I. Cell-dsRNA interactions and the induction of an antiviral state. II. Quantification and characterization of a chicken serum dsRNA endoribonuclease. III. Formation of viral pseudotypes between retroviruses and dsRNA bearing viruses

Cells respond to dsRNA, a product of viral replication, with the production of interferon (IFN) and the development of an antiviral state (AVS). AVS is a state in which cells inhibit viral replication and is characterized by the expression of many new proteins. The AVS induction by dsRNA in IFN producing (primary chicken embryo cells; CEC) and non-IFN producing cells (quail; LSCC-H32) were compared, as well as the role of dsRNA (synthetic or viral) extracellular or intracellular interactions in the induction of an AVS. CEC cells were more sensitive to minute amounts of synthetic dsRNA than LSCC-H32. Treatments of LSCC-H32 cells with NH4Cl, an inhibitor of proper endosomal processing, demonstrated that the cytosolic presence of synthetic dsRNA forms was not necessary for the induction of an AVS. Also, NH4Cl treatments demonstrated that endocytosis is important for Avian Reovirus (ARV) to successfully infect a cell. Furthermore, AVS induction was tested in the presence of 2-aminopurine (2-AP), an inhibitor of protein kinase R (PKR), a cytosolic dsRNA binding protein. 2-AP had little effect on AVS induction by synthetic dsRNA [poly r(I)-poly r(C); (pIC)], demonstrating that pIC does not enter into the cytoplasm and it does not react with PKR. ^ Our findings indicate that QM5 cells, a quail cell line, do not enter into an AVS when treated with synthetic forms of dsRNA (pIC polylysine carboxymethylcellulose; pICLC). However, when pICLC is treated with lipofectamine (a cationic surfactant), an AVS is induced in QM5 cells. This indicates that pICLC by itself is not an effective transfection vector for QM5 cells and lipofectamine is needed to assist pICLC to enter the QM5 cells. ^ The chicken dsRNase was quantified during the course of chicken development from embryo to adult and it was found to possess an endoribonucleolytic activity. Finally, the LSCC-H32 cells, which were transformed by avian leukosis virus (ALV) and actively producing virus, when treated with UV-inactivated viruses (ARV) produced a factor, which was able to induce an AVS in CEC. The factor was found in the supernatant medium and was sensitive to: (a) low pH; (b) heat; (c) UV-light; and (d) polyclonal antibodies to the inducing viruses and to ALV. From the above it was concluded that the antiviral factor found in the supernatants of UV-ARV treated LSCC-H32 cells is a viral pseudotype formed between the infecting ARV virus and the endogenous ALV.

I. Cell-dsRNA interactions and the induction of an antiviral state. II. Quantification and characterization of a chicken serum dsRNA endoribonuclease. III. Formation of viral pseudotypes between retroviruses and dsRNA bearing viruses

Cells respond to dsRNA, a product of viral replication, with the production of interferon (IFN) and the development of an antiviral state (AVS). AVS is a state in which cells inhibit viral replication and is characterized by the expression of many new proteins. The AVS induction by dsRNA in IFN producing (primary chicken embryo cells; CEC) and non-IFN producing cells (quail; LSCC-H32) were compared, as well as the role of dsRNA (synthetic or viral) extracellular or intracellular interactions in the induction of an AVS. CEC cells were more sensitive to minute amounts of synthetic dsRNA than LSCC-H32. Treatments of LSCC-H32 cells with NH4Cl, an inhibitor of proper endosomal processing, demonstrated that the cytosolic presence of synthetic dsRNA forms was not necessary for the induction of an AVS. Also, NH4Cl treatments demonstrated that endocytosis is important for Avian Reovirus (ARV) to successfully infect a cell. Furthermore, AVS induction was tested in the presence of 2-aminopurine (2-AP), an inhibitor of protein kinase R (PKR), a cytosolic dsRNA binding protein. 2-AP had little effect on AVS induction by synthetic dsRNA [poly r(I)-poly r(C); (pIC)], demonstrating that pIC does not enter into the cytoplasm and it does not react with PKR. ^ Our findings indicate that QM5 cells, a quail cell line, do not enter into an AVS when treated with synthetic forms of dsRNA (pIC polylysine carboxymethylcellulose; pICLC). However, when pICLC is treated with lipofectamine (a cationic surfactant), an AVS is induced in QM5 cells. This indicates that pICLC by itself is not an effective transfection vector for QM5 cells and lipofectamine is needed to assist pICLC to enter the QM5 cells. ^ The chicken dsRNase was quantified during the course of chicken development from embryo to adult and it was found to possess an endoribonucleolytic activity. Finally, the LSCC-H32 cells, which were transformed by avian leukosis virus (ALV) and actively producing virus, when treated with UV-inactivated viruses (ARV) produced a factor, which was able to induce an AVS in CEC. The factor was found in the supernatant medium and was sensitive to: (a) low pH; (b) heat; (c) UV-light; and (d) polyclonal antibodies to the inducing viruses and to ALV. From the above it was concluded that the antiviral factor found in the supernatants of UV-ARV treated LSCC-H32 cells is a viral pseudotype formed between the infecting ARV virus and the endogenous ALV.

Atypical Hemolytic Uremic Syndrome Treated With Ravulizumab or Eculizumab: A Claims-Based Evaluation of Health Care Resource Utilization and Clinical Outcomes in the United StatesPlain language summary

Rationale and Objective: Ravulizumab and eculizumab have shown efficacy for the treatment of atypical hemolytic uremic syndrome (aHUS), but real-world evidence for ravulizumab is limited owing to its more recent approval. This real-world database study examined outcomes for adult patients switching to ravulizumab from eculizumab and patients treated with individual treatments. Study Design: A retrospective, observational study using the Clarivate Real World Database. Setting and Population: US health-insurance billing data (January 2012 to March 2021) of patients aged 18 years or older with ≥1 diagnosis relevant to aHUS, ≥1 claim for treatment with eculizumab or ravulizumab, and no evidence of other indicated conditions. Exposures: Treatment-switch (to ravulizumab after eculizumab), ravulizumab-only, and eculizumab-only cohorts were examined. Outcomes: Clinical procedures, facility visits, health care costs, and clinical manifestations. Analytical Approach: Paired-sample statistical testing compared the mean numbers of claims for each group 0-3 months before (preindex period) and 0-3 months and 3-6 months after (postindex period) the index date (point of initiation with a single treatment or treatment switch). Results: In total, 322 patients met the eligibility criteria at 3-6 months postindex in the treatment-switch (n=65), ravulizumab-only (n=9), and eculizumab-only (n=248) cohorts. The proportions of patients with claims for key clinical procedures continued to be small after treatment switch and were small (0%-11%) across all cohorts at 3-6 months postindex. Inpatient visits were reduced in the postindex period across all cohorts. At 3-6 months after treatment switch, patients reported fewer claims for outpatient, private practice, and home visits and lower median health care costs. The proportions of patients with claims for clinical manifestations of aHUS were generally reduced in the postindex period compared with those of the preindex period. Limitations: Low patient numbers receiving ravulizumab only. Conclusions: The health-insurance claims data showed a reduced health care burden for US adult patients after treatment with ravulizumab or eculizumab for treatment of aHUS

Clinically important change for the FACIT-Fatigue scale in paroxysmal nocturnal hemoglobinuria: a derivation from international PNH registry patient data

Abstract Background Fatigue is the most common symptom associated with paroxysmal nocturnal hemoglobinuria (PNH). The objective of this analysis was to estimate values that would suggest a clinically important change (CIC) for the functional assessment of chronic illness therapy-fatigue scale (FACIT-Fatigue) in patients with PNH. Methods Adults with PNH who initiated eculizumab within 28 days of enrollment in the International PNH Registry as of January 2021 with baseline FACIT-Fatigue scores were included in the analysis. Distribution-based estimates of likely difference were calculated using 0.5 × SD and SEM. Anchor-based estimates of CIC considered the European Organization for Research and Treatment of Cancer (EORTC) global health status/quality of life summary score and the EORTC Fatigue Scale score. Changes in anchors and high disease activity (HDA) shift from start of eculizumab treatment to each follow-up visit were then assessed by FACIT-Fatigue score change (≤ 1 CIC, no change, or ≥ 1 CIC). Results At baseline, 93% of 423 patients had fatigue documented in their medical history. The distribution-based estimates for FACIT-Fatigue were 6.5 using 0.5 × SD and 4.6 using SEM; internal consistency was high (α = 0.87). For anchor-based estimates, the FACIT-Fatigue CIC ranged from 2.5 to 15.5, and generally supported 5 points as a reasonable lower end of the value for meaningful individual change. The percentage of patients who changed from having HDA at baseline to no HDA at eculizumab-treated follow-up visits increased over time. Conclusion These results support the use of 5 points as the CIC for FACIT-Fatigue in patients with PNH, which is within range of the CICs reported in other diseases (3–5 points)

Comparative efficacy of ravulizumab and eculizumab in the treatment of atypical hemolytic uremic syndrome: An indirect comparison using clinical trial data

Ravulizumab and eculizumab are approved terminal complement inhibitor treatments for atypical hemolytic uremic syndrome (aHUS). Ravulizumab was engineered from eculizumab to have an increased half-life allowing for reduced dosing frequency (8-weekly vs. 2-weekly). To account for differences in respective clinical trials, a validated balancing technique was used to enable an indirect comparison of ravulizumab and eculizumab treatment efficacy in aHUS. Patient-level data from four eculizumab clinical trials were available for pooling and comparison with data from two ravulizumab trials. In the primary analysis, adult native kidney data were compared. Propensity scores were calculated from baseline characteristics (dialysis status, estimated glomerular filtration rate, platelet count, serum lactate dehydrogenase). Stabilized inverse probability weighting was used to balance groups. Changes in outcomes from baseline to 26 weeks were compared between treatment groups. Sensitivity and subgroup analyses were conducted to assess the robustness of findings. Overall, 85 patients (46 ravulizumab, 39 eculizumab) were included in the primary analysis. Demographic and clinical characteristics were well balanced after weighting at baseline. At 26 weeks, clinical outcomes (including renal function, hematological markers, and dialysis prevalence), and fatigue and quality of life measures were improved with eculizumab and ravulizumab treatment. No differences between treatment groups reached statistical significance, although confidence intervals were wide. Sensitivity and subgroup analysis results were consistent with those of the primary analysis. Using appropriate methodology for indirect comparison of studies, no differences in outcomes were seen between ravulizumab and eculizumab, although, owing to small sample sizes, confidence intervals were wide

Frequency and age at occurrence of clinical manifestations of disease in patients with hypophosphatasia: a systematic literature review

Abstract Background Hypophosphatasia (HPP) is a rare, inherited, metabolic disease caused by tissue-nonspecific alkaline phosphatase deficiency, characterized by bone mineralization defects and systemic complications. Understanding of the clinical course and burden of HPP is limited by its rarity. This systematic literature review and synthesis of case report data aimed to determine the frequency and timing of clinical HPP manifestations and events. Methods Case reports and series of patients with HPP who had been followed longitudinally for ≥1 year were identified. Demographics and clinical data of interest, identified through consultation with clinical experts in HPP, were extracted. Occurrences of clinical manifestations/events of interest were categorized, classified by age at first reported occurrence of HPP manifestations and visualized over time. Clinical manifestations/events considered to contribute to the clinical burden of HPP were identified. Kaplan–Meier curves were used to estimate the median (range) age at first occurrence of the most frequently reported manifestations/events. Results From the 283 studies that met the inclusion criteria, 265 patients with HPP with ≥1 year of longitudinal follow-up were identified (median [interquartile range] age 4 [0–34] years; 45% male). The types of clinical manifestations/events of interest experienced by individuals with ≥1 such manifestation/event (n = 261) often differed between older and younger patients. Most (94%) of the 265 patients experienced ≥1 manifestation/event deemed to contribute to the clinical burden of HPP; premature tooth loss (53.5%), fractures (35.8%), pain (33.6%), and gross motor/ambulation difficulties (30.9%) were most frequently reported. The median (range) age at first reported occurrence of respiratory symptoms, cranial abnormalities, and premature tooth loss ranged from 0.3 to 10 years, whereas the median age at first reported occurrence of fractures, pain, gross motor/ambulation difficulties, and surgery ranged from 33 to 70 years. Conclusions HPP is associated with a high clinical burden of disease, regardless of age at first reported occurrence of HPP manifestations. Over an individual’s lifetime, the types of manifestations/events experienced can change and multiple HPP-related clinical manifestations/events can accumulate. These observations may reflect evolution and progression of the disease

Additional file 1 of The burden of mitochondrial disease with associated seizures: systematic literature reviews of health-related quality of life, utilities, costs and healthcare resource use data

Additional file 1. Detailed search methods, supplementary tables, and PRISMA checklist

Functional Assessment of Fatigue and Other Patient-Reported Outcomes in Patients Enrolled in the Global aHUS Registry

Introduction: Atypical hemolytic uremic syndrome (aHUS) is a progressive and potentially life-threatening disease characterized by complement-mediated thrombotic microangiopathy. Patients with aHUS may experience fatigue, which can negatively impact their lives, but there is a knowledge gap regarding disease burden in these patients. Methods: In this longitudinal study, patients with aHUS from the Global aHUS Registry who completed patient-reported outcome assessments (Functional Assessment of Chronic Illness Therapy-Fatigue scale [FACIT-Fatigue], general health status, and work status) at ≥2 time points were assessed relative to treatment status: (i) never treated with eculizumab; (ii) on eculizumab at registry enrollment and continued therapy; and (iii) started eculizumab after registry enrollment. Results: Patients who started eculizumab after the baseline visit (n = 23) exhibited improvements in fatigue (nearly 75% achieved clinically meaningful improvement), improved general health status (55%), and 25% to 30% rate reduction in symptoms of fatigue, weakness, irritability, nausea/vomiting, and swelling at last follow-up. Among patients already on eculizumab at registry enrollment (n = 295) and those never treated (n = 233), these parameters changed minimally relative to the baseline. Emergency room visits and hospital admissions were similar between groups. The number of health care provider visits and work days missed were higher in patients who started eculizumab after registry enrollment. Conclusion: These real-world findings confirm the detrimental effects of aHUS on patients’ daily lives, including high levels of fatigue and impairments in general health status. The results suggest clinically meaningful improvement in fatigue, other patient-reported outcomes, and symptoms with eculizumab initiation after enrollment into the aHUS registry