Evaluation of two automated cell counters for the analysis of hematopoietic progenitor cell apheresis products.

INTRODUCTION: Routine hematology parameters in hematopoietic progenitor cell apheresis products (HPC-A) are usually determined using automated cell counters. These instruments, however, are designed to analyze whole blood samples, that differ considerably from HPC-A in blood cell composition. This study evaluates the performance of two automated cell counters for the analysis of HPC-A. METHODS: Routine hematology parameters [red blood cells (RBC), hematocrit (HCT), mean corpuscular volume (MCV), white blood cells (WBC), WBC differentiation, and platelets (PLT)] were determined on the Unicel DxH 800 instrument (Beckman Coulter) and the XN-350 instrument (Sysmex). Correlations with the reference methods, intrarun precision, and linearity of the analyses were studied. RESULTS: Good correlations were found for almost all parameters. However, RBC count was overestimated by XN-350, using the impedance technique, as was neutrophil percentage using DxH 800. Coefficients of variation for intrarun precision were below 10% on both analyzers for all parameters, except for neutrophil percentage (14.7%) and PLT (10%) on DxH 800. Both instruments showed good linearity for all parameters, except for RBC and HCT on DxH 800. CONCLUSION: With the exception of the measurement of neutrophils on DxH 800 and RBC by the impedance technique on the XN-350, routine hematology parameters in HPC-A can safely be determined using automated cell counters.

Pro-inflammatory effects of matrix metalloproteinase 7 in acute inflammation.

Matrix metalloproteinase 7 (MMP7) is a member of the MMP family. In the small intestine, MMP7 is responsible for activating α-defensins, which are broad-spectrum anti-microbial peptides produced by the Paneth cells. We report that MMP7(-/-) mice are resistant to LPS-induced lethality and that this resistance is correlated with reduced levels of systemic cytokines. LPS induced the upregulation and activation of MMP7 in the small intestine, degranulation of the Paneth cells, and induction of intestinal permeability in MMP7(+/+) mice. In MMP7(-/-) mice, both LPS-induced intestinal permeability and consequent bacterial translocation to the mesenteric lymph nodes were reduced. Based on gene expression analysis and evaluation of intestinal damage, we attribute the protected state of MMP7(-/-) mice to reduced intestinal inflammation. Interestingly, we found that different α-defensins, namely Crp1 (DEFA1) and Crp4 (DEFA4), can stimulate IL-6 release in macrophages and ileum explants in a TLR4 independent way. We conclude that absence of MMP7 protects mice from LPS-induced intestinal permeability and lethality, and suggest that MMP7-activated α-defensins, in addition to their previously recognized bactericidal and anti-inflammatory roles, may exhibit pro-inflammatory activities in the intestine by activating macrophages and amplifying the local inflammatory response in the gut, leading to intestinal leakage and subsequent increase in systemic inflammation.