Binding characteristics of the doxepin E/Z-isomers to the histamine H1 receptor revealed by receptor-bound ligand analysis and molecular dynamics study.

Doxepin is an antihistamine and tricyclic antidepressant that binds to the histamine H1 receptor (H1R) with high affinity. Doxepin is an 85:15 mixture of the E- and Z-isomers. The Z-isomer is well known to be more effective than the E-isomer, whereas based on the crystal structure of the H1R/doxepin complex, the hydroxyl group of Thr1123.37 is close enough to form a hydrogen bond with the oxygen atom of the E-isomer. The detailed binding characteristics and reasons for the differences remain unclear. In this study, we analyzed doxepin isomers bound to the receptor following extraction from a purified H1R protein complexed with doxepin. The ratio of the E- and Z-isomers bound to wild-type (WT) H1R was 55:45, indicating that the Z-isomer was bound to WT H1R with an approximately 5.2-fold higher affinity than the E-isomer. For the T1123.37V mutant, the E/Z ratio was 89:11, indicating that both isomers have similar affinities. Free energy calculations using molecular dynamics (MD) simulations also reproduced the experimental results of the relative binding free energy differences between the isomers for WT and T1123.37V. Furthermore, MD simulations revealed that the hydroxyl group of T1123.37 did not form hydrogen bonds with the E-isomer, but with the adjacent residues in the binding pocket. Analysis of the receptor-bound doxepin and MD simulations suggested that the hydroxyl group of T1123.37 contributes to the formation of a chemical environment in the binding pocket, which is slightly more favorable for the Z-isomer without hydrogen bonding with doxepin.

Sequential therapy of four cycles of bortezomib, melphalan, and prednisolone followed by continuous lenalidomide and dexamethasone for transplant-ineligible newly diagnosed multiple myeloma.

The combinations of melphalan, bortezomib, and prednisolone (VMP) and of lenalidomide and dexamethasone (Rd) are standard treatment strategies for transplant-ineligible newly diagnosed multiple myeloma (NDMM). To make the most of these two strategies, we investigated the efficacy and feasibility of first-line treatment with 4 cycles of VMP followed by continuous Rd therapy in a multi-institutional phase 2 study in Japanese patients with transplant-ineligible NDMM. Thirty-six patients of median age 74 years old with NDMM initially received 35-day cycles of VMP: oral melphalan (6 mg/m2) and prednisolone (60 mg/m2) on days 1 to 4 and bortezomib (1.3 mg/m2) on days 1, 8, 15, and 22. After 4 cycles of VMP, treatment was switched to 28-day cycles of Rd, which was continued until disease progression or emergence of an unacceptable adverse event (AE) in 33 patients, while one patient who achieved CR after VMP continued VMP at the physician's discretion. The overall response rates after VMP and after Rd were 66.7% and 86.1%, including CR rates of 5.6% and 36.1%, respectively. In a median follow-up period of 34.3 months, the progression-free survival and overall survival rates at 3 years were 43.2% and 81.3%, respectively. Grade 3-4 hematological AEs included neutropenia (39% with VMP and 24% with Rd) and thrombocytopenia (11% with VMP and 3% with Rd). There was no death due to an AE. In conclusion, sequential therapy with VMP followed by Rd is effective and mostly feasible for transplant-ineligible NDMM. The study is registered as UMIN000034815.

Detection of hepatitis B virus DNA and HBsAg from postmortem blood and bloodstains.

A large number of accidental virus infections occur in medical and non-medical workers exposed to infectious individuals and materials. We evaluated whether postmortem blood and bloodstains containing hepatitis B virus (HBV) are infectious. HBV-infected blood and bloodstains were stored for up to 60 days at room temperature and subsequently screened for hepatitis B surface antigen (HBsAg) and HBV DNA. In addition, HBV-positive postmortem blood was added to a cell line and the production of HBV virions was examined over a period of 7 days. HBsAg and HBV DNA were detected in all samples stored for 60 days at room temperature. HBV-positive postmortem blood successfully infected the cell line and progeny viruses were produced for up to 6 days. Thus, it is crucial that due care is taken when handling not only living material infected with HBV, as well as other harmful viruses, but also blood or body fluids from cadavers or medical waste.

An adult-onset case of chronic active Epstein-Barr virus infection with fulminant clinical course.

A 56-year-old Japanese male with chronic active Epstein-Barr virus (EBV) infection (CAEBV) who developed systemic gamma-delta T-cell lymphoproliferative disease (LPD) is reported. Although immune cooling therapy was effective, he died of sudden and severe hypoxia and anemia soon after the initiation of cytotoxic chemotherapy that had been previously recommended. There might remain a difficulty to control fulminant adult-onset CAEBV. Additionally, we describe three types of lymphoid cells that were observed in his peripheral blood: morphologically normal lymphocytes, large blastic cells and mature ones with rough granules. Morphological observation appeared to be useful to estimate clinical manifestations. Since CAEBV is extremely rare disease in adult population, it is important to accumulate clinical data to more understand the pathogenesis or to establish treatment strategy.

High-dose chemotherapy with autologous stem cell transplantation for elderly patients with relapsed/refractory diffuse large B cell lymphoma: a nationwide retrospective study.

The number of elderly patients with diffuse large B cell lymphoma (DLBCL) continues to increase but the data regarding autologous stem cell transplantation (ASCT) for elderly patients are limited. We analyzed 484 patients, ages 60 years or over, diagnosed with relapsed/refractory DLBCL who received ASCT from 1993 to 2010 in the Japan Society for Hematopoietic Cell Transplantation database. Median age was 64 years (range, 60 to 78). To evaluate the impact of age at ASCT, patients were classified into 3 groups: those between the ages of 60 to 64, 65 to 69, and 70 years or over. Overall nonrelapse mortality (NRM) at day 100, 1 year, and 2 years was 4.1%, 5.9% and 7.7%, respectively. NRM did not significantly differ among age groups (P = .60). Two-year progression-free survival (PFS) and overall survival (OS) were 48% and 58%, respectively. PFS and OS were significantly longer in patients 60 to 64 years old; however, the survival rate was acceptable even in those 70 or over, with a 2-year OS of 46%. ASCT is feasible in selected elderly patients and age alone should not be a contraindication for ASCT. Eligibility should be individualized and identification of a subset of elderly patients at high risk of treatment-related morbidity or mortality warrants investigation.

Prognostic model for relapsed/refractory transplant-ineligible diffuse large B-cell lymphoma utilizing the lymphocyte-to-monocyte ratio.

We conducted a multi-institutional retrospective study in 100 transplant-ineligible (TI) patients with diffuse large B-cell lymphoma (DLBCL) that relapsed or progressed after first-line R-CHOP (or -like) therapy to develop a robust predictive model for TI relapsed/refractory (r/r) DLBCL, which has a heterogeneous but poor prognosis by currently available treatment modalities other than chimeric antigen receptor T-cell (CAR-T) therapy or bispecific antibodies. The median age at relapse or progression was 76 years. The median progression-free survival (PFS) and overall survival (OS) from the first progression were 11.5 months and 21.9 months, respectively. Multivariate analysis identified low lymphocyte-to-monocyte ratio (LMR), elevated high lactate dehydrogenase, and elevated C-reactive protein at progression as independent predictors of OS. A predictive model based on these three factors, here designated as the Kyoto Prognostic Index for r/r DLBCL (KPI-R), successfully stratified their OS and PFS with statistical significance. In addition, event-free survival less than 24 months for R-CHOP and low LMR were identified as significant predictive factors for non-response in any sequence of salvage therapy. We concluded that LMR is a bonafide predictor of treatment response and prognosis in patients with TI r/r DLBCL, and may be helpful in treatment decision-making.

Clinical impacts of severe thrombocytopenia in the first cycle of azacitidine monotherapy and cytogenetics in patients with myelodysplastic syndrome: The Kyoto Conditional Survival Scoring System.

Azacitidine (AZA) has been one of the standard treatments for transplantation-ineligible patients with myelodysplastic syndrome (MDS); however, hematological toxicities frequently cause treatment interruption in the early phase of the therapy. The present study conducted a multicenter retrospective study to investigate the prognostic impacts of various factors, including factors included in the Revised International Prognostic Scoring System (IPSS-R) and severe cytopenia in the early phase of AZA monotherapy in 212 patients with MDS. Severe cytopenia was evaluated after the initiation of therapy by absolute neutrophil counts on the 29th day after AZA (ANC29) initiation, and red cell concentrates (RCC) and platelet concentrate (PC) transfusion units required within 28 days from the start of AZA, designated in the present study as RCC28 and PC28, respectively. The survival period was determined from the 29th day of AZA treatment to death from any cause as the conditional survival period after the first cycle of AZA (CS-AZA1). Multivariate analysis demonstrated that severe thrombocytopenia defined by >30 units of PC28 and very poor risk cytogenetics according to IPSS-R were independent prognostic factors for CS-AZA1. The Kyoto Conditional Survival Scoring System was subsequently developed by incorporating severe thrombocytopenia defined by PC28 and very poor risk cytogenetics, which successfully stratified the risks of the patients in CS-AZA1. In conclusion, extreme PC transfusion dependency during the first cycle of AZA and very poor risk cytogenetics are important prognostic factors in AZA monotherapy for MDS.

Negative impact of immunoparesis in response to anti-SARS-CoV-2 mRNA vaccination of patients with multiple myeloma.

Multiple myeloma reduces cellular and humoral immunity. Optimal prediction of antibody response to anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with MM and related disorders is essential to prevent coronavirus disease 2019 (COVID-19) during the SARS-CoV-2 pandemic. This study analyzed the humoral response to the anti-SARS-CoV-2 messenger ribonucleic acid (mRNA) vaccine and its associated factor in 83 patients from June to November 2021 at seven member institutions of the Kyoto Clinical Hematology Study Group. SARS-CoV-2 neutralizing antibody (nAb) was measured from 12 to 210 days. The result revealed that 40 (48.2%) patients with MM and 59 (100%) healthy controls became seropositive after vaccination. Receiver operating characteristic curve analysis identified serum immunoglobulin (Ig) M of > 18 mg/dL at vaccination as the optimal threshold level associated with seropositivity in the whole cohort. Moreover, the multivariate analysis identified serum IgM of > 18 mg/dL as the independent predictor for a favorable response. Serum IgA level was positively associated with vaccine response in a sub-cohort. Our findings indicate a significant association between immunoparesis and impaired humoral response against mRNA vaccination, including that against SARS-CoV-2, and that serum non-M-protein Ig levels can serve as surrogate biomarkers of nAb production ability.

Hematopoietic progenitor cell mobilization using low-dose cyclophosphamide and granulocyte colony-stimulating factor for multiple myeloma.

High-dose chemotherapy (HDT) supported by autologous stem cell transplantation (ASCT) has long been one of the standards of care for younger patients with multiple myeloma (MM). Cyclophosphamide (CY) plus granulocyte colony-stimulating factor (G-CSF) has been the conventional preparation for hematopoietic progenitor cell (HPC) mobilization, although the optimal dosage of CY in this setting has not yet been clearly defined. This study investigated the efficacy and safety of low-dose (LD-)CY (1.5 g/m(2)) plus G-CSF for conditioning for HPC apheresis harvest (HPC-A) in 18 MM patients, and compared it with a regimen consisting of intermediate-dose (ID)-CY (4 g/m(2)) plus G-CSF for 13 MM patients. Eleven patients in the former and six in the latter were treated with bortezomib (BTZ) during the induction therapy. Both regimens were comparably effective in terms of CD34(+) cell yields, while adverse events, such as leukopenia, thrombocytopenia, and febrile neutropenia, occurred significantly less frequently in the LD-CY cohort. All patients in LD-CY cohort started and completed their apheresis on day 7 or 8, whereas for the ID-CY cohort the day of first apheresis varied widely from day 8 to 15. These findings indicate that the LD-CY regimen is as effective as ID-CY for HPC mobilization, while the former is clearly more practicable and convenient than the ID-CY regimen for patients with MM.

Genomic adaptation of giant viruses in polar oceans.

Despite being perennially frigid, polar oceans form an ecosystem hosting high and unique biodiversity. Various organisms show different adaptive strategies in this habitat, but how viruses adapt to this environment is largely unknown. Viruses of phyla Nucleocytoviricota and Mirusviricota are groups of eukaryote-infecting large and giant DNA viruses with genomes encoding a variety of functions. Here, by leveraging the Global Ocean Eukaryotic Viral database, we investigate the biogeography and functional repertoire of these viruses at a global scale. We first confirm the existence of an ecological barrier that clearly separates polar and nonpolar viral communities, and then demonstrate that temperature drives dramatic changes in the virus-host network at the polar-nonpolar boundary. Ancestral niche reconstruction suggests that adaptation of these viruses to polar conditions has occurred repeatedly over the course of evolution, with polar-adapted viruses in the modern ocean being scattered across their phylogeny. Numerous viral genes are specifically associated with polar adaptation, although most of their homologues are not identified as polar-adaptive genes in eukaryotes. These results suggest that giant viruses adapt to cold environments by changing their functional repertoire, and this viral evolutionary strategy is distinct from the polar adaptation strategy of their hosts.

Impact of Treatment with Anti-CD20 Monoclonal Antibody on the Production of Neutralizing Antibody Against Anti-SARS-CoV-2 Vaccination in Mature B-Cell Neoplasms.

Background and Purpose: Anti-CD20 monoclonal antibodies (MoAbs), rituximab (RIT), and obinutuzumab (OBZ) are the central components of immunochemotherapy for B-cell lymphoma (BCL). However, these agents potentially cause B-cell depletion, resulting in the impairment of antibody (Ab) production. During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the optimal prediction of Ab response against anti-SARS-CoV-2 vaccination is critically important in patients with BCL treated by B-cell depletion therapeutics to prevent coronavirus disease 2019 (COVID-19). Patients and Methods:  We investigated the effect of using RIT and/or OBZ on the Ab response in 131 patients with various types of BCL who received the second SARS-CoV-2 mRNA vaccine either after, during, or before immunochemotherapy containing B-cell-depleting moiety between June and November 2021 at seven institutes belonging to the Kyoto Clinical Hematology Study Group. The SARS-Cov-2 neutralizing Ab (nAb) was measured from 14 to 207 days after the second vaccination dose using the iFlash3000 automatic analyzer and the iFlash-2019-nCoV Nab kit. Results: Among 86 patients who received the vaccine within 12 months after B-cell depletion therapy, 8 (9.3%) were seropositive. In 30 patients who received the vaccine after 12 months from B-cell depletion therapy, 22 (73%) were seropositive. In 15 patients who were subjected to B-cell depletion therapy after vaccination, 2 (13%) were seropositive. The multivariate analysis indicated that an interval of 12 months between B-cell depletion therapy and the subsequent vaccination was significantly associated with effective Ab production. Receiver operating characteristic curve analysis identified the optimal threshold period after anti-CD20 MoAb treatment, which determines the seropositivity against SARS-CoV-2, to be 342 days. Conclusion: The use of anti-CD20 MoAb within 12 months before vaccination is a critical risk for poor Ab response against anti-SARS-CoV-2 vaccination in patients with BCL.

Predicting global distributions of eukaryotic plankton communities from satellite data.

Satellite remote sensing is a powerful tool to monitor the global dynamics of marine plankton. Previous research has focused on developing models to predict the size or taxonomic groups of phytoplankton. Here, we present an approach to identify community types from a global plankton network that includes phytoplankton and heterotrophic protists and to predict their biogeography using global satellite observations. Six plankton community types were identified from a co-occurrence network inferred using a novel rDNA 18 S V4 planetary-scale eukaryotic metabarcoding dataset. Machine learning techniques were then applied to construct a model that predicted these community types from satellite data. The model showed an overall 67% accuracy in the prediction of the community types. The prediction using 17 satellite-derived parameters showed better performance than that using only temperature and/or the concentration of chlorophyll a. The constructed model predicted the global spatiotemporal distribution of community types over 19 years. The predicted distributions exhibited strong seasonal changes in community types in the subarctic-subtropical boundary regions, which were consistent with previous field observations. The model also identified the long-term trends in the distribution of community types, which suggested responses to ocean warming.

Watchful waiting is an acceptable treatment option for asymptomatic primary ocular adnexal mucosa-associated lymphoid tissue lymphoma: A retrospective study.

BACKGROUND: Primary ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma (POAML) is the most common subtype of indolent ocular adnexal lymphomas. Although radiotherapy (RT) is the standard of care for localized POAML, it can occasionally lead to permanent side effects. Other treatment strategies, such as rituximab (R) monotherapy and immunochemotherapy, have been used for POAML treatment, but their long-term benefits and relative merits remain unclear. While watchful waiting (WW) is a potential option for some indolent lymphomas, the benefits of WW for POAML patients are also unclear. METHODS: We here retrospectively analyzed 75 patients who were diagnosed with POAML between 2008 and 2019 in the institutions of the Kyoto Clinical Hematology Study Group. RESULTS: Commonly involved sites were conjunctiva (42.7%), orbit (36.0%), and lacrimal gland (12.0%), and most patients (92.0%) presented with Ann Arbor stage IE disease. The treatment strategy was selected at the physicians' discretion. More patients without subjective symptoms by tumor mass were subjected to WW (29 patients), while more patients with tumor-derived subjective symptoms were treated by tumor-directed therapy (24 received focal RT, and 19 received R monotherapy). Complete response rates were 79.2% and 42.1% in the RT and R groups, respectively. At 60 months of follow-up, the estimated proportions of POAML patients not requiring new treatment were 69.4%, 85.2%, and 53.8% in the WW, RT, and R groups, respectively. There were no significant differences in the time to start a new treatment between WW and RT groups (median: both not reached [NR], p = 0.187) and between WW and R groups (median: NR vs. 69.0 months, p = 0.554). No specific predictive factor for the future need of treatment was identified in the WW group. CONCLUSION: Our results demonstrate WW may be an acceptable treatment option for POAML, especially for asymptomatic patients.

Real-world practice-based prognostic model for higher-risk myelodysplastic syndromes treated with azacitidine monotherapy: The Kyoto prognostic scoring system.

The prognostic impact of patient-related factors, including age, nutritional parameters, and inflammation status, in higher-risk myelodysplastic syndromes (HR-MDS) has been largely unexplored. This multicenter retrospective study aimed to establish a real-world practice-based prognostic model for HR-MDS by considering both disease- and patient-related parameters in 233 patients treated with AZA monotherapy at seven institutions. We found that anemia, presence of circulating blasts in peripheral blood, low absolute lymphocyte count, low total cholesterol (T-cho) and albumin serum levels, complex karyotype, and del(7q) or - 7 were poor prognostic factors. Therefore, we developed a new prognostic model called the Kyoto Prognostic Scoring System (KPSS) by incorporating the two variables with the highest C-indexes (complex karyotype and serum T-cho level). The KPSS classified patients into the following three groups: good (0 risk factors), intermediate (1), and poor (2). Median overall survival for these groups was 24.4, 11.3, and 6.9, respectively (p < 0.001). The discriminatory power of the KPSS was higher than that of the traditional International Prognostic Scoring System. In conclusion, we identified several nutritional parameters with prognostic relevance in patients with HR-MDS and generated a prognostic model consisting of complex karyotype and serum T-cho level that enabled excellent risk stratification.

Serum Albumin Levels Strongly Predict Survival Outcome of Elderly Patients with Diffuse Large B-Cell Lymphoma Treated with Rituximab-Combined Chemotherapy.

Background: In the current Japanese aging society, a high number of very elderly patients (age ranged from 80 to 93) with diffuse large B-cell lymphoma (DLBCL, most frequent hematological malignancy), who require chemotherapy are encountered. However, standard chemotherapy can result in severe adverse effects in elderly patients. Although various scoring systems are available to assess frailty, they are too complicated to immediately make a therapeutic decision, and studies on indications for chemotherapy in elderly patients are few. Materials and Methods: In the present study, we retrospectively analyzed the clinical records of 56 patients with DLBCL aged 80 or older who received R-CHOP or similar chemotherapy. Association of various clinical parameters, including performance status, stage, B symptom(s), laboratory data and relative dose intensity and survival outcomes was examined. Results: Pretreatment serum albumin level was identified as the only factor that predicts overall and progression-free survivals. Conclusion: We have concluded that very elderly DLBCL patients aged 80 or older with hypoalbuminemia may be unfit for standard chemotherapy, regardless of other factors. Alternative or palliative therapy should be considered for those patients.

Pretreatment serum level of interleukin-6 predicts carfilzomib-induced hypertension in relapsed/refractory multiple myeloma.

Carfilzomib (CFZ) constitutes powerful combinatory therapy for relapsed/refractory multiple myeloma (RRMM); however, cardiovascular adverse events (CVAEs) have been shown as major treatment obstacles with the use of CFZ. Along with our multi-institutional prospective observational study by the Kyoto Clinical Hematology Study Group on the efficacy and safety of CFZ-based treatments (UMIN000025108), we here performed an ad hoc analysis of CFZ-related CVAEs in 50 patients with RRMM. We analyzed the association between CFZ-related CVAEs and pre-planned examinations, including patients' background, electrocardiographic findings, echocardiographic findings, and serum/plasma levels of 18 potential candidate biomarkers. The common CVAEs were hypertension (42%), arrhythmia (14%), and prolongation of QT corrected interval (10%), whereas no serious CVAEs occurred. The pretreatment serum level of interleukin-6 was identified as a significant risk factor for CFZ-related hypertension. This study revealed hypertension as the most frequent CFZ-related CVAE and suggested that baseline serum interleukin-6 is a useful predictor for CFZ-induced hypertension.

Clinical impacts of frailty, poor performance status, and advanced age in carfilzomib-containing treatment for relapsed/refractory multiple myeloma: post hoc investigation of the KOTOSG multicenter pilot prospective observational study.

We conducted a post hoc analysis of our previous pilot observational study on the efficacy and safety of carfilzomib (CFZ)-containing therapy in 50 patients with relapsed/refractory multiple myeloma in routine practice to clarify the relationships between three major criteria for vulnerability (frailty, poor performance status [PS], and advanced age [≥ 75 years]) and their clinical impact on efficacy and adverse events (AEs). Sixteen patients fulfilled at least one and five patients fulfilled all three criteria. The overall response rate was not significantly affected by frailty, poor PS, and/or advanced age; however, frailty and advanced age were significantly associated with shorter progression-free survival (PFS). In contrast, no significant difference in PFS was observed between patients with PS0-1 or PS2-4. The three criteria for vulnerability were associated with more frequent hematologic AEs: frailty, poor PS, and/or advanced age significantly increased the risk of grade 3-4 anemia and lymphopenia. However, these criteria were not associated with increased risk of other non-hematologic AEs except infection. Collectively, these results demonstrate the need to carefully manage severe hematologic AEs in vulnerable patients and perform disease-specific assessment of frailty to predict prognosis.

Prognostic impact of resistance to bortezomib and/or lenalidomide in carfilzomib-based therapies for relapsed/refractory multiple myeloma: The Kyoto Clinical Hematology Study Group, multicenter, pilot, prospective, observational study in Asian patients.

BACKGROUND: Combinatory strategies with carfilzomib (CFZ), a second-generation proteasome inhibitor, plus dexamethasone (DEX) with or without lenalidomide (LEN) have shown promising efficacy for patients with relapsed/refractory multiple myeloma (RRMM) in pivotal clinical trials. However, their effects on patients who were resistance to bortezomib (BTZ) and/or LEN have not been fully evaluated in a daily practice setting. AIMS: To evaluate the real-world efficacy and safety of CFZ-based treatments; that is, CFZ with LEN plus DEX (KRD therapy) and CFZ with DEX (KD therapy), in Asian patients, we conducted a multicenter pilot prospective observational study in the Kyoto Clinical Hematology Study Group. METHODS AND RESULTS: All 50 patients with RRMM enrolled in this study were treated with CFZ-based treatments between 2017 and 2019. KRD and KD were administered to 31 and 19 patients, respectively. The overall response rates (ORRs) were 80.6% with KRD and 73.7% with KD. Two-year progression-free survival (PFS) and overall survival (OS) were 58.5% and 79.7% with KRD, and 23.1% and 52.6% with KD. By multivariate analysis, refractoriness to BTZ and to LEN were identified as independent unfavorable factors for both PFS and OS. The common non-hematologic AEs included hypertension (42.0%), fever (24.0%), fatigue (24.0%), and infection (16.0%). No serious heart failure was observed. This study is registered as UMIN000025108. CONCLUSION: This study suggests the need of the development of novel CFZ-containing strategy which can overcome the refractoriness to BTZ and/or LEN, while both KRD and KD were shown to be mostly feasible in Asian patients in a daily practice setting.

Detection of hepatitis C virus and antibodies in postmortem blood and bloodstains.

To evaluate the risk of accidental hepatitis C virus (HCV) infection, we examined whether anti-HCV antibodies and HCV RNA were detectable in HCV-infected blood samples from living donors, cadavers, and bloodstains. We showed that even after blood has left the body for several days, anti-HCV antibodies and HCV RNA may persist in it.