Development of a biodosimeter for radiation triage using novel blood protein biomarker panels in humans and non-human primates.

Purpose: In a significant nuclear event, hundreds of thousands of individuals will require rapid triage for absorbed radiation to ensure effective medical treatment and efficient use of medical resources. We are developing a rapid screening method to assess whether an individual received an absorbed dose of ≥2 Gy based on the analysis of a specific panel of blood proteins in a fingerstick blood sample.Materials and methods: We studied a data set of 1051 human blood samples obtained from radiotherapy patients, normal healthy individuals, and several special population groups. We compared the findings in humans with those from irradiation studies in non-human primates (NHPs).Results: We identified a panel of three protein biomarkers, salivary alpha amylase (AMY1), Flt3 ligand (FLT3L), and monocyte chemotactic protein 1 (MCP1), which are upregulated in human patients receiving fractionated doses of total body irradiation (TBI) therapy as a treatment for cancer. These proteins exhibited a similar radiation response in NHPs after single acute or fractionated doses of ionizing radiation.Conclusion: Our work provides confidence in this biomarker panel for biodosimetry triage using fingerstick blood samples and in the use of NHPs as a model for irradiated humans.

Usefulness of Inferior Vena Cava Filters in Stable Patients with Acute Pulmonary Embolism.

Retrospective cohort studies using administrative data from national databases or a registry suggest that there are subcategories of stable patients with acute pulmonary embolism who would show a reduced mortality with an inferior vena cava (IVC) filter in addition to anticoagulants. These subcategories are those who underwent pulmonary embolectomy, receiving thrombolytic therapy, suffering recurrent pulmonary embolism while on treatment, hospitalized with solid malignant tumors if aged >60 years, hospitalized with chronic obstructive pulmonary disease (COPD) if aged >50 years, and very elderly (aged >80 years). The following is a review of these studies. It is important to be circumspect in inferring a lower mortality with IVC filters based on comparative effectiveness research that uses national observational data. On the other hand, the likelihood of a randomized controlled trial in any of these subcategories of stable patients is remote. Whether patients are better served by inserting an IVC filter on the basis of retrospective cohort studies, or by withholding IVC filters until a randomized controlled trial can be obtained is a matter for consideration.

Pulmonary vein thrombosis in patients with medical risk factors.

Pulmonary vein thrombosis in patients with medical illnesses has been rarely reported, and it is also rarely reported in those with no risk factors. We report 2 patients with pulmonary vein thrombosis, 1 with metastatic renal cell carcinoma and 1 with presumed pulmonary aspergillosis. Thrombi or tumors in a pulmonary vein are clinically important because they may cause systemic embolism or hemoptysis.

Inferior Vena Cava Filters in Patients with Acute Pulmonary Embolism and Cancer.

BACKGROUND: Administrative data have shown a lower mortality in hospitalized patients with pulmonary embolism and cancer who receive a vena cava filter. In the absence of a randomized controlled trial of vena cava filters in such patients, further investigation is necessary. Therefore, we performed this investigation using administrative data from a different database than used previously, and we investigate patients hospitalized in more recent years. METHODS: We analyzed administrative data from the Premier Healthcare Database, 2010-2014, in patients hospitalized with pulmonary embolism and solid malignant tumors. Patients were identified on the basis of International Classification of Disease, Ninth Revision, Clinical Modification codes. RESULTS: Patients aged >60 years had a lower in-hospital all-cause mortality with vena cava filters than those who did not have filters, 346 of 4648 (7.4%) compared with 2216 of 19,847 (11.2%) (P < .0001) (relative risk 0.67). Among patients aged >60 years who received an inferior vena cava, all-cause mortality within 3 months was 704 of 4648 (15.1%), compared with 3444 of 19,847 (17.4%) among those who did not receive a filter (P < .0001) (relative risk 0.86). CONCLUSION: Elderly patients with pulmonary embolism and cancer may be a special population in whom inferior vena cava filters reduce in-hospital and 3-month all-cause mortality. Further investigation is needed, particularly in younger patients.

Follow-up CT pulmonary angiograms in patients with acute pulmonary embolism.

Computed tomographic (CT) angiography is associated with a non-negligible lifetime attributable risk of cancer. The risk is considerably greater for women and younger patients. Recognizing that there are risks from radiation, the purpose of this investigation was to assess the frequency of follow-up CT angiograms in patients with acute pulmonary embolism. This was a retrospective cohort study of patients aged ≥18 years with acute pulmonary embolism seen in three emergency departments from January 2013 to December 2014. Records of all patients were reviewed for at least 14 months. Pulmonary embolism was diagnosed by CT angiography in 600 patients. At least one follow-up CT angiogram in 1 year was obtained in 141 of 600 (23.5 %). Two follow-ups in 1 year were obtained in 40 patients (6.7 %), 3 follow-ups were obtained in 15 patients (2.5 %), and 4 follow-ups were obtained in 3 patients (0.5 %). Among young women (aged ≤29 years) with pulmonary embolism, 10 of 21 (47.6 %) had at least 1 follow-up and 4 of 21 (19.0 %) had 2 or more follow-ups in 1 year. Among all patients, recurrent pulmonary embolism was diagnosed in 15 of 141 (10.6 %) on the first follow-up CT angiogram and in 6 of 40 (15.0 %) on the second follow-up. Follow-up CT angiograms were obtained in a significant proportion of patients with pulmonary embolism, including young women, the group with the highest risk. Alternative options might be considered to reduce the hazard of radiation-induced cancer, particularly in young women.

Home Treatment of Pulmonary Embolism in the Era of Novel Oral Anticoagulants.

BACKGROUND: Outpatient therapy of patients with acute pulmonary embolism has been shown to be safe in carefully selected patients. Problems related to the injection of low-molecular-weight heparin at home can be overcome by use of novel oral anticoagulants. The purpose of this investigation is to assess the prevalence of home treatment in the era of novel oral anticoagulants. METHODS: This was a retrospective cohort study of patients aged ≥18 years with acute pulmonary embolism seen in 5 emergency departments from January 2013 to December 2014. RESULTS: Pulmonary embolism was diagnosed in 983 patients. Among these, 237 were considered ineligible for home treatment because of instability or hypoxia. Home treatment was selected for 13 of 746 (1.7%) patients who were potentially eligible. Anticoagulant treatment for those treated at home was low-molecular-weight heparin or warfarin in 9 (69.2%) and novel oral anticoagulants in 4 (30.8%). Hospitalization was chosen for 733 of 746 (98.3%). Discharge in ≤2 days was in 119 patients (16.2%). Treatment of these patients was low-molecular-weight heparin or warfarin in 76 (63.9%), novel oral anticoagulants in 34 (28.6%), and in 9 (7.6%), anticoagulants were not given because of metastatic cancer or treatment was not known. CONCLUSION: Even in the era of novel oral anticoagulants, the vast majority of patients with acute pulmonary embolism were hospitalized, and only a small proportion were discharged in ≤2 days. Although home treatment has been found to be safe in carefully selected patients, and scoring systems have been derived to identify those at low risk of adverse events, home treatment was infrequently selected.

The adaptor protein SAP regulates type II NKT-cell development, cytokine production, and cytotoxicity against lymphoma.

CD1d-restricted NKT cells represent a unique lineage of immunoregulatory T cells that are divided into two groups, type I and type II, based on their TCR usage. Because there are no specific tools to identify type II NKT cells, little is known about their developmental requirements and functional regulation. In our previous study, we showed that signaling lymphocytic activation molecule associated protein (SAP) is essential for the development of type II NKT cells. Here, using a type II NKT-cell TCR transgenic mouse model, we demonstrated that CD1d-expressing hematopoietic cells, but not thymic epithelial cells, meditate efficient selection of type II NKT cells. Furthermore, we showed that SAP regulates type II NKT-cell development by controlling early growth response 2 protein and promyelocytic leukemia zinc finger expression. SAP-deficient 24αß transgenic T cells (24αß T cells) exhibited an immature phenotype with reduced Th2 cytokine-producing capacity and diminished cytotoxicity to CD1d-expressing lymphoma cells. The impaired IL-4 production by SAP-deficient 24αß T cells was associated with reduced IFN regulatory factor 4 and GATA-3 induction following TCR stimulation. Collectively, these data suggest that SAP is critical for regulating type II NKT cell responses. Aberrant responses of these T cells may contribute to the immune dysregulation observed in X-linked lymphoproliferative disease caused by mutations in SAP.

Pulmonary embolism and deep venous thrombosis following laparoscopic cholecystectomy.

There is considerable uncertainty related to the thromboembolic risk after laparoscopic cholecystectomy. Patients with pulmonary embolism (PE), deep venous thrombosis (DVT), or venous thromboembolism (VTE) at hospital discharge following laparoscopic cholecystectomy were identified from the Nationwide Inpatient Sample. From 1998 through 2009, 4 107 430 laparoscopic cholecystectomies were performed. The in-hospital prevalence of PE was 0.15%, DVT was 0.40%, and VTE was 0.53%. The prevalence of PE increased from 0.04% in patients aged 21 to 30 years to 0.31% in patients aged 71 to 80 years. Deaths due to in-hospital PE were 780 (0.02%) of the 4 107 430 laparoscopic cholecystectomies. The rate of death increased with age. The prevalence of VTE following laparoscopic cholecystectomy is low and fatal PE is rare. The risk of VTE increased with age, as did the risk of death in those who had PE. These data may be useful in assessing the use of thromboprophylaxis in patients undergoing laparoscopic cholecystectomy.

Case fatality rate with vena cava filters in hospitalized stable patients with cancer and pulmonary embolism.

BACKGROUND: In view of the high risk of pulmonary embolism in patients with cancer, we tested the hypothesis that stable patients with pulmonary embolism who have cancer might be a subset of patients who would show a lower case fatality rate with vena cava filters than without filters. METHODS: Stable patients with pulmonary embolism and cancer at discharge from short-stay hospitals throughout the US from 1998-2009 were identified from the Nationwide Inpatient Sample. Patients with pulmonary embolism who had a diagnostic code for shock, ventilatory support, thrombolytic therapy, or pulmonary embolectomy were excluded because such patients have been shown to have lower case fatality rate with filters. RESULTS: In-hospital all-cause case fatality rate was lower with vena cava filters in stable patients with pulmonary embolism and solid malignant tumors providing they were aged >30 years, but there was variability according to type of tumor and age of patient. On average, case fatality rate among those >30 years with filters was 7070 of 69,350 (10.2%) (95% confidence interval, 10.0-10.4) versus 36,875 of 247,125 (14.9%) (95% confidence interval, 14.8-15.1) without filters (P <.0001) (relative risk 0.68). Among stable patients with hematological malignancies, case fatality rate, except in the elderly, was higher among those with vena cava filters than those without filters. CONCLUSION: Stable patients with pulmonary embolism and solid malignant tumors who are older than age 30 years appear to be a subset of patients with pulmonary embolism who would benefit from vena cava filters, but this needs to be tested prospectively.

Pulmonary embolism and deep venous thrombosis following bariatric surgery.

BACKGROUND: The contribution of obesity to the thromboembolic risks of surgery suggests that patients undergoing bariatric surgery would have a particularly high risk of postoperative pulmonary embolism (PE) and/or deep venous thrombosis (DVT). This study aimed to assess the prevalence of in-hospital PE, DVT, and venous thromboembolism (VTE) following bariatric surgery in the USA from 2007 to 2009. METHODS: We used the database of the Nationwide Inpatient Sample. RESULTS: The prevalence of PE was 4,500 of 508,230 (0.9 %). The prevalence of DVT not accompanied by PE was 6,480 of 508,230 (1.3 %) and VTE (either PE or DVT) occurred in 10,980 of 508,230 (2.2 %). In-hospital death among patients with PE was 130 of 508,231 (0.03 %). Vena cava filters were inserted in 1,515 of 508,230 (0.3 %) patients who underwent bariatric surgery. Among patients who had VTE, filters were inserted in 1,150 of 10,980 (10.5 %). Among patients who had neither PE nor DVT, prophylactic vena cava filters were inserted in 365 of 497,250 (0.07 %). Among patients with PE, in-hospital mortality was 25 of 635 (3.9 %) with a filter compared with 105 of 3,865 (2.7 %) (NS) without a filter. However, among patients with DVT alone, in-hospital mortality was 0 of 510 (0 %) with a filter compared with 80 of 5,970 (1.3 %) (P = 0.009) without a filter. CONCLUSIONS: This investigation establishes a baseline for the incidence of venous thromboembolic complications following bariatric surgery in recent years. Determination of the present in-hospital rate of PE and DVT may contribute to antithrombotic prophylactic considerations.

SAP is required for the development of innate phenotype in H2-M3--restricted Cd8(+) T cells.

H2-M3--restricted T cells have a preactivated surface phenotype, rapidly expand, and produce cytokines upon stimulation, and, as such, are classified as innate T cells. Unlike most innate T cells, M3-restricted T cells also express CD8αß coreceptors and a diverse TCR repertoire: hallmarks of conventional MHC Ia-restricted CD8(+) T cells. Although invariant NKT cells are also innate T cells, they are selected exclusively on hematopoietic cells (HC), whereas M3-restricted T cells can be selected on either hematopoietic or thymic epithelial cells. Moreover, their phenotypes differ depending on what cells mediate their selection. Although there is a clear correlation between selection on HC and development of innate phenotype, the underlying mechanism remains unclear. Signaling lymphocyte activation molecule-associated protein (SAP) is required for the development of invariant NKT cells and mediates signals from signaling lymphocyte activation molecule receptors that are exclusively expressed on HC. Based on their dual selection pathway, M3-restricted T cells present a unique model for studying the development of innate T cell phenotype. Using both polyclonal and transgenic mouse models, we demonstrate that although M3-restricted T cells are capable of developing in the absence of SAP, SAP is required for HC-mediated selection, development of preactivated phenotype, and heightened effector functions of M3-restricted T cells. These findings are significant because they directly demonstrate the need for SAP in HC-mediated acquisition of innate T cell phenotype and suggest that, due to their SAP-dependent HC-mediated selection, M3-restricted T cells develop a preactivated phenotype and an intrinsic ability to proliferate faster upon stimulation, allowing for an important role in the early response to infection.

Two SHIPs passing in the middle of the immune system.

Immunity requires a complex, multiscale system of molecules, cells, and cytokines. In this issue of the European Journal of Immunology, Collazo et al. [Eur. J. Immunol. 2012. 42: 1785-1796] provide evidence that links the lipid phosphatase SHIP1 with the coordination of interactions between regulatory T (Treg) cells and myeloid-derived suppressor cells (MDSCs). Using conditional knockouts of SHIP1 in either the myeloid or T-cell-lineage of mice, the authors show that the regulated development of Treg cells is controlled directly by cell-intrinsic SHIP1, and indirectly by extrinsic SHIP1 control of an unknown myeloid cell. Regulation of MDSCs is also determined by SHIP1 in an extrinsic manner, again via an as-yet-unknown myeloid cell. Furthermore, this extrinsic control of Treg cells and MDSCs is mediated in part by increased production of G-CSF, a growth factor critical for the production of neutrophils, in SHIP1-deficient mice. Thus, a physiologically important implication of this report is the collaboration between the innate and adaptive immune systems in fine tuning of Treg cells as discussed in this commentary.

Fyn promotes Th17 differentiation by regulating the kinetics of RORγt and Foxp3 expression.

Th17 cells constitute a proinflammatory CD4(+) T cell subset that is important for microbial clearance, but also are implicated as propagators of various autoimmune pathologies. Evidence suggests that Th17 cells share common progenitors with immunosuppressive CD4(+) inducible regulatory T cells (T(REG)) and that the developmental pathways of these two subsets are reciprocally regulated. In this study, we show evidence that the Src family tyrosine kinase Fyn helps regulate this Th17/T(REG) balance. When placed under Th17-skewing conditions, CD4(+) T cells from fyn(-/-) mice had decreased levels of IL-17, but increased expression of the T(REG) transcription factor Foxp3. The defect in IL-17 expression occurred independently of the ectopic Foxp3 expression and correlated with a delay in retinoic acid-related orphan receptor γt upregulation and an inability to maintain normal STAT3 activation. Fyn-deficient Th17 cells also exhibited delayed upregulation of Il23r, Il21, Rora, and Irf4, as well as aberrant expression of Socs3, suggesting that Fyn may function upstream of a variety of molecular pathways that contribute to Th17 polarization. The fyn(-/-) mice had fewer IL-17(+)CD4(+) T cells in the large intestinal lamina propria compared with littermate controls. Furthermore, after transfer of either wild-type or fyn(-/-) naive CD4(+) T cells into Rag1(-/-) hosts, recipients receiving fyn(-/-) cells had fewer IL-17-producing T cells, indicating that Fyn may also regulate Th17 differentiation in vivo. These results identify Fyn as a possible novel regulator of the developmental balance between the Th17 cell and T(REG) subsets.

CD1d-expressing breast cancer cells modulate NKT cell-mediated antitumor immunity in a murine model of breast cancer metastasis.

BACKGROUND: Tumor tolerance and immune suppression remain formidable obstacles to the efficacy of immunotherapies that harness the immune system to eradicate breast cancer. A novel syngeneic mouse model of breast cancer metastasis was developed in our lab to investigate mechanisms of immune regulation of breast cancer. Comparative analysis of low-metastatic vs. highly metastatic tumor cells isolated from these mice revealed several important genetic alterations related to immune control of cancer, including a significant downregulation of cd1d1 in the highly metastatic tumor cells. The cd1d1 gene in mice encodes the MHC class I-like molecule CD1d, which presents glycolipid antigens to a specialized subset of T cells known as natural killer T (NKT) cells. We hypothesize that breast cancer cells, through downregulation of CD1d and subsequent evasion of NKT-mediated antitumor immunity, gain increased potential for metastatic tumor progression. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we demonstrate in a mouse model of breast cancer metastasis that tumor downregulation of CD1d inhibits iNKT-mediated antitumor immunity and promotes metastatic breast cancer progression in a CD1d-dependent manner in vitro and in vivo. Using NKT-deficient transgenic mouse models, we demonstrate important differences between type I and type II NKT cells in their ability to regulate antitumor immunity of CD1d-expressing breast tumors. CONCLUSIONS/SIGNIFICANCE: The results of this study emphasize the importance of determining the CD1d expression status of the tumor when tailoring NKT-based immunotherapies for the prevention and treatment of metastatic breast cancer.

Risk of venous thromboembolism with inflammatory bowel disease.

The purpose of this study is to determine the incidence of venous thromboembolism (VTE) in patients with ulcerative colitis and patients with Crohn disease. The number of patients discharged from hospitals throughout the United States with a diagnostic code for ulcerative colitis and for Crohn disease from 1979 through 2005 was obtained from the National Hospital Discharge Survey. The incidence of VTE among medical patients with ulcerative colitis was 21 000 of 1 129 000 (1.85%) and among medical patients who had no inflammatory bowel disease, the incidence was 10 421 000 of 918 570 000 (1.13%; relative risk 1.64, 95% confidence interval [CI] = 1.62-1.66). The incidence of VTE among medical patients with Crohn disease was less than those with ulcerative colitis, 22 000 of 1 803 000 (1.22%). The risk, compared with patients who did not have inflammatory bowel disease, was only marginally increased (relative risk 1.08, 95% CI = 1.06-1.09).

Lck regulates IL-10 expression in memory-like Th1 cells.

The Src family kinase Lck is thought to facilitate Th2 differentiation; however, its role in Th1 cells has not been well explored. Using mice that lack Lck in mature T cells, we find that lck(-/-) Th1 skewed cells have normal expression of T-bet and produce IFN-γ at WT levels. However, there is a 3-fold increase in IL-10 producing cells in the mutant cultures. These cells do not have elevated levels of IL-4, GATA3, IL-17 or Foxp3, indicating that they are not Th2, Th17, or Foxp3(+) T regulatory cells (Treg). Nor do these cells behave in a similar manner as the type 1 Treg. Most of the IL-10 in the lck(-/-) Th1 cultures is derived from the memory/activated subset, as the cytokine profile from Th1 cultures established from purified CD62L(+) (naïve) cells are similar to WT cells. Furthermore, this IL-10 expression appears to be dependent on IL-12 and correlates with elevated c-Maf. These data highlight a previously unappreciated role for Lck in regulating IL-10 in Th1 cells.

Acute pulmonary embolism.

Most large or fatal pulmonary embolisms (PE) at autopsy were unsuspected ante mortem. Newly identified clinical characteristics of PE enhance our ability to identify potential patients. Because of laudable efforts to diagnose PE, about 90% of outpatient computed tomographic (CT) angiograms are negative. Overuse of CT angiography has resulted in huge expenses and exposure of many to radiation. Approximately 30% of patients with suspected acute PE would not need imaging if D-dimer is normal and clinical assessment is not a high probability, but such triage is uncommonly used. Perhaps perfusion imaging should be used more frequently. Radiation and cost with scintigraphy are less than with CT angiography. Single-photon emission computed tomography lung scans appear to be more effective than planar lung scans. Diseases associated with an increased risk of PE are being identified, but recommended prophylaxis usually is not given. Potential benefits and risks of treatment options need to be assessed.

Lck mediates Th2 differentiation through effects on T-bet and GATA-3.

The Src family kinase Lck has been shown to be crucial in T cell signaling and development. However, its role in Th effector functions is not well understood. Lck has previously been shown to play a role in the cytokine expression of Th2 cells, but the mechanism by which Lck influences Th2 effector functions is unknown. Using a mouse model, we report that Lck is important in regulating the expression of IL-4 in Th2 skewed cells but is not as necessary for the expression of Th2 cytokines IL-5, IL-10, and IL-13. Furthermore, in the absence of Lck, T-bet and GATA-3 expression is aberrant. Moreover, this atypical expression pattern of T-bet and GATA-3 correlates with increased histone 3 acetylation at the Ifng locus and production of the Th1 cytokine IFN-gamma. We find overexpression of GATA-3 restores IL-4 expression in lck(-/-) Th2 cells; this indicates that the decreased IL-4 expression is due in part to reduced amounts of GATA-3. Taken together, these data imply that Lck mediates Th2 differentiation through effects on T-bet and GATA-3.

Phenotypic differences between mice deficient in XIAP and SAP, two factors targeted in X-linked lymphoproliferative syndrome (XLP).

Mutations in the X-linked inhibitor of apoptosis (XIAP) have recently been identified in patients with the rare genetic disease, X-linked lymphoproliferative syndrome (XLP), which was previously thought to be solely attributable to mutations in a distinct gene, SAP. To further understand the roles of these two factors in the pathogenesis of XLP, we have compared mice deficient in Xiap with known phenotypes of Sap-null mice. We show here that in contrast to Sap-deficient mice, animals lacking Xiap have apparently normal NKT cell development and no apparent defect in humoral responses to T cell-dependent antigens. However, Xiap-deficient cells were more susceptible to death upon infection with the murine herpesvirus MHV-68 and gave rise to more infectious virus. These differences could be rescued by restoration of XIAP. These data provide insight into the differing roles of XIAP and SAP in the pathogenesis of XLP.

Diabetes mellitus and risk of venous thromboembolism.

BACKGROUND: : To determine if diabetes mellitus is a risk factor for venous thromboembolism (VTE). RESEARCH DESIGN AND METHODS: : Data from the National Hospital Discharge Survey were analyzed from 1979 to 2005. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify diseases. RESULTS: : Among 92,240,000 patients with diabetes mellitus discharged between 1979 and 2005, 1,267,000 (1.4%) had VTE. The relative risk for VTE was elevated only in patients younger than 50 to 59 years and was highest in patients aged 20 to 29 years (relative risk = 1.73). Relative risks of VTE with uncomplicated type 1 diabetes mellitus and uncomplicated type 2 diabetes mellitus were similar and also age dependent. In patients with uncomplicated diabetes mellitus who did not have obesity, stroke, heart failure, or cancer, compared with those who did not have diabetes mellitus and did not have any of these comorbid conditions, the relative risk for VTE was 1.52 in patients aged 20 to 29 years and 1.19 in patients aged 30 to 39 years. In older patients, the relative risk of VTE in patients with diabetes mellitus was not increased. CONCLUSIONS: : Diabetes mellitus carries an increased risk for VTE, which is apparent only in younger patients in whom comorbid conditions that also increase the risk of VTE are unlikely to be present.