Basal plasma glucagon levels of man.

The isolated perfused rat liver can serve as a bioassay system for glucagon, capable of detecting 10 mmug of this agent. Seven 15-ml plasma specimens obtained from different healthy volunteers after an overnight fast were assayed in this system; glucagon could not be detected in any of them, indicating concentrations significantly below 0.67 mmug per ml in all subjects. The effects of administering small doses of glucagon to patients were consistent with these results; imposition of increments to plasma glucagon concentration below 1 mmug per ml induced distinct and sustained increases in blood glucose. Observations of the biologic effects of glucagon, together with data on the rate of its inactivation by the liver, suggest that the basal concentration of this hormone in peripheral plasma probably does not exceed 0.1 mmug per ml.

Circulating colony-forming cells in different stages of chronic myelocytic leukemia.

The incidence of circulating granulocyte-macrophage colony-forming cells (CFU-c) was determined in 60 patients in different stages of chronic myelocytic leukemia (CML). Like others, we found uniformly increased circulating CFU-c during the uncontrolled chronic stage, decreasing to values indistinguishable from those of healthy controls during remission. Unlike some investigators who described grossly deficient colony formation during the blastic stage of CML, we found normal to greatly increased colony formation in the accelerated-resistant and blastic stages. The fact that laboratories using somewhat different culture techniques obtain similar results with specimens from the chronic stage of CML but divergent results with specimens from terminal stage disease suggests that CFU-c from blastic disease have more fastidious growth requirements than do those from chronic stage disease or from normal subjects. In contrast to the correlation between CFU-c and disease status in the chronic stage of CML, CFU-c incidence in the accelerated-resistant and blastic stages of the disease did not correlate with white blood cell count, percentage of immature cells, clinical status, or survival. There was no correlation between the percentage of myeloblasts and promyelocytes in circulating blood and the incidence of CFU-c in any stage of CML, which suggests that no direct relationship exists between clonogenic units and the number of identifiable proliferating cells.

Decreased stainable marrow iron in chronic granulocytic leukemia.

Stainable iron was absent or decreased in 36 of 45 bone marrow biopsy specimens (80 percent) among 33 patients with chronic-stage chronic granulocytic leukemia. Decreased iron did not correlate with sex, treatment status, duration of disease, marrow cellularity, or hemoglobin level. In contrast, marrow iron was absent or decreased in 34 percent of biopsy specimens at diagnosis of acute nonlymphocytic leukemia (p less than 0.0001) and 31 percent of biopsy specimens from patients with Hodgkin's disease (p less than 0.0001). The serum ferritin level was determined in eight patients with chronic granulocytic leukemia and absent marrow iron, and it was normal in all. Fifteen of 17 patients, followed with chronic-stage disease for one to four years after the finding of absent marrow iron, demonstrated increases in their hemoglobin levels during antileukemic therapy or maintained normal values. Thus, absent or decreased stainable marrow iron is a common finding in chronic granulocytic leukemia and usually does not indicate iron deficiency.

In vitro leukocyte thymidine uptake and prognosis in chronic lymphocytic leukemia.

Among 60 patients with chronic lymphocytic leukemia, higher in vitro uptake of tritiated (3H) thymidine by leukocytes of a standard volume of peripheral blood was associated with a higher lymphocyte count, a more advanced stage, greater frequency of functional impairment and shorter survival. Appropriate analyses demonstrated that leukocyte thymidine uptake correlated with survival independently of these other disease features. Relative thymidine uptake (radioactivity per 10(3) lymphocytes) did not prove to be a useful prognostic parameter. Among 33 patients not receiving antileukemic therapy at the time of study, 15 of 17 (88 per cent) of those with higher thymidine uptake values, but only 3 of 16 (19 per cent) of those with lower values, were treated during a median follow-up period of four and a half years (p less than 0.001). Seven of the former group, but none of the latter group, died during the first three years of follow-up (p less than 0.01). We conclude that thymidine uptake by circulating leukocytes constitutes a relatively accurate index of the proliferating leukemic cell mass in this disease and provides useful prognostic information.

Splenectomy for palliation of chronic myelocytic leukemia.

Sixty patients with chronic myelocytic leukemia (CML) (most, in the "terminal phase" of the disease) were subjected to splenectomy because of symptomatic splenomegaly, thrombocytopenia or anemia for which they required frequent transfusions. Surgical morbidity and mortality were high when the procedure was performed on a "casual" basis, but both were reduced sharply after care of these patients was restricted to a single medical-surgical-nursing team and improved technics of surgery and perioperative management were developed. Significant hematologic and clinical benefit was achieved in half of the patients and temporary arrest of the disease was often observed, but in most patients, the basic evolution of CML was not greatly altered. In eight patients, however, long-lasting improvement (one to nine years) was recorded. Measurement of the doubling time of circulating leukemic cells and other observations were consistent with the hypothesis that, in some patients, the spleen contains a more rapidly proliferating and "more malignant" population of leukemic cells than the marrow. We conclude that splenectomy is often a useful palliative procedure in advanced stages of CML, and that it may be strikingly beneficial in 10 to 15 per cent of such cases.

Evidence for a selective antileukemic effect of cytosine arabinoside in chronic granulocytic leukemia.

On the basis of in-vitro studies indicating that low concentrations of cytosine arabinoside exert preferential inhibition of granulocyte-macrophage colony-forming cells from patients with chronic granulocytic leukemia vs normal subjects, we treated two outpatients with low doses of this agent, administered by subcutaneous infusion for 12-31 days. Both patients continued their usual activities, including employment, during these infusions. They exhibited only Ph-positive metaphases at entry into the protocol but in both cases, Ph-positive cells were reduced to approx. 10% of marrow metaphases, after 2-3 successive infusions. Both patients exhibited significant increases in Ph-positive cells, to 46 and 72% of marrow metaphases, during subsequent chemotherapy with hydroxyurea, in dosage sufficient to maintain granulocytopenia and a normal serum B12 level. After additional cytosine arabinoside, both patients again showed decreases in Ph-positive cells, to 7% (p less than 0.01) and 19% (p less than 0.0001), respectively. This clinical experience is consistent with the conclusion that cytosine arabinoside (but not, hydroxyurea) exerts a selective antileukemic effect in some patients with CGL.

Survival in Ph1-positive chronic myelocytic leukemia: relationship to findings at diagnosis and to disease kinetics after the first course of treatment.

Survival in 73 patients with Ph1-positive chronic myelocytic leukemia was correlated with remission duration and leukocyte doubling time after initial treatment with busulfan and also, with clinical and laboratory features recorded at the time of diagnosis. There was a significant relationship between remission duration and leukocyte doubling time (correlation coefficient 0.94). On multivariate analysis, the most important factor influencing remission duration (and doubling time) was the percentage of circulating blasts (p less than 0.001). The spleen size (p less than 0.02), Liver size (p less than 0.03) and WBC (p less than 0.03) also added significantly to model fit; however, once a second variable was entered into the model no other factor produced significant improvement in model fit. In univariate analyses, the remission duration, doubling time, percentage of circulating blasts, spleen and liver size correlated significantly with survival. Multivariate analysis indicated that the percentage of circulating blasts was the most important factor affecting survival (p less than 0.001), with the liver size adding significantly to model fit (p less than 0.05). Remission duration, leukocyte doubling time and spleen size did not significantly influence survival once the percentage of blasts was included in the model. Thus, evaluation of clinical and laboratory data at the time of diagnosis is more important for prognostic classification of patients than the measurement of relapse kinetics after initial treatment with busulfan.

Immunotherapy of chronic myelocytic leukemia: effects of different vaccination schedules.

In a clinical trial of immunotherapy in chronic myelocytic leukemia, 62 patients received repeated intradermal injections of BCG-cultured cell mixtures, while 16 were vaccinated with BCG alone. The lymphoblastoid cell lines used for vaccination were established from blood of patients with advanced myeloid leukemia and were reactive with "specific" primate antisera against myeloid leukemic cells. Both sensitization to target cell antigens and substantial general increases in delayed hypersensitivity responses were recorded among immunized patients. Major immunologic complications (hypersensitivity and "autoimmune" phenomena) were observed in 10 patients. These complications were attributable to the BCG content of vaccines, and their incidence correlated with intensity of immunologic stimulation. Data from cases in which intermittent busulfan therapy was used provided suggestive evidence that immunotherapy (either with BCG-cell mixtures or with BCG alone) prolonged unmaintained remissions in one-third of the patients. Among 48 "good-risk" patients, there was an inverse correlation between intensity of immunologic stimulation and survival. The survival of 18 patients who received the most intensive vaccination schedule was identical to that of controls. Survival of the other 30 patients was significantly better (p = 0.03), with an increase of 2 years in median survival. Survival of 30 poor-risk patients (24, most intensive vaccination schedule) was identical to that of controls. We conclude that immunologic stimulation may produce worthwhile prolongation of life in CML but that overly aggressive schedules of immunotherapy abrogate this effect. Our experience raises the question whether results in other clinical trials of immunotherapy may have been adversely affected by excessive frequency or dosage of immunologic stimulants.