Preserved SARS-CoV-2 neutralizing IgG activity of in-house manufactured COVID-19 convalescent plasma.

PURPOSE: In the current study, we aimed to evaluate the neutralizing IgG activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as the coagulation factors of convalescent plasmas which we manufactured in-house without a fast-freezing technique. METHODS: We collected plasmas from eligible participants who had confirmed certain titers of neutralizing antibodies. The plasmas were frozen and stored in the ordinary biofreezer without a fast-freezing function. The purified-IgG neutralizing activity of 20 samples from 19 participants and the coagulation factors of 49 samples from 40 participants were evaluated before and after freezing. RESULTS: Purified-IgG maintained its neutralizing activities, with the median 50 % inhibitory concentration (IC50) of 10.11 mg/ml (IQR 6.53-18.19) before freezing and 8.90 m g/ml (IQR 6.92-28.27) after thawing (p = 0.956). On the contrary, fibrinogen and factor Ⅷ decreased significantly after freezing and thawing in our environment. No significant temperature deviation was observed during the storage period. CONCLUSION: Neutralizing IgG activity, which largely contributes to the antiviral activity of convalescent plasma, did not change through our in-house manufacturing, without fastfreezing and storage conditions for more than 200 days. Ordinary freezers without the fast-freezing function are suitable enough to manufacture and store convalescent plasmas. Hospitals or facilities without specified resources could easily collect and store convalescent plasmas in case of upcoming emerging or re-emerging infectious diseases on-demand with appropriate neutralizing antibody levels measurements.

The safety of plasma apheresis from donors recovering from COVID-19 infection in Japan.

PURPOSE: Since 2020, the novel coronavirus infection (COVID-19) has spread globally. A few studies have investigated the safety of COVID-19 convalescent plasma (CCP) apheresis from COVID-19. This study was the first retrospective observational study of CCP in Japan. METHODS: We recruit donors from April 2020 to November 2021 and plasmapheresis in our center (NCGM: national center for global health and medicine). We set the primary endpoint as the Donors Adverse Event (DAE) occurrence at the time of the CCP collection. Variable selection was used to explore the determinants of DAE. RESULTS: Mean and SD age was 50.5 (10.6) years old. Seventy-three (42.2 %) were female, and 87 (33.3 %) were multiple-times donors. Twelve (6.97 % by donors and 4.6 % in total collections) adverse events occurred. The DAEs were VVR (Vaso Vagal Reaction), paresthesia, hypotension, agitation, dizziness, malaise, and hearing impairment/paresthesia. Half of them were VVR during apheresis. DAE occurred only in first-time donors and more in severe illnesses such as using ventilation and ECMO. From the donor characteristics and variable selection, the risk factors are as follows: younger age, female, the severity of disease at the time of the disease, and lower SBP before initiation. Our DAE incidence did not differ from previous studies. DAEs were more likely to occur in CCP apheresis than in healthy donors. CONCLUSION: We confirm the safety of CCP apheresis in this study, although DAEs were more than healthy donors. More caution should be exercised in the plasma collection for future outbreaks of emerging infectious diseases.

Efficacy of convalescent plasma therapy for COVID-19 in Japan: An open-label, randomized, controlled trial.

BACKGROUND: Convalescent plasma is a potential therapeutic option for patients with coronavirus disease 2019 (COVID-19). Despite its use for treating several viral infections, we lack comprehensive data on its efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: We conducted a multicenter, open-label, randomized controlled trial of convalescent plasma therapy with high neutralizing activity against SARS-CoV-2 in high-risk patients within five days after the onset of COVID-19 symptoms. The primary endpoint was the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs from days 0-5. RESULTS: Between February 24, 2021, and November 30, 2021, 25 patients were randomly assigned to either convalescent plasma (n = 14) or standard of care (n = 11) groups. Four patients discontinued their allocated convalescent plasma, and 21 were included in the modified intention-to-treat analysis. The median interval between the symptom onset and plasma administration was 4.5 days (interquartile range, 3-5 days). The primary outcome of the time-weighted average change in the SARS-CoV-2 viral load in nasopharyngeal swabs did not significantly differ between days 0-5 (1.2 log10 copies/mL in the convalescent plasma vs. 1.2 log10 copies/mL in the standard of care (effect estimate, 0.0 [95% confidence interval, -0.8-0.7]; P = 0.94)). No deaths were observed in either group. CONCLUSIONS: The early administration of convalescent plasma with high neutralizing activity did not contribute to a decrease in the viral load within five days compared with the standard of care alone.

Factors associated with high antibody titer following coronavirus disease among 581 convalescent plasma donors: A single-center cross-sectional study in Japan.

INTRODUCTION: The ability to predict which patients with a history of coronavirus disease (COVID-19) will exhibit a high antibody titer is necessary for more efficient screening of potential convalescent plasma donors. We aimed to identify factors associated with a high immunoglobulin G (IgG) titer in Japanese convalescent plasma donors after COVID-19. METHODS: This cross-sectional study included volunteers undergoing screening for convalescent plasma donation after COVID-19. Serum anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S-protein IgG antibodies were measured using a high-sensitivity chemiluminescence enzyme immunoassay. RESULTS: IgG antibodies were measured in 581 patients, 534 of whom had full information of selected independent variables. Multiple linear regression analysis revealed that increasing age (1.037 [1,025, 1.048]), days from symptom onset to sampling (0.997 [0.995, 0.998]), fever (1.664 [1.226, 2.259]), systemic corticosteroid use during SARS-CoV-2 infection (2.382 [1.576, 3.601]), and blood type AB (1.478 [1.032, 2.117]) predict antibody titer. CONCLUSION: Older participants, those who experienced fever during infection, those treated with systemic corticosteroids during infection, those from whom samples were obtained earlier after symptom onset, and those with blood type AB are the best candidates for convalescent plasma donation. Therefore, these factors should be incorporated into the screening criteria for convalescent plasma donation after SARS-CoV-2 infection.

How we secured a COVID-19 convalescent plasma procurement scheme in Japan.

BACKGROUND: In order to tackle the COVID-19 pandemic, a COVID-19 convalescent plasma (CCP) procurement program was initiated in Japan in April 2020. The program was a collaboration between a government-managed national hospital, an infectious disease research institute, and a blood banking organization. Each party assumed different responsibilities: recruitment, SARS-CoV-2 antibody profiling, and plasmapheresis; conduction of screening tests; and SARS-CoV-2 blood testing, respectively. METHODS: We adopted a two-point screening approach before the collected CCP was labeled as a CCP product for investigational use, for which we mainly tested anti-SARS-CoV-2 antibody eligibility and blood product eligibility. Anti-SARS-CoV-2 spike protein titer was measured using enzyme-linked immunosorbent assay, and the IC50 value was denoted as the neutralizing activity. Blood donor eligibility was extended beyond the normal blood donation guidelines to include a broader range of participants. After both eligibility criteria were confirmed, participants were asked to revisit the hospital for blood donation, which is a unique aspect of the Japanese CCP program, as most donations are taking place in normal blood donation venues in other countries. Some donors were re-scheduled for repeat plasma donations. As public interest in anti-SARS-CoV-2 antibodies increased, test results were given to the participants. RESULTS: As of September 17, 2020, our collection of CCP products was sufficient to treat more than 100 patients. As a result, projects for administration and distribution are also being conducted. CONCLUSIONS: We successfully implemented a CCP procurement scheme with the goal to expand to other parts of the country to improve treatment options for COVID-19.

Epidemiology of visceral mycoses in patients with acute leukemia and myelodysplastic syndrome: Analyzing the national autopsy database in Japan.

Visceral mycoses (VM) are a deadly common infection in patients with acute leukemia and myelodysplastic syndrome (MDS). We retrospectively analyzed the data from the centralized "Annual Report of Autopsy Cases in Japan" that archives the national autopsy cases since 1989. Among the total of 175,615 archived autopsy cases, 7183 cases (4.1%) were acute leukemia and MDS patients. While VM was only found in 7756 cases (4.4% in total cases), we found VM had a disproportionally high prevalence among acute leukemia and MDS patients: 1562 VM cases (21.7%) and nearly sixfold higher in prevalence. Aspergillus spp. was the most predominant causative agent (45.0%), and Candida spp. was the second (22.7%) among confirmed single pathogen involved cases. The prevalence of Candida spp. infection decreased about 50% due to the widely use of fluconazole prophylaxis, which may skew toward doubling of the Mucormycetes incidence compared to 30 years ago. Complicated fungal infection (> one pathogen) was 11.0% in acute leukemia and MDS in 2015. It was 14.7 times higher than in other populations. Among 937 patients who received allogeneic hematopoietic cell transplantation (HCT), the prevalence of VM was 28.3% and 23.3% with GVHD. Aspergillus spp. was less prevalent, but Candida spp. was more associated with GVHD. Its prevalence remains stable. Although Aspergillus spp. was the primary causative agent, non-albicans Candida spp. was increasing as a breakthrough infection especially in GVHD cases. Complicated pathogen cases were more common in acute leukemia and MDS.

The influence of pre-admission antiplatelet and anticoagulation therapy on the illness severity in hospitalized patients with COVID-19 in Japan.

INTRODUCTION: Many articles have reported that the coronavirus disease 2019 (COVID-19) causes coagulation abnormalities and pulmonary thrombosis, contributing to a poorer prognosis. The study aimed to evaluate whether pre-admission anticoagulation and antiplatelet therapy prevented severe COVID-19 illness or not. MATERIALS AND METHODS: We conducted a study to determine whether taking antiplatelet or anticoagulation agents before admission affected the severity on admission using a large nationwide cohort of hospitalized COVID-19 patients in Japan. We analyzed a large nationwide cohort of hospitalized COVID-19 patients in Japan from February 9 to July 31, 2020. RESULTS AND CONCLUSION: A total of 4265 patients from 342 facilities in Japan were included. Their use was associated with a slight reduction in the disease severity on admission in a propensity score-matched analysis which controlled for underlying diseases. However, this difference was not statistically significant.

Direct hemoperfusion using a polymyxin B-immobilized polystyrene column for COVID-19.

OBJECTIVE: To evaluate the efficacy and safety of direct hemoperfusion using a polymyxin B-immobilized polystyrene column (PMX-DHP) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive pneumonia patients. METHODS: This study was a case series conducted at a designated infectious diseases hospital. Twelve SARS-CoV-2-positive patients with partial pressure of arterial oxygen/percentage of inspired oxygen (P/F) ratio < 300 were treated with PMX-DHP on two consecutive days each during hospitalization. We defined day 1 as the first day when PMX-DHP was performed. PMX-DHP efficacy was assessed on days 7 and 14 after the first treatment based on eight categories. Subsequently, improvement in P/F ratio and urinary biomarkers on days 4 and 8, malfunctions, and ventilator and extracorporeal membrane oxygenation avoidance rates were also evaluated. RESULTS: On day 14 after the first treatment, disease severity decreased in 58.3% of the patients. P/F ratio increased while urine ß2-microglobulin decreased on days 4 and 8. Cytokine measurement pre- and post-PMX-DHP revealed decreased levels of interleukin-6 and the factors involved in vascular endothelial injury, including vascular endothelial growth factor. Twenty-two PMX-DHPs were performed, of which seven and five PMX-DHPs led to increased inlet pressure and membrane coagulation, respectively. When the membranes coagulated, the circuitry needed to be reconfigured. Circuit problems were usually observed when D-dimer and fibrin degradation product levels were high before PMX-DHP. CONCLUSIONS: Future studies are expected to determine the therapeutic effect of PMX-DHP on COVID-19. Because of the relatively high risk of circuit coagulation, coagulation capacity should be assessed beforehand.

Efficacy of VRD(Bortezomib, Lenalidomide, and Dexamethasone) Consolidation Therapy and Maintenance Therapy with Immunomodulatory Drugs(Thalidomide or Lenalidomide) after Autologous Peripheral Blood Stem Cell Transplantation in the Era of Bortezomib-Containing Induction Therapy-A Single Institution Experience.

Autologous stem cell transplantation(ASCT)for newly-diagnosed multiple myeloma(NDMM)has underwent recent improvements in combination with novel agents-containing induction and post-ASCT therapy. Since the approval of bortezomib for NDMM in Japan, we conducted the following regimen(BD arm)in transplant-eligible patients with NDMM: BD (bortezomib and dexamethasone)induction, ASCT, VRD consolidation, and maintenance therapy with immunomodulatory drugs(IMIDs). The efficacy and safety of the BD arm were compared to those of patients treated with vincristine, doxorubicin, and dexamethasone(VAD)induction followed by ASCT(VAD arm)retrospectively. Thirty-three patients were treated with the BD arm, and 92 patients with the VAD arm. Thirty-one patients in the BD arm proceeded to ASCT. Thereafter, 23 and 17 patients received VRD consolidation and IMIDs maintenance therapy, respectively. The rates of complete response/Bvery good partial response after ASCT, consolidation, and maintenance therapy were 43%/61%, 76%/90% and 87%/93%, respectively. The response rates after ASCT did not differ between BD and VAD arms. The median PFS was 46.2 months(BD arm)and 30.6 months(VAD arm)(HR 0.48[0.27-0.85], p=0.0106). The median OS was not-reached(BD arm)and 90.6 months(VAD arm)(HR 0.21[0.05-0.87], p=0.0172). VRD consolidation and IMIDs maintenance therapies improved disease status after ASCT and prolonged PFS and OS.

The evaluation of Cannabidiol's effect on the immunotherapy of Burkitt lymphoma.

AIM: AF1q has a precise oncogenic function. The purpose of this study is to investigate whether CBD has an effect on the AF1q/ICAM-1 regulatory axis in Burkitt's lymphoma (BL), and thus has potential to enhance immunotherapy and reduce side effects. METHODS: We established BL cell lines with altered AF1q expression using lentivirus. After confirmation of gene expression by RT-PCR, cells were treated with CBD followed by co-culture of killing assay. RESULTS: AF1q increased oncogenic growth and colony formation, and induced resistance against cell-mediated cytotoxic chemotherapy through attenuation of ICAM-1 expression in BL. CBD was able to reverse the acquired resistance mediated by AF1q/ICAM-1 regulatory axis. CONCLUSION: CBD holds potential to enhance the efficacy of immunotherapy for BL with hyperactive AF1q/ICAM-1 regulatory axis, and warrants further study.

[Osteonecrosis developing after rituximab-containing chemotherapy for Waldenström macroglobulinemia].

A 71-year-old woman presented with fever, weight loss, and anemia because of recurrent Waldenström macroglobulinemia (WM) with cryoglobulinemia. Treatment with five cycles of doxorubicin, vincristine, cyclophosphamide, and prednisolone (CHOP) therapy was initiated, which resulted in insufficient improvement in anemia. Hence, a combination of rituximab and CHOP therapy was subsequently initiated. The patient complained of lumbago and lower leg pain on day 4 of the chemoimmunotherapy. X-ray findings for the affected sites were unremarkable, and the patient's symptoms gradually and spontaneously subsided. Rituximab monotherapy was then administered, which resulted in the deterioration of her symptoms. Magnetic resonance imaging revealed osteonecrosis of the bilateral distal ends of the femur, and proximal and distal ends of the tibia. This is the first case of lower leg osteonecrosis complicating chemoimmunotherapy for WM. Osteonecrosis may be an unusual adverse effect of rituximab therapy for WM. Tumor lysis by rituximab may have contributed to the pathogenesis of this complication. MRI assessment should be considered when WM patients complain of bone pain following rituximab-containing chemotherapy.

Infectious diseases in solid organ transplant recipients: Analysis of autopsied cases in Japan.

BACKGROUND: With the improvements in immunosuppressive agents and graft survival, infections such as mycoses have become major complications after solid organ transplantation (SOT). METHODS: Our group has continuously updated an epidemiological database of visceral mycoses (VM) among autopsy cases in Japan since 1989. Data on infectious agents and clinical information were complied using similar procedures. RESULTS: Among the all autopsied cases studied, 356 undergone SOT. Of these, 214 (60.1%) suffered from one or more types of infections, including 51 (14.3%) with VM. Thus, the incidence of VM was higher in SOT recipients than in non-transplanted cases (P < 0.0001). Aspergillus spp. (Asp) was the most predominant agent and Candida spp. was second. Specifically, among SOT recipients, Asp was the most predominant in liver and lung transplant recipients. Among the 217 autopsied liver transplants cases, the incidence of VM was highest in those with fulminant hepatitis (FH, P = 0.01). The incidence of cytomegalovirus infection tended to be higher in cases with mycosis (P = 0.06). Multivariate logistic regression analysis identified FH (odds ratio, 3.61, 95% confidence interval 1.34-9.75; P = 0.03) as an independent risk factor for mycosis in liver transplant recipients. CONCLUSION: This epidemiological analysis of autopsied cases provides a strong incentive to intensify efforts to diagnose and treat post-SOT infectious diseases.

Unfractionated Heparin Safety in COVID-19: Incidence and Risks of Bleeding Complications in Japan.

AIM: Several studies have shown the efficacy and safety of low-molecular-weight heparin use in coronavirus disease 2019 (COVID-19), but that of unfractionated heparin (UFH) has not been investigated. We investigated the prevalence of bleeding complications during UFH administration, its impact on mortality, and the risk factors of bleeding outcomes associated with UFH. METHODS: This retrospective cohort study was conducted at a single-center tertiary care hospital, including hospitalized patients with COVID-19. The primary outcomes were measured as the prevalence of bleeding complications during hospitalization, and the secondary outcomes were thromboembolic events and 60-day mortality rates. Logistic regression analysis and propensity score matching were used to assess risk factors for bleeding complications and their impact on mortality. RESULTS: Among 1035 included patients, 516 patients were treated with UFH. Twelve (2.3%) patients in the UFH group experienced major bleeding. The prevalence of major bleeding in patients treated with therapeutic-dose UFH was 9.2%. Logistic regression analysis showed that age ≥ 60 years (adjusted odds ratio [aOR], 3.89; 95% confidence interval [CI], 1.01-15.0; P＜.05) and COVID-19 severity (aOR, 35.9; 95% CI, 4.57-282; P ＜.05) were associated with major bleeding complications. After propensity score matching, 11 major and 11 non-major bleeding cases (including minor bleeding) were matched. The 60-day cumulative mortality rate between the two groups did not differ significantly (P=.13, log-rank test). CONCLUSIONS: The incidence of major bleeding in COVID-19 patients using therapeutic-dose UFH was relatively high. Critical COVID-19 and older age were risk factors for bleeding complications.

Ets-1 activates overexpression of JunB and CD30 in Hodgkin's lymphoma and anaplastic large-cell lymphoma.

Overexpression of CD30 and JunB is a hallmark of tumor cells in Hodgkin's lymphoma (HL) and anaplastic large-cell lymphoma (ALCL). We reported that CD30-extracellular signal-regulated kinase (ERK)1/2 mitogen-activated protein kinase (MAPK) signaling induces JunB, which maintains constitutive activation of the CD30 promoter. Herein, we localize a cis-acting enhancer in the JunB promoter that is regulated by Ets-1. We show that E26 transformation-specific-1 (Ets-1) (-146 to -137) enhances JunB promoter activation in a manner that is dependent on CD30 or the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-ERK1/2 MAPK pathway. Ets-1 knockdown reduces the expression of both JunB and CD30, and CD30 knockdown significantly reduces JunB expression in HL and ALCL cell lines. NPM-ALK knockdown also reduces JunB expression in ALCL cell lines expressing NPM-ALK. Collectively, these results indicate that CD30 and NPM-ALK cooperate to activate the ERK1/2 MAPK-Ets-1 pathway. Ets-1, constitutively activated by ERK1/2-MAPK, plays a central role in the overexpression of JunB and CD30, which are both involved in the pathogenesis of HL and ALCL.

Epidemiology of visceral mycoses in autopsy cases in Japan: the data from 1989 to 2009 in the Annual of Pathological Autopsy Cases in Japan.

To identify recent trends in the frequency of mycoses in autopsy cases, we analyzed, on a four-year basis, the 1989-2009 data in the Annual of Pathological Autopsy Cases in Japan. Of the 13,787 (9235 males) autopsies conducted in 2009, 4.5% (633/13,787) involved fungal infections and of the latter, 60.3% (368/633) were found to have severe clinical manifestations. Among the 610 (96.4%) cases involving a single etiologic angent, the predominant pathogens were Aspergillus (299 cases; 49%) and Candida (184 cases; 30.2%). However, it should be noted that the prevalence of severe aspergillosis and candidiasis has been decreasing. Although the frequency of cases involving zygomycetes seemed to be generally remaining stable from 1989-2009, we noted for the first time a peak in 2009 in such infections in patients less than one year old. Finally, deep-seated infections caused by unidentified fungi would appear to be decreasing over the time of the survey. Our finding, it is hoped, will encourage physicians to actively pursue viscerial fungal infections.

Lenalidomide-induced acute lung injury in case of multiple myeloma.

OBJECTIVE: Lenalidomide is now widely used for the treatment of multiple myeloma in virtue of its potent anti-tumor activity and low toxicity. Very few reports stressed the association of this drug with serious pulmonary toxicity. Here we present the case of multiple myeloma who underwent acute respiratory failure caused by non-specific interstitial pneumonia after few days of treatment with lenalidomide. CASE SUMMARY: A 50-year-old man diagnosed as multiple myeloma of IgA κ type, International Staging System III received a combination therapy of lenalidomide (15 mg, Day 1 - 21) with dexamethasone (40 mg, Day 1, 8, 15, 22). After 4 days on chemotherapy, he experienced worsened dyspnea and was urgently hospitalized because of acute respiratory failure. Because serial imaging procedures and thorough laboratory workup strongly suggested that his lung injury was caused by drug-induced interstitial pneumonia, lenalidomide, which was the most suspicious drug, was discontinued immediately, and the glucocorticoid pulse was performed. He showed an excellent response to the therapy. Interstitial pneumonia on the CT scan was resolved dramatically at 12 days after the start of the glucocorticoid pulse. CONCLUSION: We are convinced that our case is so instructive as to arouse attention to clinicians that lenalidomide has an extremely rare but potential adverse effect.

A novel protocol for de-isolating moderately and severely immunocompromised COVID-19 patients.

Immunocompromised coronavirus disease 2019 patients are at a higher risk of prolonged viral shedding than immunocompetent patients. However, as of August 2023, there is no clear international standard for de-isolating vulnerable patients. A comprehensive assessment is advisable based on various information, such as the increase in immune escape of specific mutant strains as well as the patient's innate immunity and vaccination status; therefore, consultation with an infectious disease specialist is recommended. The patient population defined as moderately or severely immunocompromised by the Centers for Disease Control and Prevention and the European Centre for Disease Prevention and Control is significantly broad. A boundary between the two remains to be delineated, and the existing protocols allow the release of patients based on their symptoms alone. This may lead to an unnecessary extension or premature termination of isolation. In this study, we searched for studies, particularly those that used real-world data, discussed the results with experts in our hospital, and proposed new isolation criteria based on both testing and clinical symptoms. We classified patients into three groups namely severely, moderately, and mildly immunocompromised, defined by their background and the administration of immunosuppressive drugs. A separate flowchart for ending isolation is indicated for each group. This standard may be a useful support material, especially for non-specialists. Nevertheless, our criteria must be revised and added continuously; accumulating real-world data to support revision of and addition to the list is becoming increasingly important.

Efficacy and Safety of Treatment with Plasma from COVID-19-Recovered Individuals.

Convalescent plasma therapy, which involves administering plasma from recovered coronavirus disease 2019 (COVID-19) patients to infected individuals, is being explored as a potential treatment for severe cases of COVID-19. This study aims to evaluate the efficacy and safety of convalescent plasma therapy in COVID-19 patients with moderate to severe illness. An open-label, single-arm intervention study was conducted without a control group. Plasma collected from recovered COVID-19 patients was administered to eligible participants. The primary endpoint was the proportion of patients who were placed on artificial ventilation or died within 14 days of transfusion. Secondary endpoints included clinical improvement, viral load measurements, and adverse event monitoring. A total of 59 cases were included in the study. The primary endpoint was evaluated by comparing the rate obtained in the study to an existing rate of 25%. The study also assessed clinical improvement, viral load changes, and safety endpoints through adverse event monitoring. Convalescent plasma therapy shows potential as a treatment option for COVID-19. This study aimed to provide evidence for the efficacy and safety of this therapy and may contribute to its future use in treating severe cases of COVID-19.

Trends of participants in convalescent plasma donation for COVID-19 in Japan as the pandemic evolved.

Background: We aimed to investigate chronological changes in the characteristics of participants in a coronavirus disease 2019 convalescent plasma donation study that may benefit optimal collection methods in the future. Methods: Data from a convalescent plasma donation study from April 30, 2020 to November 5, 2021 were collected and analyzed. After August 23, 2021, an interim analysis of factors linked to higher antibody titers led us to restrict our participant recruitment criteria to participants who were within 4 months of disease onset and to patients who were otherwise most likely to have sufficiently high antibody titers. Overall, 1299 samples from 1179 patients were analyzed. Results: Over the duration of the study, 35.9% of the samples were deemed eligible for convalescent plasma collection. The overall eligibility rate initially declined, dipping to <20% after one year. During this period, the proportion of enrolled samples from patients who had severe illness also declined, and the proportion of samples from participants who were >120 days post disease onset increased. After the addition of days from onset and vaccination status to our participant recruitment criteria, the eligibility rate improved significantly. Conclusions: As outbreaks of emerging infectious disease occur, it is desirable to construct and implement a scheme for convalescent plasma donation promptly and to monitor the eligibility rate over time. If it declines, promptly analyze and resolve the associated factors. Additionally, vaccine development and infection prevalence are likely to influence the effective recruitment of participants with high antibody titers.

Association of CD20 levels with clinicopathological parameters and its prognostic significance for patients with DLBCL.

Diffuse large B-cell lymphomas (DLBCL) express CD20. CD20 expression is described as negative, weak, or normal as determined by flow cytometry (FCM) and is an important target for the treatment of DLBCL. However, the impact of CD20 levels at onset of the disease on patient prognosis has not been fully elucidated. We analyzed 174 DLBCL cases newly diagnosed between January 1998 and April 2010. The relationship of the association between CD20 levels and patients' backgrounds and prognoses was analyzed using the Kaplan-Meier method and Cox proportional hazard regression. Of the 174 patients, three cases (1.7%) were defined as CD20 negative based on immunohistochemistry (IHC). Although the other 171 cases were positive by IHC, eight cases (4.7%) were defined as negative and 33 cases (19.3%) were defined as weak when analyzed by FCM. Of the 105 patients who received rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone therapy, those who were CD20 negative (FCM) showed significantly inferior overall (hazard ratios (HR): 6.79, 95% CI: 1.32-34.96, p = 0.04) and progression-free survival (HR: 7.3, 95% CI: 1.49-35.8, p = 0.04) compared to patients who were CD20 normal. Our findings indicate that the CD20 level (FCM) at onset is an independent predictor of the prognosis of patients with DLBCL.