An integrated computational pipeline for designing high-affinity nanobodies with expanded genetic codes.

Protein engineering and design principles employing the 20 standard amino acids have been extensively used to achieve stable protein scaffolds and deliver their specific activities. Although this confers some advantages, it often restricts the sequence, chemical space, and ultimately the functional diversity of proteins. Moreover, although site-specific incorporation of non-natural amino acids (nnAAs) has been proven to be a valuable strategy in protein engineering and therapeutics development, its utility in the affinity-maturation of nanobodies is not fully explored. Besides, current experimental methods do not routinely employ nnAAs due to their enormous library size and infinite combinations. To address this, we have developed an integrated computational pipeline employing structure-based protein design methodologies, molecular dynamics simulations and free energy calculations, for the binding affinity prediction of an nnAA-incorporated nanobody toward its target and selection of potent binders. We show that by incorporating halogenated tyrosines, the affinity of 9G8 nanobody can be improved toward epidermal growth factor receptor (EGFR), a crucial cancer target. Surface plasmon resonance (SPR) assays showed that the binding of several 3-chloro-l-tyrosine (3MY)-incorporated nanobodies were improved up to 6-fold into a picomolar range, and the computationally estimated binding affinities shared a Pearson's r of 0.87 with SPR results. The improved affinity was found to be due to enhanced van der Waals interactions of key 3MY-proximate nanobody residues with EGFR, and an overall increase in the nanobody's structural stability. In conclusion, we show that our method can facilitate screening large libraries and predict potent site-specific nnAA-incorporated nanobody binders against crucial disease-targets.

Abnormalities in esophageal smooth muscle induced by mutations in collagen XIX.

Collagen XIX is a nonfibrillar collagen that localizes in restricted tissues at very low amounts. A previous study on Col19a1 null mice revealed that collagen XIX is involved in esophageal muscle physiology and morphogenesis. Here, we use histological analysis to show that mice with a Col19a1 mutant lacking the NC3 domain and seven collagen triplets display abnormal transition of smooth to striated muscle in the abdominal segment of esophagus, and a widened esophagus with age. With two newly prepared antibodies, we analyzed the expression of collagen XIX in the mouse esophagus and show that collagen XIX colocalizes with α-smooth muscle actin. By immunoelectron microscopy, we confirmed the localization of collagen XIX in esophageal smooth muscle cells. Col19a1 mutant mice contained reduced levels of mutated Col19a1 mRNA. Interestingly, hepatocyte growth factor, which has an important role in esophageal striated muscle development, was reduced in the esophagus of the Col19a1 mutant mice. These findings suggest that collagen XIX may be critical for the function of esophageal smooth muscle cells as a scaffold for anteroposterior migration of esophagus-striated muscle cells.

Incorporation of Halogenated Amino Acids into Antibody Fragments at Multiple Specific Sites Enhances Antigen Binding.

Expansion of the amino-acid repertoire with synthetic derivatives introduces novel structures and functionalities into proteins. In this study, we improved the antigen binding of antibodies by incorporating halogenated tyrosines at multiple selective sites. Tyrosines in the Fab fragment of an anti-EGF-receptor antibody 059-152 were systematically replaced with 3-bromo- and 3-chlorotyrosines, and simultaneous replacements at four specific sites were found to cause a tenfold increase in the affinity toward the antigen. Structure modeling suggested that this effect was due to enhanced shape complementarity between the antigen and antibody molecules. On the other hand, we showed that chlorination in the constant domain, far from the binding interface, of Rituximab Fab also increased the affinity significantly (up to 17-fold). Our results showed that antigen binding is tunable with the halogenation in and out of the binding motifs.

The Effect of Bronchoconstriction by Methacholine Inhalation in a Murine Model of Asthma.

INTRODUCTION: Bronchoconstriction was recently shown to cause airway remodeling and induce allergic airway inflammation in asthma. However, the mechanisms how mechanical stress via bronchoconstriction could induce airway inflammation and remodeling remain unclear. OBJECTIVE: We investigated the effect of bronchoconstriction induced by methacholine inhalation in a murine model of asthma. METHODS: BALB/c female mice were sensitized and challenged with ovalbumin (OVA), followed by treatment with methacholine by a nebulizer twice a day for 7 days. Twenty-four hours after the last methacholine treatment, the bronchoalveolar lavage fluid (BALF) and lung tissues were collected. The BALF was analyzed for total and differential cell counts and cytokine levels. The lung tissues were analyzed for goblet cell metaplasia, thickness of the smooth muscle, and lung fibrosis. The expression of cytokines in the lung was also examined. RESULTS: OVA sensitization and challenge induced infiltration of total cells, macrophages, and eosinophils in the BALF along with goblet cell metaplasia and increased airway smooth muscle hypertrophy. Seven days after the last OVA challenge, untreated mice achieved reduction in airway inflammation, while methacholine maintained the number of BALF total cells, macrophages, and eosinophils. The percentage of goblet cells and the thickness of airway smooth muscle were also maintained by methacholine. Moreover, the treatment of methacholine induced the expression of transforming growth factor (TGF)-ß in the lung. This result indicates that the production of TGF-ß is involved in induction of airway remodeling caused by bronchoconstriction with methacholine. CONCLUSIONS: Repeated bronchoconstriction caused by methacholine inhalation elicited allergic airway inflammation and airway remodeling.

Inhibition of Virus-Induced Cytokine Production from Airway Epithelial Cells by the Late Addition of Budesonide.

BACKGROUND: Viral infection is the main cause of asthma and COPD (chronic obstructive pulmonary disease) exacerbation and accumulate inflammatory cells to airway tissue. We have reported poly I:C, a mimic product of the virus and ligand of toll-like receptor 3 (TLR3), induced inflammatory chemokines from airway epithelial cells and found prior incubation with corticosteroids diminishes the effect of TLR3 activation. In clinical practice, mild asthma is recommended as-needed budesonide (BUD) when symptoms occur following a viral infection, etc. However, many questions still surround BUD's usefulness if taken after a virus has already infected airway tissue. OBJECTIVE: The aim of this study was to investigate the inhibitory effects of BUD on inflammatory cytokines induced by viral infection. Methods: Normal human bronchial epithelial (NHBE) cells were stimulated with poly I:C or infected with human rhinovirus-16 (HRV16) and BUD was added after the initial stimulation. Expression of both thymic stromal lymphopoietin (TSLP) and CCL26/eotaxin-3 was quantified by real-time RT-PCR and enzyme-linked immunosorbent assay (ELISA), respectively. Knockdown study was performed. Results: Pre-or post-incubation with BUD inhibited both poly I:C- and HRV16-induced mRNAs and proteins of both thymic stromal lymphopoietin (TSLP) and CCL26 with significance. Knockdown of the glucocorticoid receptor diminished these effects of BUD. Under the same conditions of BUD's experiment, post-incubation with neither fluticasone propionate nor dexamethasone suppressed expression of both TSLP and CCL26, which induced by poly I:C. CONCLUSION: Post-addition of BUD inhibited the virus-induced TSLP and CCL26 from the airway epithelial cells. These results suggest that inhalation of BUD after viral infection has beneficial effects on asthma. CONCLUSION: Late addition of BUD may benefit among patient with viral infection and type 2 allergic airway disease such as asthma.

[A CASE OF ANAPHYLAXIS DUE TO STINGING OF A Brachyponera chinensis].

The case involved a man in his forties. While working at the restaurant that the patient runs, the patient experienced a stab-like pain on the left shoulder and developed systemic pruritic eruptions. He was diagnosed with anaphylaxis upon visiting our emergency department. Conjunctival hyperemia, lip swelling, cold sweats, and nausea presented later. A cap fluorescence enzyme immunoassay using the serum of the patient showed specific immunoglobulin E (IgE) positivity for wasps; therefore, we hypothesized that he had anaphylaxis caused by the insect's sting. Insects of the same species as that by which the patient had been stung were collected and finally identified as the Asian needle ant (Brachyponera chinensis). The freeze-dried insects' bodies were sonicated into powders and stored for following examinations. Next, a basophil activation test was performed using the patient's whole blood treated with the reagent above, which showed positivity. Furthermore, a skin prick test using the same reagent showed a positive result, and the reaction increased in a concentrationdependent manner. Based on these results, the patient was diagnosed with anaphylaxis after a sting by the ant. Based on the results of the allergen component specific IgE test, we speculated that the pathogens in this case was group5 allergen of the Asian needle ant. Anaphylaxis following insect stings by this ant has been reported frequently in South Korea. However, it is quite rare in Japan, although the ant is native to Japan. Clinicians should consider that this allergy can occur indoors, unlike allergies to other types of venom.

Beneficial Effect of Early Intervention with Garenoxacin for Bacterial Infection-Induced Acute Exacerbation of Bronchial Asthma and Chronic Obstructive Pulmonary Disease.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) and asthma have similar clinical features and are both exacerbated by airway infection. OBJECTIVE: To determine whether garenoxacin mesylate hydrate (GRNX) added to the standard care for bacterial infection-induced acute exacerbation of asthma or COPD in adults has clinical benefits. METHOD: This single-arm clinical trial was conducted from January 2015 to March 2016. Adults with a history of asthma or COPD for more than 12 months were recruited within 48 h of presentation with fever and acute deterioration of asthma or COPD requiring additional intervention. Participants were administered 400 mg GRNX daily for 7 days without additional systemic corticosteroids or other antibiotics. The primary outcome was efficacy of GRNX based on clinical symptoms and blood test results after 7 days of treatment. Secondary outcomes were: (1) comparison of the blood test results, radiograph findings, and bacterial culture surveillance before and after treatment; (2) effectiveness of GRNX after 3 days of administration; (3) analyzation of patient symptoms based on patient diary; and (4) continued effectiveness of GRNX on 14th day after the treatment (visit 3). RESULTS: The study included 44 febrile patients (34 asthma and 10 COPD). Frequently isolated bacteria included Moraxella catarrhalis (n = 6) and Klebsiella pneumoniae (n = 4). On visit 2, 40 patients responded, and no severe adverse events were observed. All secondary outcomes showed favorable results. CONCLUSION: GRNX effectively treated asthma and COPD patients with acute bacterial infection without severe adverse events. Further research with a larger study population is needed.

DNA Adductome Analysis Identifies N-Nitrosopiperidine Involved in the Etiology of Esophageal Cancer in Cixian, China.

Esophageal cancer is prevalent in Cixian, China, but the etiology of this disease remains largely unknown. Therefore, we explored this by conducting a DNA adductome analysis. Both tumorous and nontumorous tissues were collected from patients who underwent surgical procedures at Cixian Cancer Hospital and the Fourth Hospital of Hebei Medical University, which is in a low-incidence area. N2-(3,4,5,6-Tetrahydro-2H-pyran-2-yl)deoxyguanosine (THP-dG) was the major adduct detected in samples from esophageal cancer patients in Cixian. The precursor of THP-dG, N-nitrosopiperidine (NPIP), exhibited a strong mutagenic activity under metabolic activation in the Ames test and a significant dose-dependent increase in mutation frequency during an in vivo mutagenicity test with guanine phosphoribosyltransferase (gpt) delta rats. The NPIP-induced mutation was dominated by A:T to C:G transversions, followed by G:C to A:T and A:T to G:C transitions, in the liver and esophagus of animal samples. A similar mutational pattern was observed in the mutational signature of esophageal cancer patients that demonstrated weak correlation with THP-dG levels. These findings suggested that NPIP exposure is partly involved in the development of esophageal cancer in Cixian residents.

Proteolytic analysis of Trichoderma reesei in celluase-inducing condition reveals a role for trichodermapepsin (TrAsP) in cellulase production.

Filamentous fungi produce a variety of proteases with significant biotechnological potential and show diverse substrate specificities. Proteolytic analysis of the industrial enzyme producer Trichoderma reesei has been sparse. Therefore, we determined the substrate specificity of T. reesei secretome and its main protease Trichodermapepsin (TrAsP) up to P1 position using FRETS-25Xaa-libraries. The role of TrAsP was analyzed using T. reesei QM9414 and the deletant QM∆trasp in Avicel. We observed higher activities of CMCase, Avicelase, and Xylanase in QM∆trasp compared to that of QM9414. Saccharification rate of cellulosic biomass also increased when using secretome of QM∆trasp but the effect was not significant due to the absence of difference in BGL activity compared to QM9414. Higher TrAsP was produced when monosaccharides were used as a carbon source compared to cellulase inducers such as Avicel and α-sophorose. These results elucidate the relationship between TrAsP and cellulase production in T. reesei and suggest a physiological role for TrAsP.

Establishment of an in vivo simulating co-culture assay platform for genotoxicity of multi-walled carbon nanotubes.

Engineered nanomaterials (ENM) are now used in a wide variety of fields, and, thus, their safety should urgently be assessed and secured. It has been suggested that inflammatory responses via the phagocytosis of ENM by macrophages is a key mechanism for their genotoxicity. The present study was conducted to establish a mechanism-based assay to evaluate the genotoxicity of ENM under conditions simulating an in vivo situation, featuring a co-culture system of murine lung resident cells (GDL1) and immune cells (RAW264.7). GDL1 were cultured with or without RAW264.7, exposed to a multi-walled carbon nanotube (MWCNT), and then analyzed for mutagenicity and underlying mechanisms. Mutation frequencies induced in GDL1 by the MWCNT were significantly greater with the co-existence of RAW264.7 than in its absence. Mutation spectra observed in GDL1 co-cultured with RAW264.7 were different from those seen in GDL1 cultured alone, but similar to those observed in the lungs of mice exposed to the MWCNT in vivo. Inflammatory cytokines, such as IL-1ß and TNF-α, were produced from RAW264.7 cells treated with the MWCNT. The generation of reactive oxygen species and the formation of 8-oxodeoxyguanosine in GDL1 exposed to the MWCNT were greater in the co-culture conditions than in the single culture conditions. Based on these findings, it is indicated that inflammatory responses are involved in the genotoxicity of MWCNT, and that the presently established, novel in vitro assay featuring a co-culture system of tissue resident cells with immune cells is suitable to evaluate the genotoxicity of ENM.

Human cytomegalovirus downregulates SLITRK6 expression through IE2.

Congenital human cytomegalovirus (HCMV) infection causes sensorineural hearing loss (SNHL) and other neurological disorders, although the neuropathogenesis of HCMV infection is not well understood. Here, we show that the expression of SLITRK6, one of causative genes for hereditary SNHL, was robustly downregulated by HCMV infection in cultured neural cells. We also show that HCMV-encoded immediate-early 2 (IE2) proteins mediate this downregulation and their carboxy-terminal region, especially amino acid residue Gln548, has a critical role. These findings suggest that the downregulation of SLITRK6 expression by IE2 may have a role in HCMV-induced SNHL and other neurological disorders.

Predicting future risk of exacerbations in Japanese patients with adult asthma: A prospective 1-year follow up study.

BACKGROUND: To avoid future risk is a definitive goal of long-term asthma management. Exacerbations are considered to be the most relevant future risk in real life asthma management. Few comparative studies have evaluated the risk factors associated with exacerbations in Japanese patients with asthma. METHODS: We performed the prospective 1-year follow up study in Japanese patients with adult asthma. A total of 189 patients with asthma were enrolled and followed up for 1 year. Finally, 181 patients completed the study protocol. RESULTS: Of 181 patients, 43 patients (23.8%) had exacerbations during the follow-up period. Among the 45 patients who had exacerbations during the preceding year, 32 patients (71.1%) had exacerbations. Prevalence of patients with previous exacerbations and those with previous admissions were significantly higher in patients with exacerbations than those with no exacerbation. Logistic regression analysis also identified a significant association between exacerbations during the follow-up period and exacerbations during the preceding year, admissions during the preceding 3 years, ACT score below 20, low %FVC (<80%), or low FEV1 (<70%), respectively. Of the 55 patients with severe asthma, 29 patients (52.7%) had exacerbations. Among the 36 patients with severe asthma with previous exacerbations, 26 patients (72.2%) had exacerbations. The history of exacerbations during the preceding year was associated with a significantly increased risk of exacerbations both among the patients with severe asthma and those with non-severe asthma. CONCLUSIONS: This study implicated that exacerbations during the preceding year reliably predict future risk of exacerbations in Japanese patients with asthma.

Aromatic oil from lavender as an atopic dermatitis suppressant.

In atopic dermatitis (AD), nerves are abnormally stretched near the surface of the skin, making it sensitive to itching. Expression of neurotrophic factor Artemin (ARTN) involved in such nerve stretching is induced by the xenobiotic response (XRE) to air pollutants and UV radiation products. Therefore, AD can be monitored by the XRE response. Previously, we established a human keratinocyte cell line stably expressing a NanoLuc reporter gene downstream of XRE. We found that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan metabolite and known inducer of the XRE, increased reporter and Artemin mRNA expression, indicating that FICZ-treated cells could be a model for AD. Lavender essential oil has been used in folk medicine to treat AD, but the scientific basis for its use is unclear. In the present study, we investigated the efficacy of lavender essential oil and its major components, linalyl acetate and linalool, to suppress AD and sensitize skin using the established AD model cell line, and keratinocyte and dendritic cell activation assays. Our results indicated that lavender essential oil from L. angustifolia and linalyl acetate exerted a strong AD inhibitory effect and almost no skin sensitization. Our model is useful in that it can circumvent the practice of using animal studies to evaluate AD medicines.

An Experimental Study on the Addition of Bacteria to Residual Anticancer Drugs: Evaluation of the Effect on Bacterial Growth.

Using anticancer drugs as examples, we examined the possibility of reusing residual drugs. The use of residual drugs is not widespread owing to concerns regarding bacterial contamination. We combined anticancer drugs and bacteria to investigate their effects on bacterial growth. The anticancer drugs carboplatin, paclitaxel, etoposide, irinotecan, methotrexate, and 5-fluorouracil (5-FU) were mixed with Staphylococcus aureus, Enterococcus faecalis, Serratia marcescens, and Escherichia coli. After a certain period, the bacteria were counted. Irinotecan showed no antibacterial activity, whereas 5-FU exhibited high antibacterial activity against the tested bacteria. The 5-FU also showed a minimum inhibitory concentration value in the range of 8-80 µg/mL, depending on the bacterial species. 5-FU dose-dependently inhibited S. aureus growth at more than 0.8 µg/mL. Because protein synthesis systems are reportedly antibiotic targets, we used a cell-free protein synthesis system to confirm the mechanism of the antibacterial activity of the anticancer agent. 5-FU and methotrexate had direct inhibitory effects on protein synthesis. It has been suggested that even if residual drugs are contaminated with bacteria, there will be no microbial growth, or the microbes will be killed by the drug. With careful monitoring, 5-FU can potentially be used for antimicrobial purposes.

A Case Series on Pain Accompanying Photoimmunotherapy for Head and Neck Cancer.

One of the most severe side effects of photoimmunotherapy (PIT) for head and neck cancer is pain. As there are presently no detailed reports on pain and pain management in PIT, we conducted a retrospective case series study. We conducted a retrospective study of five patients who had received PIT at the National Cancer Center Hospital East between January 2021 and June 2022 using medical chart data. All patients experienced pain, evidenced by an increased numerical rating scale (NRS) after PIT, regardless of the illumination method. The daily change in mean NRS rating shows that the pain was highest on the day of PIT, with ratings of 6.8 and 7.8 for the frontal and cylindrical diffuser methods, respectively; it dropped the following day quickly. Four of the five patients received fentanyl injections for postoperative pain management beginning on postoperative day (POD) 0. All patients who underwent therapy using a cylindrical diffuser required postoperative pain management with opioid drugs. Pain after PIT tended to be most intense immediately after or one hour after illumination and declined the following day, suggesting the need to have a pain relief plan in place in advance.

SRT1720 induces SIRT1-independent cell death in adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) develops after a long period of human T-cell leukemia virus (HTLV)-1 infection and is associated with host aging in addition to genetic abnormalities in HTLV-1 infected cells. SIRT1 is a histone deacetylase involved in cell cycle and apoptosis. We previously showed the high expression of SIRT1 protein in peripheral blood mononuclear cells from patients with ATL. There have been many reports that SIRT1 inhibitors show tumor-suppressive effects. On the other hand, SIRT1 activator SRT1720 induces the cell death of multiple myeloma and breast cancer cells. However, the effect of SRT1720 on ATL is unknown. This study aimed to evaluate the effect of SRT1720 on cell death in leukemic cell lines in vitro and freshly isolated ATL cells ex vivo and in an ATL in vivo mouse model. SRT1720 reduced cell viability in vitro and ex vivo. Additionally, SRT1720 increased the number of apoptotic cells, as shown by annexin V positive cells, cleaved poly (ADP-ribose) polymerase 1, cleaved caspase-3, and fragmented DNA. SRT1720 also induced mitochondrial outer membrane permeabilization with the generation of mitochondrial reactive oxygen species and autophagy. However, SIRT1 knockdown did not attenuate SRT1720-induced cell death in leukemic cell lines. Finally, SRT1720 treatment decreased the growth of human ATL tumor xenografts in immunodeficient mice. Our study shows that while SRT1720 does not target SIRT1, it induces cell death in ATL cells via apoptosis and autophagy and has antitumor activity.

Serum cystatin C and CRP are early predictive biomarkers for emergence of hypoxia in COVID-19.

BACKGROUND: In Japan, during the coronavirus disease 2019 (COVID-19) pandemic, patients with non-hypoxia are recommended to recuperate at home or in pre-hospital facilities. However, it was observed that unexpected hypoxia may occur and become severe subsequently in patients whose symptoms were initially expected to improve naturally. The aim of this study is to validate biomarkers that can predict at an early stage the emergence of hypoxia in COVID-19 patients without hypoxia. METHODS: We retrospectively enrolled 193 patients with COVID-19, excluding patients with hypoxia and severe disease from the onset. Participants were classified into two groups according to the emergence of hypoxia during the clinical course, and the laboratory data were compared to identify biomarkers that could predict early the emergence of hypoxia. RESULTS: The areas under the curve for serum cystatin C (CysC) and C-reactive protein (CRP) levels for the emergence of hypoxia during the clinical course were higher than those for other biomarkers (CysC, 0.84 and CRP, 0.83). Multivariate analysis showed that high serum CysC and CRP levels were associated with the emergence of hypoxia during the clinical course. CONCLUSIONS: Elevated serum CysC and CRP levels were associated with the emergence of hypoxia during the clinical course in COVID-19 patients without hypoxia. These findings may help determine the need for hospitalization in initially non-hypoxic COVID-19 patients.

Refolding single-chain antibody (scFv) using lauroyl-L-glutamate as a solubilization detergent and arginine as a refolding additive.

Therapeutic potential of immunoconjugates has opened a new window for antibody-based biopharmaceuticals. Greater tissue penetration and hence enhanced cell toxicity are obtained with a smaller version of antibodies. While the whole antibody can be readily produced via mammalian expression system, antibody fragments often require refolding of insoluble proteins. Here we report a new refolding method for antibody fragments using a novel amino acid-based detergent as a solubilizing agent and arginine-assisted refolding. Inclusion bodies of antibody fragments were solubilized by 2.5% lauroyl-L-Glu (C12-L-Glu) and successfully refolded by multi-step dilution into a buffer solution containing arginine hydrochloride and thiol/disulfide-exchange reagents. Adjustment of temperature was found to be critical for increase in the refolding yield. Although each protein requires appropriate optimization, solubilization by C12-L-Glu and dilution refolding assisted by arginine can generate the native, functional antibody fragments. The procedure should enable us to utilize bacterial expression systems for the large-scale manufacturing.

MEP HyperCel chromatography II: binding, washing and elution.

Binding, washing and elution conditions for MEP HyperCel chromatography were examined using two conditioned media (CM) containing monoclonal antibodies (humanized IgG1) and bovine serum albumin (BSA). Monoclonal antibodies derived from mammalian expression system bound to the column without pretreatment, although a majority of contaminating proteins present in the CM also showed binding. Inorganic salts, ethanol and glycerol were ineffective in eluting proteins under the conditions examined, suggesting that electrostatic or hydrophobic interactions are not a major factor for antibody binding to the MEP resin. Ethylene glycol, 2-propanol, urea and arginine were effective, to varying degrees, in elution of the bound proteins. The bound contaminating proteins and BSA were effectively eluted with ethylene glycol and the bound antibodies were finally eluted with aqueous arginine solutions at neutral pH. MEP showed selectivity toward BSA and hence utility for removing BSA from the samples. Interestingly, Fc-fusion proteins derived from silkworm larvae showed no detectable binding. Serum proteins present in silkworm larvae strongly competed with the Fc-fusion proteins and monoclonal antibody for binding to MEP resin, while the same Fc-fusion proteins can be readily purified in one-step by Protein-A resin, again confirming weak selectivity of the MEP resin.

Combination treatment of short-course systemic corticosteroid and favipiravir in a successfully treated case of critically ill COVID-19 pneumonia with COPD.

Use of systemic corticosteroids for the treatment for coronavirus disease 2019 (COVID-19) among chronic obstructive pulmonary disease (COPD) patients is not well described. A 58-year-old man with fever and progressive dyspnea was admitted to the Showa University Hospital, and showed severe respiratory failure which needed mechanical ventilation. His chest computed tomography scanning showed emphysema and bilateral ground-glass opacity caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. He received 30 mg prednisolone for five days with antiviral drug of favipiravir, and was successfully extubated on day five. A SARS-CoV-2 polymerase chain reaction (PCR) test became negative on day 15. He was discharged on day 21. Serum IgM and IgG antibodies against SARS-CoV-2 converted to positive on day 7 and they kept positive on day 54 for both IgM and IgG. Combination treatment of short-course systemic corticosteroid and favipiravir might improve the prognosis for critically ill COVID-19 pneumonia with COPD without negative influence on viral clearance or antibody production.