Neutrophil Count in African Americans: Lowering the Target Cutoff to Initiate or Resume Chemotherapy?

Molecular and Clinical Hematology Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Heart, Lung, and Blood Institute, Bethesda, MD, USA.
Journal of Clinical Oncology (Impact Factor: 17.88). 03/2010; 28(10):1633-7. DOI: 10.1200/JCO.2009.24.3881
Source: PubMed
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    ABSTRACT: Background Long-term monitoring of white blood cell count is compulsory in patients taking clozapine, although the incidence of drug-induced agranulocytosis is lower than previously expected. The cost-eff ectiveness of this monitoring is unknown. We aimed to assess the cost-eff ectiveness of various strategies to monitor white blood cell count in adult patients with schizophrenia taking clozapine. Methods We assessed the cost-eff ectiveness of four strategies for monitoring white blood cell count (national strategies used in the UK, USA, and European countries, and a hypothetical 8-week strategy) compared with that of no monitoring. We used a semi-Markov model to do the cost–utility analysis from a health-care perspective with a 3-year time horizon, assuming a probability of 0·7% that a patient would develop agranulocytosis. Clinical and resource parameters were based on data from national registries of patients treated with clozapine, study cohorts, and a pharmacovigilance database; we derived estimates of health-related quality of life and mortality from the scientific literature. We assessed model uncertainty, including time horizon, with one-way and probabilistic sensitivity analyses. Findings Compared with no monitoring, all four monitoring strategies increased quality-adjusted survival by less than 1 day per patient; more than 5000 patients would need to be monitored to avoid one death. The incremental cost-effectiveness ratios (ICERs) were at least US$970 000 per quality-adjusted life-year gained for all four strategies compared with no monitoring. The ICERs were highest in the strategies with highest frequencies and longest durations of monitoring. The results remained robust in the one-way and probabilistic sensitivity analyses, suggesting that no monitoring had the highest probability of being cost eff ective. Interpretation Existing strategies for monitoring white blood cell count in patients taking clozapine, based on divergent national requirements, do not seem to be cost eff ective. This fi nding should be taken into account by public health authorities and policy makers in the revision of guidance for clozapine prescription.
    The Lancet Psychiatry 06/2014; 1(1):55-62. DOI:10.1016/S2215-0366(14)70245-7
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    ABSTRACT: Little information exists on the effect of race and ethnicity on collection of peripheral blood stem cells (PBSC) for allogeneic transplantation. We studied 10776 donors from the National Marrow Donor Program who underwent PBSC collection from 2006-2012. Self-reported donor race/ethnic information included Caucasian, Hispanic, Black/African American (AA), Asian/Pacific Islander (API), and Native American (NA). All donors were mobilized with subcutaneous filgrastim (G-CSF) at an approximate dose of 10 μg/kg/d for 5 days. Overall, AA donors had the highest median yields of mononuclear cells (MNC)/L and CD34(+) cells/L blood processed (3.1 x 10(9) and 44 x 10(6) respectively) while Caucasians had the lowest median yields at 2.8 x 10(9) and 33.7 x 10(6) respectively. Multivariate analysis of CD34(+)/L mobilization yields using Caucasians as the comparator and controlling for age, gender, body mass index, and year of apheresis revealed increased yields in overweight and obese AA and API donors. In Hispanic donors, only male obese donors had higher CD34(+)/L mobilization yields compared to Caucasian donors. No differences in CD34(+)/L yields were seen between Caucasian and NA donors. Characterization of these differences may allow optimization of mobilization regimens to allow enhancement of mobilization yields without compromising donor safety.
    Biology of blood and marrow transplantation: journal of the American Society for Blood and Marrow Transplantation 10/2014; DOI:10.1016/j.bbmt.2014.10.007 · 3.35 Impact Factor
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    ABSTRACT: Similar to other populations, full blood count reference (FBC) intervals in Malaysia are generally derived from non-Malaysian subjects. However, numerous studies have shown significant differences between and within populations supporting the need for population specific intervals. Two thousand seven hundred twenty five apparently healthy adults comprising all ages, both genders and three principal races were recruited through voluntary participation. FBC was performed on two analysers, Sysmex XE-5000 and Unicel DxH 800, in addition to blood smears and haemoglobin analysis. Serum ferritin, soluble transferrin receptor and C-reactive protein assays were performed in selected subjects. All parameters of qualified subjects were tested for normality followed by determination of reference intervals, measures of central tendency and dispersion along with point estimates for each subgroup. Complete data was available in 2440 subjects of whom 56% (907 women and 469 men) were included in reference interval calculation. Compared to other populations there were significant differences for haemoglobin, red blood cell count, platelet count and haematocrit in Malaysians. There were differences between men and women, and between younger and older men; unlike in other populations, haemoglobin was similar in younger and older women. However ethnicity and smoking had little impact. 70% of anemia in premenopausal women, 24% in postmenopausal women and 20% of males is attributable to iron deficiency. There was excellent correlation between Sysmex XE-5000 and Unicel DxH 800. Our data confirms the importance of population specific haematological parameters and supports the need for local guidelines rather than adoption of generalised reference intervals and cut-offs.
    PLoS ONE 03/2014; 9(3):e91968. DOI:10.1371/journal.pone.0091968 · 3.53 Impact Factor

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