Multicenter CT Image-Based Anatomic Assessment of Patients with Aortoiliac Aneurysm Undergoing Endovascular Repair with Iliac Branch Devices.

BACKGROUND: The Global Iliac Branch Study (NCT05607277) is an international, multicenter, retrospective cohort study of anatomic predictors of adverse iliac events (AIEs) in aortoiliac aneurysms treated with iliac branch devices (IBDs). METHODS: Patients with pre-IBD and post-IBD computed tomography imaging were included. We measured arterial diameters, stenosis, calcification, bifurcation angles, and tortuosity indices using a standardized, validated protocol. A composite of ipsilateral AIE was defined, a priori, as occlusion, type I or III endoleak, device constriction, or clinical event requiring reintervention. Paired t-test compared tortuosity indices and splay angles pretreatment and post-treatment for all IBDs and by device material (stainless steel and nitinol). Two-sample t-test compared anatomical changes from pretreatment to post-treatment by device material. Logistic regression assessed associations between AIE and anatomic measurements. Analysis was performed by IBD. RESULTS: We analyzed 297 patients (286 males, 11 females) with 331 IBDs (227 stainless steel, 104 nitinol). Median clinical follow-up was 3.8 years. Iliac anatomy was significantly straightened with all IBD treatment, though stainless steel IBDs had a greater reduction in total iliac artery tortuosity index and aortic splay angle compared to nitinol IBDs (absolute reduction -0.20 [-0.22 to -0.18] vs. -0.09 [-0.12 to -0.06], P < 0.0001 and -19.6° [-22.4° to -16.9°] vs. -11.2° [-15.3° to -7.0°], P = 0.001, respectively). There were 54 AIEs in 44 IBDs in 42 patients (AIE in 13.3% of IBD systems), requiring 35 reinterventions (median time to event 41 days; median time to reintervention 153 days). There were 18 endoleaks, 29 occlusions, and 5 device constrictions. There were no strong associations between anatomic measurements and AIE overall, though internal iliac diameter was inversely associated with AIE in nitinol devices (nAIE, nitinol = 8). CONCLUSIONS: Purpose-built IBDs effectively treat aortoiliac disease, including that with tortuous anatomy, with a high patency rate (91.5%) and low reintervention rate (9.1%) at 4 years. Anatomic predictors of AIE are limited.

Image-based assessment of aortoiliac aneurysm anatomical characteristics in patients from the global iliac branch study.

OBJECTIVE: Endovascular repair is the preferred treatment for aortoiliac aneurysm, with preservation of at least one internal iliac artery recommended. This study aimed to assess pre-endovascular repair anatomical characteristics of aortoiliac aneurysm in patients from the Global Iliac Branch Study (GIBS, NCT05607277) to enhance selection criteria for iliac branch devices (IBD) and improve long-term outcomes. METHODS: Pre-treatment CT scans of 297 GIBS patients undergoing endovascular aneurysm repair were analyzed. Measurements included total iliac artery length, common iliac artery length, tortuosity index, common iliac artery splay angle, internal iliac artery stenosis, calcification score, and diameters in the device's landing zone. Statistical tests assessed differences in anatomical measurements and IBD-mediated internal iliac artery preservation. RESULTS: Left total iliac artery length was shorter than right (6.7 mm, P = .0019); right common iliac artery less tortuous (P = .0145). Males exhibited greater tortuosity in the left total iliac artery (P = .0475) and larger diameter in left internal iliac artery's landing zone (P = .0453). Preservation was more common on right (158 unilateral, 34 bilateral) than left (105 unilateral, 34 bilateral). There were 192 right-sided and 139 left-sided IBDs, with 318 IBDs in males and 13 in females. CONCLUSION: This study provides comprehensive pre-treatment iliac anatomy analysis in patients undergoing endovascular repair with IBDs, highlighting differences between sides and sexes. These findings could refine patient selection for IBD placement, potentially enhancing outcomes in aortoiliac aneurysm treatment. However, the limited number of females in the study underscores the need for further research to generalize findings across genders.

Effect of Doxycycline on Progression of Arterial Calcification in the Noninvasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA(3)CT).

BACKGROUND: Doxycycline has been shown to prevent arterial calcification via attenuation of matrix metalloproteinases (MMP) in preclinical models. We assessed the effects of doxycycline on progression of arterial calcification in patients enrolled in the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT). METHODS: Two hundred and sixty-one patients were randomized to 100 mg doxycycline twice daily or placebo. Arterial calcification was measured in abdominal vessels on noncontrast computed tomography scans. Patients with baseline computed tomography scan and 1 or more follow-up scans within the 2-year study were included for analysis. For individual arteries, mean change in iliofemoral artery calcification over time was calculated via linear regression. Serum MMP-3 and MMP-9 levels were measured at baseline and 6 months. RESULTS: Sixty-five patients in the doxycycline and 66 in the placebo arm were included in this analysis. Baseline characteristics between the groups were similar. The unadjusted mean change in iliofemoral calcium score per year trended toward higher values in patients treated with doxycycline compared with placebo (322 ± 399 units/year vs. 217 ± 307 units/year, P = 0.09). After 6 months, changes in serum MMP-3 and MMP-9 levels were not significantly different between study arms. CONCLUSIONS: In patients with small aortic aneurysm, treatment with doxycycline 100 mg twice daily did not decrease circulating levels of the matrix degrading enzymes MMP-3 and 9 or alter the progression of arterial calcification.

Mucosal Immune Profiles Associated with Diarrheal Disease Severity in Shigella- and Enteropathogenic Escherichia coli-Infected Children Enrolled in the Global Enteric Multicenter Study.

Enteropathogenic Escherichia coli (EPEC) and Shigella are etiologic agents of diarrhea in children <5 years old living in resource-poor countries. Repeated bouts of infection lead to lifelong morbidity and even death. The goal of this study was to characterize local mucosal immune responses in Shigella- and EPEC-infected children <5 years of age with moderate to severe diarrhea (MSD) enrolled in the Global Enteric Multicenter Study (GEMS). We hypothesized that infection with each of these pathogens would induce distinct gut mucosal immune profiles indicative of disease etiology and severity. To test this hypothesis, innate and adaptive immune markers were measured in stools from children with diarrhea due to EPEC, Shigella, or other organisms and in children who had no diarrhea. Shigella-positive diarrhea evoked robust proinflammatory and TH1/TH2 cytokine responses compared to diarrhea caused by EPEC or other organisms, with the exception of interleukin 5 (IL-5), which was associated with EPEC infection. The presence of IL-1ß, IL-4, IL-16, and tumor necrosis factor beta (TNF-ß) was associated with the absence of dysentery. EPEC-positive diarrhea evoked high levels of IL-1ß, vascular endothelial growth factor (VEGF), and IL-10. Granulocyte-macrophage colony-stimulating factor (GM-CSF) had opposing roles in disease severity, being associated with absence of diarrhea in EPEC-infected children and with dysenteric Shigella infection. High levels of antigen-specific antibodies were detected in the controls and children with Shigella without dysentery, which suggests a protective role against severe disease. In summary, this study identified distinct local immune responses associated with two clinically relevant diarrheagenic pathogens, Shigella and EPEC, in children and identified protective immune phenotypes that can inform the development of preventive measures. IMPORTANCE Shigella and enteropathogenic Escherichia coli are primary agents of moderate to severe diarrhea in children <5 years of age living in resource-poor countries. Repeated bouts of illness lead to lifelong health impairment and even death. Aiming to understand the local host immunity to these pathogens in relation to disease prognosis and to identify prophylaxis and therapeutic targets, we investigated innate and adaptive immune profiles in stools from children infected with EPEC with and without diarrhea, Shigella with and without dysentery, and controls in well characterized clinical samples obtained during the Global Enteric Multicenter Study. For the first time, we report pathogen-specific mucosal immune profiles associated with severity or absence of disease in children <5 years of age that can inform prevention and treatment efforts.

Role of volume in small abdominal aortic aneurysm surveillance.

OBJECTIVE: Current management of small abdominal aortic aneurysms (AAAs) primarily involves serial imaging surveillance of maximum transverse diameter (MTD) to estimate rupture risk. Other measurements, such as volume and tortuosity, are less well-studied and may help characterize and predict AAA progression. This study evaluated predictors of AAA volume growth and discusses the role of volume in clinical practice. METHODS: Subjects from the Non-invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (baseline AAA MTD, 3.5-5.0 cm) with ≥2 computed tomography scans were included in this study (n = 250). Computed tomography scans were conducted approximately every 6 months over 2 years. MTD, volume, and tortuosity were used to model growth. Univariable and multivariable backwards elimination least squares regressions assessed associations with volume growth. RESULTS: Baseline MTD accounted for 43% of baseline volume variance (P < .0001). Mean volume growth rate was 10.4 cm3/year (standard deviation, 8.8 cm3/year) (mean volume change +10.4%). Baseline volume accounted for 30% of volume growth variance; MTD accounted for 13% of volume growth variance. More tortuous aneurysms at baseline had significantly larger volume growth rates (difference, 32.8 cm3/year; P < .0001). Univariable analysis identified angiotensin II receptor blocker use (difference, -3.4 cm3/year; P = .02) and history of diabetes mellitus (difference, -2.8 cm3/year; P = .04) to be associated with lower rates of volume growth. Baseline volume, tortuosity index, current tobacco use, and absence of diabetes mellitus remained significantly associated with volume growth in multivariable analysis. AAAs that reached the MTD threshold for repair had a wide range of volumes: 102 cm3 to 142 cm3 in female patients (n = 5) and 105 cm3 to 229 cm3 in male patients (n = 20). CONCLUSIONS: Baseline AAA volume and MTD were found to be moderately correlated. On average, AAA volume grows about 10% annually. Baseline volume, tortuosity, MTD, current tobacco use, angiotensin II receptor blocker use, and history of diabetes mellitus were predictive of volume growth over time.

The Impact of Dedicated Cardiac Intensive Care Units on Outcomes in Pediatric Cardiac Surgery: A Virtual Pediatric Systems Database Analysis.

Care of children undergoing cardiac surgery occurs in dedicated cardiac intensive care units (CICU) or mixed intensive care units. In this article, we analyzed data from Virtual Pediatric Systems (VPS, LLC) database (2009-2014) for children < 18 years of age undergoing cardiac surgery, classified according to Society of Thoracic Surgery-European Association of Cardiothoracic Surgery (STS-EACTS) risk category. We had 25,052 (52%) patients in 53 mixed units (mortality rate, 2.99%), and 22,762 (48%) patients in 19 dedicated CICUs (mortality rate, 2.62%). There was a direct relationship between STS-EACTS risk category and death rate in both units. By multivariable logistic and linear regression, there was no difference in mortality between mixed unit and CICU death rates within STS-EACTS risk categories. We found no difference in outcomes for children undergoing cardiac surgery based on the unit type (dedicated CICU or mixed unit).

Evaluating Growth Patterns of Abdominal Aortic Aneurysm Diameter With Serial Computed Tomography Surveillance.

Importance: Small abdominal aortic aneurysms (AAAs) are common in the elderly population. Their growth rates and patterns, which drive clinical surveillance, are widely disputed. Objective: To assess the growth patterns and rates of AAAs as documented on serial computed tomography (CT) scans. Design, Setting, and Participants: Cohort study and secondary analysis of the Non-Invasive Treatment of Abdominal Aortic Aneurysm Clinical Trial (N-TA3CT), a randomized, double-blind placebo-controlled clinical trial conducted from 2013 to 2018, with CT imaging every 6 months for 2 years. The trial was a multicenter, observational secondary analysis, not related to treatment hypotheses of data collected in the N-TA3CT. Participants included 254 patients with baseline AAA diameter between 3.5 and 5.0 cm. Exposures: Patients received serial CT scan measurements, analyzed for maximum transverse diameter, at 6-month intervals. Main Outcomes and Measures: The primary study outcome was AAA annual growth rate. Secondary analyses included characterizing AAA growth patterns, assessing likelihood of AAA diameter to exceed sex-specific intervention thresholds over 2 years. Results: A total of 254 patients, 35 women with baseline AAA diameter 3.5 to 4.5 cm and 219 men with baseline diameter 3.5 to 5.0 cm, were included. Yearly growth rates of AAA diameters were a median of 0.17 cm/y (interquartile range [IQR], 0.16) and a mean (SD), 0.19 (0.14) cm/y. Ten percent of AAAs displayed minimal to no growth (<0.05 cm/y), 62% displayed low growth (0.05-0.25 cm/y), and 28% displayed high growth (>0.25 cm/y). Baseline AAA diameter accounted for 5.4% of variance of growth rate (P < .001; R2, 0.054). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth and 4% exponential growth); and some patients' growth patterns were not clearly classifiable (23% indeterminate). No patients with a maximum transverse diameter less than 4.25 cm exceeded sex-specific repair thresholds at 2 years (men, 0 of 92; 95% CI, 0.00-0.055; women, 0 of 25 ; 95% CI, 0.00-0.247). Twenty-six percent of patients with a maximum transverse diameter of at least 4.25 cm exceeded sex-specific repair thresholds at 2 years (n = 12 of 83 men with diameter ranging from 4.25 to <4.75 cm; 95% CI, 0.091-0.264; n = 21 of 44 men with diameter ranging from 4.75-5.0 cm; 95% CI, 0.362-0.669; n = 3 of 10 women with diameter ≥4.25 cm; 95% CI, 0.093-0.726). Conclusions and Relevance: Most small AAAs showed linear growth; large intrapatient variations in interval growth rates were infrequently observed over 2 years. Linear growth modeling of AAAs in individual patients suggests smaller AAAs (<4.25 cm) can be followed up with a CT scan in at least 2 years with little chance of exceeding interventional thresholds. Trial Registration: ClinicalTrials.gov Identifier: NCT01756833.

Characteristics and outcomes of children with congenital heart disease needing diaphragm plication.

BACKGROUND: Diaphragm dysfunction following surgery for congenital heart disease is a known complication leading to delays in recovery and increased post-operative morbidity and mortality. We aimed to determine the incidence of and risk factors associated with diaphragm plication in children undergoing cardiac surgery and evaluate timing to repair and effects on hospital cost and length of stay. METHODS: We conducted a multi-institutional retrospective observational cohort study. Forty-three hospitals from the Pediatric Health Information System database were included, and a total of 112,110 patients admitted between January 2004 and December 2014 were analysed. RESULTS: Patients less than 18 years of age who underwent cardiac surgery were included. Risk Adjustment for Congenital Heart Surgery was utilized to determine procedure complexity. The overall incidence of diaphragm dysfunction was 2.2% (n = 2513 out of 112,110). Of these, 24.0% (603 patients) underwent diaphragm plication. Higher complexity cardiac surgery (Risk Adjustment for Congenital Heart Surgery 5-6) and age less than 4 weeks were associated with a higher likelihood of diaphragm plication (p-value < 0.01). Diaphragmatic plication was associated with increased hospital length of stay (p-value < 0.01) and increased medical cost. CONCLUSIONS: Diaphragm plication after surgery for congenital heart disease is associated with longer hospital length of stay and increased cost. There is a strong correlation of prolonged time to plication with increased length of stay and medical cost. The likelihood of plication increases with younger age and higher procedure complexity. Methods to improve early recognition and treatment of diaphragm dysfunction should be developed.

Asymptomatic carotid stenosis is associated with mobility and cognitive dysfunction and heightens falls in older adults.

BACKGROUND: Atherosclerosis of the carotid bifurcation with plaque formation causes asymptomatic carotid artery stenosis (ACAS), which may also be associated with cerebral hypoperfusion. Cerebral hypoperfusion adversely affects multiple aspects of mobility and cognition. This study tests the hypothesis that community-dwelling older adults with a 50% or greater diameter-reducing ACAS will have mobility and cognitive impairments that heighten their risk for falls. METHODS: Eighty community-dwelling adults completed a mobility assessment (Short Physical Performance Battery, Berg Balance Scale, Four Square Step Test, Dynamic Gait Index, Timed Up and Go, and gait speed), self-reported physical function (Activities-Specific Balance Confidence, SF-12 Physical Function Component), and cognitive tests (Mini-Mental State Examination). Falls were recorded for the past 6 months. Standardized carotid ultrasound examination classified participants into no stenosis (<50% diameter reduction) (n = 54), moderate stenosis (50%-69%) (n = 17), and high-grade stenosis (70%-99%) (n = 9) groups. Linear and logistic regression analyses determined the associations between these measures and the degree of stenosis (three groups). RESULTS: Logistic regression analysis showed their degree of stenosis was associated with reductions in mobility (Short Physical Performance Battery [P = .008], Berg Balance Scale [P = .0008], Four Square Step Test [P = .005], DGI [P = .0001], TUG [P = .0004], gait speed [P = .02]), perceived physical function (ABC [P < .0001], SF-12 Physical Function Component [P < .0001]), and cognition (MMSE [P = .003]). Adults with moderate- and high-grade stenosis had a greater incidence of falls compared with those without stenosis (relative risk, 2.86; P = .01). Results remained unchanged after adjustment for age, sex and cardiovascular risk factors. CONCLUSIONS: ACAS is associated with impaired mobility and cognition that are accompanied with increased fall risk. These impairments increased with worsening severity.

Use of quantitative molecular diagnostic methods to identify causes of diarrhoea in children: a reanalysis of the GEMS case-control study.

BACKGROUND: Diarrhoea is the second leading cause of mortality in children worldwide, but establishing the cause can be complicated by diverse diagnostic approaches and varying test characteristics. We used quantitative molecular diagnostic methods to reassess causes of diarrhoea in the Global Enteric Multicenter Study (GEMS). METHODS: GEMS was a study of moderate to severe diarrhoea in children younger than 5 years in Africa and Asia. We used quantitative real-time PCR (qPCR) to test for 32 enteropathogens in stool samples from cases and matched asymptomatic controls from GEMS, and compared pathogen-specific attributable incidences with those found with the original GEMS microbiological methods, including culture, EIA, and reverse-transcriptase PCR. We calculated revised pathogen-specific burdens of disease and assessed causes in individual children. FINDINGS: We analysed 5304 sample pairs. For most pathogens, incidence was greater with qPCR than with the original methods, particularly for adenovirus 40/41 (around five times), Shigella spp or enteroinvasive Escherichia coli (EIEC) and Campylobactor jejuni o C coli (around two times), and heat-stable enterotoxin-producing E coli ([ST-ETEC] around 1·5 times). The six most attributable pathogens became, in descending order, Shigella spp, rotavirus, adenovirus 40/41, ST-ETEC, Cryptosporidium spp, and Campylobacter spp. Pathogen-attributable diarrhoeal burden was 89·3% (95% CI 83·2-96·0) at the population level, compared with 51·5% (48·0-55·0) in the original GEMS analysis. The top six pathogens accounted for 77·8% (74·6-80·9) of all attributable diarrhoea. With use of model-derived quantitative cutoffs to assess individual diarrhoeal cases, 2254 (42·5%) of 5304 cases had one diarrhoea-associated pathogen detected and 2063 (38·9%) had two or more, with Shigella spp and rotavirus being the pathogens most strongly associated with diarrhoea in children with mixed infections. INTERPRETATION: A quantitative molecular diagnostic approach improved population-level and case-level characterisation of the causes of diarrhoea and indicated a high burden of disease associated with six pathogens, for which targeted treatment should be prioritised. FUNDING: Bill & Melinda Gates Foundation.

Shigella IpaB and IpaD displayed on L. lactis bacterium-like particles induce protective immunity in adult and infant mice.

Shigella spp. are among the enteric pathogens with the highest attributable incidence of moderate-to-severe diarrhea in children under 5 years of age living in endemic areas. There are no vaccines available to prevent this disease. In this work, we investigated a new Shigella vaccine concept consisting of nonliving, self-adjuvanted, Lactococcus lactis bacterium-like particles (BLP) displaying Shigella invasion plasmid antigen (Ipa) B and IpaD and examined its immunogenicity and protective efficacy in adult and newborn/infant mice immunized via the nasal route. Unique advantages of this approach include the potential for broad protection due to the highly conserved structure of the Ipas and the safety and practicality of a probiotic-based mucosal/adjuvant delivery platform. Immunization of adult mice with BLP-IpaB and BLP-IpaD (BLP-IpaB/D) induced high levels of Ipa-specific serum IgG and stool IgA in a dose-dependent manner. Immune responses and protection were enhanced by BLP delivery. Vaccine-induced serum antibodies exhibited opsonophagocytic and cytotoxic neutralizing activity, and IpaB/D IgG titers correlated with increased survival post-challenge. Ipa-specific antibody secreting cells were detected in nasal tissue and lungs, as well as IgG in bronchoalveolar lavage. Bone marrow cells produced IpaB/D-specific antibodies and contributed to protection after adoptive transfer. The BLP-IpaB/D vaccine conferred 90% and 80% protection against S. flexneri and S. sonnei, respectively. Mice immunized with BLP-IpaB/D as newborns also developed IpaB and IpaD serum antibodies; 90% were protected against S. flexneri and 44% against S. sonnei. The BLP-IpaB/D vaccine is a promising candidate for safe, practical and potentially effective immunization of children against shigellosis.

CD28 homodimer interface mimetic peptide acts as a preventive and therapeutic agent in models of severe bacterial sepsis and gram-negative bacterial peritonitis.

BACKGROUND: Severe gram-negative bacterial infections and sepsis are major causes of morbidity and mortality. Dysregulated, excessive proinflammatory cytokine expression contributes to the pathogenesis of sepsis. A CD28 mimetic peptide (AB103; previously known as p2TA) that attenuates CD28 signaling and T-helper type 1 cytokine responses was tested for its ability to increase survival in models of polymicrobial infection and gram-negative sepsis. METHODS: Mice received AB103, followed by an injection of Escherichia coli 0111:B4 lipopolysaccharide (LPS); underwent induction E. coli 018:K1 peritonitis induction, followed by treatment with AB103; or underwent cecal ligation and puncture (CLP), followed by treatment with AB103. The effects of AB103 on factors associated with and the lethality of challenge infections were analyzed. RESULTS: AB103 strongly attenuated induction of tumor necrosis factor α and interleukin 6 (IL-6) by LPS in human peripheral blood mononuclear cells. Receipt of AB103 following intraperitoneal injection of LPS resulted in survival among 73% of CD1 mice (11 of 15), compared with 20% of controls (3 of 15). Suboptimal doses of antibiotic alone protected 20% of mice (1 of 5) from E. coli peritonitis, whereas 100% (15 of 15) survived when AB103 was added 4 hours following infection. Survival among mice treated with AB103 12 hours after CLP was 100% (8 of 8), compared with 17% among untreated mice (1 of 6). In addition, receipt of AB103 12 hours after CLP attenuated inflammatory cytokine responses and neutrophil influx into tissues and promoted bacterial clearance. Receipt of AB103 24 hours after CLP still protected 63% of mice (5 of 8). CONCLUSIONS: Single-dose AB103 reduces mortality in experimental models of polymicrobial and gram-negative bacterial infection and sepsis, warranting further studies of this agent in clinical trials.

Streptococcal pharyngitis in schoolchildren in Bamako, Mali.

BACKGROUND: Group A streptococcus (GAS) pharyngitis is associated with high rates of rheumatic heart disease in developing countries. We sought to identify guidelines for empiric treatment of pharyngitis in low-resource settings. To inform the design of GAS vaccines, we determined the emm types associated with pharyngitis among African schoolchildren. METHODS: Surveillance for pharyngitis was conducted among children 5-16 years of age attending schools in Bamako, Mali. Students were encouraged to visit a study clinician when they had a sore throat. Enrollees underwent evaluation and throat swab for isolation of GAS. Strains were emm typed by standard methods. RESULTS: GAS was isolated from 449 (25.5%) of the 1,759 sore throat episodes. Painful cervical adenopathy was identified in 403 children (89.8%) with GAS infection and was absent in 369 uninfected children (28.2%). Emm type was determined in 396 (88.2%) of the 449 culture-positive children; 70 types were represented and 14 types accounted for 49% of isolates. Based on the proportion of the 449 isolates bearing emm types included in the 30-valent vaccine (31.0%) plus nonvaccine types previously shown to react to vaccine-induced bactericidal antibodies (44.1%), the vaccine could protect against almost 75% of GAS infections among Bamako schoolchildren. CONCLUSIONS: Two promising strategies could reduce rheumatic heart disease in low-resource settings. Administering antibiotics to children with sore throat and tender cervical adenopathy could treat most GAS-positive children while reducing use of unnecessary antibiotics for uninfected children. Broad coverage against M types associated with pharyngitis in Bamako schoolchildren might be achieved with the 30-valent GAS vaccine under development.

Neuraminidase reprograms lung tissue and potentiates lipopolysaccharide-induced acute lung injury in mice.

We previously reported that removal of sialyl residues primed PBMCs to respond to bacterial LPS stimulation in vitro. Therefore, we speculated that prior desialylation can sensitize the host to generate an enhanced inflammatory response upon exposure to a TLR ligand, such as LPS, in a murine model of acute lung injury. Intratracheal instillation of neuraminidase (NA) 30 min prior to intratracheal administration of LPS increased polymorphonuclear leukocytes (PMNs) in the bronchoalveolar lavage fluid and the wet-to-dry lung weight ratio, a measure of pulmonary edema, compared with mice that received LPS alone. Administration of NA alone resulted in desialylation of bronchiolar and alveolar surfaces and induction of TNF-α, IL-1ß, and chemokines in lung homogenates and bronchoalveolar lavage fluid; however, PMN recruitment in mice treated with NA alone did not differ from that of PBS-administered controls. NA pretreatment alone induced apoptosis and markedly enhanced LPS-induced endothelial apoptosis. Administration of recombinant Bcl-2, an antiapoptotic molecule, abolished the effect of NA treatment on LPS-induced PMN recruitment and pulmonary edema formation. We conclude that NA pretreatment potentiates LPS-induced lung injury through enhanced PMN recruitment, pulmonary edema formation, and endothelial and myeloid cell apoptosis. A similar "reprogramming" of immune responses with desialylation may occur during respiratory infection with NA-expressing microbes and contribute to severe lung injury.

Advanced phase I/II studies of targeted gene delivery in vivo: intravenous Rexin-G for gemcitabine-resistant metastatic pancreatic cancer.

Rexin-G, a nonreplicative pathology-targeted retroviral vector bearing a cytocidal cyclin G1 construct, was tested in a phase I/II study for gemcitabine-resistant pancreatic cancer. The patients received escalating doses of Rexin-G intravenously from 1 x 10(11) colony-forming units (cfu) 2-3x a week (dose 0-1) to 2 x 10(11) cfu 3x a week (dose 2) for 4 weeks. Treatment was continued if there was less than or equal to grade 1 toxicity. No dose-limiting toxicity (DLT) was observed, and no vector DNA integration, replication-competent retrovirus (RCR), or vector-neutralizing antibodies were noted. In nine evaluable patients, 3/3 patients had stable disease (SD) at dose 0-1. At dose 2, 1/6 patients had a partial response (PR) and 5/6 patients had SD. Median progression-free survival (PFS) was 3 months at dose 0-1, and >7.65 months at dose 2. Median overall survival (OS) was 4.3 months at dose 0-1, and 9.2 months at dose 2. One-year survival was 0% at dose 0-1 compared to 28.6% at dose 2, suggesting a dose-response relationship between OS and Rexin-G dosage. Taken together, these data indicate that (i) Rexin-G is safe and well tolerated, and (ii) Rexin-G may help control tumor growth, and may possibly prolong survival in gemcitabine-resistant pancreatic cancer, thus, earning US Food and Drug Administration's (FDA) fast-track designation as second-line treatment for pancreatic cancer.

Phase I/II and phase II studies of targeted gene delivery in vivo: intravenous Rexin-G for chemotherapy-resistant sarcoma and osteosarcoma.

Rexin-G, a pathotropic nanoparticle bearing a cytocidal cyclin G1 construct was tested in a phase I/II study for chemotherapy-resistant sarcomas and a phase II study for chemotherapy-resistant osteosarcoma. Twenty sarcoma patients and 22 osteosarcoma patients received escalating doses of Rexin-G intravenously from 8 x 10(11) to 24 x 10(11) colony forming units (cfu)/cycle. Treatment was continued if there was or=3 months and median OS, 6.9 months. These studies suggest that Rexin-G is safe, may help control tumor growth, and may possibly improve survival in chemotherapy-resistant sarcoma and osteosarcoma.

Inferiority of IL-2 alone versus IL-2 with HAART in maintaining CD4 T cell counts during HAART interruption: a randomized controlled trial.

OBJECTIVE: To evaluate whether interleukin (IL)-2 in patients with chronic HIV infection can maintain CD4 T cell counts during 6 months of HAART interruption. DESIGN: Prospective, randomized, controlled, open-label phase II noninferiority trial comparing IL-2 with HAART interruption or continuous HAART. METHODS: Forty-one IL-2-experienced (three or more prior cycles) HIV-1-infected adults with CD4 cell count at least 500 cells/microl were randomized in the ratio 2: 1 to interrupted (I = 27) or continuous (C = 14) HAART for 6 months following an initial IL-2 cycle. Subsequent IL-2 cycles were triggered by CD4 T cell counts less than 90% of baseline. Immune, metabolic, and quality of life indices were compared (Mann-Whitney and Fisher's exact tests), defining noninferiority as a percentage difference (C- I) in treatment success (CD4 T cells > or =90% of baseline at 6 months) with a 95% confidence interval (CI) lower limit greater than -20%. RESULTS: Demographic and immune parameters were similar between the groups at baseline. Median CD4 T cell count, HIV viral load, and treatment success differed significantly at 6 months (I: 866 cells/microl, 39,389 copies/ml, 48.1%; C: 1246 cells/microl, <50 copies/ml, 92.3%; P < or = 0.001). Group I was inferior to C (% difference = -44.2%; 95% CI: -64.2%, -11.2%; P = 0.013). Minor statistically significant differences in HgbA1c and energy level occurred at 6 months (I > C). Following HAART interruption, single cases of acute retroviral syndrome, secondary syphilis, non-Hodgkin's lymphoma, and Kaposi's sarcoma recurrence were observed. CONCLUSION: IL-2 alone was inferior to IL-2 with HAART in maintaining baseline CD4 T cell counts. HAART interruption had a small impact on metabolic parameters and quality of life.

Use of mchI encoding immunity to the antimicrobial peptide microcin H47 as a plasmid selection marker in attenuated bacterial live vectors.

Live attenuated bacterial strains expressing heterologous antigens represent an attractive vaccine development strategy. However, the use of drug resistance genes for the selection of expression plasmids introduced into live vectors poses theoretical health risks. Therefore, we developed a novel approach for plasmid selection based on immunity to the antimicrobial peptide microcin H47 (MccH47). Two expression plasmids encoding the reporter green fluorescent protein (GFPuv) were constructed; selection markers comprised either mchI, conferring immunity to MccH47 (pGEN222I), or bla (encoding beta-lactamase), conferring conventional resistance to ampicillin (pGEN222). GFPuv-specific serum immunoglobulin G (IgG) antibody responses were analyzed in mice immunized intranasally either with Salmonella enterica serovar Typhi CVD 908-htrA or Shigella flexneri 2a CVD 1208S live vector and were boosted parenterally with purified GFPuv. Similar IgG antibody responses were observed for both pGEN222 and pGEN222I when either CVD 1208S or CVD 908-htrA(pGEN222I) was used as the carrier. Interestingly, CVD 908-htrA(pGEN222I) elicited a significantly higher IgG response than CVD 908-htrA(pGEN222). We also compared the priming potential of homologous priming either with CVD 908-htrA(pGEN222I) or CVD 1208S(pGEN222I) to heterologous priming first with CVD 908-htrA(pGEN222I) and then with CVD 1208S(pGEN222I) and vice versa. Immunization with two unrelated live vectors significantly enhanced the IgG responses compared to responses engendered by homologous CVD 908-htrA(pGEN222I) but not to those of CVD 1208S(pGEN222I). MccH47 offers an alternate system for plasmid selection in bacterial live vectors that greatly improves their clinical acceptability. Furthermore, the success of the heterologous priming strategy supports the feasibility of the future development of multivalent live vector-based immunization strategies against multiple human pathogens.

Restoration of immunity in lymphopenic individuals with cancer by vaccination and adoptive T-cell transfer.

Immunodeficiency is a barrier to successful vaccination in individuals with cancer and chronic infection. We performed a randomized phase 1/2 study in lymphopenic individuals after high-dose chemotherapy and autologous hematopoietic stem cell transplantation for myeloma. Combination immunotherapy consisting of a single early post-transplant infusion of in vivo vaccine-primed and ex vivo costimulated autologous T cells followed by post-transplant booster immunizations improved the severe immunodeficiency associated with high-dose chemotherapy and led to the induction of clinically relevant immunity in adults within a month after transplantation. Immune assays showed accelerated restoration of CD4 T-cell numbers and function. Early T-cell infusions also resulted in significantly improved T-cell proliferation in response to antigens that were not contained in the vaccine, as assessed by responses to staphylococcal enterotoxin B and cytomegalovirus antigens (P < 0.05). In the setting of lymphopenia, combined vaccine therapy and adoptive T-cell transfer fosters the development of enhanced memory T-cell responses.

In vitro assay for neutralizing antibody to hepatitis C virus: evidence for broadly conserved neutralization epitopes.

Our understanding of the humoral immune response to hepatitis C virus (HCV) is limited because the virus can be studied only in humans and chimpanzees and because previously described neutralization assays have not been robust or simple to perform. Nevertheless, epidemiologic and laboratory studies suggested that neutralizing Ab to HCV might be important in preventing infection. We have recently described a neutralization assay based on the neutralization of pseudotyped murine retrovirus constructs bearing HCV envelope glycoproteins on their surface. We have applied the assay to well characterized clinical samples from HCV-infected patients and chimpanzees, confirmed the existence of neutralizing Ab to HCV, and validated most previously reported neutralizations of the virus. We did not find neutralizing anti-HCV in resolving infections but did find relatively high titers (>1:320) of such Ab in chronic infections. Neutralizing Ab was directed not only to epitope(s) in the hypervariable region of the E2 envelope protein but also to one or more epitopes elsewhere in the envelope of the virus. Neutralizing Ab was broadly reactive and could neutralize pseudotype particles bearing the envelope glycoproteins of two different subgenotypes (1a and 1b). The ability to assay neutralizing anti-HCV should permit an assessment of the prospects for successful Ab-mediated passive and active immunoprophylaxis against hepatitis C.