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Achievement of complete donor chimerism (CDC) after allogeneic nonmyeloablative hematopoietic stem cell transplantation (NMHSCT) is important for preventing graft rejection and for generating a graft-vs-malignancy effect. The alloreactivity of NK cells and some T-cell subsets is mediated through the interaction of their killer immunoglobulin-like receptors (KIRs) with target cell HLA/KIR ligands. The influence of KIR matching on the achievement of T-cell CDC after NMHSCT has not been previously described. We analyzed 31 patients undergoing T-cell replete related donor NMHSCT following fludarabine and 200 cGy TBI. Recipient inhibitory KIR genotype and donor HLA/KIR ligand matches were used to generate an inhibitory KIR score from 1 to 4 based upon the potential number of recipient inhibitory KIRs that could be engaged with donor HLA/KIR ligands. Patients with a score of 1 were less likely to achieve T-cell CDC (P=0.016) and more likely to develop graft rejection (P=0.011) than those with scores greater than 1. Thus, patients with lower inhibitory KIR scores may have more active anti-donor immune effector cells that may reduce donor chimerism. Conversely, patients with greater inhibitory KIR scores may have less active NK cell and T-cell populations, which may make them more likely to achieve CDC.Bone Marrow Transplantation (2008) 41, 709–714; doi:10.1038/sj.bmt.1705954; published online 14 January 2008 [ABSTRACT FROM AUTHOR]

The reactivity of natural killer cells and some T-cell populations is regulated by killer immunoglobulin-like receptors (KIR) interactions with target cell HLA class I molecules. Such interactions have been suggested to influence outcomes after allogeneic hematopoietic stem cell transplantation, particularly for myeloid malignancies and with T-cell depletion. Donor KIR genotypes and recipient HLA KIR ligands were analyzed in 60 AML patients receiving T-cell replete, HLA-matched-related donor allogeneic bone marrow transplants. Patients were categorized according to their HLA inhibitory KIR ligand groups by determining whether or not they expressed: HLA-A3 or -A11; HLA-Bw4 and HLA-Cw groups (homozygous C1, homozygous C2 or heterozygous C1/C2). Heterozygous C1/C2 patients had significantly worse survival than those homozygous for C1 or C2 (5.8 vs 43.5 months, respectively, P=0.018) and the C1/C2 group had a higher relapse rate (47 vs 31%, respectively, P=0.048). Multivariate analysis found C1/C2 status to be an independent predictor for mortality (P=0.007, HR 2.54, confidence interval 1.29–5.00). C1/C2 heterozygosity was also associated with a delayed time to platelet engraftment, particularly for those with concurrent HLA-Bw4 expression (P=0.003). Since C1/C2 heterozygotes have a greater opportunity to engage inhibitory KIRs than do C1 or C2 homozygotes, they may more effectively inhibit KIR-positive NK- and T-cell populations involved in graft vs leukemia responses.Bone Marrow Transplantation (2007) 39, 417–424. doi:10.1038/sj.bmt.1705609; published online 19 February 2007 [ABSTRACT FROM AUTHOR]

Background: Simple anthropometric indices of body composition have particular appeal for use in children, and as such body mass index (BMI) has been used to predict percentage body fat in a number of studies. Aim: To evaluate the relationship between BMI and percentage body fat (%body fat) and a proposed, more appropriate relationship between BMI and fat mass/height[sup 2] in a cohort of young children. Subjects and methods: Cross-sectional study of 109 children aged between 6 and 10 years residing in either Sydney or Brisbane, Australia. Weight and height were measured using standard methods. Body composition was measured using a stable isotope method to firstly determine total body water and subsequently fat free mass. Results: The correlation between BMI and fat mass/height[sup 2] was markedly greater than that between BMI and percentage body fat. In the entire group of children the R[sup 2] (×100%) value for the relationship between BMI and fat mass/height[sup 2] was 73.3% compared with 46.5% for the relationship between BMI and percentage body fat. Conclusions: We have shown that the use of BMI to predict fat mass/height[sup 2] , and consequently percentage body fat, is superior to the use of BMI to predict percentage body fat based directly upon the R[sup 2] values of the above analysis. [ABSTRACT FROM AUTHOR]