Levels of 2'-deoxycoformycin, adenosine, and deoxyadenosine in patients with acute lymphoblastic leukemia

2'-Deoxycoformycin (dCF), a potent inhibitor of adenosine deaminase, has recently undergone Phase I clinical trials and has been found to be therapeutically active in acute lymphoblastic leukemia. In this report, levels of dCF in plasma, plasma concentrations of adenosine and deoxyadenosine, and urine levels of deoxyadenosine were measured in leukemic patients undergoing treatment with dCF during a Phase I clinical trial. dCF was administered i.v. at a dose of 0.25 to 1.0 mg/kg (7.5 to 30 mg/sq m) for 3 consecutive days. Plasma drug levels of 2 to 6 microM were observed following the third dose of dCF, and drug accumulation occurred only at the 1-mg/kg dosage. In this limited series of patients, the plasma concentrations of adenosine and deoxyadenosine and the urine concentrations of deoxyadenosine did not show an obvious correlation with dCF dose, therapeutic response, or toxicity.

Phase I study of 2'-deoxycoformycin in acute lymphoblastic leukemia

2'-Deoxycoformycin (2'-dCF), a tight-binding inhibitor of adenosine deaminase, was administered to 26 pediatric patients with acute lymphoblastic leukemia in a Phase I study. Doses ranged from 0.25 to 1.0 mg/kg given i.v. for 3 consecutive days. Common toxicity included nausea, vomiting, diarrhea, hepatocellular enzyme elevations, and conjunctivitis. Lymphopenia occurred in all patients. The most serious adverse effects were acute tubular necrosis and central nervous system toxicity, which appeared to be dose related. In addition, two patients given the 0.75-mg/kg dose developed severe hepatic toxicity, although this could not be ascribed definitively to 2'-dCF. Antitumor activity was observed in eight patients, two of whom experienced a complete remission. Inhibition of lymphoblast adenosine deaminase activity was noted in the majority of cases and was observed at all doses. Antileukemic activity occurred at doses of 2'-dCF which were not associated with limiting toxicities. These results suggest that 2'-dCF is active against acute lymphoblastic leukemia and that a starting dose of 0.5 mg/kg/day be utilized in Phase II studies.

Lymphoblast purine pathway enzymes in B-cell acute lymphoblastic leukemia

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.

Testicular function in boys after chemotherapy for acute lymphoblastic leukemia

Fourteen boys with acute lymphoblastic leukemia who had been treated with combination chemotherapy (prednisone, vincristine, methotrexate, and 6-mercaptopurine) were followed prospectively to assess the effect of this regimen on gonadal function. At the start of therapy, nine patients were prepubertal, four were intrapubertal, and one was sexually mature. The interval between discontinuation of chemotherapy and the most recent endocrine evaluation ranged from two months to 8 1/2 years (median, 5 1/2 years). Throughout the follow-up period, all patients had normal testicular function as determined by Tanner staging at physical examination and by serum gonadotropin and testosterone levels. Semen samples from six patients were unremarkable except for one sperm count that fell in the low-normal range. These results indicate that the administration of antileukemic chemotherapy can be compatible with normal gonadal development.

Tolerance to single-dose dactinomycin in combination chemotherapy for solid tumors

We have reviewed our experience using single-dose dactinomycin (Act D). Twenty-nine patients with Ewing's sarcoma or rhabdomyosarcoma received 114 courses of Act D (2 mg/m2) in combination with vincristine, cyclophosphamide, or DTIC with or without radiotherapy. Side effects included nausea and vomiting (100% of the courses), severe thrombocytopenia (16%), granulocytopenia (18%), and mucositis (25%). In addition, skin reactions were observed in 74% of the courses following concomitant radiotherapy. These results were compared with those following 152 courses of combination chemotherapy which contained doxorubicin in place of Act D and which were administered to these same patients. It is concluded that single-bolus Act D is no more toxic, is at least as effective, and is more conveniently administered than the traditional divided daily dose of Act D.

Pregnancy outcome following cancer chemotherapy

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.

Purine nucleoside phosphorylase activity in acute lymphoblastic leukemia

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.

Microanalysis and X-ray fluorescence spectrometry of platelets in diseases with elevated muscle calcium

Electron microscopic X-ray microanalysis and X-ray fluorescence spectrometry were done on platelets from patients with Duchenne muscular dystrophy and idiopathic scoliosis (both these conditions are known to be associated with increased intramyofibre calcium). A significant increase in calcium and phosphorus concentrations was found in the dense granules and whole cells of both conditions. The findings suggest that idiopathic scoliosis like Duchenne muscular dystrophy is a multisystem disease with detectable changes in platelets.

Pyomyositis in acute lymphocytic leukemia heralded by cutaneous vasculitis: brief communication

We have observed two cases of staphylococcal myositis in patients with acute lymphocytic leukemia which are distinguished from previously reported cases by a history of cutaneous vasculitis overlying the area of subsequent infection.