Identification and characterization of a novel α-haemolytic streptococci, Streptococcus parapneumoniae sp. nov., which caused bacteremia with pyelonephritis.

OBJECTIVES: We report a case of bacteremia with pyelonephritis in an adult male with an underlying disease caused by α-hemolytic streptococci. α-Hemolytic streptococci were isolated from blood, but it was challenging to identify its species. This study aimed to characterize the causative bacterium SP4011 and to elucidate its species. METHODS: The whole-genome sequence and biochemical characteristics of SP4011 were determined. Based on the genome sequence, phylogenetic analysis was performed with standard strains of each species of α-hemolytic streptococci. Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values were calculated. RESULTS: SP4011 showed optochin susceptibility and bile solubility, but did not react with pneumococcal omni antiserum. Phylogenetic analysis of the whole-genome sequence showed that SP4011 clustered with S. pneumoniae and S. pseodopneumoniae and was most closely related to S. pseodopneumoniae. Genomic analysis revealed that ANI and dDDH values between SP4011 and S. pseodopneumoniae were 94.0 % and 56.0 %, respectively, and between SP4011 and S. pneumoniae were 93.3 % and 52.2 %, respectively. Biochemical characteristics also showed differences between SP4011 and S. pseodopneumoniae and between SP4011 and S. pneumoniae. These results indicate that SP4011 is a novel species. CONCLUSION: Our findings indicate that SP4011 is a novel species of the genus Streptococcus. SP4011 has biochemical characteristics similar to S. pneumoniae, making it challenging to differentiate and requiring careful clinical diagnosis. This isolate was proposed to be a novel species, Streptococcus parapneumoniae sp. nov. The strain type is SP4011T (= JCM 36068T = KCTC 21228T).

Blood perfusion with polymyxin B immobilized columns in patients with COVID-19 requiring oxygen therapy.

Extracorporeal blood purification with polymyxin B immobilized fiber column direct hemoperfusion (PMX-DHP), is reported to be effective in treating COVID-19 pneumonitis with oxygen demand. This multicenter prospective study evaluated the efficacy and safety of PMX-DHP in oxygen-requiring patients with COVID-19 admitted between September 28, 2020, and March 31, 2022. The primary endpoint was the percentage of clinical improvement 15 days after treatment. The secondary endpoint was the percentage of worsened disease status. Data from the COVID-19 patient registry were used for the synthetic control group. The improvement rate on Day 15 did not differ between PMX-treated patients and controls; however, the deterioration rate was 0.38 times lower in the PMX-treated group, and the death rates on Day 29 were 0 and 11.1% in the PMX-treated and control groups, respectively. The PMX group showed a 0.73 times higher likelihood for reduced intensive care demand, as 16.7% of PMX-treated patients and 22.8% of controls worsened. After treatment blood oxygenation improved, urinary ß2-microglobulin and liver-type fatty acid-binding protein showed significant decreases, and IL-6 decreased once during treatment but did not persist. In this study, PMX treatment effectively prevented the worsening of COVID-19 pathology, accompanied by improved oxygenation. PMX treatment to remove activated cells may effectively improve patient outcomes.

Urinary liver-type fatty acid-binding protein level as a prognostic indicator of acute kidney injury secondary to severe falciparum malaria.

Acute kidney injury (AKI) secondary to severe falciparum malaria possesses a high mortality rate; however, a prognostic marker of renal dysfunction has not yet been identified. Thus, we reported a case of a patient with AKI secondary to falciparum malaria who underwent hemodialysis and a renal biopsy due to prolonged renal dysfunction. The male patient, in his 50 s, presented to our hospital with vomiting, diarrhea, fever, and decreased level of consciousness. The Giemsa-stained peripheral blood film revealed approximately 5% parasitemia, and a rapid diagnostic test was positive for Plasmodium falciparum. He was diagnosed with severe falciparum malaria and was started on quinine hydrochloride. Hemodialysis was initiated due to the decreased urine output and fluid retention. Subsequently, he was weaned off hemodialysis. The histopathological analysis of a renal biopsy revealed interstitial fibrosis, tubular atrophy, and chronic inflammatory cell infiltration; thus, malarial nephropathy was diagnosed. Thereafter, his renal function stabilized, and he was discharged from the hospital. The urinary liver-type fatty acid-binding protein (L-FABP) level decreased before renal function improved. Our report highlighted that long-term follow-up is essential for severe AKI secondary to malaria. The urinary L-FABP level may be a useful prognostic indicator of AKI secondary to severe falciparum malaria.

Pancreaticoduodenectomy after bilirubin adsorption for distal cholangiocarcinoma with severe obstructive jaundice refractory to repeat preoperative endoscopic biliary drainage: a case report.

The necessity of biliary drainage before pancreaticoduodenectomy remains controversial in cases involving malignant obstructive jaundice; however, the benefits of biliary drainage have been reported in cases with severe hyperbilirubinemia. Herein, we present the case of a 61-year-old man suffering from jaundice due to distal cholangiocarcinoma. In this case, obstructive jaundice was refractory to repeat endoscopic drainage and bilirubin adsorption. Hyperbilirubinemia persisted despite successful implementation of biliary endoscopic sphincterotomy and two rounds of plastic stent placements. Stent occlusion and migration were unlikely and oral cholagogues proved ineffective. Owing to the patient's surgical candidacy and his aversion to nasobiliary drainage due to discomfort, bilirubin adsorption was introduced as an alternative therapeutic intervention. Following repeated adsorption sessions, a gradual decline in serum total bilirubin levels was observed and pancreaticoduodenectomy was scheduled. The patient successfully underwent pancreaticoduodenectomy with portal vein resection and reconstruction and D2 lymph node dissection. After the surgery, the serum bilirubin levels gradually decreased and the patient remained alive, with no recurrence at 26 months postoperatively. Therefore, this case highlights the feasibility and safety of performing pancreaticoduodenectomy in patients with severe, refractory jaundice who have not responded to repeated endoscopic interventions and have partially responded to bilirubin adsorption.

A retrospective study describing the effective exchange of total blood plasma for disease control in the exacerbation of serpiginous choroiditis.

INTRODUCTION: Serpiginous choroiditis presents with large yellow-white exudative lesions that occur near the optic nerve papillae, that progresses slowly with repeated relapses and cures. Although infection and autoimmunity have been implicated, the cause is unknown. METHODS: A man was diagnosed with serpiginous choroiditis on clinical and other examinations. He started treatment with oral corticosteroids, cyclophosphamide, adalimumab, azathioprine, rituximab, and mycophenolate mofetil. Only the steroids and cyclophosphamide had a therapeutic effect. Plasma exchange was initiated, and the lesions quickly resolved. RESULTS: Disease control has been maintained by plasma exchange and cyclophosphamide during flare-ups in the fall and winter, suggesting that plasma exchange is effective in the treatment of serpiginous choroiditis. CONCLUSION: The reproducible response with each recurrence suggests a strong association between the disease and autoimmunity. Furthermore, that some, as yet unknown, autoantibodies are involved in the pathogenesis of serpiginous choroiditis.

Urine oxygenation predicts COVID-19 risk.

Since February, 2023, the omicron variant has accounted for essentially all new coronavirus infections in Japan. If future infections involve mutant strains with the same level of infectivity and virulence as omicron, the government's basic policy will be to prevent the spread of infection, without compromising socioeconomic activities. Objectives include protecting pregnant women and elderly persons, and focusing on citizens requiring hospitalization and those at risk of serious illness, without imposing new social restrictions. Although the government tries to raise public awareness through education, most people affected by COVID-19 stay at home, and by the time patients become aware of the seriousness of their disease, it has often reached moderate or higher severity. In this review, we discuss why this situation persists even though the disease seems to have become milder with the shift from the delta variant to omicron. We also propose a pathophysiological method to determine the risk of severe illness. This assessment can be made at home in the early stages of COVID-19 infection, using urine analysis. Applicability of this method to drug discovery and development is also discussed.

A case of rapidly progressive glomerulonephritis with double-positive anti-GBM antibody and MPO-ANCA after SARS-CoV-2 vaccination and relapse during 1 year follow-up.

Although mRNA vaccines for COVID-19 are highly beneficial and are recommended for patients with kidney disease, adverse reactions in some patients after vaccination have been problematic. Various vasculitis and renal disorders have been reported after vaccination; however, a causal relationship has not yet been identified. In this report, we describe a case of rapidly progressive glomerulonephritis that developed after SARS-CoV-2 vaccination, in which both anti-glomerular basement membrane (anti-GBM) and myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) were present. The patient's renal biopsy showed that of the 48 glomeruli in total, four showed global sclerosis and none showed segmental sclerosis. The biopsy showed 11 cellular glomerular crescents and 5 fibrocellular glomerular crescents. Renal function improved with steroids, rituximab, and plasma exchange. Approximately 9 months later, MPO-ANCA was again elevated, and the pulmonary lesions worsened, again requiring multidisciplinary treatment. This case suggests that caution should be exercised in the development of double-positive disease after vaccination, and that long-term observation may be necessary because of the possibility of relapse.

Kidney Biopsy Proven Thrombotic Microangiopathy Induced by Methamphetamine: A Case Report.

A 47-year-old man was admitted to our hospital with acute kidney injury, severe hypertension, heart failure, thrombocytopenia, and elevated lactate dehydrogenase. Renal biopsy revealed fibrin thrombi within the glomerular capillaries and moderate fibrotic intimal thickening in the interlobular arteries. The histological diagnosis was thrombotic microangiopathy (TMA). Regarding cardiac involvement, we found marked stenosis in the left anterior descending artery on coronary angiography and cardiomyopathy on myocardial biopsy. Blood concentrations of amphetamine and methamphetamine were high (14.1 ng/mL and 333 ng/mL, respectively). It is important to consider methamphetamine as a cause of renal TMA and multi-organ dysfunction.

Urinary L-Type Fatty Acid-Binding Protein Predicts Oxygen Demand of COVID-19 in Initially Mild Cases.

Early detection of illness trajectory in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients is crucial for patients and healthcare workers. An effective, noninvasive approach, with simple measurement for decision-making, is necessary in a pandemic to discriminate between high- and low-risk patients, even though both groups may exhibit mild symptoms in the beginning. OBJECTIVES: To predict COVID-19 disease severity within 10 days, distinguishing cases that will progress to moderate or severe versus mild, patient urinary L-type fatty acid-binding protein (L-FABP) was assayed within 4 days of receiving a diagnosis. The study also examined whether L-FABP point of care (POC) test is helpful in risk screening. DESIGN: Symptomatic subjects who tested positive for SARS-CoV-2 and were hospitalized were prospectively enrolled at the National Center for Global Health and Medicine (NCGM), Yamanashi Prefectural Central Hospital (YPCH), and Sinai Hospital in Maryland. The outcome of each case was evaluated 7 days after admission and the diagnostic performance of L-FABP was assessed. SETTING AND PARTICIPANTS: Subjects were treated for COVID-19 at public healthcare centers in Japan from January 31, 2020, to January 31, 2021, to NCGM, YPCH, and at Sinai Hospital in Baltimore, MD, during the same period. MAIN OUTCOMES AND MEASURES: The primary outcome was to determine whether urinary L-FABP within 48 hours of admission can predict the patient's severity of COVID-19 1 week later. We obtained demographic data, information on clinical symptoms, radiographic images, and laboratory data. RESULTS: Diagnostic performance was assessed using receiver operating characteristic analysis. Of the 224 participants in the study, 173 initially had a mild form of COVID-19. The area under the curve (AUC) for a severe outcome was 93.5%. L-FABP POC risk prediction of a severe outcome had an AUC of 88.9%. CONCLUSIONS AND RELEVANCE: Urinary L-FABP can predict patient risk of COVID-19 illness severity. L-FABP POC is implementable for patient management. (ClinicalTrials.gov number, NCT04681040).

The Impact and Treatment of COVID-19 in Hemodialysis Patients.

BACKGROUND: Patients with coronavirus disease 2019 (COVID-19) undergoing maintenance hemodialysis have a poor prognosis and limited treatment options. METHODS: This paper outlines the impact of COVID-19, its treatment, and the efficacy of vaccines in Japanese patients undergoing hemodialysis with a review of the literature. RESULTS: Patients undergoing dialysis in dialysis facilities are at greater risk of exposure to severe acute respiratory syndrome coronavirus 2 than the general population due to limited isolation capabilities. Therefore, vaccines are expected to be effective for patients undergoing dialysis. In addition, effective use of available medications is important because treatment options are limited. CONCLUSIONS: Efforts should be made to prevent the spread of the infection to high-risk patients undergoing dialysis while ensuring the effective use of vaccines.

Pheochromocytoma Crisis Rescued by Veno-Arterial Extracorporeal Membrane Oxygenation and Continuous Renal Replacement Therapy.

Pheochromocytoma is a rare catecholamine producing adrenal tumor. Pheochromocytoma crisis is a life-threatening condition inducing multiple organ failure and hemodynamic instability caused by too much catecholamines produced from pheochromocytoma. We report a 59-year-old woman with pheochromocytoma crisis rescued by veno-arterial extracorporeal membrane oxygenation (VA-ECMO), continuous renal replacement therapy (CRRT), and interval tumor resection. In June 2020, the patient was taken to our institution complaining of headache and left lower back pain. The patient developed cardiopulmonary arrest while at the emergency department. After extracorporeal cardiopulmonary resuscitation, the patient required VA-ECMO for hemodynamic support, and subsequently CRRT for catecholamine removal and acute kidney injury. After 1 month of hemodynamic management, the patient underwent left adrenalectomy. The postoperative course was uneventful and she was discharged on postoperative day 23. CRRT would be a safe and feasible option for catecholamine control in patients with acute kidney injury in pheochromocytoma crisis.

Adjuvant diagnosis of tuberculosis in hemodialysis patients using fourth generation interferon γ releasing assay.

INTRODUCTION: Dialysis patients have a 10-25 times higher risk of reactivation of tuberculosis (TB). In this study, we investigated the diagnostic ability of QuantiFERON (QFT)-plus for TB in hemodialysis patients. QFT-plus, an interferon gamma release assay, is characterized by its use of CD4 and CD8 T cell signals. METHODS: Hemodialysis patients aged 20 years or older who underwent QFT-plus measurement in our hospital were included, inclusion criteria being fever above 37°C, high inflammatory response, and infiltrative pulmonary shadows. RESULTS: Forty-six patients were enrolled. Of these, 15% were QFT positive, 4% were diagnosed with active TB, 76% were QFT negative, 8% had inconclusive results. Sensitivity, specificity, positive predictive value, and negative predictive value were 100%, 87.5%, 28%, and 100%, respectively. CONCLUSIONS: QFT-plus may be useful for the diagnosis of active TB in dialysis patients. Further studies in cohorts with larger sample sizes are expected.

Efficacy and Safety of Direct Hemoperfusion Using Polymyxin B-Immobilized Polystyrene Column for Patients With COVID-19: Protocol for an Exploratory Study.

BACKGROUND: Polymyxin B-immobilized fiber column (PMX; Toraymyxin column) was approved for the relief of systemic inflammatory response syndrome caused by bacterial infection or endotoxemia. PMX reduces lung damage by removing leukocytes and cytokines in addition to endotoxin removal in the setting of idiopathic pulmonary fibrosis. Acute exacerbation of interstitial pneumonia pathologically presents with diffuse alveolar damage (DAD). PMX direct hemoperfusion (PMX-DHP) demonstrated efficacy, improving oxygenation. The SARS-CoV-2 virus causes COVID-19, which emerged in December 2019. The condition may become severe about 1 week after onset, and respiratory failure rapidly develops, requiring intensive care management. A characteristic of COVID-19-related severe pneumonia is ground-glass opacities rapidly progressing in both lungs, which subsequently turn into infiltrative shadows. This condition could be classified as DAD. As for the congealing fibrinogenolysis system, D-dimer, fibrin/fibrinogen degradation product quantity, and prolonged prothrombin time were significant factors in nonsurviving COVID-19 cases, associated with aggravated pneumonia. Clinical trials are being conducted, but except for remdesivir and dexamethasone, no treatments have yet been approved. COVID-19 aggravates with the deterioration of oxygen saturation, decrease in lymphocytes, and the occurrence of an abnormal congealing fibrinogenolysis system, leading to diffuse lung damage. Once the condition transitions from moderate to severe, it is necessary to prevent further exacerbation by providing treatment that will suppress the aforementioned symptoms as soon as possible. OBJECTIVE: This study aims to access treatment options to prevent the transition from acute exacerbation of interstitial pneumonia to DAD. The mechanism of action envisioned for PMX-DHP is to reduce congealing fibrinogenolysis system abnormalities and increase oxygenation by removing activated leukocytes and cytokines, which are risk factors for the aggravation of COVID-19-related pneumonia. METHODS: We will conduct a multicenter, prospective, intervention, single-group study to evaluate the efficacy and safety of direct hemoperfusion using PMX-DHP for patients with COVID-19. Efficacy will be evaluated by the primary end point, which is the rate of Ordinal Scale for Clinical Improvement after PMX-DHP of at least 1 point from a status of 4, 5, or 6 on day 15. The effect of PMX-DHP will be estimated by setting a control group with background factors from non-PMX-DHP patients enrolled in the COVID-19 registry. This study will be carried out as a single-group open-label study and will be compared with a historical control. The historical control will be selected from the COVID-19 registry according to age, gender, and severity of pneumonia. RESULTS: The study period is scheduled from September 28, 2020, through April 30, 2023. Patient enrollment was scheduled from the Japan Registry of Clinical Trials publication for March 31, 2022. Data fixation is scheduled for October 2022, with the publication of the results by March 2023. CONCLUSIONS: From a clinical perspective, PMX-DHP is expected to become an adjunctive therapy to address unmet medical needs and prevent the exacerbation from moderate to severe acute respiratory distress syndrome in COVID-19 cases. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/37426.

Association of intraoperative gross hematuria with acute kidney injury after cytoreductive surgery.

Objectives: Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) has been established in the management of peritoneal carcinomatosis. Although it is still necessary to take adequate measures against major postoperative complications including acute kidney injury (AKI), consensus is lacking on how to assess and stratify risk for patients with postoperative AKI after CRS-HIPEC. The aim of this retrospective cohort study was to investigate the association of intraoperative gross hematuria as a surrogate marker of ureter injury with postoperative AKI incidence. Methods: This retrospective cohort study investigated patients without impaired preoperative kidney function who underwent CRS-HIPEC at a single referral center, and evaluated the relationship between intraoperative gross hematuria and incidence of postoperative AKI as defined by the Kidney Disease Improving Global Outcomes practice guidelines. Logistic regression analysis was performed to calculate the odds ratio of intraoperative gross hematuria for AKI, adjusting for confounding factors and other risk factors for AKI. Results: We enrolled 185 patients (males, 37%). Twenty-five patients developed intraoperative gross hematuria. Postoperative AKI occurred in 10 (40%) of 25 patients with hematuria and 28 (17.5%) of 160 patients without hematuria. The crude odds ratio for exposure to hematuria was 3.14 (95% confidence interval, 1.30-7.60; p=0.020) for postoperative AKI. Adjusted odds ratio as estimated by multivariate logistic regression was 4.57 (95% confidence interval, 1.55-13.45; p=0.006). Conclusions: Intraoperative gross hematuria is significantly associated with postoperative AKI incidence after CRS-HIPEC.

For safe and adequate blood purification therapy in severe COVID-19 ‒ what we have learned so far.

Acute kidney injury (AKI) is defined as an increase in serum creatinine within 48 h or 1 week, or a decrease in urine output within 6-24 h. Continuous renal replacement therapy (CRRT) plays an important role in patients with severe AKI. In addition to direct cytotoxicity caused by the severe acute respiratory syndrome coronavirus 2, patients with coronavirus disease (COVID-19) experience endothelial cell damage, increased thrombogenic inflammation, and impaired immune responses. It has been reported that the more severe the case, the greater overproduction of cytokines and the more advanced the multiorgan failure. The kidney is widely recognized as one of the primary target organs; and COVID-19 positive AKI has been reported to have a greater rate of subsequent decline in renal function than COVID-19 negative AKI. Blood purification therapy has been used to prevent or alleviate organ damage in patients with moderate-to-severe COVID-19. Cytokine regulation is one of the primary therapeutic goals for these patients. Even with the widespread use of vaccines and antibody therapy, a certain percentage of patients develop moderate-to-severe diseases.

A case of COVID-19 reinfection in a hemodialysis patient: the role of antibody in SARS-CoV-2 infection.

Hemodialysis patients are vulnerable to severe and lethal COVID-19, and their protective immunity against COVID-19 is not yet fully understood. Therefore, we report a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and discuss the role of antibodies in SARS-CoV-2 infection. A hemodialysis patient developed asymptomatic COVID-19 due to an outbreak in a hospital on October 29th, 2020. As he was hospitalized and did not develop any symptoms, he was discharged on November 9th. On January 18th, he presented with symptomatic COVID-19 due to close household contact. Then, he developed respiratory failure and was transferred to National Center for Global Health and Medicine if he would need intensive care. He recovered with oxygen inhalation, favipiravir, and steroid treatment, and was discharged on February 12th. To evaluate anti-SARS-CoV-2 antibodies during two hospital stays, we measured immunoglobulin (Ig) G specific for S1 subunit of Spike (S) protein of SARS-CoV-2 (IgG-S1) , IgG specific for the full-length S protein (anti-Spike IgG) and neutralizing antibodies. No seroconversion occurred 5 days after initial infection, the seroconversion of IgG-S1 was observed 10 days after the second infection. Similar to IgG-S1 antibody titer results, anti-Spike IgG and neutralizing antibodies increased from 12 days after the second infection. In conclusion, we experienced a case of COVID-19 reinfection in a hemodialysis patient 81 days after the first episode and showed the kinetics and role of antibodies in SARS-CoV-2 infection. Further studies are needed to understand SARS-CoV-2 reinfection risk in hemodialysis patients and its clinical significance.

Safety of casirivimab/imdevimab administration in a SARS-CoV-2 positive maintenance dialysis patient in Japan.

Controlling excessive cytokine secretion is a crucial therapeutic strategy for managing coronavirus disease 2019 (COVID-19). Patients on dialysis are at a high risk of severe disease, given abnormal immune responses that can lead to prolonged inflammation. Moreover, patients undergoing dialysis have limited treatment options, as neither remdesivir nor baricitinib is available. The novel neutralizing monoclonal antibody cocktail REGEN-COV (formerly known as REGN-COV2; casirivimab/imdevimab), recently approved in Japan, is a promising drug for preventing severe diseases. However, there are few reports regarding its use in patients undergoing dialysis in Japan. Herein, we report the safe use of antibody cocktail therapy in patients with COVID-19 on hemodialysis receiving maintenance dialysis in Japan. Infusion reactions were not observed during administration. Due to the increasing number of patients with COVID-19 and the limited capacity of the healthcare system, antibody cocktail therapy needs to be enhanced. Antibody cocktail therapy for severe diseases can be safely administered to patients undergoing dialysis who do not require supplemental oxygen.

Extracorporeal membrane oxygenation may decrease the plasma concentration of remdesivir in a patient with severe coronavirus disease 2019.

Remdesivir is an antiviral drug that results in clinical improvement after five days of treatment and accelerates recovery by 31%. No studies have discussed the pharmacokinetic analysis of remdesivir in patients with severe COVID-19 requiring extracorporeal membrane oxygenation (ECMO). A 63-year-old American man who underwent mechanical ventilation and ECMO for severe COVID-19 was administered remdesivir for ten days. The loading dosage was 200 mg at 7 PM on day 12 and 100 mg daily at 0:00 PM from day 13-21, administered within 1 h. The pharmacokinetic analysis was performed. The serum creatinine concentration was within the normal range of 0.5-0.7 mg/dL during treatment. According to the pharmacokinetic analysis, the plasma concentrations of remdesivir and GS-441524 4 h after administration (C4) were 662 ng/mL and 58 ng/mL, respectively, and the concentrations 18 h after administration (C18) were 32 ng/mL and 44 ng/mL, respectively. Therefore, the half-life of remdesivir and GS-441524 was 3.2 and 35.1 h, respectively. Monitoring the plasma concentrations of remdesivir and GS-441524 in patients undergoing ECMO may be necessary.

External validation and update of prediction models for unfavorable outcomes in hospitalized patients with COVID-19 in Japan.

INTRODUCTION: Most of the currently used prognostic models for COVID-19 are based on Western cohorts, but it is unknown whether any are applicable to patients with COVID-19 in Japan. METHODS: This retrospective cohort study included 160 patients with COVID-19 who were admitted to the National Center for Global Health and Medicine between January 26, 2020 and July 25, 2020. We searched PubMed for prognostic models for COVID-19. The predicted outcome was initiation of respiratory support or death. Performance of the candidate models was evaluated according to discrimination and calibration. We recalibrated the intercept of each model with our data. We also updated each model by adding ß2-microglobulin (ß2MG) to the model and recalculating the intercept and the coefficient of ß2MG. RESULTS: Mean patient age was 49.8 years, 68% were male, 88.7% were Japanese. The study outcomes occurred in 15 patients, including two deaths. Two-hundred sixty-nine papers were screened, and four candidate prognostic models were assessed. The model of Bartoletti et al. had the highest area under receiver operating characteristic curve (AUC) (0.88; 95% confidence interval 0.81-0.96). All four models overestimated the probability of occurrence of the outcome. None of the four models showed statistically significant improvement in AUCs by adding ß2MG. CONCLUSIONS: Our results suggest that the existing prediction models for COVID-19 overestimate the probability of occurrence of unfavorable outcomes in a Japanese cohort. When applying a prediction model to a different cohort, it is desirable to evaluate its performance according to the prevalent health situation in that region.