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Biomedical subjects

D Kalwinsky

Publications and source records attributed to D Kalwinsky.

At least 19 recordsLinked to original sources
PubMed2001

Preponderance of thiopurine S-methyltransferase deficiency and heterozygosity among patients intolerant to mercaptopurine or azathioprine.

PURPOSE: To assess thiopurine S-methyltransferase (TPMT) phenotype and genotype in patients who were intolerant to treatment with mercaptopurine (MP) or azathioprine (AZA), and to evaluate their clinical management. PATIENTS AND METHODS: TPMT phenotype and thiopurine metabolism were assessed in all patients referred between 1994 and 1999 for evaluation of excessive toxicity while receiving MP or AZA. TPMT activity was measured by radiochemical analysis, TPMT genotype was determined by mutation-specific polymerase chain reaction restriction fragment length polymorphism analyses for the TPMT*2, *3A, *3B, and *3C alleles, and thiopurine metabolites were measured by high-performance liquid chromatography. RESULTS: Of 23 patients evaluated, six had TPMT deficiency (activity < 5 U/mL of packed RBCs [pRBCs]; homozygous mutant), nine had intermediate TPMT activity (5 to 13 U/mL of pRBCs; heterozygotes), and eight had high TPMT activity (> 13.5 U/mL of pRBCs; homozygous wildtype). The 65.2% frequency of TPMT-deficient and heterozygous individuals among these toxic patients is significantly greater than the expected 10% frequency in the general population (P <.001, chi(2)). TPMT phenotype and genotype were concordant in all TPMT-deficient and all homozygous-wildtype patients, whereas five patients with heterozygous phenotypes did not have a TPMT mutation detected. Before thiopurine dosage adjustments, TPMT-deficient patients experienced more frequent hospitalization, more platelet transfusions, and more missed doses of chemotherapy. Hematologic toxicity occurred in more than 90% of patients, whereas hepatotoxicity occurred in six patients (26%). Both patients who presented with only hepatic toxicity had a homozygous-wildtype TPMT phenotype. After adjustment of thiopurine dosages, the TPMT-deficient and heterozygous patients tolerated therapy without acute toxicity. CONCLUSION: There is a significant (> six-fold) overrepresentation of TPMT deficiency or heterozygosity among patients developing dose-limiting hematopoietic toxicity from therapy containing thiopurines. However, with appropriate dosage adjustments, TPMT-deficient and heterozygous patients can be treated with thiopurines, without acute dose-limiting toxicity.

Adolescent↗
PubMed1991

Altered mercaptopurine metabolism, toxic effects, and dosage requirement in a thiopurine methyltransferase-deficient child with acute lymphocytic leukemia.

Thiopurine methyltransferase deficiency, inherited as an autosomal codominant trait, is associated with aberrant mercaptopurine metabolism leading to excessive cellular accumulation of 6-thioguanine nucleotides, the active metabolites of mercaptopurine. We describe a case of severe thiopurine methyltransferase deficiency (activity less than 1 U/8 x 10(8) erythrocytes) in a young girl with acute lymphocytic leukemia. The level of 6-thioguanine nucleotide in the patient's erythrocytes was seven times the population median value, and she had intolerable hematologic toxic effects during postremission therapy with a standard dosage of mercaptopurine (75 mg/m2 per day). Subsequent therapy with 6% of this dosage (10 mg/m2 three times weekly) yielded erythrocytic 6-thioguanine nucleotide concentrations consistently above the population median but not associated with prohibitively toxic effects. This case demonstrates that thiopurine methyltransferase deficiency does not absolutely contraindicate mercaptopurine therapy, and it also provides insight into the mechanism of excessive toxic effects of mercaptopurine sometimes observed in children with acute lymphocytic leukemia.

Child↗
PubMed1991

A phase I clinical trial of 2-chlorodeoxyadenosine in pediatric patients with acute leukemia.

To evaluate its toxicity and clinical efficacy in children with relapsed or refractory leukemia, we performed a phase I trial of 2-chloro-2'-deoxy-adenosine (2-chlorodeoxyadenosine; 2-CDA) given as a continuous 5-day infusion at doses of 3 to 10.7 mg/m2/d. In this study of 31 children with acute leukemia, the only dose-limiting toxicity was myelosuppression. At the highest dose level, three of seven patients developed fatal systemic bacterial or fungal infections. At dose levels above 6.2 mg/m2/d, significant oncolytic responses occurred in all patients. In addition, there was a significant correlation between both the responsiveness by cell type and dose of 2-CDA, such that more oncolytic responses were noted in acute myeloid leukemia (AML) patients than acute lymphoblastic leukemia (ALL) patients (P = .02). Although this was a phase I trial in heavily pretreated patients with refractory disease, two AML patients treated at 5.2 and 10.7 mg/m2/d, respectively, had complete hematologic responses, and one patient treated at 10.7 mg/m2/d had a partial response. In addition, there was a dose-response relationship in all patients with improved cytoreduction of peripheral blast cells at higher doses of 2-CDA. In vitro evaluation of 2-CDA uptake and anabolism by leukemic blast cells from 22 patients demonstrated that 2-chloro-2'-deoxyadenosine (Cld-AMP) and 2-chloro-2'-deoxyadenosine 5'-striphosphate (CldATP) reached concentrations close to steady-state levels within 1 hour. Intracellular nucleotide disappearance rates were high with half-lives of 1.29 and 2.47 hours for CldAMP and CldATP, respectively. This suggests that continuous infusion is necessary to maintain the desired plasma concentration. The results of this study confirm the antileukemic activity of 2-CDA and the lack of prohibitive nonhematologic toxicity. Phase II trials in patients with AML and ALL are warranted.

2-Chloroadenosine↗
PubMed1990

Renal dysfunction and hyperuricemia at presentation and relapse of acute lymphoblastic leukemia.

Hyperuricemia is an unusual presenting feature of acute lymphoblastic leukemia (ALL) and is generally associated with a large leukemic cell burden. We describe three children with T-cell ALL who presented with acute renal failure and very high serum uric acid concentrations, despite a relatively small leukemic cell burden. Two of the three patients had normal complete blood counts without circulating blasts or other physical evidence of leukemia. An isolated renal relapse in one case was associated with hyperuricemia, increased renal excretion of uric acid, and renal dysfunction. An unusually high rate of purine catabolism of the lymphoblasts may cause hyperuricemia in these cases. Unexplained hyperuricemia should prompt a search for occult malignancy.

Acute Kidney Injury↗
PubMed1988

High-dose methotrexate improves clinical outcome in children with acute lymphoblastic leukemia: St. Jude Total Therapy Study X.

High-dose methotrexate (HDMTX, 1,000 mg/m2) and cranial irradiation/sequential chemotherapy (RTSC) were compared for ability to extend complete remission durations in children with acute lymphoblastic leukemia (ALL). Three hundred thirty patients were enrolled in the study, according to our criteria for standard-risk ALL: a leukocyte count less than 100 X 10(9)/L, no mediastinal mass, no leukemic involvement of the central nervous system (CNS), and blast cells lacking sheep erythrocyte receptors and surface immunoglobulin. Prednisone-vincristine-asparaginase induced complete remissions in 95% of the patients, who were then randomized to receive either HDMTX (n = 154) or RTSC (n = 155). HDMTX was administered with intrathecal MTX for the first 3 weeks following remission induction, and then every 6 weeks with daily mercaptopurine (MP) and weekly oral MTX for a total of 18 months. The RTSC regimen consisted of 1,800 cGy cranial irradiation and intrathecal MTX for 3 weeks, followed by MP/MTX, cyclophosphamide/doxorubicin, and teniposide/cytarabine administered sequentially over 18 months. The final 12 months of treatment for both groups was MP and oral MTX; all patients received intrathecal MTX every 12 weeks. With a median follow-up of 5 years, complete remission durations have been significantly longer among children treated with HDMTX, compared with RTSC (P = .049) or historical institutional control regimens (P = .002). Approximately 67% of the patients receiving HDMTX and 56% of those receiving RTSC are expected to be in continuous complete remission at 4 years. Overall, isolated CNS relapse rates were similar (P = .17) in the two treatment groups, although by newer risk criteria cranial irradiation could be expected to provide better protection in patients with an unfavorable prognosis. These findings indicate that addition of intermittent HDMTX infusions to conventional chemotherapy is an effective method for extending complete remissions in children with ALL.

Child↗
PubMed1988

Early intensification of chemotherapy for childhood acute nonlymphoblastic leukemia: improved remission induction with a five-drug regimen including etoposide.

We tested the value of early intensification of chemotherapy in 68 consecutive children with acute nonlymphocytic leukemia (ANLL) who were admitted to St. Jude Children's Research Hospital from November 1983 through March 1987. Fifty-eight patients (85%) entered complete remission after treatment with etoposide (VP-16)/cytarabine (ara-C) (A), followed by daunorubicin (Dauno)/ara-C/thioguanine (6-TG) (B) and then VP-16/azacytidine (5-AZ) (C). Thirty percent of the complete responders, mainly those with an M4 or M5 leukemia subtype, attained M1 marrow status after component A, 60% after A + B, and 10% after A + B + C. Induction failures resulted primarily from absolute or relative drug resistance; there was only one death during this phase of therapy. Postremission treatment consisted of three pairs of drugs (vincristine [VCR]/amsacrine [m-AMSA], or doxorubicin [Doxo]/6-TG/ara-C, and VP-16/cyclophosphamide [CTX]) administered sequentially in 6-week cycles for 22 months. Despite the high rate of remission induction, only 33% +/- 7% SE of the patients are expected to be failure-free survivors at 2 years. Remission durations were not significantly affected by the majority of factors examined in this study, with the exception of marrow cellularity after VP-16/ara-C induction therapy. Patients with less than or equal to 5% leukemic cells survived relapse-free for a median of 36.1 months, compared with 11.3 months for the group with a larger infiltrate (P = .01). Although postremission therapy did not improve the percentage of long-term failure-free survivors, the induction regimen we used appears highly effective, and its components should be considered for inclusion in other treatment programs.

Acute Disease↗
PubMed1987

Pharmacokinetics and toxicity of methotrexate in children with Down syndrome and acute lymphocytic leukemia.

Children with Down syndrome and acute lymphocytic leukemia (ALL) have poor tolerance to antineoplastic drugs, including methotrexate (MTX). We evaluated MTX pharmacokinetics and toxicity in five patients with Down syndrome and ALL who had received multiple high doses of MTX (1 g/m2). Three control patients without Down syndrome were matched to each case according to sex, race, age, and initial leukocyte count. Median MTX plasma concentrations, measured 42 hours after infusion, were significantly higher in patients with Down syndrome versus control patients (average 0.47 vs 0.24 mumol/L, respectively, P = 0.03). When a 42-hour MTX concentration of 0.5 mumol/L was used to identify patients at risk for toxicity, more courses were considered at high risk for toxicity among patients with Down syndrome (31 of 62, 50%) than in control patients (13 of 214, 6.1%, P less than 0.0001). The average MTX clearance was 64.1 mL/min/m2 in Down syndrome vs an average control value of 80.6 mL/min/m2 (P = 0.13). Toxicity after each high-dose MTX course was graded according to standardized criteria. Grades 2 through 4 gastrointestinal toxicity and grades 3 and 4 hematologic toxicity occurred more frequently in the patients with Down syndrome (36% and 13.4% of courses, respectively) vs the control patients (3.6% and 0.9% respectively, P less than 0.0001 for both). This higher frequency of toxicity occurred despite higher doses and prolonged duration of leucovorin given to all patients with Down syndrome. We conclude that altered MTX pharmacokinetics may contribute to the higher incidence of MTX-induced toxicity seen in patients with Down syndrome.

Adolescent↗
PubMed1987

Childhood monosomy 7 syndrome: clinical and in vitro studies.

The clinical and cell growth characteristics of 11 children with monosomy 7 presenting as preleukemia (eight cases) or acute nonlymphoblastic leukemia (three cases) were studied. Anemia was common to all patients, with nine showing leukocytosis, seven thrombocytopenia, and one thrombocytosis. There was a striking predominance of males (M/F ratio, 10:1) and a young median age (3 years). Preleukemia evolved to acute nonlymphoblastic leukemia in five patients and to myelofibrosis in one. In vitro studies of bone marrow progenitor cells cultured in leukocyte feeder-stimulated agar revealed abnormal cell proliferative patterns, most often an increased number of small clusters, for all 11 subjects. The cells of some preleukemic patients showed increased growth even in the absence of an exogenous source of colony-stimulating factor, suggesting autonomous growth or possibly autocrine stimulation. Combination chemotherapy or bone marrow transplantation failed to induce complete remission in the seven patients who were treated. Our findings in these 11 cases confirm the poor prognosis of monosomy 7 presenting as preleukemia in children. The in vitro studies suggest an association between altered cell growth in vitro and clinical evolution to frank leukemia.

Acute Disease↗
PubMed1986

Intensive retreatment of childhood acute lymphoblastic leukemia in first bone marrow relapse. A Pediatric Oncology Group Study.

We devised a plan of intensive chemotherapy to address the problem of inadequate results of treatment in children with acute lymphoblastic leukemia in first bone marrow relapse. Immediately after remission was induced with four conventional drugs, a two-week intensification course of teniposide and cytarabine was given to eradicate subclinical leukemia. Patients in remission were then treated for two years with rapid rotation of pairs of drugs that were not cross-resistant and periodic courses of the same agents used to induce remission. A second complete remission was induced in 31 of the 39 patients in whom response to chemotherapy could be assessed. The probability of maintaining bone marrow remission in these patients for one year was 0.38 +/- 0.19 (95 percent confidence interval); the two-year probability was 0.29 +/- 0.17. Seven patients completed the treatment program, five of whom have been in continuous second complete remission 17 to 20 months after the cessation of therapy. Children whose initial bone marrow remission lasted less than 18 months had significantly poorer responses to retreatment than did those with a longer first remission (P = 0.004). Intensive chemotherapy, as described here, may save half of the children with acute lymphoblastic leukemia in whom bone marrow relapse occurs after a relatively long initial remission.

Adolescent↗
PubMed1985

Prognostic importance of blast cell DNA content in childhood acute lymphoblastic leukemia.

Using flow cytometric techniques, we determined the pretreatment distribution of DNA content in propidium iodide-stained leukemic blasts from 205 children with "standard-risk" acute lymphoblastic leukemia (ALL). Risk assignment was based on an initial WBC count less than 100 X 10(9)/L, no thymic mass, no meningeal leukemia, and lymphoblasts lacking sheep erythrocyte receptors or surface immunoglobulin. A single aneuploid leukemic line was detected in 74 cases (36.1%): 70 hyperdiploid and four hypodiploid. For hyperdiploid cases, the DNA index (DI, or ratio of the DNA content of leukemic v normal G0/G1 cells) ranged from 1.06 to 2.0 (median, 1.20). A secondary leukemic line with hyperdiploid cellular DNA content was identified in 21 cases with diploid primary lines. Children whose primary leukemic line showed a DI greater than or equal to 1.16 (n = 57) had significantly better responses to treatment than did those with either a diploid DI (n = 130; P = .002) or values in the range of 1.01 to 1.15 (n = 14; P = .001). The relative risk of failure for hyperdiploid cases with DI greater than or equal to 1.16, corresponding to greater than or equal to 53 chromosomes, was one-third that of the other two groups. Treatment responses of patients with both diploid and hyperdiploid lines were identical to those associated with single diploid lines, but significantly worse than those associated with single hyperdiploid lines with DI greater than or equal to 1.16 (P = .016). The most favorable prognostic variables selected by a Cox proportional hazards model were: DI greater than or equal to 1.16 (P = .001), white race (P = .022), WBC less than or equal to 25 X 10(9)/L (P = .032), age between 2 and 9 years (P = .075), and hemoglobin less than 7.0 g/dL (P = .094). DNA index greater than or equal to 1.16 retained its significant prognostic impact even after adjustment for other variables (P = .001). With the combination of DI greater than or equal to 1.16 and WBC less than or equal to 25 X 10(9)/L, one can identify a group of children with ALL who have a low probability of relapse when treated with current therapy. If they remain disease-free after longer follow-up, it may be advisable to treat them with less intensive, hence less toxic, chemotherapy than patients with higher WBC counts or lower DI values.

Antigens, Neoplasm↗
PubMed1985

Coagulopathy induced by continuous infusion of high doses of human lymphoblastoid interferon.

Seven patients with myeloblastic leukemia were treated for 10 days with high-dose (15 or 30 million units/m2/day), human lymphoblastoid interferon (Wellferon) by continuous iv infusion. All patients developed prolonged activated partial thromboplastin time, and four developed prolonged prothrombin time. Factor assays demonstrated low levels of II, VII, IX, X, and XII. Coagulation abnormalities improved after discontinuation of interferon therapy.

Adolescent↗
PubMed1985

Serum lactic dehydrogenase level has prognostic value in childhood acute lymphoblastic leukemia.

Serum lactic dehydrogenase (LDH) levels were measured at diagnosis in 293 children with "standard-risk" acute lymphoblastic leukemia (ALL) to determine the prognostic value of this biologic feature. Standard risk assignment was based on an initial leukocyte count of less than 100 X 10(9)/L, the absence of a mediastinal mass, the absence of meningeal involvement, and the presence of lymphoblasts lacking sheep erythrocyte receptors or surface immunoglobulin. Serum LDH levels ranged from 97 to 6,595 U/L, with a mean of 547 U/L. Higher LDH levels were associated with higher leukocyte counts, lower blast cell DNA indices, lower platelet counts, a larger spleen size, and nonwhite race. LDH levels were not related to the percentage of marrow S-phase cells, liver size, French-American-British (FAB) classification, hemoglobin levels, age, sex, or the presence of the common ALL antigen on marrow blasts. Patients with the highest LDH levels (greater than 1,000 U/L) were most likely to fail treatment, whereas those with the lowest levels (less than 300 U/L) had the lowest risk of failure (P less than .0001). The prognostic significance of serum LDH level was retained in a subset of patients that included only those with leukocyte counts less than 25 X 10(9)/L (P = .0018). When 11 presenting characteristics were subjected to multivariate analysis, serum LDH level was found to have independent prognostic strength, contributing clinically important information to that gained from leukocyte count. Early measurement of serum LDH could be useful in identifying a group of standard-risk ALL patients with a high relapse hazard.

Analysis of Variance↗
PubMed1984

Regulation of prolyl hydroxylase activity in L-929 cells by mechanisms unrelated to glycolytic metabolism.

Previous studies showing that prolyl hydroxylase is activated by addition of lactate to logarithmic cultures of L-929 and 3T6 mouse cell lines and that the enzyme normally increases in dense cultures which accumulate lactic acid, have led to the hypothesis that regulation is mediated through glycolytic metabolism. We present evidence that the extent of lactate production plays a minor role in controlling the density-dependent activation of prolyl hydroxylase in L-929 cells. The initial rate of glycolysis in stationary phase cells was lower than that in the logarithmic phase so that intracellular levels of glycolytic intermediates would not be related to activation of the enzyme. Nevertheless, because of increased numbers of cells in stationary phase, higher concentrations of lactate occur in the culture medium. Eliminating accumulation of lactate during the growth of L-929 cells by reducing the normal glucose concentration (5.5 mM) to low-glucose (0.5 mM) did not significantly affect the growth rate and still allowed a 10-fold activation of prolyl hydroxylase when cells reached stationary phase. Growth in normal glucose resulted in only an additional 2-fold increase in specific enzyme activity. These results imply that density-dependent activation of prolyl hydroxylase occurs mainly through a mechanism independent of lactate production. The elevated enzyme activity in dense cells was not decreased when lactate was removed and its production prevented by replacement of high-glucose medium with low-glucose medium for 24 hours. This result differed markedly from the dramatic decrease in enzyme activity observed within several hours after replating stationary phase cells in fresh medium, but at a lower cell density. The conclusion that there are at least two mechanisms regulating prolyl hydroxylase activity in L-929 cells was further supported by the observation that the maximal extent of enzyme activation by ascorbate or lactate in logarithmic phase L-929 cells was much less than the extent of density-dependent activation.

Animals↗
PubMed1984

Sudan black B positive acute lymphoblastic leukaemia.

The presence of greater than 3% Sudan black B (SBB) positivity in leukaemic blasts has been considered diagnostic of acute non-lymphocytic leukaemia (ANLL). A rare report has indicated that this finding may not be specific for ANLL. In order to determine whether SBB could be found in acute lymphoblastic leukaemia (ALL) the data on 350 patients with newly diagnosed ALL were reviewed. Six patients (1.6%) were found to have 5% or greater SBB positive blasts. The diagnosis of ALL was supported by morphology, cytochemistries, immunologic markers, therapeutic response, and in one case immunoglobulin gene rearrangement. It is important to recognize the fact that SBB is not specific for AML and may be found in the blasts of patients with ALL.

Adolescent↗
PubMed1983

Phenotypic conversion of acute leukaemia from T-lymphoblastic to myeloblastic induced by therapy with 2'-deoxycoformycin.

A 6-year-old boy with T-cell acute lymphoblastic leukaemia (ALL) in relapse was treated with the adenosine deaminase inhibitor, 2'-deoxycoformycin (DCF). Remarkably, his residual leukaemia underwent an abrupt phenotypic shift, coincident with a massive anti-leukaemic effect of DCF. Both at diagnosis and prior to therapy with DCF, blast cells had typical lymphoblastic morphology and T-cell characteristics (terminal transferase +, T-antigen +, Ia -, cALLa -, myeloperoxidase -, and high in adenosine deaminase content). After four courses of DCF by constant infusion, the blast cells were myeloid in appearance and reactivity to a variety of tests (terminal transferase -, myeloperoxidase +, Sudan black B +, esterase +, My-1 +). We hypothesize that DCF therapy created a selection pressure, blocking pathways of T-cell differentiation and proliferation, permitting the emergence of a newly dominant myeloid subclone of a multipotential leukaemic cell progenitor with the innate capacity for both T-lymphocytic and myeloid differentiation.

Adenosine Deaminase Inhibitors↗
PubMed1983

Second central nervous system prophylaxis in children with acute lymphoblastic leukemia who relapse after elective cessation of therapy.

A treatment plan to achieve better disease control in patients with acute lymphoblastic leukemia (ALL) who relapse after elective cessation of therapy was assessed. The principal modifications were (1) a second preventive treatment of the central nervous system (CNS) at relapse and every six weeks throughout therapy, using intrathecal methotrexate with cytosine arabinoside, and (2) a four-week course of systemic chemotherapy given immediately before therapy was stopped a second time. Twenty-four patients were studied. There have been no meningeal relapses, in contrast to seven among 16 similar patients who were retreated without CNS prophylaxis. Although the median length of second hematologic remission was not significantly different from the outcome in the comparison group, a much higher proportion of patients (eight of 24 versus zero of 17) remain in prolonged reinduced complete remission (48-79 months). Children whose first relapse occurred later than six months after cessation of therapy had significantly longer subsequent remissions. These end results establish the value of intrathecal CNS prophylaxis in relapsed ALL and suggest that a late intensive phase of therapy will extend remissions in a substantial proportion of patients.

Antineoplastic Combined Chemotherapy Protocols↗