One hundred and fourteen patients with acute leukemia, 57 children (10 AML and 47 ALL) and 57 adults (37 AML and 20 ALL) were treated with L-asparaginase (Asnase) 200 or 1000 IU/kg daily for 30 days unless withdrawn on account of side effects. Combinations with other cytotoxic drugs were used in all but eight patients. Hypersensitive reactions, decrease in Asnase activity in plasma, and bivalent antibodies to Asnase appeared more frequently in adults (28%, 46%, and 79%, respectively) than in children (16%, 17%, and 25% respectively). There was a clear association between these three parameters. Thus hypersensitive reactions generally developed at the time of or after the decrease in plasma Asnase activity. Antibodies were detected only where Asnase activity had disappeared from the plasma. This time sequence, and in vitro experiments, suggest the formation of antigen-antibody complexes which might be responsible for inactivation of Asnase and for the development of hypersensitive reactions. However in many cases antibodies were found without concomitant enzyme inactivation or hypersensitive reactions. Antibodies to Asnase of IgE type (reagins) were found in only 10 children and 6 adults. There was no correlation between hypersensitive reactions, decrease in Asnase activity, and IgE antibodies. The frequency of remission among patients developing bivalent antibodies to Asnase was 68% (13/19) in contrast to 27% (3/11) among patients whose sera contained no detectable antibodies to Asnase, but the difference was not statistically significant.

The preliminary results of a controlled clinical trial organized by the S.I.O.P. of radiotherapy and chemotherapy in patients with nephroblastoma are presented. Forty-two centers have participated. Between September 1971 and October 1974,398 patients were registered; 195 were eligible for the trial and were randomized. The remaining 203 patients were excluded from the trial, but were followed in the same way as the patients in the trial. The results were evaluated in terms of recurrence-free survival rate and survival rate. Results in patients who received preoperative and postoperative radiotherapy (group A, 73 patients) were compared with the results in patients who recieved only postoperative radiotherapy (group B, 64 patients). The tumor ruptured at surgery in three patients of group A, and in 20 patients of group B, a difference that is statistically significant. No significant difference in survival a n d recurrence-free survival between groups A and B is observed at present. Results in patients treated with a single course of actinomycin D (group I, 80 patients)were compared with the results in patients treated with multiple courses (group 11, 80 patients). At present, no significant difference is found between the two groups.

Ten (24%) of the 41 patients had abnormal findings on radiological examination of the lungs at long-term follow-up and seven are or had been smokers. It is of great importance that patients with LCH be informed about smoking-related pulmonary morbidity. Prolonged monitoring of the lungs for smokers and patients with known pulmonary involvement is recommended.

Multi-system LCH is associated not only with increased mortality but also pronounced propensity for severe late sequelae; 51% of the patients (multi-system=33%, single-system=67%) were alive without sequelae at follow-up. Among multi-system patients, at least 19% suffered CNS sequelae.