Gut leakage enhances sepsis susceptibility in iron-overloaded β-thalassemia mice through macrophage hyperinflammatory responses.
- 作者列表："Visitchanakun P","Saisorn W","Wongphoom J","Chatthanathon P","Somboonna N","Svasti S","Fucharoen S","Leelahavanichkul A
:Iron overload induces intestinal-permeability defect (gut leakage), and gut translocation of organismal molecules might enhance systemic inflammation and sepsis severity in patients with thalassemia (Thal). Hence, iron administration in Hbbth3/+ mice, heterozygous β-globin-deficient Thal mice, was explored. Oral iron administration induced more severe secondary hemochromatosis and gut leakage in Thal mice compared with wild-type (WT) mice. Gut leakage was determined by 1) FITC-dextran assay, 2) spontaneous serum elevation of endotoxin (LPS) and (1→3)-β-d-glucan (BG), molecular structures of gut-organisms, and 3) reduction of tight-junction molecules with increased enterocyte apoptosis (activated caspase-3) by immunofluorescent staining. Iron overload also enhanced serum cytokines and increased Bacteroides spp. (gram-negative bacteria) in feces as analyzed by microbiome analysis. LPS injection in iron-overloaded Thal mice produced higher mortality and prominent cytokine responses. Additionally, stimulation with LPS plus iron in macrophage from Thal mice induced higher cytokines production with lower β-globin gene expression compared with WT. Furthermore, possible gut leakage as determined by elevated LPS or BG (>60 pg/mL) in serum without systemic infection was demonstrated in 18 out of 41 patients with β-thalassemia major. Finally, enhanced LPS-induced cytokine responses of mononuclear cells from these patients compared with cells from healthy volunteers were demonstrated. In conclusion, oral iron administration in Thal mice induced more severe gut leakage and increased fecal gram-negative bacteria, resulting in higher levels of endotoxemia and serum inflammatory cytokines compared with WT. Preexisting hyperinflammatory cytokines in iron-overloaded Thal enhanced susceptibility toward infection.NEW & NOTEWORTHY Although the impact of iron accumulation in several organs of patients with thalassemia is well known, the adverse effect of iron accumulation in gut is not frequently mentioned. Here, we demonstrated iron-induced gut-permeability defect, impact of organismal molecules from gut translocation of, and macrophage functional defect upon the increased sepsis susceptibility in thalassemia mice.
: 铁过载诱导肠通透性缺陷 (肠道渗漏)，生物体分子的肠道易位可能增强地中海贫血 (Thal) 患者的全身炎症和脓毒症严重程度。因此，在Hbbth3/+ 小鼠 (杂合 β-珠蛋白缺陷的Thal小鼠) 中研究了铁的施用。与野生型 (WT) 小鼠相比，口服铁给药在Thal小鼠中诱导更严重的继发性血色病和肠道渗漏。通过1) FITC-葡聚糖测定，2) 内毒素 (LPS) 的自发血清升高和 (1 → 3)-β-d-葡聚糖 (BG)，肠道生物的分子结构和3) 确定肠道渗漏。通过免疫荧光染色减少肠细胞凋亡增加的紧密连接分子 (活化的caspase-3)。通过微生物组分析分析，铁过载还增强了粪便中的血清细胞因子和增加的拟杆菌属 (革兰氏阴性细菌)。在铁超负荷的Thal小鼠中注射LPS产生更高的死亡率和显著的细胞因子反应。此外，与WT相比，来自Thal小鼠的巨噬细胞中LPS加铁的刺激诱导更高的细胞因子产生，具有更低的 β-珠蛋白基因表达。此外，在41名患有重型 β-地中海贫血的患者中的18名中，证明了在没有全身性感染的情况下通过血清中的升高的LPS或BG (>60 pg/mL) 确定的可能的肠道渗漏。最后，证明了与来自健康志愿者的细胞相比，来自这些患者的单核细胞的LPS诱导的细胞因子应答增强。总之，与WT相比，Thal小鼠口服铁引起更严重的肠道渗漏和粪便革兰氏阴性菌增加，导致更高水平的内毒素血症和血清炎性细胞因子。铁过载Thal中预先存在的炎性细胞因子增强了对感染的易感性。新的 & 值得注意的是，尽管地中海贫血患者的几个器官中铁积累的影响是众所周知的，但肠道中铁积累的不良影响并不经常被提及。在这里，我们证明了铁诱导的肠道通透性缺陷，肠道易位的生物体分子的影响，以及巨噬细胞功能缺陷对地中海贫血小鼠脓毒症易感性增加的影响。
METHODS:BACKGROUND:Thalassemia is one of the most common monogenetic diseases in the south of China and Southeast Asia. Hemoglobin Bart's hydrops fetalis syndrome was caused by a homozygous Southeast Asian deletion (-/-) in the HBA gene. Few studies have proved the potential of screen for Bart's hydrops fetalis using fetal cell-free DNA. However, the number of cases is still relatively small. Clinical trials of large samples would be needed. OBJECTIVE:In this study, we aimed to develop a noninvasive method of target-captured sequencing and genotyping by the Bayesian method using cell-free fetal DNA to identify the fetal genotype in pregnant women who are at risk of having hemoglobin Bart hydrops fetalis in a large-scale study. STUDY DESIGN:In total, 192,173 couples from 30 hospitals were enrolled in our study and 878 couples were recruited, among whom both the pregnant women and their husbands were detected to be carriers of Southeast Asian type (-/αα) of α-thalassemia. Prenatal diagnosis was performed by chorionic villus sampling, amniocentesis, or cordocentesis using gap-polymerase chain reaction considered as the golden standard. RESULTS:As a result, we found that the sensitivity and specificity of our noninvasive method were 98.81% and 94.72%, respectively, in the training set as well as 100% and 99.31%, respectively, in the testing set. Moreover, our method could identify all of 885 maternal samples with the Southeast Asian carrier and 36 trisomy samples with 100% of sensitivity in T13, T18, and T21 and 99.89% (1 of 917) and 99.88% (1 of 888) of specificity in T18 and T21, respectively. CONCLUSION:Our method opens the possibility of early screening for maternal genotyping of α-thalassemia, fetal aneuploidies in chromosomes 13/18/21, and hemoglobin Bart hydrops fetalis detection in 1 tube of maternal plasma.
METHODS:OBJECTIVES:Sickle cell disease (SCD) is a serious illness with disabling acute and chronic pain that needs better therapies, but insufficient patient participation in research is a major impediment to advancing SCD pain management. The purpose of this article is to discuss the challenges of conducting an SCD study and approaches to successfully overcoming those challenges. DESIGN:In a repeated-measures, longitudinal study designed to characterize SCD pain phenotypes, we recruited 311 adults of African ancestry. Adults with SCD completed 4 study visits 6 months apart, and age- and gender-matched healthy controls completed 1 visit. RESULTS:We recruited and completed measures on 186 patients with SCD and 125 healthy controls. We retained 151 patients with SCD with data at 4 time points over 18 months and 125 healthy controls (1 time point) but encountered many challenges in recruitment and study visit completion. Enrollment delays often arose from patients' difficulty in taking time from their complicated lives and frequent pain episodes. Once scheduled, participants with SCD cancelled 49% of visits often because of pain; controls canceled 30% of their scheduled visits. To facilitate recruitment and retention, we implemented a number of strategies that were invaluable in our success. CONCLUSION:Patients' struggles with illness, chronic pain, and their life situations resulted in many challenges to recruitment and completion of study visits. Important to overcoming challenges was gaining the trust of patients with SCD and a participant-centered approach. Early identification of potential problems allowed strategies to be instituted proactively, leading to success.
METHODS:OBJECTIVES:Sickle cell anemia is the commonest genetic disorder in India, and the frequency of the sickle cell gene is very high in the remote tribal areas where facilities are generally limited. Therefore, a rapid and affordable point-of-care test for sickle cell disease is needed. METHODS:The diagnostic accuracy of HemoTypeSC was evaluated against automated high-performance liquid chromatography (HPLC) as the gold standard for its efficacy in a newborn screening program. RESULTS:A total of 1,559 individuals (980 newborns and 579 adults) from four participating centers were analyzed by both methods. HemoTypeSC correctly identified 209 of 211 total hemoglobin (Hb) SS cases, for a 99.1%/99.9% total HbSS sensitivity/specificity. Overall, HemoTypeSC exhibited sensitivity and specificity of 98.1% and 99.1% for all possible phenotypes (HbAA, HbAS, and HbSS) detected. HPLC is relatively expensive and not available in most laboratories in remote tribal areas. CONCLUSIONS:We conclude that the rapid, point-of-care testing device HemoTypeSC test is suitable for population and newborn screening for the HbS phenotype.