Effect of the COVID-19 pandemic on outpatient care and rehabilitation in neuromuscular clinical practice in Japan: a health insurance claims database analysis.

OBJECTIVES: To evaluate the impact of the COVID-19 pandemic on outpatient care in Japanese patients with neuromuscular diseases (NMDs). DESIGN: This retrospective cohort study included patients between January 2018 and February 2019; the follow-up period was divided into 'before COVID-19' (March 2019-February 2020) and 'during COVID-19' (March 2020-February 2021). SETTING: JMDC claims database study. PARTICIPANTS: Of the 10 655 557 patients identified, we included patients with spinal muscular atrophy (SMA; n=82), neuromyelitis optica (NMO; n=342), myasthenia gravis (MG; n=1347), Guillain-Barré syndrome (GBS; n=442) or autoimmune encephalitis/encephalopathy (AIE; n=133). Patients were required to have ≥1 month of data available, have a diagnosis of NMD during the enrolment period and be available for follow-up. PRIMARY AND SECONDARY OUTCOME MEASURES: We estimated the proportion of patients with >30% change in outpatient consultation and rehabilitation visits before versus during the COVID-19 pandemic. RESULTS: Small reductions in the proportion of patients with outpatient consultation/rehabilitation visits were observed before versus during the pandemic. Compared with before the pandemic, 30.4%, 27.8%, 28.7%, 49.4% and 50.0% of patients showed a >30% decrease in outpatient consultation visits and 58.6%, 75.0%, 50.0%, 76.3% and 84.6% showed a >30% decrease in outpatient rehabilitation visits during the pandemic for SMA, NMO, MG, GBS and AIE, respectively. The median change in the number of outpatient consultation visits per year before versus during pandemic was -1.0 day for all NMDs, and that in outpatient rehabilitation visits per year was -6.0, -5.5, -1.5, -6.5 and -9.0 days for SMA, NMO, MG, GBS and AIE, respectively. The reduction in outpatient rehabilitation visits was greater in the absence versus presence of a neurology specialist. CONCLUSIONS: Outpatient consultation and rehabilitation visits during the COVID-19 pandemic were affected in Japanese patients with NMDs. Longer-term evaluations are required to understand if these reductions in outpatient care would affect patient prognosis.

ORIHIME study: real-world treatment patterns and clinical outcomes of 338 patients with acquired hemophilia A from a Japanese administrative database.

BACKGROUND: Acquired hemophilia A (AHA) is a rare disorder, and clinical practices for treating AHA have not been fully clarified in Japan. OBJECTIVES: This study aims to investigate the epidemiology of AHA and real-world treatment practices in Japan. PATIENTS/METHODS: This observational study was based on a health administrative database of hospitalized patients diagnosed with AHA who were treated with immunosuppressants. RESULTS: The study included 214 males and 124 females (mean age 75.7 years). The most frequently used bypassing agent was recombinant activated factor VII. The predominant choice of immunosuppressant for first-line treatment was steroid monotherapy. Median days from the index date to the start of rehabilitation was 65.0 for cardiovascular, 35.5 for respiratory and 23.0 for locomotor. The proportion of patients with an activities of daily living (ADL) score < 70 points was high at both first admission and final discharge (47.4% and 38.8%). The percentage of deaths during hospitalization was 18.6%. CONCLUSIONS: This study clarified the treatment patterns and clinical outcomes of AHA in a large population in Japan. This was the first study showing ADL score distribution and time to rehabilitation. Further investigation is needed to develop better clinical practices for treatment of AHA.

T2 ∗ Relaxation Time Obtained from Magnetic Resonance Imaging of the Liver Is a Useful Parameter for Use in the Construction of a Murine Model of Iron Overload.

Aim: Iron overload is a life-threatening disorder that can increase the risks of cancer, cardiovascular disease, and liver cirrhosis. There is also a risk of iron overload in patients with chronic kidney disease. In patients with renal failure, iron storage is increased due to inadequate iron utilization associated with decreased erythropoiesis and also to the inflammatory status. To evade the risk of iron overload, an accurate and versatile indicator of body iron storage in patients with iron overload is needed. In this study, we aimed to find useful iron-related parameters that could accurately reflect body iron storage in mice in order to construct a murine model of iron overload. Methods: To select an appropriate indicator of body iron status, a variety of parameters involved in iron metabolism were evaluated. Noninvasively measured parameters were R1, R2, and R2 ∗ derived from magnetic resonance imaging (MRI). Invasively measured parameters included serum hepcidin levels, serum ferritin levels, and liver iron contents. Histopathological analysis was also conducted. Results/Conclusion: Among the several parameters evaluated, the MRI T2 ∗ relaxation time was able to detect iron storage in the liver as sensitively as serum ferritin levels. Moreover, it is expected that using an MRI parameter will allow accurate evaluation of body iron storage in mice over time.

Iron attenuates erythropoietin production by decreasing hypoxia-inducible transcription factor 2α concentrations in renal interstitial fibroblasts.

Iron is an essential mineral for oxygen delivery and for a variety of enzymatic activities, but excessive iron results in oxidative cytotoxicity. Because iron is primarily used in red blood cells, defective erythropoiesis caused by loss of the erythroid growth factor erythropoietin (Epo) elevates iron storage levels in serum and tissues. Here, we investigated the effects of iron in a mouse model of Epo-deficiency anemia, in which serum iron concentration was significantly elevated. We found that intraperitoneal injection of iron-dextran caused severe iron deposition in renal interstitial fibroblasts, the site of Epo production. Iron overload induced by either intraperitoneal injection or feeding decreased activity of endogenous Epo gene expression by reducing levels of hypoxia-inducible transcription factor 2α (HIF2α), the major transcriptional activator of the Epo gene. Administration of an iron-deficient diet to the anemic mice reduced serum iron to normal concentration and enhanced the ability of renal Epo production. These results demonstrate that iron overload due to Epo deficiency attenuates endogenous Epo gene expression in the kidneys. Thus, iron suppresses Epo production by reducing HIF2α concentration in renal interstitial fibroblasts.

Visualization of 57Fe-Labeled Heme Isotopic Fine Structure and Localization of Regions of Erythroblast Maturation in Mouse Spleen by MALDI FTICR-MS Imaging.

Epoetin beta pegol (continuous erythropoiesis receptor activator; C.E.R.A.), or methoxy-polyethylene glycol-modified epoetin beta, is a long-acting erythropoiesis stimulating agent (ESA) that effectively maintains hemoglobin levels. It promotes proliferation of erythroid progenitor cells in hematopoietic organs and leads to increased reticulocyte and hemoglobin levels. However, the detailed erythropoietic effects of various ESAs on their target organs have yet to be clarified, and new approaches are needed to analyze tissue iron localization with structural information. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) techniques are widely used in basic pharmaceutical research. High-resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) imaging enables the spatial mapping and identification of biomolecules. In this study, mice administered with C.E.R.A. were fed a diet containing the stable iron isotope 57Fe. The 57Fe-heme+ isotopic fine structure peak (m/z 617.1772) was separated from the non-labeled heme+ isotopic peak (Δ0.0029) by FTICR-MS with a resolving power of more than 500,000. We optimized the platform to analyze the distribution of 57Fe-heme in the spleen using MALDI FTICR-MS imaging. The combination of the ultrahigh resolution power of FTICR-MS and a stable isotope labeling technique has the potential to be very effective in basic pharmaceutical research. Graphical Abstract ᅟ.

The effect of frequency of C.E.R.A. administration on the contribution of dietary iron for erythropoiesis.

Erythropoiesis-stimulating agents are among the therapeutic options for renal anemia. Under erythropoietic stimulation, the synthesis of hemoglobin requires a large amount of iron, which is supplied both from absorption of dietary iron and the mobilization of stored iron. However, under iron-loading conditions, dietary iron absorption is suppressed via down-regulation of duodenal iron transporters. Because the contribution of dietary iron is essential for erythropoiesis, we aimed to investigate the conditions in which dietary iron is efficiently used for erythropoiesis. To quantify the contribution of dietary iron for erythropoiesis, we labelled dietary iron using the stable iron isotope 57Fe, and assessed 57Fe-derived hemoglobin synthesis under erythropoietic stimulation by C.E.R.A. (Continuous Erythropoietin Receptor Activator) and iron loading in mice. Our results show that the contribution of dietary iron to erythropoiesis is not changed by different increments of C.E.R.A. dose. However, iron loading suppressed the contribution of dietary iron to erythropoiesis. To confirm these results under conditions mimicking clinical settings, we compared single and intermittent administration of C.E.R.A. in mice under both physiological and iron-loaded conditions, and found that the contribution of dietary iron to erythropoiesis is more strongly affected by body iron status than by erythropoietic stimulation.

Quantitative analysis of dietary iron utilization for erythropoiesis in response to body iron status.

Erythropoiesis requires large amounts of iron for hemoglobin synthesis. There are two sources of iron for erythropoiesis, dietary and stored iron; however, their relative contributions to erythropoiesis remain unknown. In this study, we used the stable iron isotope (57)Fe to quantify synthesis of hemoglobin derived from dietary iron. Using this method, we investigated the activities of dietary iron absorption and the utilization of dietary iron for erythropoiesis in responses to stimulated erythropoiesis and to interventions to alter body iron status. Under iron-loaded conditions, the activity of dietary iron absorption was clearly lowered in response to up-regulation of hepcidin, although the estimated activity of iron release from stored iron was not compared with that under control conditions. This result was supported by the observation that two duodenal iron transporters, divalent metal transporter 1 (DMT1) and ferroportin, were downregulated by iron loading, although the levels of expression of ferroportin in iron storage tissues were not changed by iron loading under erythropoietic stimulation by epoetin-ß pegol (C.E.R.A., a long-acting erythropoiesis-stimulating agent). These results indicate that the dietary iron absorption system is more sensitive to body iron status than are reticuloendothelial iron- release mechanisms. Our data indicated that there could be a regulatory mechanism favoring use of stored iron over dietary iron under iron-loaded conditions.

Reduction of a marker of oxidative stress with enhancement of iron utilization by erythropoiesis activation following epoetin beta pegol administration in iron-loaded db/db mice.

UNLABELLED: Iron, an essential element for various biological processes, can induce oxidative stress. We hypothesized that iron utilization for erythropoiesis, stimulated by epoetin beta pegol (C.E.R.A.), a long-acting erythropoiesis-stimulating agent, contributes to the reduction of iron-induced oxidative stress. We first investigated the sensitivity of several biomarkers to detect oxidative stress in mice by altering the amount of total body iron; we then investigated whether C.E.R.A. ameliorated oxidative stress through enhanced iron utilization. We treated db/db mice with intravenous iron-dextran and evaluated several biomarkers of iron-induced oxidative stress. In mice loaded with 5 mg/head iron, hepatic iron content was elevated and the oxidative stress marker d-ROMs (serum derivatives of reactive oxygen metabolites) was increased, whereas urinary 8-hydroxy-2'-deoxyguanosine and serum malondialdehyde were not, indicating that d-ROMs is a sensitive marker of iron-induced oxidative stress. To investigate whether C.E.R.A. ameliorated oxidative stress, db/db mice were intravenously administered iron-dextran or dextran only, followed by C.E.R.A. Hemoglobin level increased, while hepatic iron content decreased after C.E.R.A. TREATMENT: Serum d-ROMs decreased after C.E.R.A. treatment in the iron-dextran-treated group. Our results suggest that C.E.R.A. promotes iron utilization for erythropoiesis through mobilization of hepatic iron storage, leading to a decrease in serum oxidative stress markers in iron-loaded db/db mice.

Epoetin beta pegol (C.E.R.A.) promotes utilization of iron for erythropoiesis through intensive suppression of serum hepcidin levels in mice.

Epoetin beta pegol (C.E.R.A.) is a novel, long-acting, erythropoiesis-stimulating agent. We investigated iron utilization associated with erythropoiesis, and how it is affected by the long-term suppression of hepcidin following C.E.R.A. treatment in mice. C57BL/6N mice were administered a single intravenous injection of C.E.R.A. Hemoglobin (Hb) levels were significantly elevated following C.E.R.A. administration, while serum hepcidin levels were continuously suppressed. Expression levels of duodenal iron transporters, ferroportin (FPN) which is internalized by hepcidin binding and divalent metal transporter 1 (DMT1), increased after C.E.R.A. administration. To evaluate the contribution of dietary iron absorption to erythropoiesis following C.E.R.A. treatment, C.E.R.A.-treated mice were fed either an iron-deficient diet to restrict dietary iron absorption or a control diet. The restriction of dietary iron absorption resulted in impaired Hb elevation after C.E.R.A. administration. To investigate the utilization of stored iron for erythropoiesis following C.E.R.A. treatment, iron indices were analyzed in C.E.R.A.-treated mice given an intraperitoneal pre-treatment injection of iron-dextran. Serum hepcidin levels and splenic hemosiderin deposition decreased after C.E.R.A. administration. These results indicate that C.E.R.A. promotes utilization of iron for erythropoiesis both through enhancement of dietary iron absorption and mobilization of iron storage from reticuloendothelial cells.