Clinical features of parainfluenza infections among young children hospitalized for acute respiratory illness in Amman, Jordan.

BACKGROUND: Parainfluenza virus (PIV) is a leading cause of acute respiratory illness (ARI) in children. However, few studies have characterized the clinical features and outcomes associated with PIV infections among young children in the Middle East. METHODS: We conducted hospital-based surveillance for ARI among children < 2 years of age in a large referral hospital in Amman, Jordan. We systematically collected clinical data and respiratory specimens for pathogen detection using reverse transcription polymerase chain reaction. We compared clinical features of PIV-associated ARI among individual serotypes 1, 2, 3, and 4 and among PIV infections compared with other viral ARI and ARI with no virus detected. We also compared the odds of supplemental oxygen use using logistic regression. RESULTS: PIV was detected in 221/3168 (7.0%) children hospitalized with ARI. PIV-3 was the most commonly detected serotype (125/221; 57%). Individual clinical features of PIV infections varied little by individual serotype, although admission diagnosis of 'croup' was only associated with PIV-1 and PIV-2. Children with PIV-associated ARI had lower frequency of cough (71% vs 83%; p < 0.001) and wheezing (53% vs 60% p < 0.001) than children with ARI associated with other viruses. We did not find a significant difference in supplemental oxygen use between children with PIV-associated infections (adjusted odds ratio [aOR] 1.12, 95% CI 0.66-1.89, p = 0.68) and infections in which no virus was detected. CONCLUSIONS: PIV is frequently associated with ARI requiring hospitalization in young Jordanian children. Substantial overlap in clinical features may preclude distinguishing PIV infections from other viral infections at presentation.

T-Cell Therapeutics Targeting Human Parainfluenza Virus 3 Are Broadly Epitope Specific and Are Cross Reactive With Human Parainfluenza Virus 1.

Human Parainfluenza Virus-3 (HPIV3) causes severe respiratory illness in immunocompromised patients and lacks approved anti-viral therapies. A phase I study of adoptively transferred virus-specific T-cells (VSTs) targeting HPIV3 following bone marrow transplantation is underway (NCT03180216). We sought to identify immunodominant epitopes within HPIV3 Matrix protein and their cross-reactivity against related viral proteins. VSTs were generated from peripheral blood of healthy donors by ex-vivo expansion after stimulation with a 15-mer peptide library encompassing HPIV3 matrix protein. Epitope mapping was performed using IFN-γ ELIspot with combinatorial peptide pools. Flow cytometry was used to characterize products with intracellular cytokine staining. In 10 VST products tested, we discovered 12 novel immunodominant epitopes. All products recognized an epitope at the C-terminus. On IFN-γ ELISpot, individual peptides eliciting activity demonstrated mean IFN-γ spot forming units per well (SFU)/1x105 cells of 115.5 (range 24.5-247.5). VST products were polyfunctional, releasing IFN-γ and TNF-α in response to identified epitopes, which were primarily HLA Class II restricted. Peptides from Human Parainfluenza Virus-1 corresponding to the HPIV3 epitopes showed cross-reactivity for HPIV1 in 11 of 12 tested epitopes (mean cross reactivity index: 1.19). Characterization of HPIV3 epitopes may enable development of third-party VSTs to treat immune suppressed patients with HPIV infection.

Human parainfluenza virus-3 can be targeted by rapidly ex vivo expanded T lymphocytes.

BACKGROUND AIMS: Human parainfluenza virus-3 (HPIV) is a common cause of respiratory infection in immunocompromised patients and currently has no effective therapies. Virus-specific T-cell therapy has been successful for the treatment or prevention of viral infections in immunocompromised patients but requires determination of T-cell antigens on targeted viruses. METHODS: HPIV3-specific T cells were expanded from peripheral blood of healthy donors using a rapid generation protocol targeting four HPIV3 proteins. Immunophenotyping was performed by flow cytometry. Viral specificity was determined by interferon (IFN)-γ ELISpot, intracellular cytokine staining and cytokine measurements from culture supernatants by Luminex assay. Cytotoxic activity was tested by 51Cr release and CD107a mobilization assays. Virus-specific T cells targeting six viruses were then produced by rapid protocol, and the phenotype of HPIV3-specific T cells was determined by immunomagnetic sorting for IFN-γ-producing cells. RESULTS: HPIV3-specific T cells were expanded from 13 healthy donors. HPIV3-specific T cells showed a CD4+ predominance (mean CD4:CD8 ratio 2.89) and demonstrated specificity for multiple HPIV3 antigens. The expanded T cells were polyfunctional based on cytokine production but only had a minor cytotoxic component. T cells targeting six viruses in a single product similarly showed HPIV3 specificity, with a predominant effector memory phenotype (CD3+/CD45RA-/CCR7-) in responder cells. DISCUSSION: HPIV3-specific T cells can be produced using a rapid ex vivo protocol from healthy donors and are predominantly CD4+ T cells with Th1 activity. HPIV3 epitopes can also be successfully targeted alongside multiple other viral epitopes in production of six-virus T cells, without loss of HPIV3 specificity. These products may be clinically beneficial to combat HPIV3 infections by adoptive T-cell therapy in immune-compromised patients.

[Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report]. / Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3.

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

Encefalomielitis aguda diseminada grave: Comunicación de un caso asociado a infección por virus parainfluenza 3 / Severe acute disseminated encephalomyelitis associated with parainfluenza 3 infection: Case report

Disseminated encephalomyelitis (ADEM) is an infrequent condition with considerable morbidity and mortality in adult patients. It requires a high level of suspicion and diagnosis emerges by gathering clinical information, laboratory exams and images studies. ADEM is related to an immunological phenomena occurring after a bacterial/viral infection or recent vaccination. Glucocorticoids are the first line treatment, reserving immunoglobulins and plasmapheresis to refractory cases. We report a male patient aged 25, with ADEM associated to parainfluenza 3 virus respiratory infection that required mechanical ventilation and that had a complete recovery only after plasmapheresis.

La encefalomielitis aguda diseminada es una enfermedad infrecuente pero de elevada morbi-mortalidad en pacientes adultos. Demanda una sospecha y diagnóstico precoz que requiere el concurso de información clínica, pruebas de laboratorio y estudio de imágenes. De sustrato inmunológico, se puede relacionar a una infección viral, bacteriana o inmunización reciente. Los glucocorticoides son el tratamiento de elección, mientras que la inmunoglobulina intravenosa y la plasmaféresis se reservan para casos refractarios. Se presenta el caso de una encefalomielitis aguda diseminada grave, en un paciente de sexo masculino de 25 años, asociado a una infección respiratoria por virus parainfluenza 3. Requirió conexión a ventilación mecánica y tuvo una respuesta completa con plasmaféresis.

Fulminant type 1 diabetes mellitus and fulminant viral myocarditis. A case report and literature review.

A 35-year-old Japanese woman was admitted with coma following flu-like symptoms. She was diagnosed with diabetic ketoacidosis and fulminant type 1 diabetes (FT1D) and received intravenous infusion of insulin and saline. The next day, the ketoacidosis disappeared, and she recovered consciousness. However, extensive ST-segment elevations in the electrocardiogram appeared with a positive troponin test, and the patient developed pulmonary edema on day 3. An echocardiogram showed globally reduced wall motion of the left ventricle and mild pericardial effusion. Despite medical therapy with intravenous furosemide, carperitide, and catecholamines, her cardiac function deteriorated rapidly, with the left ventricular ejection fraction decreasing to 26% within 7 hours, and progressed to cardiogenic shock that afternoon. The patient received mechanical circulatory support for 4 days with intra-aortic balloon pumping and percutaneous cardiopulmonary support, and recovered fully from circulatory failure. A paired serum antibody test showed a significantly elevated titer against parainfluenza-3 virus, indicating a diagnosis of fulminant viral myocarditis. She was discharged on multiple daily insulin injection therapy, and her subsequent clinical course has been uneventful. In summary, we present a case of concurrent FT1D and fulminant viral myocarditis. Parainfluenza-3 viral infection was confirmed serologically and was considered to be a cause of both the FT1D and fulminant myocarditis.

Impaired CD8(+) T cell immunity after allogeneic bone marrow transplantation leads to persistent and severe respiratory viral infection.

RATIONALE: Bone marrow transplant (BMT) recipients experience frequent and severe respiratory viral infections (RVIs). However, the immunological mechanisms predisposing to RVIs are uncertain. Therefore, we hypothesized that antiviral T cell immunity is impaired as a consequence of allogeneic BMT, independent of pharmacologic immunosuppression, and is responsible for increased susceptibility to RVI. METHODS: Bone marrow and splenocytes from C57BL/6(H2(b)) mice were transplanted into B10.BR(H2(k)) (Allo) or C57BL/6(H2(b)) (Syn) recipients. Five weeks after transplantation, recipient mice were inoculated intranasally with mouse parainfluenza virus type 1 (mPIV-1), commonly known as Sendai virus (SeV), and monitored for relevant immunological and disease endpoints. MAIN RESULTS: Severe and persistent airway inflammation, epithelial injury, and enhanced mortality are found after viral infection in Allo mice but not in control Syn and non-transplanted mice. In addition, viral clearance is delayed in Allo mice as evidenced by prolonged detection of viral transcripts at Day 15 post-inoculation (p.i.) but not in control mice. In concert with these events, we also detected decreased levels of total and virus-specific CD8(+) T cells, as well as increased T cellexpression of inhibitory receptor programmed death-1 (PD-1), in the lungs of Allo mice at Day 8 p.i. Adoptive transfer of CD8(+) T cells from non-transplanted mice recovered from SeV infection into Allo mice at Day 8 p.i. restored normal levels of viral clearance, epithelial repair, and lung inflammation. CONCLUSIONS: Taken together these results indicate that allogeneic BMT results in more severe RVI based on the failure to develop an appropriate pulmonary CD8(+) T cell response, providing an important potential mechanism to target in improving outcomes of RVI after BMT.

Morbidity of parainfluenza 3 outbreak in preterm infants in a neonatal unit.

INTRODUCTION: Parainfluenza type 3 virus (PIV-3) is an important nosocomial pathogen which causes pneumonia and bronchiolitis in infants. We report an outbreak of PIV-3 respiratory infection which occurred in the neonatal unit of KK Hospital in June 2005. This is the second PIV-3 outbreak in our unit after the fi rst in December 1994. MATERIALS AND METHODS: The clinical characteristics and outcome of 7 infants tested positive for PIV-3 on nasopharyngeal aspirate in June 2005 were reviewed retrospectively. RESULTS: Seven cases were infected with PIV-3 during this outbreak. The median birthweight of affected infants was 970 g (range, 740 to 2585 g), gestational age was 27 weeks and 4 days (range, 24 to 35 weeks), and postnatal age was 84 days (range, 28 to 250 days). Apnoeas and bradycardias were significant symptoms in 3 infants, 5 infants had progressive respiratory distress while the remaining 2 infants had flu-like illness. Five infants required ventilatory support and there were no deaths. The index case was an infant with chronic lung disease who was on oxygen supplementation and subsequently required ventilatory support with nasal CPAP. Despite implementation of control measures to prevent the spread of infection through early identification with strict cohorting of infected cases, contact tracing/screening, and reinforcement of hand hygiene precautions, the outbreak lasted for 24 days. CONCLUSION: PIV-3 respiratory infection in preterm infants can present with non-specific symptoms, leading to significant morbidity especially in those with underlying pulmonary pathology. Early recognition of symptoms and diagnosis by physicians, and prompt institution of control measures are necessary to prevent the spread of infection.

Kawasaki disease associated with parainfluenza type 3 virus infection.

Kawasaki disease (KD) is an acute, febrile and multisystem vasculitis of early childhood with a striking predilection for the coronary arteries. In developed countries, the incidence of KD has replaced acute rheumatic fever as the leading cause of acquired heart disease in children. The etiologic agent of KD remains unknown, although clinical and epidemiologic features strongly indicate an infectious cause. Parainfluenza viruses are the major cause of laryngotracheobronchitis (croup), but they also commonly cause upper respiratory tract infection, pneumonia, or bronchiolitis. Types 1 and 2 viruses are the most common pathogens associated with croup, and type 3 viruses are associated with bronchiolitis and pneumonia in infants and young children. Rarely, mumps, aseptic meningitis, and encephalitis have been associated with type 3 infections. We report a patient with typical KD during parainfluenza type 3 infection.

Rhabdomyolysis, acute renal failure, and compartment syndrome in a child with parainfluenza type 1 infection.

We present a case of para-influenza type 1 induced rhabdomyolysis, acute renal failure, and extensive compartment syndrome in a 6-year-old previously well child. Fasciotomies and subsequent skin grafting of both lower extremities and a prolonged course of hemodialysis led to a complete clinical and biochemical recovery.

Outbreak of parainfluenza virus type 3 in a neonatal intensive care unit.

Parainfluenza virus (PIV) causes > 30% of all acute respiratory infections in infants and children and is second only to respiratory syncytial virus as a cause of lower respiratory tract infection. However in the neonatal intensive care unit (NICU), PIV outbreaks are highly uncommon. This case report describes an outbreak of 3 cases of PIV type 3 in a regional NICU.

T cell memory in the lung airways.

The respiratory tract poses a substantial challenge to the immune system due to its large surface area, an extensive vasculature that is in very close proximity to the external environment, and repeated exposure to potentially pathogenic organisms in the air. Yet many lung pathogens are controlled by appropriate immune responses. The underlying mechanisms of the adaptive cellular immune response in protecting the respiratory tract are poorly understood. Recently, it has emerged that memory CD4(+) and CD8(+) T cells are present in the lung airways, and evidence is mounting that these cells play a key role in pulmonary immunity to pathogen challenge by immediately engaging the pathogen at the site of infection when pathogen loads are low. For example, in the case of respiratory virus infections, there is evidence that both CD4(+) and CD8(+) memory cells in the lung airways mediate substantial control of a secondary respiratory virus infection in the lungs. Here we address recent developments in our understanding of lung airway memory T cells and their role in infectious disease.

Entry of parainfluenza virus into cells as a target for interrupting childhood respiratory disease.

Human parainfluenza viruses cause several serious respiratory diseases in children for which there is no effective prevention or therapy. Parainfluenza viruses initiate infection by binding to cell surface receptors and then, via coordinated action of the 2 viral surface glycoproteins, fuse directly with the cell membrane to release the viral replication machinery into the host cell's cytoplasm. During this process, the receptor-binding molecule must trigger the viral fusion protein to mediate fusion and entry of the virus into a cell. This review explores the binding and entry into cells of parainfluenza virus type 3, focusing on how the receptor-binding molecule triggers the fusion process. There are several steps during the process of binding, triggering, and fusion that are now understood at the molecular level, and each of these steps represents potential targets for interrupting infection.

Adenovirus-mediated gene therapy enhances parainfluenza virus 3 infection in neonatal lambs.

Parainfluenza viruses are a common cause of seasonal respiratory disease, but in high-risk individuals (e.g., young children) these viruses can cause severe clinical manifestations that require hospitalization. Beta-defensins are a subclass of antimicrobial peptides with antiviral activity. Use of adenovirus-mediated beta-defensin gene expression has been proposed as therapy for chronic bacterial infections commonly seen in cystic fibrosis patients; however, its use during parainfluenza virus 3 (PIV3) infection has not been evaluated. The hypothesis in this experiment was that adenovirus expression of human beta-defensin 6 (HBD6) would diminish concurrent PIV3 infection in neonatal lambs. The group infected with adenovirus HBD6 and PIV3 had increased levels of pulmonary neutrophil recruitment compared to those for the group infected with PIV3 or PIV3 and adenovirus, with an increased respiration rate and body temperature late in the course of the PIV3-adenovirus HBD6 infection. Interestingly, the adenovirus-treated groups had higher levels of immunohistochemical staining for PIV3 and syncytial cell formation than the group infected with PIV3, suggesting that treatment with the adenovirus vector, regardless of whether it was carrying a target gene, exacerbated the PIV3 infection. The levels of expression of mRNA for antimicrobial surfactant proteins A and D and sheep beta-defensin 1 were increased by PIV3 and adenovirus treatment, and the increased levels of expression roughly corresponded to the degree of inflammation. While pulmonary administration of a high-dose adenovirus vector has been associated with undesirable inflammation, this is the first study to show that it can exacerbate concurrent viral infection, a concern that needs to be addressed for future studies of adenovirus in the lung. Additionally, this study showed that adenovirus-mediated HBD6 expression increases neutrophil recruitment, a recently described attribute of beta-defensins, with mild accentuation of PIV3 activity and inflammation.

A cotton rat model of human parainfluenza 3 laryngotracheitis: virus growth, pathology, and therapy.

Parainfluenza virus type 3 (PIV3) infection led to laryngotracheitis in cotton rats. Laryngeal virus titers peaked at 10(5.0)-10(6.0) plaque-forming units (pfu)/g of tissue from days 2 through 5 after inoculation with 10(5.5) pfu of PIV3. Lymphocytic and neutrophilic inflammatory infiltrates were present in the subglottic and proximal tracheal regions, whereas respiratory epithelial cells were blunted with loss of cilia. Topical therapy with moderate doses of triamcinolone acetonide, an anti-inflammatory glucocorticoid, greatly reduced the extent of lesions. Interferon-gamma messenger RNA production was increased by infection and was suppressed by the highest dose of glucocorticoid. Topical glucocorticoid therapy, with or without concurrent topical immunotherapy with antibody to PIV3, did not lead to a rebound of viral replication.

Atypical extrapulmonary presentations of severe respiratory syncytial virus infection requiring intensive care.

The patterns and nature of a four-month epidemic of severe respiratory syncytial virus (RSV)-associated disease were analyzed using presenting, demographic, clinical, and therapeutic data. Of 218 infants with RSV infection admitted to Rainbow Babies and Childrens Hospital, 49 (22.4%), most born prematurely, entered the pediatric intensive care unit (PICU). Fluorescent antibody and/or enzyme-linked immunosorbent assay documented RSV infection. PICU patients underwent airway stabilization; 53.5% were intubated and evaluated for sepsis. Patients with positive bacterial cultures received antibiotics; 18% were given ribavirin. Patterns of infection included hypothermia, septic shock appearance, apnea, pneumonia, and wheezing due to bronchiolitis. The average age difference between patients with hypothermia (23.3 days) and those with pneumonia (11.2 months) was statistically significant. There were no significant differences in average age, gestational age at birth, number intubated, worst pH and PCO2, duration of intensive care, or treatment modalities between infants with bronchopulmonary dysplasia who received ribavirin and those who did not.