Hematologic and immunophenotypic characterization of human umbilical cord blood.

In this work, cord blood cells from 30 healthy term newborns were analyzed for complete blood counts with an automated cytometer and, in part of the sample, for surface molecules in cord blood monocytes, lymphocytes and CD34+ cells by two-color flow cytometry. Hematological parameters were as follows: WBC = 12.85 (5.24-15.10) x10(9)/l; platelets = 304.33 (156.00-469.00) x 10(9)/l; Hb = 14.45 (11.90-17.82) g/dl; RBC = 3.99 (3.14-5.12) x 10(12)/l; MCV 107.25 (99.60-115.00) fl; reticulocytes = 157.80 (101.00-124.00) x 10(9)/l or 3.99 (2.45-6.01)%; erythroblasts = 0.88 (0.15-2.58) x 10(9)/l or 6.63 (2.86-16.80) per 100 WBC [corrected]. The mononuclear population, as evaluated by flow cytometry, was composed of 22.9 +/- 7.2% monocytes and 77.05 +/- 7.24% lymphocytes, among which 46.59 +/- 15.62% were T lymphocytes (43.94 +/- 16.94% CD3+/CD4+ and 13.45 +/- 7.46% CD3+/CD8+). CD34+ cells were on average 0.54 +/- 0.24% of the mononuclear fraction. CD11c, CD49e and HLA-DR were found mainly on monocytes, and CD31 and CD62L occurred in similar levels on monocytes and lymphocytes. CD117+ cells were less than 5% of these populations. Among CD34+ cells, CD31 and HLA-DR were the molecules with higher frequencies (79.7 +/- 19.9 and 65.7 +/- 23.0%, respectively), followed by CD62L (41.8 +/- 31.9%) and CD117 (20.1 +/- 15.8%). The presence of CD11c and CD49e on CD34+ cells was low (below 10%). The results stress the phenotypic heterogeneity of cord blood CD34+ cells, and the different behavior of the cells when manipulated in vitro in different degrees of isolation.

Comparison of central nervous system prophylaxis with cranial radiation and intrathecal methotrexate versus intrathecal methotrexate alone in acute lymphoblastic leukemia.

In acute lymphoblastic leukemia (ALL), central nervous system (CNS) prophylaxis with cranial irradiation plus 5 doses of intrathecal methotrexate (i.t. MTX) reduces the incidence of CNS relapse to 7%-15%. However, increased evidence of CNS delayed toxicity started to be recognized as CT scan abnormalities and neuropsychologic alterations, mainly in children. Two questions were analyzed in the present report: (1) Will further doses of i.t. methotrexate and dexamethasone (i.t. MTX-DMT) decrease the incidence of CNS relapse in patients treated early in remission with cranium irradiation plus i.t. MTX-DMT even more? (2) Is i.t. MTX-DMT given during induction and maintenance equally as effective as cranium irradiation plus i.t. MTX-DMT? A randomized study was designed to answer the first question. Incidence of primary CNS relapse in i.t. MTX-DMT-treated patients with a WBC count less than 50,000 was 11% (15 of 135 patients) and was 11% (17 of 150) in the untreated group. In patients with a WBC count greater than 50,000, it was 16% (6/37) in the treated group and 19% (6/31) in the control group. No difference was observed according to treatment in both prognostic groups. Patients in this study were retrospectively compared with a consecutive protocol in which patients received 3 doses of i.t. MTX-DMT alone during induction plus 3 doses weekly during the first month of remission and every 3 mo thereafter. The incidence of primary CNS leukemia at 60 mo in patients with a WBC count less than 50,000 was 20% in the irradiated group and 32% in the group with i.t. MTX-DMT alone. This difference was not significant. However, the relapse-free survival at 60 mo was 26% and 41%, respectively, (p less than 0.0005). The incidence of primary CNS relapse in patients with a WBC count more than 50,000 at 48 mo was 28% in the irradiated group and 42% in the nonirradiated group. The difference was not significant. The duration of complete remission was similar, remaining at 15% and 16% of patients disease-free at 48 mo, respectively. We conclude that (A) after cranial irradiation plus i.t. MTX-DMT X 5, the use of additional doses of i.t. MTX-DMT is not of further benefit in preventing CNS relapse; (B) the use of i.t. MTX-DMT alone compares similarly with cranial irradiation plus i.t. MTX-DMT in the incidence of CNS relapse; and (C) relapse-free survival and survival in patients with a WBC count less than 50,000 were significantly longer in those without cranial irradiation.

Chemoimmunotherapy with levamisole in acute lymphoblastic leukemia.

Patients with acute lymphoblastic leukemia (ALL) who were in two consecutive protocols and in complete remission (CR) with maintenance therapy, were randomized to receive or not receive levamisole. A total of 15 of 55 low-risk patients of protocol 10-LLA-72 with levamisole had relapses, compared with 25 of 54 not receiving levamisole; 67 and 49%, respectively, remain in CR at 48 months (P less than 0.025). In protocol 1-LLA-76, 14 of 91 low-risk patients on levamisole and 25 of 93 patients receiving levamisole had relapses; 78 and 61%, respectively, remain in CR at 36 months (P less than 0.05). Seventeen of 39 high-risk patients (children with a leukocyte count higher than 50,000 and adults) receiving levamisole had relapses compared with 37 of 61 not on levamisole. The DNCB skin test showed at 18 and 24 months a 74 and 85% positivity in the levamisole groups vs. a 38 and 35% positivity in the control group (P less than 0.025). We conclude that levamisole prolongs the duration of CR and survival in low-risk patients with ALL.

Evaluation of intensification and maintenance programs in the treatment of acute lymphoblastic leukemia.

This cooperative prospective study was designed to answer the following questions in cases with acute lymphoblastic leukemia induced to achieve complete remission with the combination of vincristine and prednisone (if by day 29 the bone marrow was not M1, daunorubicin was added to the former regimen) and who received preventive CNS therapy with 2400 rad of cobalt-60 to craniocervical region and simultaneously intrathecal methotrexate and dexamethasone: 1) Is a short intensification with cytosine-arabinoside and cyclophosphamide immediately after complete remission useful? 2) Does the use of weekly doses of 6-mercaptopurine and methotrexate have the same maintenance effect as daily 6-mercaptopurine and twice weekly methotrexate? and 3) Do further 3 month-doses of intrathecal methotrexate and dexamethasone help to decrease still more the incidence of meningeal leukemia? From October 1972 to December 1975, 473 previously untreated patients entered this study and 465 (390 children and 75 adults) are evaluated in this paper. Of them, 373 (80%) achieved complete remission (children 84% and adults 61%). Out of 109 "high risk" children (one or more of the following characteristics at diagnosis: marked organomegaly, mediastinal widening, leukocytosis above 50000/mm3 and CNS involvement) 83 (76%) and out of 281 "standard risk" children (all the others) 244 (87%) achieved complete remission. The median duration of complete remission according to different prognostic factors was as follows: "high risk" children 10 months, adults 24 months and "standard risk" children 25 months. Duration of complete remission of the "standard risk" children in relation to with or without intensification, daily or weekly maintenance and additional intrathecal therapy or none, showed no significant difference; however, those who received intensification, daily maintenance and further intrathecal therapy behaved slightly better. Median survival for all the cases of this study was as follows: adults 10 months, "high risk" children 12 months and "standard risk" children 26 months. At 36 months, 13% of "high risk" children, 25% of adults and 39% of "standard risk" children are still alive. We conclude that the variables studied in this protocol did not show significant extension of complete remission, however the sum of them seems to offer some advantage. Moreover, what appears clear is the importance of prognostic factors which must be taken into account in future studies.