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Polymorphonuclear leukocytes (PMN) from 11 patients with acute non-lymphoid leukemia (ANLL) in complete remission and off therapy for at least 22 months were studied for their oxidative metabolism and motility. In all patients, PMN motility tests revealed no consistent abnormality, whereas cells from 2 patients showed a selective impairment of oxidative metabolism, as assessed by the low capacity to reduce nitroblue tetrazolium and/or to generate chemiluminescence when stimulated with phorbol myristate acetate. No morphological change was detectable in PMN from these patients. However, the functional alterations appeared related to an early tendency to relapse, as both patients developed an acute phase after 5 and 9 months from testing, respectively. This suggests that abnormal PMN may circulate in ANLL patients in complete remission in spite of a normal differential count and that functional studies may be useful for detecting such a population.

Forty-seven patients with primary refractory, relapsed, and previously untreated, poor risk AML were entered into a phase II study of intermediate dose ARA-C (IDAC) (1 g/m2 i.v. over 6 hr, daily for 6 days) with sequential mitoxantrone (MITOX) (6 mg/m2 i.v. bolus 3 hr after the end of each ARA-C infusion). Overall, complete remission was induced in 31 patients (66%), and 1 additional patient entered a partial remission. Seven patients (15%) died of infection during marrow hypoplasia. Response to IDAC + MITOX was influenced by sensitivity to previous therapy: patients with primary refractory and early relapse AML responded less well to the regimen (CR rate 28% and 33%, respectively), as compared to those with previously untreated (CR rate 64%) or late relapse disease (CR rate 85%). Sixteen patients continue in CR at 1-12+ months. Except for the expected severe myelosuppression, the regimen was well tolerated with minimal extramedullary toxicity. The data indicate that the sequential combination of IDAC and MITOX is an effective and tolerable regimen for AML. Consideration should be given to applying this program at earlier stages of AML therapy.

We studied a group of patients with myelodysplastic syndromes (MDS) for surface markers and cytotoxic activities of peripheral blood mononuclear cells (PBMNC). The results indicate a significant increase in the total count of CD11b+, Leu7+ and CD16+ with a percent reduction in CD4+. A reduction in PHA-induced cellular cytotoxicity (PHA-ICC) and NK activity were found. A similar phenotype was found both in refractory anemia (RA) and (RA) with excess of blasts (RAEB/RAEB-t). However, the functional activities reached the normal level only in RA patients; while in RAEB/RAEB-t patients a significant reduction was detected in PHA-ICC and NK activity.

Sixty-three patients with acute nonlymphoid leukemia (ANLL) under cytostatic treatment were investigated in a randomized trial to determine whether oral administration of cotrimoxazole (TMP/STX) would reduce the rate of infection. Four significant differences were observed between the group given TMP/STX (30 patients) and the control group (33 patients): 1) the mean duration of severe granulocytopenia (less than or equal to 500 PMN/mm3) before the first febrile episode was longer in prophylaxis group, 14.26 days versus four in the control group (p less than 0.001); 2) the number of febrile episodes was 37 in TMP/STX group and 69 in control group (p less than 0.01); 3) 23 patients on prophylaxis presented at least one febrile episode versus 33 in the control group (p less than 0.01); 4) deaths due to infection were two in the TMP/STX group versus 11 in control group (p less than 0.05). Prophylaxis with TMP/STX appears to be useful since by reducing the number of febrile episodes and deaths due to infection, it increases the survival of leukemia patients under cytostatic drugs. Nevertheless, further studies on a larger number of patients are necessary in order to confirm the true efficacy of the drug in the reduction of sepsis and death due to infection.