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A prolonged decrease in circulating granulocytes accompanied transfusions of HL-A-incompatible platelet concentrates in two afebrile patients with aplastic anemia. The median granulocyte count measured at 20 hours after incompatible platelet concentrates was reduced by 30.8 per cent and remained depressed below pretransfusion levels for as long as four days (median of two days). HL-A-matched platelet concentrates obtained either from siblings or from nonfamily donors did not cause granulocytopenia. The rebound granulocytosis that usually follows transfusion reactions was not observed in these patients presumably because of severely comprised bone-marrow reserves. The prolonged delay in recovery of circulating granulocytes caused by incompatible platelet concentrates may lower host defenses and thus increase the risk of infection. (N Engl J Med 290:1220–1223, 1974)

To better characterize the disposition of cytosine arabinoside (Ara-C) in cerebrospinal fluid (CSF), its kinetics were studied in seven patients with meningeal leukemia in complete remission. After intraventricular injection of 30 mg Ara-C, CSF and plasma samples were obtained over a 24-hr period. Ara-C levels were measured by a reverse-phase HPLC assay (with a sensitivity of 0.5 microM in CSF and 1.0 microM in plasma) that readily separated Ara-C from its major metabolite uracil arabinoside (Ara-U). Elimination of Ara-C from CSF followed a biphasic pattern, with an initial t1/2 of 1 hr and a terminal t1/2 of 3.4 hr. Ara-C clearance from CSF was 0.42 ml/min, suggesting that drug elimination was primarily by CSF bulk flow. The ratio of the AUC of Ara-U to the AUC of Ara-C was 0.08, indicating only minor metabolism of Ara-C to Ara-U in CSF, in contrast to that after systemic Ara-C. Despite initial CSF Ara-C concentrations exceeding 2 mM, Ara-C was not detectable in plasma in any patient. Intraventricular Ara-C results in very high levels in CSF, but systemic tissues are relatively spared from exposure to Ara-C.

A four-year-old child with recurrent infections and increasing hepatosplenomegaly over a three-year period was evaluated. Increased numbers of myeloid precursors packed the bone marrow and infiltrated the peripheral blood. A diagnosis of chronic myelogenous leukemia (CML) was considered but could not be confirmed by laboratory studies appropriate for the types of CML usually observed in childhood. Examination of the patient's peripheral blood smears revealed many atypical monocytoid cells with unipolar hairy projections. Scanning electron microscopy showed these to be leukemic monoblasts with characteristic broad-based ruffles on the cell surface. A population of myeloid precursors possessing narrow ridge-like profiles was also observed. Progressive infiltration of the spleen caused hypersplenism which necessitated splenectomy. Subsequently, massive liver and bone marrow involvement led to the patient's death. Terminally, the proliferating blast cells were demonstrated to be leukemic monoblasts by analysis of cytochemical staining patterns, surface immunoglobulins, serum lysozyme levels, and monocyte-mediated antibody-dependent cellular cytotoxicity studies. The findings in this case are most compatible with a diagnosis of chronic myelomonocytic leukemia (CMML), a condition not previously described in childhood. Several myeloproliferative disorders with prolonged survival have been reported in children, but special studies were not performed to determine which cell lines were abnormally proliferating. The similarities between these children and our patient with CMML suggest that monocyte studies may be useful in the diagnosis of these unusual disorders, provide insights into their pathogenesis, and aid in the selection of appropriate therapy.

SINCE leukemic cells express certain cell-surface markers common to normal human lymphocytes, acute lymphoblastic leukemia can be differentiated immunologically into T-cell, B-cell and null (non-T,...

Lymphoblasts from 18 patients with untreated acute lymphoblastic leukemia were investigated for the presence of conventional cell surface markers (spontaneous sheep red blood cell rosette formation, complement receptors, and surface immunoglobulin). The expression of Fc receptors for both IgG and IgM was investigated using indicator bovine erythrocytes coated with rabbit anti-BRBC (IgG and LgM fractions). The leukemic cells of all patients in this tudy expressed Fc receptors for both IgC and LgM. In contrast with previous reports, null (non-T non-B) lymphoblasts as well as T lymphoblasts demonstrated Fc-IgG and Fc-IgM receptors. However, these two immunologic subclasses of leukemic cells demonstrated significantly different patterns of Fc receptor distribution. These data suggest that expression of Fc receptors is an early event in cellular differentiation in this lymphoid malignancy.

A 4-year-old boy with orbital rhabdomyosarcoma developed central nervous system (CNS) metastases as a meningeal disease without clinically apparent local recurrence. Abnormal cells in the cerebrospinal fluid (CSF) antedated the symptoms and signs of increased intracranial pressure. This suggests that the CSF of patients with rhabdomyosarcoma should be monitored and that prophylactic therapy of the CNS might be indicated, especially in those patients with head and neck or metastatic disease.

The disposition of the synthetic corticosteroids, dexamethasone and prednisolone, in CSF was evaluated following bolus intravenous (IV) and intrathecal (IT) injection in a nonhuman primate model. Steroid concentration in plasma and CSF was measured with a radioimmunoassay following celite column chromatography. The CSF to plasma ratios of dexamethasone and prednisolone following IV bolus administration were 0.15 +/- 0.02 and 0.08 +/- 0.03, respectively. Although peak levels of the two steroids in the CSF reached equally potent levels when administered systemically in equipotent doses, the half-life of prednisolone in the CSF was shorter. In addition, there was a significant difference in the plasma protein binding of the two steroids, which may account for the differences in their CSF pharmacokinetics. Dexamethasone was 70% protein bound over a wide concentration range, while the protein binding of prednisolone was concentration dependent, ranging from 60% at 10 mumol/L to 95% at 0.5 mumol/L and below. After the initial distribution phase in plasma, CSF concentrations of dexamethasone and prednisolone approximated free plasma concentrations, indicating that penetration into the CSF was limited primarily by protein binding. At the plasma concentrations achieved following oral administration of standard doses of prednisone in children, the prednisolone (the active metabolite) is greater than 90% protein bound. The proportionally higher free plasma levels of dexamethasone result in greater penetration into the CSF. These findings may explain the lower rates of meningeal leukemia observed in children receiving dexamethasone instead of prednisone for the treatment of acute lymphoblastic leukemia (ALL).

Testing of paired serum samples of 12 children with the Wiskott-Aldrich syndrome for the presence of hepatitis B surface antigen (HB s Ag), antibody to HB s Ag, and antibody to the hepatitis B core antigen revealed evidence of hepatitis B virus infection in three. None of the three, however, developed overt clinical hepatitis or the chronic HB s Ag carrier state. These data suggest that the immunologic defects seen in the Wiskott-Aldrich syndrome permit adequate immune responses to the hepatitis B virus and do not predispose to the chronic HB s Ag carrier state.

The expression of the interleukin-2 (IL-2) receptor was studied in neoplastic cells derived from acute leukemias, T-cell lymphoblastic lymphomas, peripheral T-cell lymphomas, chronic lymphocytic leukemias, well-differentiated lymphocytic lymphomas, and established cell lines by both flow cytometric analysis and sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) after affinity crosslinking of radiolabeled IL-2. Cells from most acute leukemias (19 of 22), irrespective of their subtype (T, common or nonlymphoid leukemias), as well as T-cell lymphoblastic lymphomas and peripheral T- cell lymphomas expressed only the p70–75 beta subunit of the IL-2 receptor. Cells from the more mature B-cell neoplasms, chronic lymphocytic leukemia, and well-differentiated lymphocytic lymphoma, expressed predominantly alpha beta IL-2 receptors (11 of 14). In contrast to these results, most cell lines established from hematopoietic malignancies do not express either chain of the IL-2 receptor. Further studies are necessary to determine the exact function of the IL-2R p70–75 beta subunit in immature hematopoietic cells, but its wide distribution throughout the hematopoietic system suggests that IL-2 may play a role in the early stages of hematopoiesis.

One hundred twenty-five hematologic relapses of acute lymphoblastic leukemia (ALL) were treated with a four-drug reinduction regimen consisting of L-asparaginase, vincristine, daunomycin, and prednisone (Asp-VDP). Complete remission was achieved in 114 of 125 (91%) treatment courses. The regimen also proved to be highly effective in the management of multiple subsequent relapses which occurred in patients who had previously attained complete remissions with this regimen. The rates of remission induction for second and third reinduction attempts were 89% and 90%, respectively. Ten patients received this regimen for the treatment of four or more consecutive relapses and achieved complete remissions on each occasion. Toxicities related to therapy were not excessive. Although myelosuppression was the most frequently encountered toxicity, documented infection complicated only 14% of the treatment courses. These results constitute a considerable improvement in the management of recurrent ALL.

Earlier studies suggested that the dose of 6-mercaptopurine (6-MP) can be reduced substantially when the drug is given with allopurinol. We studied the effect of allopurinol on the kinetics of oral and intravenous 6-MP. Studies conducted initially in rhesus monkeys and subsequently in man with 6-MP doses of 100 mg/m2 and 75 mg/m2, demonstrated that allopurinol pretreatment resulted in a nearly 400% increase in peak plasma concentration of oral 6-MP in monkeys (from a mean of 0.54 microM to a mean of 2.1 microM) and a 500% increase in man (0.74 microM to 3.7 microM). Allopurinol pretreatment also led to a 300% increase in plasma AUC in monkeys after oral 6-MP (from a mean of 121 microM/min to a mean of 391 microM/min) and a 500% increase in AUC in man (from a mean of 142 microM/min to a mean of 716 microM/min). In contrast, allopurinol pretreatment had no effect on the kinetics of intravenous 6-MP. This difference was found to be due to inhibition of first-pass metabolism of oral 6-MP as the result of the action of allopurinol on liver or intestinal xanthine oxidase. Our results indicate that, although dose reduction of oral 6-MP given in conjunction with allopurinol is appropriate, it is not necessary when 6-MP is injected intravenously.

Routine morphologic and cytochemical study of the leukemic cells of a 13-month-old child did not permit definitive determination of either a lymphoid or a myeloid cell origin. However, ultrastructural cytochemical analysis revealed platelet peroxidase (PPO) reactivity. The malignant cells expressed PPO in both unfixed and fixed preparations. PPO was observed in the perinuclear space and reticulum but not in the Golgi saccules. In a 1% glutaraldehyde, 1% formaldehyde solution known to inhibit PPO but not myeloperoxidase, no reaction product was observed. The demonstration of PPO activity in these undifferentiated cells established their megakaryoblastic lineage. Further studies including DNA flow cytometry confirmed that these cells were megakaryoblasts. This study demonstrates that megakaryoblastic malignancy may occur as an acute leukemia of childhood and emphasizes the value of ultrastructural cytochemistry in cases of acute leukemia which defy routine classification. Abnormalities of chromosome 21 were present in our patient as in four previous cases of megakaryoblastic leukemia in childhood. The nonrandomness of chromosome 21 involvement in this disease should therefore be considered.

Ten children had recurrence of central-nervous-system (CNS) leukemia despite monthly injections of methotrexate into their lumbar cerebrospinal fluid. Each child was then reinduced into remission and maintained with intraventricular methotrexate administered via an Ommaya reservoir and the length of this remission was compared with the duration of the child's previous intralumbar-treated remission. Of eight evaluable patients, seven had longer CNS remissions with intraventricular therapy than with intralumbar therapy (P less than 0.02). The median CNS remission duration in all patients was 475 days with intraventricular and 286 days with intralumbar therapy (P less than 0.05). The rate of CNS relapse was reduced from 2.94 relapses per thousand days at risk during intralumbar therapy to 0.93 relapse per thousand days of intraventricular therapy. We conclude that intraventricular chemotherapy is significantly more effective against CNS leukemia than the same therapy given by lumbar puncture.

The function of the hypothalamic-adenohypophyseal unit was tested in 2 groups of rhesus monkeys before and at periodic intervals after the administration of 2400 and 4000 rads cranial radiation. This therapy was given in 10 fractions over a 2-week period. Plasma TSH, basally and after TRH administration, and LH and FSH, before and after gonadotropin-releasing hormone stimulation, were normal up to 1 yr after radiation. Plasma GH at the basal state and after arginine and L-dopa stimulation was also normal. An insulin tolerance test, however, demonstrated a blunted GH response at a dose (0.1 U/kg) that caused brisk stimulation of GH secretion in normal control monkeys. A larger dose of insulin (0.2 U/kg) resulted in ample secretion of GH in these animals, suggesting decreased hypothalamic sensitivity to insulin in treated animals. The measurement of GH every 20 min for 24 h in animals treated with 4000 rads showed a dramatically altered secretory pattern of GH 1 yr after radiation. GH secretory spikes were markedly decreased in both frequency and amplitude, suggesting a reduction in the normal daily production of GH.

Cytogenetic studies on neuroblastoma tissue from a 17-year-old girl showed a single karyotypic abnormality, del(22)(q13). The relationship of this abnormality to previously described abnormalities in neuroblastoma and to other malignancies is discussed.

A 13-yr-old male with acute myelogenous leukemia was treated with various chemotherapy regimens for 3 1/2 yr and then underwent an allogeneic bone marrow transplantation. The donor marrow was successfully engrafted, and the patient remained in remission free of all chemotherapy. Then, 5 1/2 yr later, he developed an extramedullary relapse with a chloroma of his maxillary sinus. This case illustrates the need for prolonged followup of transplant recipients and suggest that statements proposing cure as a result of this procedure may be premature.

Two patients with acute lymphoblastic leukemia treated on the same protocol became blind during complete remission. Therapy consisted of systemic combination chemotherapy, prophylactic central nervous system irradiation and monthly intrathecal cytosine arabinoside. Eight months after CNS irradiation visual acuity in both patients began to decrease. Meningeal leukemia in the area of the chiasm was suspected but despite additional radiotherapy, steroids and continued intrathecal therapy, both patients were blind within 6 months. Numerous lumbar punctures were negative for leukemic cells. Extensive investigation, including craniotomy in one case, failed to reveal the cause of blindness. Biopsy of the optic nerve in one case was compatible with radiation toxicity. We postulate that potentiation of radiation toxicity to the optic nerves and chiasm by systemic chemotherapy, intrathecal chemotherapy, or both, may have led to blindness. The patients continue in complete hemotologic and CNS remission 12 and 29 months after becoming blind.

Plasma levels of 6-mercaptopurine (6-MP) were measured after oral administration in 17 children with acute lymphoblastic leukemia (ALL). In the fasting state or after a breakfast consisting of 250 ml milk and 50 g biscuits, 6-MP was administered at a dose of 75 mg/m2. In patients studied in a fasting state, the mean time to plasma peak (tmax) level was 1.2 h, whereas in patient studied after breakfast the mean tmax was 2.3 h. This difference is statistically significant (p less than 0.001). Moreover, the 6-MP peak plasma concentration (cmax) and the areas under the plasma concentration time curves (AUC) were significantly reduced when the drug was administered after breakfast. The mean Cmax +/- SD were 0.98 +/- 0.54 microM and 0.63 +/- 0.48 microM, respectively (p less than 0.05). The mean 6-MP AUC +/- SD in patients studied in a fasting state and after breakfast were 143 +/- 69 microM min and 105 +/- 68 microM, respectively (p less than 0.01). These results indicated that 6-MP should be taken in a fasting state to optimize drug absorption in children undergoing chemotherapy for ALL.

The blood-brain barrier provides a pharmacologic sanctuary for leukemic cells within the central nervous system (CNS), protecting them from the cytotoxic effects of systemic antileukemic therapy. Attempts to overcome this problem have included specific CNS-directed treatment in the form of direct intrathecal drug injection, cranial irradiation, and alteration in the dose and schedule of systemic agents to enhance their CNS penetration. Use of these treatments and strategies has led to the effective prevention and control of meningeal leukemia. Intrathecal therapy, primarily with methotrexate or cytosine arabinoside, is a form of regional chemotherapy that can achieve very high drug concentrations at the target site [i.e., in the meninges and cerebrospinal fluid (CSF)] with a low total dose. Therefore, there is minimal systemic toxicity. The dose and schedules, clinical pharmacology, and toxicities of the commonly used intrathecal agents are discussed in detail in this article. Another approach to overcoming the limited penetration of antileukemic drugs into the CNS has been the use of high-dose systemic therapy. Methotrexate and cytosine arabinoside in high doses have produced favorable clinical responses in patients with overt meningeal disease, and pharmacokinetic studies have documented cytotoxic concentrations of these drugs within the cerebrospinal fluid. A clear understanding of the CNS pharmacology of the antileukemic drugs is required in order to use these agents in the safest and most efficacious manner for the treatment of meningeal leukemia.

To characterize the suppressor activity of neoplastic T cells from a child with acute lymphoblastic leukemia and hypogammaglobulinemia, we applied an in vitro assay that determines the capacity of pokeweed-mitogen-stimulated lymphocytes to mature into immunoglobulin-secreting cells. The geometric mean synthesis by peripheral blood lymphocytes from 12 normal persons was 3200 ng for IgM, 2447 ng for IgG and 1825 ng for IgA (2 X 106 cells per 12 days in culture). The patient's leukemic cells produced no detectable immunoglobulin and depressed the immunoglobulin production of normal lymphocytes by 85 to 100 per cent in co-culture experiments. However, suppression was observed only when co-operating normal T cells were present. Prior irradiation of either the leukemic T cells or the co-operating normal T cells nullified the suppressor effect. Therefore, an interaction between at least two different T-cell subsets may be required for the generation of suppressor effector T cells in man. (N Engl J Med 2...

The pharmacokinetics of subcutaneously administered methotrexate was studied as a parenteral alternative to oral administration. An initial feasibility study was performed in Rhesus monkeys comparing the subcutaneous route to intravenous (IV) injection and oral administration. The subcutaneous dose was completely absorbed and a sustained-release effect was observed when compared with the IV dose. No local or systemic toxicities resulted from subcutaneous methotrexate in the animals. Twelve children with acute lymphoblastic leukemia on maintenance therapy protocols prescribing either 7.5 mg/m2 biweekly or 40 mg/m2 weekly were also monitored after both a subcutaneous and an oral dose of methotrexate. Four children at the higher dosage level were also studied after an equal IV dose. The subcutaneous dose was again completely absorbed in these children at both dose levels, whereas the oral dose, which produced comparable plasma drug concentrations at the lower dosage level, resulted in a total drug exposure (area under the plasma concentration-time curve) that was one third that of the equal subcutaneous dose at the higher dosage level. No local or systemic toxicity was attributed to the subcutaneous methotrexate. Subcutaneous administration of methotrexate is well tolerated and well absorbed and appears to overcome the problems associated with oral administration, including variable absorption and saturation of the absorption mechanism with increasing doses.

The interleukin 2 (IL 2) receptor was studied in three cases of large granular lymphocyte (LGL) lymphocytosis. All cases were nonreactive with anti-Tac monoclonal antibody (MoAb; recognizing the p55 alpha subunit of the IL 2 receptor). Sodium dodecyl sulfate (SDS)/polyacrylamide gel electrophoretic analysis (PAGE) of cells to which radio-labeled rIL 2 had been chemically crosslinked revealed uniform expression of the p70/75 beta subunit of the IL 2 receptor in the absence of the alpha subunit. Stimulation of this receptor with 2 nmol/L rIL 2 for five days led to acquisition of anti-CD3 redirected cytotoxicity. This was accompanied by a fivefold to tenfold elevation in the activity of intracellular N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl esterase, an LGL granule marker enzyme. These effects of IL 2 did not require induction of the Tac peptide.

Increased expression of the multidrug resistance gene (mdr-1/P-170) and the dihydrofolate reductase (DHFR) gene have been implicated in the development of in vitro drug resistance. Overexpression, with or without gene amplification, is seen in the development of drug resistance in culture and it has been postulated that genetic modulation of mdr-1/P-170 and DHFR may also be involved in the development of clinical drug resistance. We screened lymphoblasts from 28 patients with acute lymphoblastic leukemia (ALL) for evidence of overexpression of mdr-1/P-170 using RNAse protection, RNA in situ hybridization and immunohistochemistry. Overexpression of mdr-1/P-170 without gene amplification was detected in samples from four patients (three after multiple relapses, one at presentation). Overexpression of mdr-1/P-170 was heterogeneous within the population of malignant lymphoblasts as demonstrated by RNA in situ hybridization, immunohistochemistry, and drug uptake using daunomycin autofluorescence analysis. There was no evidence of overexpression of DHFR in any of the eight patient samples tested by RNAse protection nor was there any evidence of gene amplification in 11 patient samples on Southern blot analysis. From these observations it appears that overexpression without gene amplification of mdr-1/P-170 may be one mechanism of clinical drug resistance in ALL.

Immunoglobulin (Ig) heavy (H) and light (L) chain gene rearrangements were used as molecular markers of clonal evolution and minimal residual disease in B cell precursor acute lymphoblastic leukemia (ALL). All leukemic episodes within individual patients shared at least one identical Ig rearrangement and thus arose from a common clonal progenitor cell. Nine of 11 patients displayed completely identical patterns between leukemic episodes, while two of 11 patients demonstrated genetic progression between diagnosis and relapse as evidenced by additional rearrangements. These genetic changes marked the emergence of leukemic subclones. Ig gene rearrangements were also used as sensitive markers to identify clonal cell populations in ALL patients following induction or reinduction therapy and to search for residual bone marrow disease in patients in clinical remission or with isolated extramedullary relapse. DNA rearrangements provide tumor-specific markers to follow the genetic variation of ALL and may facilitate the early detection of recurrent disease.

Fourteen patients with American Burkitt's lymphoma resistant to conventional chemotherapy were treated with high-dose combination chemotherapy and intensive supportive care. Four patients died shortly after chemotherapy, 3 of an acute carditis. All ten remaining patients demonstrated tumor regression and 3 remain in prolonged complete unmaintained remission 29+, 19+, and 9+ months after treatment. These findings demonstrate that high-dose chemotherapy will benefit some patients with Burkitt's lymphoma unresponsive to conventional chemotherapy, but the medullary and extramedullary toxicity of this treatment strategy remains a formidable obstacle.

Second hematologic malignancies occur rarely in patients previously treated for leukemia. This report describes a patient with acute lymphoblastic leukemia who remained in complete remission for 5 yr and then developed chronic myelocytic leukemia (CML). The original lymphoblasts were associated with a partial deletion of chromosome 21, while CML was associated with a classic Philadelphia marker, indicating the independent origin of the two leukemias.

The ability of cis-DDP and several analogs to enter the CSF was investigated in rhesus monkeys that had subcutaneously implanted Ommaya reservoirs connected to catheters in each monkey's fourth ventricle. Plasma and CSF samples were analyzed for platinum content by atomic absorption spectroscopy. Plasma platinum curves were biphasic with a very slowly declining terminal phase. CSF platinum curves rose to maximum concentrations 30-40 min after an IV bolus injection and declined mono-exponentially (T 1/2 = 60 min) without displaying a detectable slow terminal phase. cis-DDP given as an IV bolus of 1.5 mg/kg or 3.0 mg/kg produced peak CSF concentrations of 0.35 and 0.78 microM platinum. The ratio of CSF platinum:plasma platinum never exceeded 0.04. When cis-DDP at 3.0 mg/kg was given as a 2- or 7-h infusion, the peak CSF concentrations were 0.28 and 0.17 microM platinum, respectively. The total CSF exposure, measured as concentration X time, was the same for bolus and for 2- and 7-h infusions. Studies with analogs showed that neither malonato 1,2-diaminocyclohexane platinum (II) nor 4-carboxyphthalato 1,2-diaminocyclohexane platinum (II) had better CSF penetrance than cis-DDP. Sulfato 1,2-diaminocyclohexane platinum (II) could not be detected in the CSF. The ratio of CSF platinum:plasma platinum was never greater tha 0.02-0.03 for any of the analogs.

Three parameters of macrophage function: random migration, chemotaxis, and pinocytosis, were studied in the guinea pig after administration of Corynebacterium parvum, methanol-extraction residue of BCG, and levamisole (LMS), a synthetic anthelmintic. Macrophage migration studies were performed with a modified Boyden chamber. Pinocytosis was assessed by the uptake of colloidal 198Au. After ip administration, each of the three immunostimulators induced an increase in macrophage chemotactic responsiveness and, to a lesser extent and duration, in random motility. Kinetic, dose-response, and time course data for the effect of each agent on macrophage movement were explored. LMS was the most effective stimulator of macrophage activation, which occurred earlier and persisted longer than it did with the other agents. Macrophages from animals receiving each of the agents showed enhanced pinocytosis. Measurement of macrophage random migration, chemotaxis, and pinocytosis appeared to provide a rapid and quantitative assessment of several parameters of macrophage function and, when studied with other immunologic parameters, may provide useful tools for the evaluation of potential immunoadjuvants.

CSF and plasma antifolate concentrations during 257 intravenous (IV) infusions of high-dose methotrexate were measured in 60 children with acute lymphoblastic leukemia. In 49 children who have never had evidence for CNS leukemia, the mean steady-state CSF to plasma methotrexate ratio was 0.013 (SD = 0.01). In contrast, 11 children with overt meningeal leukemia had a 12-fold higher mean ratio of 0.157 (range, 0.013 to 0.844, p less than .01). In the group of patients studied, all of those with a CSF methotrexate concentration greater than 2 SD above the mean either had leukemic cells in the CSF or subsequently developed this condition. In two patients, overt CNS leukemia was preceded by a high CSF:plasma drug ratio at a time when there was no cytologic or clinical evidence for CNS leukemia. As previously observed with intrathecal methotrexate, we conclude that overt meningeal leukemia increases CSF drug concentrations during IV methotrexate therapy. An elevated CSF to plasma ratio may be useful to predict imminent CNS relapse or to verify completeness of response to therapy.

Two of 27 patients treated with intraventricular chemotherapy via an Ommaya reservoir developed unusual life-threatening complications attributable to the reservoir. In one patient treated for meningeal Burkitt's lymphoma, the cause of death was a large mass of tumor cells growing around the cannula. Also the tip of the cannula was found in the contralateral cerebral peduncle. In the other patient, the tip of the cannula apparently perforated the ventricular wall postoperatively and migrated into the contralateral thalamus. In both cases evidence for methotrexate-associated leukoencephalopathy was present at autopsy. Based on the experience with these two patients, we offer specific recommendations for reservoir insertion and use.

The outcome of pregnancies of patients who received aggressive chemotherapy was examined. Of 448 patients screened, 30 had 12 abortions (10 elective and two spontaneous) and 28 live births. Follow-up of off spring revealed no major malformations. In addition, growth, development and school performance were normal. These results support the contention that chemotherapy administered to women prior to gestation or after the first trimester may result in normal births in the majority of cases. Moreover, the available data suggest that chemotherapy given to men at or prior to the time of conception does not appear to result in fetal damage. These results may be of value in counseling cancer patients regarding risks to their offspring.

To produce concentrations of zidovudine (AZT) in plasma and cerebrospinal fluid that would provide constant inhibition of the replication of human immunodeficiency virus (HIV), we gave AZT by continuous intravenous infusion to 21 children ranging in age from 14 months to 12 years who had acquired HIV infection through transfusions or perinatally. All patients were symptomatic before AZT treatment (Class P2 of the Centers for Disease Control); 13 (62 percent) had evidence of neurodevelopmental abnormalities. The mean CD4/CD8 ratio was 0.18; 11 patients had CD4 counts below 0.2 x 10(9) per liter. We administered AZT at four dose levels: 0.5, 0.9, 1.4, and 1.8 mg per kilogram of body weight per hour. The plasma drug concentrations achieved at the respective dose levels were 1.9 +/- 0.3, 2.8 +/- 1.4, 3.1 +/- 1.1, and 4.5 +/- 1.0 microM. The steady-state cerebrospinal fluid:plasma ratio was 0.24 +/- 0.07. The only evidence of toxicity was bone marrow suppression. Transfusion was required in 14 patients because of low levels of hemoglobin (5 mmol per liter [less than 8 g per deciliter]). Dose-limiting neutropenia (less than 0.5 x 10(9) polymorphonuclear leukocytes per cubic millimeter) occurred in most patients who received doses of 1.4 mg per kilogram per hour or more. Improvement in neurodevelopmental abnormalities occurred in all 13 children who had presented with encephalopathy before treatment. Serial measurements of IQ before therapy and after three and six months of continuous therapy with AZT showed that IQ scores, including those for verbal and performance IQ, rose in these 13 patients and in 5 other children who had no detectable evidence of encephalopathy before treatment. Most patients also had increased appetite and weight, decreased lymphadenopathy and hepatosplenomegaly, decreased immunoglobulin levels, and increased numbers of CD4 cells. In some patients the improvement in the features of encephalopathy occurred despite the absence of immunologic improvement. We conclude that AZT is beneficial in children with symptomatic HIV infection, especially those with encephalopathy (which may be subclinical), and that the optimal continuous intravenous dose of AZT in children is between 0.9 and 1.4 mg per kilogram per hour.

The ability of a new antitumor agent, AZQ (2,5-diaziridinyl-3,6-bis-carboethoxyamino-1,4-benzoquinone), NSC No. 182986, to enter the cerebrospinal fluid (CSF) was studied in nonhuman primates. Following parenteral administration of 14C-AZQ, CSF radioactivity rose quickly and reached a maximum value 60 min after administration. Total radioactivity in the CSF was about 25-35% of the corresponding plasma level at time points subsequent to maximum CSF concentration. Chloroform extraction and thin-layer chromatography revealed that much of the total radioactivity was not parent AZQ and that parent AZQ declined rapidly in both plasma and CSF with a half-life less than 1 h. AZQ clearly entered the CSF and yielded CSF concentrations comparable to plasma values.

During maintenance therapy with intraventricular methotrexate, progressive dementia developed in a child with meningeal leukemia. Cerebrospinal fluid levels of MTX were in the nontoxic range and neurologic evaluation failed to demonstrate anatomic obstruction, infection, or folate depletion. The patient's symptoms gradually resolved when the methotrexate was discontinued, suggesting that methotrexate neurotoxicity may occur in the absence of an elevated CSF concentration of MTX.

The ability of antiserum against murine L1210 leukemia to remove residual leukemia cells from murine bone marrow was investigated. Leukemic marrow was treated in vitro with antiserum and complement and used to hematologically reconstitute mice that had been irradiated with doses lethal to bone marrow. Following infusion of treated leukemic marrow, normal marrow returned without evidence of leukemia. More than 90 percent of the animals have survived for 11 months without untoward effects, suggesting that the technique may be of use in the treatment of acute leukemia in humans.

The combination of the lipophilic antifolate trimetrexate and the rescue agent leucovorin has shown promise in the treatment of Pneumocystis carinii pneumonia in patients with acquired immunodeficiency syndrome. The pharmacokinetic behavior of trimetrexate administered either by intravenous bolus or orally was studied in six patients with acquired immunodeficiency syndrome with a reversed-phase high-pressure liquid chromatography assay. The mean clearance following bolus injection was 38 ml/min per m2, with a range of 15 to 55 ml/min per m2. The postdistributive half-life ranged from 6 to 16 h. With oral administration, the mean bioavailability was 44% (range, 19 to 67%). An oral dose of 60 mg/m2 (162 mumol/m2) resulted in concentrations in plasma that approximated those achieved with a 30-mg/m2 (81-mumol/m2) intravenous dose. The toxicity of this combination regimen was minimal. It appears that the oral route is a practical route of administration for trimetrexate in patients with acquired immunodeficiency syndrome requiring long-term outpatient treatment or prophylaxis for P. carinii pneumonia.

Activities of enzymes of the purine metabolic pathway, adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP), and 5′- nucleotidase (5′-N), were investigated in the lymphoblasts of a patient with B-cell acute lymphoblastic leukemia. These lymphoblasts exhibited increased ADA activity and diminished activities of both PNP and 5′N' as compared to normal lymphocytes as well as non-T, non-B leukemia cells. This enzymatic pattern is identical to that which has been described in T-cell leukemic lymphoblasts and differs from that which has been observed in the malignant cells of undifferentiated B-cell lymphomas. These data suggest that there is biochemical heterogeneity within the spectrum of B-cell malignancies. Furthermore, inhibitors of ADA may be of use in those B-cell lymphoid neoplasms that exhibit increased ADA activity.

Purine nucleoside phosphorylase (PNP) activity has been measured in the lymphoblasts of 22 patients with acute lymphoblastic leukemia (ALL) and correlated with routine immunologic cell surface markers. Fourteen of the 22 patients were considered to have non-T, non-B-cell ALL; 8 patients had T-cell disease. The median PNP activity in 21 control samples of normal peripheral blood mononuclear cells was 83 U. The median PNP activity of the non-T, non-B lymphoblasts was 79 U. No statistical difference in PNP activity between these two groups could be discerned (p < 0.37). In contrast, T-cell lymphoblasts demonstrated diminished PNP activity with a median of 38 U. The differences in activity between T lymphoblasts and both non-T, non-B leukemic cells and normal peripheral blood mononuclear cells were significant (p < 0.001 and p < 0.003, respectively). Evaluation of PNP activity provides further evidence of biochemical heterogeneity among immunologic subclasses of ALL.

L-asparaginase, a highly effective anti-leukemic enzyme preparation is now frequently being administered intramuscularly in order to decrease the incidence of severe sensitivity reactions. Although the occurrence of immediate hypersensitivity reactions and anaphylaxis has been diminished through this technique, we report three patients who developed delayed allergic reactions occurring hours after drug administration. This suggests that patients receiving L-asparaginase intramuscularly merit prolonged observation periods beyond the usual one half to one hour.

We studied the suppressor activity and surface-membrane antigens of immunoregulatory neoplastic T cells from a child with acute lymphoblastic leukemia and hypogammaglobulinemia. The neoplastic T cells were potent inhibitors of immunoglobulin production by pokeweed-mitogen-stimulated normal B cells when radiosensitive cooperative normal T cells were present. Preculturing the leukemic cells with normal T cells or soluble factors allowed them to mediate suppression without the need for cooperating T cells. While acquiring new functional capabilities, approximately 95 per cent of the leukemic cells displayed an antigen (OKT-3) that is found on mature normal T cells; 77 per cent displayed an antigen (Tac) that is found on normal activated immunoregulatory effector cells but not on thymocytes or circulating T cells that are precursors of these effector cells. The results suggest that a population of leukemic prosuppressor cells can be induced to undergo both functional and antigenic differentiation by the influence of normal T cells.

The use of radiation and chemotherapy has resulted in significant improvement in the treatment of central nervous system (CNS) malignancy.5,73 However, despite their positive therapeutic impact, it is now clear that both these modalities may be associated with a variety of adverse neurological sequelae.57,58,73 Indeed, many of the neurological complications of CNS therapy have only recently become apparent. Neurological sequelae may occur acutely or they may be delayed, occurring months to years following the initiation of therapy.73 Although the acute neurological problems secondary to radiation and chemotherapy are now well recognized, delayed toxicities are less clearly characterized and may be more difficult to diagnose. This presents a significant dilemma to the clinician, since it is known that some forms of delayed neurotoxicity can be reversed if detected at an early stage.56

The authors report a patient with acute lymphocytic leukemia in hematological remission who presented with both intracranial and otological manifestations of the disease. The patient presented with clinical symptoms and computed tomographic findings consistent with otomastoiditis and a contiguous brain abscess. However, both lesions were identified at operation as leukemic infiltrates. Intracranial mass lesions and otological complications associated with leukemia are reviewed.

The development of effective chemotherapy for the treatment of central nervous system (CNS) malignancy poses a major challenge to the oncologist. Although the use of antineoplastic drugs has been responsible for considerable improvement in the treatment of a variety of extracerebral malignancies, the mainstays of treatment for tumors of the brain remain surgery and radiation therapy. This circumstance has resulted in part from problems relating to difficulties in the delivery of chemotherapeutic agents to the CNS. Thus, somewhat ironically, although a wide variety of chemotherapeutic agents are available to the oncologist, relatively few of these compounds possess the pharmacological characteristics that render them suitable to treat CNS malignancy.

We have used a special class of human acute lymphocytic leukemias, the common "non-T/non-B" cell type, to define a hierarchy of genetic rearrangements that occur during the earliest stages of B-cell maturation. This has allowed us to identify intermediate cells predicted by a hierarchial model in which immunoglobulin heavy chain variable region gene formation precedes that of light chain and in which kappa light chain gene formation precedes that of lambda. The model emphasizes the flexible nature of immunoglobulin gene recombination that not infrequently produces aberrant or null genes that are phenotypically excluded from expression. Remaining alleles or isotypic genes can then be utilized as "spares" undergoing recombination until a valid gene is formed. Significantly, the excluded allele or isotype is frequently deleted from the genome. In addition to defining a pathway of genetic maturation, this analysis provides a powerful means to further classify cases of non-T/non-B-cell acute lymphocytic leukemia, most of which seem to reside at early stages along the B-cell pathway of differentiation.

In the past several years, molecular biologic techniques have been applied to complement immunologic methodologies in defining lineage, clonality and differentiation of lymphoproliferative diseases. In addition to these insights, molecular characterization of lymphoid cells has provided a sensitive way to detect small populations of clonal cells. This is of particular importance in diseases such as pre-B acute lymphoblastic leukemia (ALL), in which tumor-specific surface markers have not been identified.1

4'-(9-Acridinylamino)-methanesulfon-m-anisidide (m-AMSA) is an acridine compound that has been found useful in the systemic treatment of acute leukemia. This paper specifically investigates the CSF pharmacokinetics of m-AMSA following both intravenous and intraventricular administration in a subhuman primate model. Following intravenous administration, m-AMSA crossed the blood-brain barrier poorly; cerebrospinal fluid (CSF) concentrations were only 1-3% of systemic concentrations. Intraventricular administration of drug achieved high initial ventricular fluid concentrations, but the drug was rapidly cleared with a half-life of 115 min. Following 500 micrograms of intraventricular drug, CSF concentrations of m-AMSA remained above 1 microM for only 6 h. These data suggest that m-AMSA has potential as an intrathecal agent against meningeal leukemia refractory to more conventional therapy, but detailed toxicology and neurohistopathology will be required before intra-CSF m-AMSA can be considered for human use.

Monoclonal antibody WT1 (anti-CD7), conjugated to ricin A chain, was administered intrathecally to rhesus monkeys to test its suitability for use in the therapy of leukemic meningitis. The WT1-SMPT-dgRTA conjugate was cytotoxic to CEM (T-lymphoblastic leukemia) cells in vitro with an ID50 of 53 pM. Immunoperoxidase testing showed no binding of WT1 to normal human tissues other than lymph nodes. Thirteen animals received one or more intrathecal 60-micrograms doses of WT1-SMPT-dgRTA. All monkeys receiving repeated doses developed a cerebrospinal fluid (CSF) pleocytosis (primarily eosinophils), which was generally resolving by 3-4 weeks after therapy. Pharmacokinetic studies showed a half-life of 99 min, consistent with CSF clearance by bulk flow. Peak CSF immunotoxin concentrations exceeded the ID50 for CEM cells by more than 2 log units and a concentration exceeding the ID50 was maintained for as long as 24 h. All eight monkeys receiving repeated doses of immunotoxin developed serum antibodies against both WT1 and ricin A chain. In six of these monkeys antibodies were also present in the CSF. Both anti-WT1 and anti-(ricin A chain) antibodies were able to inhibit in vitro cytotoxicity of the immunotoxin for CEM cells; however, only anti-WT1 antibodies could block immunotoxin binding to the cell surface. No monkey developed anti-immunotoxin antibodies fewer than 7 days after the initiation of therapy, suggesting that repeated doses could be administered for up to 1 week without inhibition of clinical activity.

Early initiation of empiric antibiotic therapy in febrile cancer patients has become established practice, but the appropriate duration of antibiotic therapy when no infectious source can be identified is unknown. The complications of broad-spectrum antibiotics argue for brief treatment, but the risk of an inadequately treated infection in the granulocytopenic patient favors longer therapy. We prospectively studied 306 episodes of fever and granulocytopenia in 143 patients with leukemia or solid tumor (age one to 33 years) with respect to the duration of empiric antibiotic treatment. Eligible patients (fever > 38 °C three times/24 hours or > 38.5 °C once, plus polymorphonuclear leukocytes 3 ) had an extensive diagnostic evaluation, including at least two preantibiotic blood cultures, and therapy was then started with a broad-spectrum antibiotic regimen— Keflin ® , gentamicin and carbenicillin (KGC). Initial evaluation failed to identify an infectious etiology for the fever in 142 of 306 (46 per cent) episodes. Fifty-six of 142 (39 per cent) of these fevers of unknown origin were associated with persistent granulocytopenia for more than seven days; in 33 of these, defervescence occurred while the patients received KGC. After seven days of empiric KGC therapy, the 33 patients with fevers of unknown origin who had become afebrile with empiric antibiotics but whose polymorphonuclear leukocytes remained less than 500/mm 3 were randomized to either continue or discontinue (dc) to receive KGC. The patients who continued to receive KGC until their polymorphonuclear leukocytes were more than 500/mm 3 had no infectious sequelae. However, in seven of 17 (41 per cent) of the patients randomized to dc KGC infectious sequelae developed (p = 0.007) within a median of two days of discontinuing KGC (two with fever which again responded to KGC therapy, and five with a documented infection [two ultimately fatal]). In none of the patients did a resistant microbial flora or superinfection develop. These data suggest that the patient with a fever of unknown origin who becomes afebrile during empiric antibiotic therapy may profit from continued therapy while granulocytopenia persists.