Background Activated human eosinophils, as well as neutrophils, can release extracellular chromatin to form DNA traps through cytolytic extracellular trap cell death (ETosis). Although formations of neutrophil DNA traps are recognized in various inflammatory conditions, neither the presence of ETosis-derived eosinophil DNA traps in human allergic diseases nor the characteristics of these DNA traps have been studied. Objective We investigated the presence of ETosis-derived DNA traps in eosinophil-rich sinus and ear secretions and the functional attributes of ETosis DNA traps. Methods Eosinophil-rich secretions obtained from patients with eosinophilic chronic rhinosinusitis (ECRS) and eosinophilic otitis media (EOM) were studied microscopically. In vitro studies of ETosis and DNA trap formation used blood-derived eosinophils and neutrophils, and binding capacities of DNA traps used labeled bacteria and fluorescent microbeads. Stabilities of DNA traps were evaluated by fluorescence microscopy. Results Abundant nuclear histone H1-bearing DNA traps had formed in vivo in the eosinophilic secretions and contributed to their increased viscosity. In vitro, following brief shear flow, eosinophil ETosis-elicited DNA traps assembled to form stable aggregates. Eosinophil DNA traps entrapped bacteria and fungi and by hydrophobic interactions microbeads. In comparison with neutrophil-derived DNA traps, eosinophil DNA traps ultrastructurally exhibited thicker fibers with globular structures and were less susceptible to leukocyte-derived proteolytic degradation, likely due to the lesser protease activities of eosinophils. Conclusions In human allergic diseases, the local cytolysis of eosinophils not only releases free eosinophil granules but also generates nuclear-derived DNA traps that are major extracellular structural components within eosinophil-rich secretions.

Pure red cell aplasia (PRCA) is a syndrome characterized by a severe normocytic anaemia, reticulocytopenia, and absence of erythroblasts from an otherwise normal bone marrow. Primary PRCA, or secondary PRCA which has not responded to treatment of the underlying disease, is treated as an immunologically-mediated disease. Although vigorous immunosuppressive treatments induce and maintain remissions in a majority of patients, they carry an increased risk of serious complications. Corticosteroids were used in the treatment of PRCA and this has been considered the treatment of first choice although relapse is not uncommon. Cyclosporine A (CsA) has become established as one of the leading drugs for treatment of PRCA. However, common concerns have been the number of patients treated with CsA who achieve sustained remissions and the number that relapse. This article reviews the current status of CsA therapy and compares it to other treatments for diverse PRCAs.

Abstract Protein crystallization in human tissue rarely occurs. Charcot-Leyden crystals (CLCs) were described in various eosinophilic diseases >150 years ago, but our understanding of CLC formation still remains limited. In this study, we demonstrate that CLCs observed in varied inflamed human tissues are closely associated with eosinophil cell-free granules and nuclear envelope/plasma membrane disintegration with release of filamentous chromatin (extracellular traps), typical morphologies of a regulated pathway of extracellular trap cell death (ETosis). During the process of eosinophil ETosis, eccentrically localized cytoplasmic and perinuclear CLC protein (galectin-10) is homogeneously redistributed in the cytoplasm. Rapid (1-2 minutes) formation of intracytoplasmic CLCs was observed using time-lapse imaging. Plasma membrane rupture enabled the release of both intracellularly formed CLCs and soluble galectin-10 that further contributed to formation of CLCs extracellularly, in parallel with the expulsion of free intact granules and extracellular traps. CLC formation and galectin-10 release were dependent on nicotinamide adenine dinucleotide phosphate oxidase activation. To our knowledge, this is the first demonstration of natural formation of CLCs in association with an active physiological process (ie, ETosis). These results indicate that dynamic changes in intracellular localization and release of galectin-10 contribute to CLC formation in vivo and suggest that CLC/galectin-10 might serve as an indicator of ETosis.

BackgroundAlthough the AB0 blood group is one of two major antigen systems of relevance for transplantation in humans, there are still conflicting data concerning the influence of AB0 incompatibility on transplant outcome. This study investigated the effect of AB0 incompatibility in recipients of bone marrow transplants from unrelated donors.

Summary The efficacy of allogeneic haematopoietic stem‐cell transplantation (allo‐HSCT) for natural killer (NK)‐cell neoplasms is unknown. We investigated the results of allo‐HSCT for NK‐cell neoplasms between 1990 and 2003 through questionnaires. After reclassification by a haematopathologist, of 345 patients who underwent allo‐HSCT for malignant lymphoma, 28 had NK‐cell neoplasms (World Health Organization classification): extranodal NK/T‐cell lymphoma (n = 22), blastic NK‐cell lymphoma (n = 3), and aggressive NK‐cell leukaemia (n = 3). Twelve were chemosensitive and 16 chemorefractory. Twenty‐two had matched‐related donors. Stem‐cell source was bone marrow in eight and mobilised peripheral blood in 20. Conditioning regimens were myeloablative (n = 23) and non‐myeloablative (n = 5). Grade 2–4 acute graft‐versus‐host disease (GVHD) and chronic GVHD developed in 12 and 8 respectively. Eight died of disease progression, three of infection, two of acute GVHD, one of veno‐occlusive disease, one of interstitial pneumonitis, and one of thrombotic microangiopathy. Two‐year progression‐free and overall survivals were 34% and 40% respectively (median follow‐up, 34 months). All patients who did not relapse/progress within 10 months achieved progression‐free survival (PFS) during the follow‐up. In multivariate analysis, stem cell source (BM versus peripheral blood; relative risk 3·03), age (≥40 years vs. <40 years; relative risk 2·85), and diagnoses (extranodal NK/T‐cell lymphoma versus others; relative risk 3·94) significantly affected PFS. Allo‐HSCT is a promising treatment for NK‐cell neoplasms.

Imatinib mesylate (IM) trough concentration varies among IM-treated chronic myeloid leukemia (CML) patients. Although IM pharmacokinetics is influenced by several enzymes and transporters, little is known about the role of pharmacogenetic variation in IM metabolism. In this study, associations between IM trough concentration, clinical response and 11 single-nucleotide polymorphisms in genes involved in IM pharmacokinetics (ABCB1, ABCC2, ABCG2 CYP3A5, SLC22A1 and SLCO1B3) were investigated among 67 Japanese chronic phase CML patients. IM trough concentration was significantly higher in patients with a major molecular response than in those without one (P¼0.010). No significant correlations between IM trough concentration and age, weight, body mass index or biochemical data were observed. However, the dose-adjusted IM trough concentration was significantly higher in patients with ABCG2 421A than in those with 421C/C (P=0.015). By multivariate regression analysis, only ABCG2 421A was independently predictive of a higher dose-adjusted IM trough concentration (P¼0.015). Moreover, previous studies have shown that the ABCG2 421C4A (p.Q141K) variant is prevalent among Japanese and Han Chinese individuals and less common among Africans and Caucasians. Together, these data indicate that plasma IM concentration monitoring and prospective ABCG2 421C4A genotyping may improve the efficacy of IM therapy, particularly among Asian CML patients.

Lymphatic flux from a primary tumor initially flows into a tumor-draining lymph node (LN), the so-called sentinel LN (SLN). Carried by the lymph fluid are a variety of mediators produced by the tumor that can influence immune responses within the SLN, making it a good model with which to investigate tumor-related immunology. For instance, dendritic cell (DC) numbers are reduced in SLNs from melanoma and breast cancer patients. In the present study, we investigated the mechanism by which DC numbers were reduced within SLNs from patients with non-small cell lung cancer. We found that the incidence of apoptosis among DCs was higher in SLNs than in non-SLNs, as were levels of TGFβ-1. In contrast, levels of TGFβ-1 mRNA did not differ between SLNs and non-SLNs, but were 30 times higher in tumors than in either LN type. In vitro, incubation for 2 days with TGFβ-1 induced apoptosis among both cultured DCs and DCs acutely isolated from normal thoracic LNs, effects that were blocked by the TGFβ-1 inhibitor DAN/Fc chimera. Taken together, these results suggest that tumor-derived TGFβ-1 induces immunosuppression within SLNs before the movement of tumor cells into the SLNs, thereby facilitating metastasis within those nodes.

Anemia is one of the most common health problems in the primary care setting. Macrocytosis in adults is defined as a red blood cell (RBC) mean corpuscular volume (MCV) >100 femtoliter (fL). Macrocytic anemias are generally classified into megaloblastic or nonmegaloblastic anemia. Megaloblastic anemia is caused by deficiency or impaired utilization of vitamin B12 and/or folate, whereas nonmegaloblastic macrocytic anemia is caused by various diseases such as myelodysplastic syndrome (MDS), liver dysfunction, alcoholism, hypothyroidism, certain drugs, and by less commonly inherited disorders of DNA synthesis. Macrocytic anemias are treated with cause‐specific therapies, and it is crucial to differentiate nonmegaloblastic from megaloblastic anemia. Because MDS and myeloid neoplasms commonly affect the elderly, primary care physicians may encounter more cases of macrocytic anemias in the near future, as the older population increases. When MDS is suspected along with leukocytopenia and/or thrombocytopenia with anemia, a hematology consultation may be appropriate.