Inter-alpha-trypsin inhibitor (IαI) and hyaluronan modifications enhance the innate immune response to influenza virus in the lung

The inter-alpha-trypsin inhibitor (IαI) complex is composed of the bikunin core protein with a single chondroitin sulfate (CS) attached and one or two heavy chains (HCs) covalently linked to the CS chain. The HCs from IαI can be transferred to hyaluronan (HA) through a TNFα-stimulated gene-6 (TSG-6) dependent process to form an HC•HA matrix. Previous studies reported increased IαI, HA, and HC•HA complexes in mouse bronchoalveolar lavage fluid (BALF) post-influenza infection. However, the expression and incorporation of HCs into the HA matrix of the lungs during the clinical course of influenza A virus (IAV) infection and the biological significance of the HC•HA matrix are poorly understood. The present study aimed to better understand the composition of HC•HA matrices in mice infected with IAV and how these matrices regulate the host pulmonary immune response. In IAV infected mice bikunin, HC1-3, TSG-6, and HAS1-3 all show increased gene expression at various times during a 12-day clinical course. The increased accumulation of IαI and HA was confirmed in the lungs of infected mice using immunohistochemistry and quantitative digital pathology. Western blots confirmed increases in the IαI components in BALF and lung tissue at 6 days post-infection (dpi). Interestingly, HCs and bikunin recovered from BALF and plasma from mice 6 dpi with IAV, displayed differences in the HC composition by Western blot analysis and differences in bikunin's CS chain sulfation patterns by mass spectrometry analysis. This strongly suggests that the IαI components were synthesized in the lungs rather than translocated from the vascular compartment. HA was significantly increased in BALF at 6 dpi, and the HA recovered in BALF and lung tissues were modified with HCs indicating the presence of an HC•HA matrix. In vitro experiments using polyinosinic-polycytidylic acid (poly(I:C)) treated mouse lung fibroblasts (MLF) showed that modification of HA with HCs increased cell-associated HA, and that this increase was due to the retention of HA in the MLF glycocalyx. In vitro studies of leukocyte adhesion showed differential binding of lymphoid (Hut78), monocyte (U937), and neutrophil (dHL60) cell lines to HA and HC•HA matrices. Hut78 cells adhered to immobilized HA in a size and concentration-dependent manner. In contrast, the binding of dHL60 and U937 cells depended on generating a HC•HA matrix by MLF. Our in vivo findings, using multiple bronchoalveolar lavages, correlated with our in vitro findings in that lymphoid cells bound more tightly to the HA-glycocalyx in the lungs of influenza-infected mice than neutrophils and mononuclear phagocytes (MNPs). The neutrophils and MNPs were associated with a HC•HA matrix and were more readily lavaged from the lungs. In conclusion, this work shows increased IαI and HA accumulation and the formation of a HC•HA matrix in mouse lungs post-IAV infection. The formation of HA and HC•HA matrices could potentially create specific microenvironments in the lungs for immune cell recruitment and activation during IAV infection.

Risk of Severe Abnormal Uterine Bleeding Associated with Rivaroxaban Compared with Apixaban, Dabigatran and Warfarin

INTRODUCTION

There have been reports of clinically relevant uterine bleeding events among women of reproductive age exposed to rivaroxaban.

OBJECTIVE

The aim of this study was to compare the risk of severe abnormal uterine bleeding (SAUB) resulting in transfusion or surgical intervention among women on rivaroxaban versus apixaban, dabigatran and warfarin.

METHODS

We conducted a retrospective cohort study in the FDA's Sentinel System (10/2010-09/2015) among females aged 18+ years with venous thromboembolism (VTE), or atrial flutter/fibrillation (AF) who newly initiated a direct oral anticoagulant (DOAC; rivaroxaban, apixaban, dabigatran) or warfarin. We followed women from dispensing date until the earliest of transfusion or surgery following vaginal bleeding, disenrollment, exposure or study end date, or recorded death. We estimated hazard ratios (HRs) using Cox proportional hazards regression via propensity score stratification. Four pairwise comparisons were conducted for each intervention.

RESULTS

Overall, there was an increased risk of surgical intervention with rivaroxaban when compared with dabigatran (HR 1.19; 95% CI 1.03-1.38), apixaban (1.23; 1.04-1.47), and warfarin (1.34; 1.22-1.47). No difference in risk for surgical intervention was observed for dabigatran-apixaban comparisons. Increased risk of transfusion was observed for rivaroxaban compared with dabigatran (1.49; 1.03-2.17) only. For patients with no gynecological history, rivaroxaban was associated with risk of surgical intervention compared with dabigatran (1.22; 1.05-1.42), apixaban (1.25; 1.04-1.49), and warfarin (1.36; 1.23-1.50).

CONCLUSION

Our study found increased SAUB risk with rivaroxaban use compared with other DOACs or warfarin. Increased risk with rivaroxaban was present among women without underlying gynecological conditions. Women on anticoagulant therapy should be aware of a risk of SAUB.

Hemophagocytic lymphohistiocytosis associated with the use of lamotrigine

Objective

To describe adverse event reports of hemophagocytic lymphohistiocytosis (HLH) reported in association with lamotrigine.

Methods

The Food and Drug Administration Adverse Event Reporting System database of spontaneous adverse event reports and medical literature databases were searched for cases of HLH reported in association with lamotrigine. Cases were included if they met the case definition of suspected or confirmed HLH and if causal association was assessed as robust or supportive.

Results

Eight cases met the case definition for HLH and were deemed causally associated with lamotrigine. These 8 cases of HLH had a plausible temporal relationship because they occurred within a 24-day interval from lamotrigine initiation. The doses ranged from 25 mg every other day to 250 mg once daily in the 6 cases that reported this information. Seven patients improved with drug discontinuation and one patient died after drug discontinuation and receiving an unspecified chemotherapy.

Conclusions

Lamotrigine is associated with immune-related adverse reactions including HLH. HLH is a potentially fatal event; prompt recognition and early therapeutic intervention to mitigate the event is important in improving patient outcomes.

1558. Commensal Neisseria Species as a Cause of Disease in Patients Taking Eculizumab

Background

Non-meningococcal and nongonococcal Neisseria spp. are usually commensal and rarely cause invasive disease in humans. Eculizumab, a terminal complement inhibitor, increases susceptibility to meningococcal disease, but data on atypical Neisseria spp. disease in persons receiving eculizumab are lacking. This case series describes postmarketing reports of disease by commensal Neisseria spp. in patients receiving eculizumab.

Methods

The FDA Adverse Event Reporting System (FAERS) database and the medical literature were searched for cases of disease by any nonmeningococcal and nongonococcal Neisseria spp. in patients receiving eculizumab. Included cases had a diagnosis of disease by any atypical Neisseria spp. with onset on or before January 31, 2018 and ≥1 dose of eculizumab in the 3 months prior to disease.

Results

The search identified seven FAERS cases, including one case also reported in the literature. Patient ages ranged from 4 to 38 years. Five patients had positive blood cultures, of which three had an indwelling catheter for vascular access (n = 2, N. sicca/subflava) or hemodialysis (n = 1, N. cinerea). Two patients with bacteremia had N. cinerea septic shock with possible cholecystitis, and N. mucosa sepsis with concurrent Streptococcus bacteremia after gastroenteritis. The remaining two cases in the series included one with N. sicca bacterial peritonitis associated with a peritoneal dialysis catheter (negative blood cultures, other cultures not specified), and one with a diagnosis of N. flavescens sepsis while neutropenic (specimen source not specified). All seven patients were hospitalized and three had sepsis or septic shock. All cases resolved with antibiotics and supportive care.

Conclusion

We identified seven cases of serious disease caused by atypical Neisseria spp. among eculizumab recipients. Since these organisms are typical inhabitants of the oropharynx and urogenital tract and are not skin flora, the source of disease was unclear. Our data suggest that eculizumab may confer increased risk for disease by usually commensal Neisseria spp. Healthcare professionals are encouraged to treat all Neisseria spp. isolated from sterile sites as pathogenic, and not as contaminants, in patients receiving eculizumab.

Disclosures

All authors: No reported disclosures.

Extracting coupling and loss coefficients from a ring resonator

A method is developed for extracting the coupling and loss coefficients of ring resonators from the peak widths, depths, and spacings of the resonances of a single resonator. Although the formulas used do not distinguish which coefficient is coupling and which is loss, it is shown how these coefficients can be disentangled based on how they vary with wavelength or device parameters.

Silicon-on-insulator guided mode resonant grating for evanescent field molecular sensing

We present experimental and theoretical results of label-free molecular sensing using the transverse magnetic mode of a 0.22 mum thick silicon slab waveguide with a surface grating implemented in a guided mode resonance configuration. Due to the strong overlap of the evanescent field of the waveguide mode with a molecular layer attached to the surface, these sensors exhibit high sensitivity, while their fabrication and packaging requirements are modest. Experimentally, we demonstrate a resonance wavelength shift of approximately 1 nm when a monolayer of the protein streptavidin is attached to the surface, in good agreement with calculations based on rigorous coupled wave analysis. In our current optical setup this shift corresponds to an estimated limit of detection of 0.2% of a monolayer of streptavidin.

Folded cavity SOI microring sensors for high sensitivity and real time measurement of biomolecular binding

We demonstrate folded waveguide ring resonators for biomolecular sensing. We show that extending the ring cavity length increases the resonator quality factor, and thereby enhances the sensor resolution and minimum level of detection, while at the same time relaxing the tolerance on the coupling conditions to provide stable and large resonance contrast. The folded spiral path geometry allows a 1.2 mm long ring waveguide to be enclosed in a 150 microm diameter sensor area. The spiral cavity resonator is used to monitor the streptavidin protein binding with a detection limit of approximately 3 pg/mm(2), or a total mass of approximately 5 fg. The real time measurements are used to analyze the kinetics of biotin-streptavidin binding.

Interference effect in scattering loss of high-index-contrast planar waveguides caused by boundary reflections

We present theoretical and experimental results on an interference effect caused by boundary reflections on the optical scattering loss in high-index-contrast planar waveguides. Analytical expressions for the polarization-dependent scattering loss are derived using a surface Green's function. For high-index-contrast waveguides of submicrometer dimensions a significant deviation from accepted theory arises, including scattering loss suppression owing to a thin-film interference effect. Our theoretical predictions are confirmed by loss measurements on silicon-on-insulator channel waveguides.

Spiral-path high-sensitivity silicon photonic wire molecular sensor with temperature-independent response

We demonstrate a new silicon photonic wire waveguide evanescent field (PWEF) sensor that exploits the strong evanescent field of the transverse magnetic mode of this high-index-contrast, submicrometer-dimension waveguide. High sensitivity is achieved by using a 2 mm long double-spiral waveguide structure that fits within a compact circular area of 150 microm diameter, facilitating compatibility with commercial spotting apparatus and the fabrication of densely spaced sensor arrays. By incorporating the PWEF sensor element into a balanced waveguide Mach-Zehnder interferometer circuit, a minimum detectable mass of approximately 10 fg of streptavidin protein is demonstrated with near temperature-independent response.

A high-resolution silicon-on-insulator arrayed waveguide grating microspectrometer with sub-micrometer aperture waveguides

We demonstrate a 50-channel high-resolution arrayed waveguide grating microspectrometer with a 0.2 nm channel spacing on a silicon-on-insulator (SOI) platform. The chip size is 8 mm x 8 mm. High channel density and spectral resolution are achieved using high aspect ratio 0.6 mum x 1.5 mum waveguide apertures to inject the light into the input combiner and to intercept different spectral channels at the output combiner focal region. The measured crosstalk is <-10 dB, the 3 dB channel bandwidth is 0.15 nm, and the insertion loss is -17 dB near the central wavelength of lambda = 1.545 mum.

Mycoplasma disease and acute chest syndrome in sickle cell disease

BACKGROUND

Acute chest syndrome (ACS) is the leading cause of hospitalization, morbidity, and mortality in patients with sickle cell disease. Radiographic and clinical findings in ACS resemble pneumonia; however, etiologies other than infectious pathogens have been implicated, including pulmonary fat embolism (PFE) and infarction of segments of the pulmonary vasculature. The National Acute Chest Syndrome Study Group was designed to identify the etiologic agents and clinical outcomes associated with this syndrome.

METHODS

Data were analyzed from the prospective study of 671 episodes of ACS in 538 patients with sickle cell anemia. ACS was defined as a new pulmonary infiltrate involving at least 1 complete segment of the lung, excluding atelectasis. In addition, the patients had to have chest pain, fever >38.5C, tachypnea, wheezing, or cough. Samples of blood and deep sputum were analyzed for evidence of bacteria, viruses, and PFE. Mycoplasma pneumoniae infection was determined by analysis of paired serologies. Detailed information on patient characteristics, presenting signs and symptoms, treatment, and clinical outcome were collected.

RESULTS

Fifty-one (9%) of 598 episodes of ACS had serologic evidence of M pneumoniae infection. Twelve percent of the 112 episodes of ACS occurring in patients younger than 5 years were associated with M pneumoniae infection. At the time of diagnosis, 98% of all patients with M pneumoniae infection had fever, 78% had a cough, and 51% were tachypneic. More than 50% developed multilobar infiltrates and effusions, 82% were transfused, and 6% required assisted ventilation. The average hospital stay was 10 days. Evidence of PFE with M pneumoniae infection was seen in 5 (20%) of 25 patients with adequate deep respiratory samples for the PFE assay. M pneumoniae and Chlamydia pneumoniae was found in 16% of patients with diagnostic studies for C pneumoniae. Mycoplasma hominis was cultured in 10 (2%) of 555 episodes of ACS and occurred more frequently in older patients, but the presenting symptoms and clinical course was similar to those with M pneumoniae.

CONCLUSIONS

M pneumoniae is commonly associated with the ACS in patients with sickle cell anemia and occurs in very young children. M hominis should be considered in the differential diagnosis of ACS. Aggressive treatment with broad-spectrum antibiotics, including 1 from the macrolide class, is recommended for all patients as well as bronchodilator therapy, early transfusion, and respiratory support when clinically indicated.

Chlamydia pneumoniae and acute chest syndrome in patients with sickle cell disease

PURPOSE Few studies address the association of Chlamydia pneumoniae infection with pulmonary disease and outcome in patients with underlying pathology such as sickle cell disease (SCD). SCD patients are susceptible to the pulmonary disorder known as acute chest syndrome (ACS), where the etiology remains ill defined. The purpose of this study was to analyze the clinical course and outcome of C. pneumoniae-associated ACS among SCD patients as part of the National Acute Chest Syndrome Study.

PATIENTS AND METHODS

This was a longitudinal study of SCD patients presenting with ACS to multiple U.S. medical centers. Two hundred ninety-six SCD patients who developed ACS were tested by PCR for C. pneumoniae and by standard techniques for other respiratory pathogens. These infections were evaluated for association with ACS, clinical course, and complications.

RESULTS

Forty-one (14%) patients with first episodes of ACS were PCR positive for C. pneumoniae. Compared with other infections, C. pneumoniae-infected patients were older, were more likely to present with chest pain, and had higher hemoglobin levels at diagnosis. Both groups had similar rates of respiratory failure and prolonged hospitalization. Of the 89 patients with single-pathogen infections, 27 (30%) were due to C. pneumoniae, 21% to Mycoplasma pneumoniae, 10% to RSV, 4% to Staphylococcus aureus, and 3% to Streptococcus pneumoniae.

CONCLUSIONS

C. pneumoniae was the most prevalent pathogen in this study of ACS and was responsible for significant morbidity. Additional research is required to develop effective treatment guidelines for ACS.

ABO hemolytic disease of the newborn: a unique constellation of findings in siblings and review of protective mechanisms in the fetal-maternal system

Two siblings born 6 years apart presented with similar findings of hepatosplenomegaly, dermal hematopoiesis, hemoglobinuria, and increased platelet consumption, but only moderate anemia and normal serum bilirubin. ABO incompatibility was identified, and other causes were excluded. A review of the current understanding of mechanisms that promote and prevent antibody-mediated hemolysis in the fetus is reviewed. Due to the low ratio of observed to expected significant clinical events among ABO incompatible mother-infant pairs, and the multiplicity of mechanisms that diminish hemolysis, we speculate that severe ABO hemolytic disease of the newborn occurs when there is a specific failure in one of these preventive mechanisms.

Interferon treatment of chronic active hepatitis C during therapy of acute lymphoblastic leukemia

Due to concerns that antineoplastic therapy produces prolonged decrease in immune function, interferon treatment of chronic active hepatitis C (CAHC) has been used only at one year or longer after the end of cancer therapy. We report the experience of an 11-year-old who developed symptomatic CAHC at the start of maintenance therapy for testicular relapse of acute lymphoblastic leukemia (ALL). Significant dose reduction of maintenance therapy did not improve the tolerance of antileukemic treatment. In an effort to improve his liver disease and to deliver effective antileukemic therapy, interferon alpha and an alternative maintenance therapy regimen for ALL were initiated. The patient tolerated the combined therapy well. Interferon therapy was continued for 27 months, which was three months from the end of antineoplastic therapy. At that time serum transaminase values were normal, and no HCV viral genome was detectable. Viral genome was detected 10 months later. The combined effects of interferon and antineoplastic therapy resulted in myelosuppression requiring dose reduction of both treatments. The patient remains asymptomatic and with no evidence of recurrent leukemia more than six years from diagnosis of relapse. The effect on the status of this patient's CAHC was similar to that reported among leukemic patients who underwent an interferon course more than one year from the end of antineoplastic therapy. Interferon treatment of CAHC can be given concomitantly with antineoplastic therapy.

Tonsillectomy, adenoidectomy, and myringotomy in sickle cell disease: perioperative morbidity. Preoperative Transfusion in Sickle Cell Disease Study Group

PURPOSE

To compare the rates of perioperative morbidity of patients with sickle cell anemia who were randomly assigned to 2 preoperative transfusion regimens and to identify predisposing factors for perioperative complications.

PATIENTS AND METHODS

Investigators at 36 centers enrolled 118 patients who were scheduled to have elective surgery and agreed to randomization between 2 preoperative transfusion regimens. Forty-seven subjects were enrolled but not randomized, including 20 who were not transfused before surgery. Perioperative management was based on a prescribed care plan.

RESULTS

Tonsillectomy and/or adenoidectomy (TA) were performed on 136 persons, and 29 had myringotomy as their primary procedure. There were no differences in the frequency of complications between the randomized groups. The serious, non-transfusion complication rates for randomized patients were 32% (34 of 107) for TA and 36% (4 of 11) for myringotomy. A history of pulmonary disease was a predictor of postoperative sickle cell-related events for patients undergoing TA surgery.

CONCLUSIONS

The more intensive transfusion regimen did not result in fewer perioperative complications. The high frequency of complications emphasizes the need for anticipatory management of persons undergoing TA. A history of pulmonary disease identifies patients at increased risk for sickle cell-related events after TA surgery. Patients undergoing myringotomy have a low frequency of sickle cell-related events but a significant frequency of other serious perioperative complications.

Malignant rhabdoid tumor of the kidney: involvement of chromosome 22

Cytogenetic and molecular studies have demonstrated that involvement of 22q is a non-random finding in malignant rhabdoid tumors (MRTs) of the brain. We present an MRT of the kidney with the karyotype 47,XY, + i(1)(q10), der(8)t(8;22)(q12;q11.2),der(22)t(8;22)(q23 or q24.1;q11.2). This unbalanced reciprocal translocation was confirmed by fluorescence in situ hybridization (FISH) with chromosome-specific paints for chromosomes 8 and 22. Molecular analysis demonstrated a partial deletion of 22q in the BCR region at q11.2, strengthening the suspicion that this is a critical region for the initiation or progression of these highly malignant neoplasms. Establishing non-random cytogenetic changes in MRTs arising from the kidney may be of value in distinguishing these rare, but often fatal tumors from other renal neoplasms that mimic them histologically. The similarity in cytogenetic and molecular abnormalities between renal and extra-renal MRTs argues against the concept that extra-renal MRTs are only representative of a rhabdoid phenotype, rather than being true rhabdoid tumors.

Cytosine arabinoside and mitoxantrone treatment of relapsed or refractory childhood leukemia: initial response and relationship to multidrug resistance gene 1

The objective of this study was to determine the response rate and toxicity of high-dose cytosine arabinoside (AC) and mitoxantrone (M) in relapsed or refractory childhood acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) and to correlate response with the expression of the multidrug resistance gene 1 (mdr1). Twenty-nine patients were treated with AC 1.0 g/m2 infused over 2 h every 12 h for eight doses (days 1-4) and M 12 mg/m2 infused over 1 h (days 3-6). Mdr1 expression was determined by a polymerase chain reaction (pcr) assay. Ten of 15 patients (67%) with AML obtained a complete remission (CR) of 3 to 30+ months duration. Eight of 14 (57%) ALL patients obtained a CR of 1 to 23+ months duration. The major toxicities were hematopoietic and infectious. Seventy-nine per cent of patients developed a documented infection during induction. Mdr1 did not correlate with a lower induction rate. This AC/M regimen is active in childhood AML and ALL.

Clonal remission in childhood acute myeloid leukemia is an infrequent event

Acute myeloid leukemia (AML) is a heterogeneous group of diseases that differ in pattern of both remission and lineage involvement. The observation that hematopoiesis remains clonal in some patients with AML in complete clinical remission suggests that the acute phase may develop from a clinically unrecognized preleukemic clone. To investigate the characteristics and significance of clonal remissions in childhood AML, we used X-chromosome-linked polymorphisms to study granulocytes obtained from pediatric female patients in complete clinical remission. Remission granulocytes from only one of 17 evaluable patients were clonally derived, suggesting that clonal remission is an infrequent event in childhood AML.

Cognitive tempo and cognitive level relationships among mentally retarded children

The purpose of this investigation was to ascertain predictive relationships between and within cognitive tempo and cognitive level characteristics of 33 moderately retarded junior high school children. The Matching Familiar Figures Test was used to establish cognitive tempo characteristics and the Essential Math and Language Skills Inventory was used to determine cognitive level characteristics. A multiple regression analysis indicated no significant predictive relationship from elements of cognitive tempo to elements of cognitive level. Elements of cognitive level, however, could predict elements of cognitive tempo. Implications for future research were discussed. Cross-validation on a larger sample is required.