[The status of natural immunity in children with acute lymphoblastic leukemia evaluated by long-term monitoring of complement-dependent bacteriocidal antibodies against B. anthracis and its relation to prognosis].

The authors investigated the function of the time factor as regards changes of bacteriocidity levels of serum against B. anthracis. Due to the fact that anthrax has not occurred in this country for several decades, we can speak of an investigation of natural immunity in the wider sense of the word. In the course of 15 years the authors collected repeatedly blood specimens from 53 children with ALL before, during and after treatment. Active sera were examined by quantitative titration by means of microbes labelled with 51Cr. The results of the investigation revealed that mean values of bacteriocidity calculated from all specimens and for each child separately are higher in the groups of children with a favourable course of the disease, as compared with children with an adverse course of the disease. It was also found that in a high percentage (78%) patients with long-term remission of leukaemia have a rising trend of bacteriocidity and the majority of children with a relapse of the disease (69%) had a bacteriocidity of serum with a declining trend (p = 0.01). The prognostic value of the test is unequivocally apparent from the results of the "life table" analysis. Children with an event free survival as well as the number of surviving children was significantly higher in the group with a rising trend of bacteriocidity than in patients with a declining trend of bacteriocidity (p = 0.008 and p = 0.02).