Methotrexate, cyclosporine, or both to prevent graft-versus-host disease after HLA-identical sibling bone marrow transplants for early leukemia?

Optimal prophylaxis of graft-versus-host disease (GVHD) is controversial. We compared efficacy of three posttransplant immune suppressive regimens in 2,286 recipients of HLA-identical sibling bone marrow transplants for acute lymphoblastic leukemia (ALL) in first remission, acute myelogenous leukemia (AML) in first remission, or chronic myelogenous leukemia (CML) in first chronic phase. Six hundred forty received methotrexate, 977 received cyclosporine, and 669 received combined cyclosporine and methotrexate. In children, the three regimens resulted in similar outcomes. In adults, cyclosporine and methotrexate had comparable risks of acute and chronic GVHD. Compared with methotrexate, cyclosporine was associated with less interstitial pneumonia (relative risk [RR] = 0.6; P < .001), less treatment-related mortality (RR = 0.6; P < .001), more relapses (RR = 1.6; P < .05), and less treatment failure (relapse or death from any cause; RR = 0.7; P < .001). Different effects were observed in different leukemias. In ALL, the rate of leukemia relapse was increased with cyclosporine versus methotrexate, with no effect on other outcomes. In AML and CML, interstitial pneumonia, treatment-related mortality, and treatment failures were decreased with cyclosporine, with no increase in relapse. Similar analyses comparing cyclosporine plus methotrexate with cyclosporine alone showed that adults receiving the combination had less acute GVHD (RR = 0.5; P < .001), less chronic GVHD (RR = 0.7; P < .01), and less interstitial pneumonia (RR = 0.7; P < .001). Treatment failure (RR = 0.8; P < .05) was marginally reduced. Separate analyses in ALL and AML showed less acute GVHD with combined therapy, but no significant effect on other outcomes. In CML, acute GVHD, interstitial pneumonia, treatment-related mortality, and treatment failure were decreased with combined therapy.     

P-selectin glycoprotein ligand-1 (PSGL-1) is a ligand for L-selectin in neutrophil aggregation

In inflammation, activated neutrophils adhere to endothelial cells and aggregate with one another. While beta 2-integrin and L-selectin are essential for aggregation, their ligands remain to be identified. We have previously shown that L-selectin mediates a carbohydrate-dependent interaction in aggregation (Simon et al: J Immunol 149:2765, 1992; Rochon et al: J Immunol 152:1385, 1994). We have suggested that the L- selectin counter-structure is a mucinlike protein and proposed that aggregation occurs through a two-step process involving L-selectin, beta 2-integrin, and their distinct counter-structures (Bennett et al: J Leuk Biol 58:510, 1995). A candidate ligand for L-selectin is P- selectin glycoprotein ligand-1 (PSGL-1), a mucinlike protein on neutrophils that binds P-and E-selectin. Using flow cytometry we show that the number and size of neutrophil aggregates is reduced with Fab fragments of PL1, an anti-PSGL-1 monoclonal antibody that blocks the interaction between P-selectin and PSGL-1 (Moore et al: J Cell Biol 128:661, 1995). In addition, monoclonal antibodies to L-selectin and PSGL-1 were used simultaneously to modulate the availability of these adhesion molecules on individual cell populations. The inhibition of aggregation by these antibodies is consistent with L-selectin and PSGL- 1 being counter-structures. We suggest that L-selectin and PSGL-1 support a collisional cell-cell interaction that represents the first step in neutrophil aggregation.     

Lipid hydroperoxides permit deformation-dependent leak of monovalent cation from erythrocytes

Subtle peroxidative perturbation of normal red blood cells (RBC) using t-butylhydroperoxide creates a leak pathway for monovalent cations that is reversibly activated by cell deformation. To determine what factor promotes expression of this unique membrane defect, we have dissected "peroxidation" into components that can be evaluated separately by comparing K leak from suitably modified RBC during elliptical deformation and parallel control incubation. Selective introduction of phospholipid hydroperoxides into normal RBC membranes successfully induces a deformation-dependent leak pathway having the same phenomenology as that previously documented for cells treated with t- butylhydroperoxide itself (fully recoverable; calcium-independent; inhibited at lower pH; K efflux balanced by Na influx). This leak pathway occurs in the absence of detectable secondary peroxidative change and appears to reflect a direct influence of lipid hydroperoxide. Using micropipette examination of vesicular bilayers reconstituted from RBC lipid extracts, we find that lipid from peroxidized RBC exhibits only a slight tendency to be less cohesive than normal lipid, apparently precluding isolated lipid properties as an explanation for altered permeability barrier function. However, addition of a hydrophobic membrane-spanning peptide to these same lipids significantly diminishes bilayer cohesion, an effect that is exacerbated further by the presence of peroxidized lipid. These observations suggest that lipid hydroperoxide is a necessary, but perhaps not sufficient, factor for induction of this unique leak pathway. Our results may be relevant to the abnormal cation homeostasis of sickle RBC in which deformation of an oxidatively perturbed membrane occurs during the sickling phenomenon.     

Anti-Jka, -C, and -E in a single patient, initially demonstrable only by the manual hexadimethrine bromide (Polybrene) test, with incompatibilities confirmed by 51Cr-labeled red cell studies

Published reports have confirmed the superior sensitivity of the manual hexadimethrine bromide (Polybrene) test (MPT) for demonstrating many alloantibodies in vitro; however, the clinical significance of alloantibodies demonstrable exclusively by MPT has not been shown conclusively. A patient with macroglobulinemia experienced chills, fever, hemoglobinemia, and hemoglobinuria following the transfusion of 1 unit of red cells (RBCs) shown to be compatible by the low-ionic-strength antiglobulin (LIS-AG) method. Serologic investigation was negative. Intravascular hemolysis occurred with a second "compatible" unit. Serologic studies were again negative by LIS-AG and ficin-AG methods, but revealed anti-Jka by MPT. Both donors were Jk(a+b-), and 51Cr studies of the second donor's RBCs revealed a t1/2 of less than 30 minutes, with marked intravascular hemolysis. A LIS-AG-compatible Jk(a-) unit was transfused uneventfully, but with no rise in hematocrit. MPT next revealed anti-C; subsequent 51Cr studies with the Jk(a-), Cc donor's RBCs showed a 51Cr t1/2 of 100 minutes with slight intravascular lysis. Four transfusions of Jk(a-), C- blood were uneventful, but 5 days later the patient's hemoglobin declined. The following day, anti-E was demonstrable exclusively by MPT. 51Cr-labeled Jk(a-), C-, E- RBCs had normal 24-hour survival. The patient's hemoglobin rose to 11 g per dl following transfusions of Jk(a-), C-, E- RBCs, and he was discharged. In vitro studies employing the patient's purified IgM paraprotein revealed no interference with alloantibody binding or detection.     

精子释放时精子质量的检测方法

评价新修订的《世界卫生组织人类精液分析实验室技术手册》(简称手册)中涉及精子释放(精子脱离支持细胞从睾丸中排出)时的精子特征。修订手册的目的是在不影响临床应用的情况下改善"精液分析的质量"。手册指出,精液分析还有助于①研究男性生殖状态。②在男性生殖调节期间和之后监测精子的发生状态。但是,如果对射精精液精子的分析是用于上述②的目的,那么就必须识别出精子释放时的异常精子。手册未提出精子释放时精子质量的检测方法。相反,采用了精子穿过宫颈黏液或到达受精位置这一"金标准"。这个标准虽然适合于判断个体使其伴侣妊娠的可能性,但却不适用于研究睾丸本身的疾病。因此,手册介绍的测定精子质量的方法无法鉴别精子异常是发生在精子释放同时还是之后。基于活动或"活"精子的百分率评价精子释放时的精子质量是没有意义的。介绍了能反映精子释放时精子质量的其他特征,基于射出精液中单个精子的质量特征评价精子释放时精子质量可采用以下方法:①采用新的精子质量形态评估体系。②采用现代技术评价一定样本中单个精子的几个合适和独立的特征,以便更准确地确定异常精子的比例。