Enrichment of atypical hyperdiploidy and IKZF1 deletions detected by SNP-microarray in high-risk Australian AIEOP-BFM B-cell acute lymphoblastic leukaemia cohort.

Acute lymphoblastic leukaemia (ALL) is the most common childhood malignancy with the majority of patients being classified as B-cell lineage (B-ALL). The sub-classification of B-ALL is based on genomic architecture. Recent studies have demonstrated the capability of SNP-microarrays to detect genomic changes in B-ALL which cannot be observed by conventional cytogenetic methods. In current clinical trials, B-ALL patients at high risk of relapse are mainly identified by adverse cancer genomics and/or poor response to early therapy. To test the hypothesis that inclusion of SNP-microarrays in frontline diagnostics could more efficiently and accurately identify adverse genomic factors than conventional techniques, we evaluated the Australian high-risk B-ALL cohort enrolled on AIEOP-BFM ALL 2009 study (n = 33). SNP-microarray analysis identified additional aberrations in 97% of patients (32/33) compared to conventional techniques. This changed the genomic risk category of 24% (8/33) of patients. Additionally, 27% (9/33) of patients exhibited a 'hyperdiploid' genome, which is generally associated with a good genomic risk and favourable outcomes. An enrichment of IKZF1 deletions was observed with one third of the cohort affected. Our findings suggest the current classification system could be improved and highlights the need to use more sensitive techniques such as SNP-microarray for cytogenomic risk stratification in B-ALL.

Anesthesia for children with hyperleukocytosis a retrospective review.

BACKGROUND: Hyperleukocytosis (a white cell count in peripheral blood >100 x 10(9) l(-1)) is a well-recognized medical emergency. Rates of morbidity associated with anesthesia in hyperleukocytotic patients have not been previously described. This retrospective study describes the perioperative morbidity and mortality of children who present acutely with hyperleukocytosis. METHODS: All patients under 17 years of age with leukemia complicated by hyperleukocytosis and who received general anesthesia as part of their acute care at the Children's Hospital in Westmead from July 1999 to June 2008 were included. Data describing perioperative adverse events within 48 h of anesthesia were collected using a systematic chart review. RESULTS: Over the 8- year period, 60 children were admitted with hyperleukocytosis related to a new diagnosis of leukemia. Fifty-two children had general anesthesia within 48 h of their admission. Eleven children required two separate general anesthetics within this same time frame. Two deaths were recorded within 48 h of anesthesia; one child died from neurological complications of her disease, and the second died from multi-organ failure. Three children had serious respiratory adverse events requiring postanesthesia intensive care. Thirteen children had notable but less serious adverse events. These were typically respiratory in nature and required supplemental oxygen for more than 2 h after anesthesia. CONCLUSION: Children with leukemia-related hyperleukocytosis often require general anesthesia at the time of presentation and are at significant perioperative risk. Respiratory adverse events are very common and mandate close postanesthesia care.