-40 cases, there were no initial clinical features that distinguished these patients from the general ALL population. Despite intensive treatment and short follow-up, 17 of the 27 patients have relapsed. This study suggests that the poor treatment responsiveness of hypodiploid ALL is not limited to the more than 80% of the patients who have 45 chromosomes per leukemic cell and demonstrates that cytogenetic and flow cytometric analyses are complementary in the evaluation of children with ALL.

Aneuploidy↗

Heterogeneity of presenting features and their relation to treatment outcome in 120 children with T-cell acute lymphoblastic leukemia.

Presenting features of 120 consecutive children with T-cell acute lymphoblastic leukemia (ALL), representing 15% of all patients diagnosed as having ALL during the study period, were analyzed to determine relationships with treatment outcome. Patients' ages ranged from 1.7 to 18.8 years (median, 10.3 years) and their leukocyte counts from 1.7 to 1,070 x 10(9)/L (median, 100 x 10(9)/L). Central nervous system (CNS) leukemia was present in 12.5% of the cases, a mediastinal mass in 61%, and L2 lymphoblast morphology in 32%. A relatively high proportion of cases, 26%, had normal karyotypes at presentation. Of the cases tested, membrane CD1 expression was found in 38% of cases, CD3 in 33%, CD4 in 50%, CD5 in 94%, CD8 in 55%, and CD10 in 35%. Four presenting features were found to confer an increased risk of treatment failure: age greater than or equal to 15 years, L2 lymphoblast morphology, abnormal karyotype, and membrane CD3 expression. This study illustrates the heterogeneity of presentations of childhood T-cell ALL and suggests that the relative importance of risk factors in ALL differs according to immunophenotype and treatment strategy.

Age Factors↗

Myeloid-associated antigen expression lacks prognostic value in childhood acute lymphoblastic leukemia treated with intensive multiagent chemotherapy.

Frequency and clinical significance of myeloid-associated antigen expression in blast cells were assessed in 372 consecutive children with acute lymphoblastic leukemia (ALL). A comprehensive panel of myeloid monoclonal antibodies representing seven cluster groups showed myeloid-associated antigen expression in 61 cases (16.4%), 18 of which expressed two or more antigens. The antigens expressed comprised CD11b (8.9% of the total series), CD13 (6.5%), CD33 (3.2%), CD36 (1.9%), CD15 (1.6%), CD14 (1.3%), and CDw12 (1.1%). No significant associations were found between myeloid-associated antigen expression and the presence of known adverse prognostic features (eg, higher leukocyte count, nonwhite race, older age). Myeloid-associated antigen expression had no effect on remission induction or event-free survival for the 267 children who had been treated with the same combination of chemotherapeutic agents (P = .34). Thus, blast cell expression of myeloid-associated antigens in childhood ALL appears to lack prognostic value in the context of contemporary intensive chemotherapy.

Antibodies, Monoclonal↗

Clinical and biological characteristics of acute lymphocytic leukemia in children with Down syndrome.

Twenty-eight children with Down syndrome (DS) and acute lymphocytic leukemia (ALL) were compared to non-DS control leukemics matched by age, white blood cell (WBC) count, and treatment protocol to evaluate presenting manifestations, toxicity, and outcome. The DS children with ALL did not have unique clinical or biologic characteristics to distinguish their disease from that of non-DS patients. Eleven of the DS patients had successfully banded cytogenetic studies of their leukemic cells with the distribution of model chromosome number of 46 (n = 1), 47 (2), 48 (5), and greater than 50 (3). The abnormal leukemic line involved an isochromosome of the long arm of chromosome 9[i(9q)] in 3 cases. Multiagent chemotherapies induced complete remissions in 25 patients (85%), yet overall 5 year event-free survival was only 23 +/- 8% when compared to 64 +/- 9% for control children receiving similar therapies (P less than 0.01). A significant cause of treatment failure was late marrow recurrence in the DS children. Host toxicity was striking in these children. Severe congenital heart disease present in one-third contributed to 2 deaths during antileukemia therapy. Hyperglycemia secondary to diabetogenic agents and repeated bronchitis were common toxicities. Intolerance to the antifolate methotrexate with severe gastrointestinal and skin toxicities was universal. We conclude that the poor prognosis for the child with DS and ALL stems in part from their increased risk of complications and toxicity from intensive modern leukemia therapies, specifically antifolates.

Antineoplastic Combined Chemotherapy Protocols↗