Drug-Induced Eosinophilic Myocarditis

Amin S. Kanani, Division of Allergy and Clinical Immunology, St. Paul's Hospital, University of British Columbia, Vancouver, BC

A50-year-old gentleman presented with class III NYHA heart failure associated with malaise and low-grade fever. He had increased migraine headaches in the pre-ceeding one month. During this period he was taking sumatriptan (Imitrex) for approximately 4 days per week and ibuprofen daily. He denied taking other medications. He did not have any recent travels. He does not have a history of asthma or sinusitis. His physical examination was consistent with congestive heart failure. There were no rashes. The ECG showed changes suggestive of ischemia. There was a mild rise in troponin level. White blood cell count was elevated at 15.1 g/L (4.0-11.0 g/L) with increased neutrophils at 13.4 g/L (2.3-7.7 g/L). Peripheral eosinophil count was 0. Blood work from 4 weeks prior to presentation indicated a normal WBC with 0 eosinophils. Blood tests were negative for ANA, rheumatoid factor, ANCA, cryoglobulins, HIV serology, and hepatitis B serology. CT scan of the head was normal and CSF analysis was normal. Echocardiogram showed left ventricular hypertrophy and an ejection fraction of 45%. Coronary angiography revealed normal coronary arteries. Endomyocardial biopsy revealed necrotizing myocarditis with prominent eosinophil infiltrate. The sumatriptan and non-steroidal anti-inflammatory drugs were discontinued. He was started on prednisone 60 mg daily which after 2 months was tapered down to 15 mg daily. He was also initially treated with furosemide, ramipril and carvedilol. Echocardiogram 3 months after initial presentation showed a normal ejection fraction. The furosemide and ramipril were discontinued. Peripheral eosinophil count has remained normal. This is a unique case of eosinophilic myocarditis potentially associated with sumatriptan and/or non-steroidal anti-inflammatory drugs.

Socioeconomic Status and the Development of Asthma

A.L. Kozyrskyj, A.B. Becker, Faculty of Pharmacy and Faculty of Medicine, University of Manitoba, Winnipeg, MB

The association between low socioeconomic status and asthma is inconsistent, and not compatible with the hygiene hypothesis. We undertook this research to determine the relationship between socioeconomic status and the development of asthma, and to identify environmental factors that may explain this relationship. In 2002/03, a survey was sent to 12,556 households of children born in Manitoba in 1995, asking parents whether they or their 7-year old child had asthma, and whether smokers or pets were present in the birth home. Survey responses were linked to health care records for lower respiratory tract infections (LRI) during infancy, and to a census-based measure of income. The likelihood (odds ratio, OR) of asthma was determined according to income, and exposure to tobacco smoke, pets and LRI within the first year of life. 3,564 (28.4%) of the surveys were returned. Parents reported asthma in 12% of children living in urban areas. Asthma prevalence declined progressively by income area from 17% to 11% in the highest income neighbourhoods. Asthma prevalence was not related to income in rural areas. Lower income, urban children were more likely to be exposed to tobacco smoke, cats and LRI during infancy. In comparison to high income, urban children, the odds ratio for asthma in low and middle income children was 1.74 (95% CI: 1.07-2.83) and 1.32 (95% CI: 0.98-1.78), respectively. The increased likelihood of asthma in lower income children was independent of family history of asthma/allergy (OR = 3.93, 95% CI: 2.93-5.28) and of exposure to LRI in infancy (OR = 3.29, 95% CI: 1.37-7.88). The income-asthma association in urban children was not diminished by early childhood exposure to tobacco smoke, cats or dogs. An inverse association between the development of asthma and socioeconomic status was only observed in Manitoba children living in urban areas. This association was not explained by early exposure to household allergens.

The Natural History of Wheezing Syndromes in Pre-Term Children

J.J. Liem, A.L. Kozyrskyj, A.B. Becker

Rationale: To describe the natural history of wheezing syndromes in premature/low birthweight babies compared to term/normal birthweight babies. Methods: The Manitoba Health Services Insurance Plan (MHSIP) database is a population-based, health care administrative and prescription database. It has records of every child born in 1995 and subsequent utilization of the provincial health care system. The number of children diagnosed with a wheezing syndrome (defined as an ICD-9 code of 493 [asthma diagnosis for hospitalization or physician visit] or a prescription of an asthma medication) was obtained. The relative risks (RRs) of wheezing in premature/low birthweight children compared to term/normal birthweight were determined up to 7 years of age. Results: 13,980 children were born in 1995 and are currently living in the province of Manitoba. In comparison to term infants (37-42 weeks gestational age [GA]), the RRs of a wheezing syndrome in infants born <28 weeks GA (n = 45) at 1, 3, 5, and 7 years were 1.76*, 1.44, 1.75* and 1.30. RRs for 28-32 weeks GA(n = 84) were 1.72*, 2.39*, 2.26* and 1.25* and for 32-37 weeks GA(n = 763), RRs were 1.17*, 1.14, 1.14, and 1.25* at 1, 3, 5, and 7 years. In comparison to normal birthweight infants (2,500-4,500 g), the RRs of a wheezing syndrome in infants born <1,000 g (n = 37) at 1, 3, 5, and 7 years were 2.25*, 2.12*, 2.14* and 1.35. In babies with birthweights between 1,000-1,500 g (n = 70), RRs were 1.52*, 1.94*, 1.92* and 1.55 at 1, 3, 5, and 7 years. Conclusion: Babies born at low gestational ages and with low birth-weights have an increased risk of a wheezing syndrome in the first seven years of life.

*Denotes statistical significance.

Cytokine Responses to Toll-Like Receptor Stimulation in Children

Yuriy Lissitsyn, Allan B. Becker, Kent T. HayGlass, Departments of Immunology and Pediatrics/Child Health, University of Manitoba, Winnipeg, MB

Introduction: Activation of Toll-like receptors (TLRs) by distinct microbial ligands triggers not only innate immunity, but also regulates the nature of the adaptive immune response, and thus may influence either development of, or exacerbation of, allergic diseases such as asthma. The role of TLR responsiveness in human asthma remains unknown. We hypothesize that functional responsiveness to TLR stimulation by physiologically relevant ligands differs in asthmatic and healthy control children. The specific objective of this study has been (i) to identify "optimal" and "threshold" doses of a panel of relevant TLR ligands and (ii) to determine optimal experimental conditions for quantitative analysis of patterns of cytokine and chemokine responses. Methods: PBMC obtained from ~200 8-9 year old children were stimulated with distinct TLR ligands: lipopolysaccharide, peptidoglycan, 3M-011 compound or poly(I:C) at concentrations over five log range for 24 h. This time point was chosen on the basis of kinetic studies. Absence of endotoxin contamination was verified by LAL assay. Levels of cytokines and chemokines produced by these children were measured by ELISA. Results: All individuals studied responded to these TLR ligands. The "optimal" and "threshold" conditions were identified. Specifically, lipopolysaccharide and peptidoglycan have the ability to stimulate production of cytokines (IL-6, TNF-α, IL-1∃, IL-12p40, IL-10) and chemokines (CCL2, CCL22) in a dose dependent manner. 3M-011 elicits a similar pattern of cytokine responses and induces significant levels of IFN-α and CXCL10. Stimulation with poly(I:C) resulted in production of IFN-α and CCL2; levels of other tested cytokines and chemokines were below the limit of detection for these ligands. Conclusion: Lipopolysaccharide, a TLR4 ligand, peptidoglycan, a TLR2 ligand, 3M-011, a TLR7 ligand, are potent stimuli of cytokine and chemokine production by PBMC derived from children. Poly(I:C), a TLR3 ligand, induced production of IFN-α and CCL2, but few other cytokines. "Optimal" and "threshold" stimulation concentrations of lipopolysaccharide, peptidoglycan, 3M-011 and poly(I:C) were identified that will be used to test the main hypothesis upon unblinding of the study. Research support: SAGE, Canadian Institutes of Health Research, CRC Chair Program.

Peptide-Based Vaccines against Human Interleukin-13 (hIL-13)

Yanbing Ma, Qingliang Liu, Tingting Zhang, Kent HayGlass, Allan Becker, Zhikang Peng, Department of Pediatrics and Child Health and Department of Immunology, University of Manitoba, Winnipeg, MB

IL-13 is one of the key contributors in allergic asthma. It promotes IgE class switching and in the lung upregulates eosinophilic inflammation, mucus secretion, and airway hyperresponsiveness. Immunologically down-regulating the level of IL-13 may be a better approach for asthma treatment than the current pharmaceutical therapies. This is supported by the successful administration of humanized monoclonal antibodies to IgE as passive immunotherapy in asthma treatment. However, a short half-life and extremely high cost limit the use of this approach. To overcome these disadvantages, we aimed to develop active immunotherapy using an anti-hIL-13 vaccine which induced auto-neutralizing antibodies to hIL-13. The vaccine conjugate consisted of a hIL-13 peptide (12-17 amino acid residues) derived from hIL-13 receptor binding sites, made immunogenic by linking it to a foreign carrier protein via two approaches. (1) Chemical methods: synthesized peptides were coupled to bovine serum albumin (BSA) using the glutaraldehyde method; (2) molecular engineering: the peptide was fused to the hepatitis B core antigen (HBcAg) to form chimeric HBcAg. Three chemically coupled conjugates and one chimeric HBcAg that presents as capsule-like particles were tested in mice. Mice were immunized three times with a vaccine conjugate emulsified in an adjuvant. Immunization with the carrier BSA or natural HBcAg served as controls. Sera were collected two weeks after the last immunization. Titres to hIL-13 were measured by an ELISA. Two vaccine conjugates and the chimeric HBcAg were found to elicit high titres of antibodies to hIL-13. Inhibition tests revealed that these vaccinated sera inhibited the binding of hIL-13 to its receptors in a dose-dependent manner using receptor-capture ELISA and hIL-13- induced B cell proliferation tests, suggesting that vaccine-induced antibodies are able to inactive hIL-13 in vitro. Studies of the in vivo effect of the vaccine are currently in progress in a mouse model of asthma. This study was supported by The Hospital for Sick Children Foundation (Toronto) and the Children's Hospital Foundation of Manitoba Inc.

Is There an Association between Childhood Immunizations and Childhood Asthma?

Kara McDonald, Department of Community Health Sciences, University of Manitoba, Winnipeg, MB

Background: The prevalence of childhood asthma has steadily increased over the past two decades. This is of great concern as the implications of this have been huge both socially and economically (direct and indirect costs). There are many theories as to why there has been such an increase in asthma and allergies in the developed world. One such theory is the Hygiene Hypothesis. This particular theory has provided the background for my current research. It states that our immune systems have not been able to adapt quickly enough to the rapidly occurring changes in our living environments (improved sanitation, new and improved antibiotics and immunizations). Thus, these changes have made it much easier for our immune systems to slip into unbalanced states where allergies and asthma can arise [1]. Methods: My thesis is a retrospective birth cohort of Manitoba children born in 1995. My outcome of "asthma" has been validated by Dr. Anita Kozyrskyj and Dr. Allen Becker in their NET study. I have been linking immunization data from the Manitoba Immunization Monitoring System (MIMS) to other administrative data such as drug, medical and hospital data using SAS (Statistical Analyses Software). I am particularly interested with the diphtheria combination vaccines (both cellular and acellular), the measles/mumps/rubella (MMR), as well as the BCG vaccine. I am analyzing the types of vaccines which are given, the time frame in which they are given, the children's immunization status, and their possible association with asthma. Results: My results and the statistical relevance of my findings have yet to be completed. However, as an example of my preliminary findings on the 13, 980 children in the cohort I have found the following: 1, 569 of the children have been determined to have asthma at age 7 with the onset varying from 0 to 7 years of age. Only 416 children were vaccinated with BCG, of which 33 had asthma (7.93%) compared to an asthma rate of 11.32% in the rest of the population. Of the children in the cohort 97.5% of them had had one or more MMR vaccines, while only 110 children or 0.79% had never received any immunizations. Conclusion: It is premature to state my final conclusions for the specific questions raised in my thesis. However, regardless of the final outcome I believe that this research is timely and will be of value to the scientific community.

Human Eosinophils Constitutively Express Indoleamine 2,3-Dioxygenase and Regulate T-Cell Function

S.O. Odemuyiwa, A.G. Ghahary, Y. Li, L. Puttagunta, A. Ghahary, R. Moqbel, Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, AB

Indoleamine 2,3-dioxygenase (IDO) catabolizes tryptophan to kynurenines (KYN), which in turn inhibit proliferation and survival of T cells, especially Th1. Regulatory dendritic and T-cells down-regulate T-cell function via KYN-mediated mechanisms. Eosinophils, whose numbers increase following allergen challenge, have the potential to interact with T-cells. We hypothesized that increase in IDO-expressing eosinophils during allergic inflammation is an immunoregulatory mechanism in the maintenance of -Th2 polarization in allergic inflammation. Eosinophils from atopic and non-atopic donors were probed for IDO expression using RT-PCR and Western blotting. The effect of IL-3, IL-5 and GM-CSF on IDO expression was determined using quantitative PCR. KYN was measured to determine enzymatic activity of IDO. Eosinophils were co-cultured with IFNγ- or IL-4-producing T cell lines or clones before measuring apoptosis or proliferation of T cells. IDO expression in lung tissue of allergic subjects, and in tissues from a mouse model of allergic inflammation, was examined using immunohisto-chemistry. Eosinophils express IDO mRNA and protein constitutively and produce KYN following IL-3, IL-5, GM-CSF, and IFNγ treatment, leading to T-cell apoptosis and inhibition of PHA-induced proliferation of PBLs. While IL-3 reduced IFN_γ-induced IDO mRNA below resting levels in Eos, IL-5 induced only a 2-fold reduction. Conversely, treatment with GM-CSF led to a 3-fold increase in IFN_γ-induced mRNA expression. Crosslinking of CD28 on eosinophils induced IFN_γ release with autocrine effects, leading to trypto-phan catabolism to KYN. Co-culture of T cells with eosinophils inhibited proliferation of an IFNγ-producing T cell line but not an IL-4-producing T cell clone. There was extensive infiltration of IDO-expressing eosinophils into lymphoid aggregates from atopic subjects. Eosinophils were the main IDO-expressing cells found in the lung tissues of OVA-sensitized mouse model of allergic inflammation. Our data suggest that eosinophils may potentially regulate T-cell function in vivo through IDO-dependent pathways, thus contributing to the maintenance of Th2 polarization characteristic of atopic disease.

Interleukin-17 Modulates IL-13 Induction of IL-8 and IL-6 Expression in Human Airway Smooth Muscle Cells: Role in Neutrophilic Inflammation

Muhammad Shahidur Rahman, Jie Yang, LianYu Shan, Andrew J. Halayko, Abdelilah Soussi Gounni, Department of Immunology, Physiology and Respiratory Division, University of Manitoba, Winnipeg, MB

Background: Airway neutrophilia is a predominant feature of acute lung disorders such as chronic obstructive pulmonary disease (COPD) and severe asthma. While IL-17 induced expression of the CXC chemokines in the airways leading to neutrophil recruitment is well established, potential direct effects of IL-17 on airway smooth muscle (ASM) function have not been determined. Aim: This study aimed to investigate the role of IL-17R in the activation of human ASM cells and release of inflammatory mediators. Experimental Procedures: IL-17R mRNA and surface bound receptor expression were investigated by RT-PCR and flow cytometry. Immunofluorescence study was carried out to detect IL-17R within bronchial smooth muscle. ELISA and quantitative real-time PCR were carried out to investigate the effect of IL-17 and IL-13 stimulation on IL-8 and IL-6 mRNA and protein expression. In vitro chemotaxis assay measured the effect of conditioned medium of IL-17 stimulated ASM cells on the migratory capacity of human neutrophils. In vivo expression of IL-17R in human ASM bundle within bronchial sections of COPD patients was performed by immuno-fluorescence coupled to confocal microscopy. Results: ASM cells expressed steady state of IL-17R protein, mRNA and surface bound receptor. IL-17 stimulated IL-8 and IL-6 release from ASM cells in a time- and dose-dependent manner that was significantly inhibited by neutralizing anti-IL-17 mAb. Interestingly, IL-17 dramatically enhanced IL-1β induced expression of IL-6 and IL-8 protein and mRNA. The effect of IL-17, alone or in combination with IL-1β, was abrogated by actin-omycin-D, suggesting that IL-17 regulates IL-6 and IL-8 at the transcriptional level. In vitro chemotaxis assay showed that IL-17 induced IL-8 release from ASM cell conditioned medium attracted neutrophils. Finally, ASM cells bundle within human airway sections from COPD patients showed IL-17R positive immunostaining. Conclusion: These data clearly demonstrate that ASM cells are a target for IL-17 and suggest that ASM cells participate via an IL-17 dependent manner in the recruitment of inflammatory cells, particularly neutrophils, into the airway.

Syk Tyrosine Kinase Participates in β1 Integrin Signaling and Inflammatory Responses in Airway Epithelial Cells

Marina Ulanova, Lakshmi Puttagunta, Marcelo Marcet-Palacios, Florentina Duta, Moo-Kyung Kim, Alan D. Schreiber, A. Dean Befus, Department of Medicine, University of Alberta, Edmonton, AB; University of Pennsylvania School of Medicine, Philadelphia, PA

The protein tyrosine kinase Syk is best known as a critical component of immunoreceptor signaling complexes in hematopoietic cells. Recent studies showed Syk expression in some nonhematopoietic cells, implicating its involvement in other important cellular functions. We have recently demonstrated that Syk is widely expressed in respiratory epithelial cells (EC) in situ, as well as in cultured primary bronchial EC and cell lines HS-24 and BEAS-2B. We hypothesized that Syk functions as a signaling molecule involved in inflammatory responses in the epithelium. To characterize Syk expression in airway EC, immunohistochemistry, Western blot, PCR, and laser scanning confocal microscopy were used. Syk-dependent signaling pathways in EC were initiated by engagement of β1 integrin receptors. Stimulation of β1 integrin receptors by fibronectin or antibody cross-linking caused redistribution of Syk from a cytoplasmic to plasma membrane localization. In stimulated cells, Syk and integrin β1 co-localized. In addition, following β1 integrin receptor engagement, tyrosine phosphorylation of Syk was observed. Expression of the adhesion molecule ICAM-1 and production of IL-6, both important molecules in lung inflammation, was down-regulated in EC treated with Syk small interfering RNA, or Syk inhibitor piceatannol. We propose that Syk is involved in signaling pathways induced by integrin engagement in airway EC. Syk-mediated signaling regulates IL-6 and ICAM-1 expression and may be important in the pathophysiology of lung inflammation. Funded by CIHR, CSACI/CAAIF/Merck Frosst, Alberta Heritage Foundation for Medical Research, and NIH.

Anaphylactic Reaction during Intrauterine Insemination Caused by Egg Yolk Allergy

N. Verreault, R. Gagnon, R. Kagan, J. Mailloux, P.M. Bédard, Allergy and Clinical Immunology, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC; Allergy and Clinical Immunology, Centre Hospitalier Universitaire de Québec-CHUL, Quebec City, QC; Gynecology and Obstetrics, Centre Hospitalier Universitaire de Québec-CHUL, Quebec City, QC

Introduction: Anaphylaxis during artificial insemination usually occurs with the following allergens: latex, human spermatic fluid, drugs added to the sperm processing media, and the preservative bovine serum albumin (BSA). Case History: This 27 year old woman with allergic rhinoconjonctivitis and asthma has had 10 attempts of artificial insemination since 1999. After each injection of thawed semen, she experienced within a few minutes severe lower abdominal pain accompanied by pallor and malaise. These episodes were thought to be vaso-vagal reactions. On the tenth attempt, she immediately developed generalized pruritus, urticaria, angioedema, vomiting, respiratory distress and hypotension. After standard emergency treatment, she recovered without complications. All artificial inseminations use sperm processed in a solution supplemented by sterile egg yolk. Further history revealed that the patient never had an anaphylactic food or drug reaction. However, during the past 5 years she could not eat raw eggs because of a tingling sensation in her mouth and a tight throat. She tolerates baked goods containing eggs and cooked eggs. The skin prick tests were positive for egg white (4 mm of induration) and egg yolk (8 mm), and the specific IgE level was slightly positive (0.43 KUA/L) for egg yolk. Testing was negative for latex and spermatic fluid. Finally, she had an uneventful artificial insemination using sperm preserved with BSA three months after the anaphylactic reaction. Conclusion: We describe the first case of a life threatening anaphylaxis in an egg allergic woman who underwent an artificial insemination using sperm processed in fresh egg yolk. Even if egg allergy is extremely uncommon in adults, enquiry about food allergies remains an important part of all medical histories and particularly before prescribing injectable medicines or biological products.

Successful Treatment with Subcutaneous Immunoglobulin Infusion in a Primary Immunodeficiency Patient with Severe Adverse Reactions to Intravenous Immunoglobulin

Joyce Yu, Nina Verrault, Ahmed Ali, Chantal Lemire, Rhoda Kagan, Bruce Mazer, Christine McCusker, Division of Allergy and Clinical Immunology, Montreal Children's Hospital, McGill University Health Centre, Montreal, QC

Background: Intravenous immunoglobulin (IVIG) infusion is an effective treatment for children with primary immunodeficiencies but it requires administration in a hospital setting and can be complicated by systemic reactions or poor venous access. Subcutaneous immunoglobulin (SCIG) infusion is an alternate treatment option. It is as effective as IVIG with no reported life-threatening systemic side effects and can be administered at home. Case History: A 5 year old girl with DiGeorge syndrome and hypogammaglobulinemia was referred because of severe adverse reactions to IVIG. She had features of DiGeorge including a vascular ring, speech delay, high arched palate, distinct facial features and combined immunodeficiency. She was positive for the chromosome 22 deletion. She had recurrent infections complicated by bronchiectasis, low antibody levels and poor specific responses to her vaccines. She was started on IVIG. She suffered severe headaches, vomiting, pallor and one episode of loss of consciousness 48 hours after several of the infusions of IVIG. Pretreatments with Benadryl, Tylenol, corti-costeroids either immediately before or for 3 days following IVIG were all ineffective. Trial of different IVIG preparations did not change frequency or severity of adverse reactions. We elected to give her a trial of SCIG. The first infusion without any premedication had an uneventful course. She received 10 cc of Behring immunoglobulin (16%) solution over 1 hour given by syringe pump into her right thigh. She developed a local painless swelling at the injection site, which resolved over 2 hours. She subsequently received a total of three uneventful infusions in hospital, and then was discharged to continue outpatient treatment at her local hospital. Conclusion: We describe the first case in Canada of a primary immunodeficient child with adverse reactions temporally related to IVIG who tolerated treatment with SCIG. This case demonstrates that SCIG is a suitable treatment option for patients with adverse reactions to IVIG.

Different Antigens with and without Adjuvant in the Induction of Airway Inflammation and IgE and IgG Responses in Mice

Tingting Zhang, Yanbing Ma, Zhikang Peng, Department of Pediatrics and Child Health and Department of Immunology, University of Manitoba, Winnipeg, MB

Background: Mouse models of allergic asthma with ovalbumin (OVA) in alum have been used for many years. However, OVA is not a common allergen to humans and using alum for mouse sensitization is not close to human allergic diseases. Objective: To evaluate the effect of different antigens and the use of natural allergens without alum in the induction of IgE and IgG responses and airway inflammation in mice. Methods: Mice were intraperitoneal (i.p.) sensitized and intranasal (i.n.) challenged as below: A: sensitized twice with 2 μg of OVA in alum at weeks 0 and 2 and challenged (50 μg of OVA) at week 4; B: sensitized with 10 μg of OVA twice a week for 4 weeks, and challenged at week 5; C: the same as protocol "A," except that OVA was replaced with 100 μg of ragweed; D: the same as protocol "B," expect that OVA was replaced with ragweed. Sera were obtained every 2 weeks, and bronchoalveolar lavage fluids (BALFs) were collected 1 week after the nasal challenge. Serum total IgE, OVA- or ragweed-specific IgE and IgG2a levels were measured by ELISAs. BALF eosinophils were stained and counted. Results: Mice sensitized with OVA in alum had the highest total IgE level followed by groups B, C and D (mean OD₄₁₀ = 3.39, 2.11, 1.42, and 1.12 for groups A, B, C, and D, respectively). Antigen-specific IgE levels were higher and specific IgG2a levels were lower in groups with alum than groups without alum (p < .01). There is no significant difference of eosinophilic percentages in OVA groups with or without alum (60% for A and 59% for B), which were higher than ragweed groups (24% for C and 41% for D). Conclusion: OVA induces higher IgE and eosinophilic responses in BALB/c mice than ragweed. Injections of natural antigens without alum are able to induce IgE and airway inflammation responses. This study was supported by The Hospital for Sick Children Foundation (Toronto).

2004 Awards Recipients