Predictive value of hematological and phenotypical parameters on postchemotherapy leukocyte recovery

High molecular risk variants, severe thrombocytopenia and large unstained cells count affect the outcome in primary myelofibrosis

Apart from the driver mutations, high molecular risk (HMR) variants and other factors have been reported to influence the prognosis of primary myelofibrosis (PMF). The aim of our study was to investigate the impact of laboratory and molecular characteristics at the time of diagnosis (TOD) on the PMF outcome. The study group consisted of 82 patients recruited from three Polish university centers. Among the driver mutations, only CALR type 1 positively influenced the overall survival (OS). The risk of progression to accelerated or blastic disease phase (AP/BP) did not depend on the driver mutation type, but was closely associated with the presence of HMR variants (p = 0.0062). The risk of death (ROD) was higher in patients with HMR variants (OR[95%CI] = 4.33[1.52;12.34], p = 0.0044) and in patients with a platelet count at the TOD between 50-100 G/L (HR[95%CI] = 2.66[1.11;6.35]) and < 50 G/L (HR[95%CI] = 8.44[2.50;28.44]). Median survival time was 7.8, 2.2 and 1.4 years in patients with large unstained cells (LUC) count of [0.0-0.2], (0.2-0.4] and > 0.4 G/L at the TOD, respectively. We found an unexpected, hitherto undescribed, association between LUC count at the TOD and PMF prognosis. Our analysis led to the following conclusions: in PMF patients at the TOD 1) the presence of HMR variants, especially combined, is associated with an increased risk of progression to the AP and BP, and shorter OS, 2) severe thrombocytopenia confers worse prognosis than the moderate one, 3) LUC count is closely related with the disease phase, and associated with the ROD and OS.

Pathogenesis of bloodstream infection in children with blood cancer

The aim of the present study was to characterize the distribution and antibiotic resistance of pathogens isolated from patients with bloodstream infections (BSIs) in the Hematology and Oncology department of the Affiliated Children’s Hospital of Zhejiang University Medical School (Hangzhou, China), between January and December 2010 and to provide early and appropriate support for the clinical administration of antibiotics. Out of 1,500 inpatients, 161 children who were diagnosed with BSI based on the national diagnostic criteria were retrospectively analyzed. Neutropenia was defined as an absolute neutrophil count (ANC) in the peripheral blood of less than 0.5×10⁹ cells/l. A microbiologically documented infection (MDI) was defined as when the causative pathogen was isolated from the blood. Drug susceptibility tests were performed using a VITEK-60 AutoMicrobic System and the Kirby-Bauer disk diffusion method. The data were analyzed using STATA software (version 9.0) and a two-sided P-value of ≤0.05 was considered to indicate a statistically significant difference. A total of 79 strains were isolated from the blood specimens. The incidence of BSI was 10.73% (161/1,500). Gram-positive cocci, Gram-negative bacilli and fungi accounted for 55.70, 43.04 and 1.27% of the BSIs, respectively. Staphylococcus epidermidis (20.25%), Escherichia coli (15.19%) and Klebsiella pneumoniae (15.19%) were frequently identified isolates. The staphylococci were susceptible to vancomycin and linezolid, while Escherichia coli and Klebsiella pneumoniae were sensitive to cefoperazone/sulbactam, imipenem and meropenem. In conclusion, Gram-positive bacteria are slightly more prevalent than Gram-negative bacteria in BSI and the selection of antibiotics according to the susceptibility test results is superior to empirical treatment. It is essential to administer antimicrobial agents early and appropriately to treat child blood cancer patients with BSI.