Characterization and antiviral susceptibility of SARS-CoV-2 Omicron BA.2.

The recent emergence of SARS-CoV-2 Omicron (B.1.1.529 lineage) variants possessing numerous mutations has raised concerns of decreased effectiveness of current vaccines, therapeutic monoclonal antibodies and antiviral drugs for COVID-19 against these variants1,2. The original Omicron lineage, BA.1, prevailed in many countries, but more recently, BA.2 has become dominant in at least 68 countries3. Here we evaluated the replicative ability and pathogenicity of authentic infectious BA.2 isolates in immunocompetent and human ACE2-expressing mice and hamsters. In contrast to recent data with chimeric, recombinant SARS-CoV-2 strains expressing the spike proteins of BA.1 and BA.2 on an ancestral WK-521 backbone4, we observed similar infectivity and pathogenicity in mice and hamsters for BA.2 and BA.1, and less pathogenicity compared with early SARS-CoV-2 strains. We also observed a marked and significant reduction in the neutralizing activity of plasma from individuals who had recovered from COVID-19 and vaccine recipients against BA.2 compared to ancestral and Delta variant strains. In addition, we found that some therapeutic monoclonal antibodies (REGN10987 plus REGN10933, COV2-2196 plus COV2-2130, and S309) and antiviral drugs (molnupiravir, nirmatrelvir and S-217622) can restrict viral infection in the respiratory organs of BA.2-infected hamsters. These findings suggest that the replication and pathogenicity of BA.2 is similar to that of BA.1 in rodents and that several therapeutic monoclonal antibodies and antiviral compounds are effective against Omicron BA.2 variants.

Real-world clinical characteristics of post-essential thrombocythemia and post-polycythemia vera myelofibrosis.

There are few prospective studies on patients with post-essential thrombocythemia myelofibrosis (PET-MF) and post-polycythemia vera myelofibrosis (PPV-MF). Therefore, we conducted a nationwide longitudinal prospective survey to clarify the clinical characteristics of these diseases. A total of 197 PET-MF and 117 PPV-MF patients diagnosed between 2012 and 2021 were analyzed. The median age at diagnosis was 70.0 years for both diseases. The time from diagnosis of ET or PV to that of MF was 9.6 and 10.4 years, respectively, with no significant difference. Patients with PPV-MF had higher hemoglobin levels and white blood cell counts than those with PET-MF, whereas those with PET-MF had higher platelet counts than those with PPV-MF. Although splenomegaly was more frequent in patients with PPV-MF at diagnosis, there was no difference in the frequency of constitutional symptoms. Ruxolitinib was the most common treatment administered to 74.6% and 83.8% of patients with PET-MF and PPV-MF, respectively. Patients with PET-MF and PPV-MF had similar prognoses, with 3-year overall survival (OS) of 0.742 in PET-MF and 0.768 in PPV-MF patients. In both diseases, leukemic transformation was the leading cause of death, followed by infection. The 3-year OS for patients with PET/PPV-MF and primary MF diagnosed during the same period was 0.754 and 0.626, respectively, with no significant difference. This survey provides real-world clinical features and prognostic data on secondary myelofibrosis in the ruxolitinib era.

Seroprevalence of severe acute respiratory syndrome coronavirus 2 N antibodies between December 2021 and march 2023 in Japan.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in 2019 in China and rapidly spread worldwide, leading to a pandemic. The threat of SARS-CoV-2 is subsiding as most people have acquired sufficient antibodies through vaccination and/or infection to prevent severe COVID-19. After the emergence of the omicron variants, the seroprevalence of antibodies against the N protein elicited by SARS-CoV-2 infection ranged from 44.4% to 80.2% in countries other than Japan. Here, we assessed the seroprevalence in Japan before and after the appearance of omicron variants. Serosurveillance of antibodies against N was conducted between December 2021 and March 2023 in Japan. In total, 7604 and 3354 residual serum or plasma samples were collected in the Tokyo metropolitan area and Sapporo, respectively. We found that the seroprevalence in representative regions of Japan increased approximately 3% to 23% after the emergence of the omicron variants. We also found higher seroprevalence among the young compared with the elderly. Our findings indicate that unlike other countries, most of the Japanese population has not been infected, raising the possibility of future SARS-CoV-2 epidemics in Japan.

[Diffuse large B-cell lymphoma concurrent with Kaposi's sarcoma in the same lymph node in a human immunodeficiency virus-negative patient].

An 80-year-old Japanese man presented with systemic lymphadenopathy, including the para-aortic area and left inguinal nodes, which was diagnosed as diffuse large B-cell lymphoma (DLBCL) and human herpesvirus (HHV) 8-positive/HIV-negative Kaposi's sarcoma (KS). Immunohistochemical examination revealed that the lymphoma cells were negative for HHV-8. The patient received combined chemotherapy with rituximab, pirarubicin, cyclophosphamide, vincristine, and prednisolone for six cycles and achieved complete remission. In the literature, five cases of simultaneous appearance of malignant lymphoma and KS in the same lymph node have been reported, but DLBCL as a histological subtype has not yet been reported.

Mutational analysis of DNMT3A improves the prognostic stratification of patients with acute myeloid leukemia.

Nucleophosmin1 (NPM1) mutations are the most frequently detected gene mutations in acute myeloid leukemia (AML) and are considered a favorable prognostic factor. We retrospectively analyzed the prognosis of 605 Japanese patients with de novo AML, including 174 patients with NPM1-mutated AML. Although patients with NPM1-mutated AML showed a high remission rate, this was not a favorable prognostic factor for overall survival (OS); this is contrary to generally accepted guidelines. Comprehensive gene mutation analysis showed that mutations in codon R882 of DNA methyltransferase 3A (DNMT3AR882 mutations) were a strong predicative factor indicating poor prognosis in all AML (p < 0.0001) and NPM1-mutated AML cases (p = 0.0020). Furthermore, multivariate analysis of all AML cases showed that DNMT3AR882 mutations and the co-occurrence of internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3-ITD), NPM1 mutations, and DNMT3AR882 mutations (triple mutations) were independent factors predicting a poor prognosis related to OS, with NPM1 mutations being an independent factor for a favorable prognosis (hazard ratios: DNMT3AR882 mutations, 1.946; triple mutations, 1.992, NPM1 mutations, 0.548). Considering the effects of DNMT3AR882 mutations and triple mutations on prognosis and according to the classification of NPM1-mutated AML into three risk groups based on DNMT3AR882 /FLT3-ITD genotypes, we achieved the improved stratification of prognosis (p < 0.0001). We showed that DNMT3AR882 mutations are an independent factor for poor prognosis; moreover, when confounding factors that include DNMT3AR882 mutations were excluded, NPM1 mutations were a favorable prognostic factor. This revealed that ethnological prognostic discrepancies in NPM1 mutations might be corrected through prognostic stratification based on the DNMT3A status.

Prevention of pneumocystis pneumonia in patients with hematological diseases: Efficacy of low-dose atovaquone.

OBJECTIVE: At our institution, patients with hematological disease who require Pneumocystis jirovecii pneumonia (PJP) prophylaxis were administered atovaquone at a low dose (750 mg/day). However, there have been few reports on the efficacy of low-dose atovaquone administration, and the purpose of this study is, therefore, to investigate its effectiveness. MATERIALS AND METHODS: We investigated the expression of PJP in patients with hematological disease who received atovaquone administration. Atovaquone was administered at a low dose of 750 mg once daily, and the follow-up time was the period of PJP prophylaxis that included atovaquone administration. RESULTS: 85 patients were included in the study. The median age of the study population was 72 years (range: 33 - 97). The duration of atovaquone treatment and follow-up time were 150 days (22 - 1,018) and 258 days (22 - 1,457), respectively. In hematologic diseases, multiple myeloma was high in 31 patients and malignant lymphoma in 28 patients. No patients exhibited PJP during the observation period. CONCLUSION: In hematological disease patients with relatively low risk of PJP, low-dose atovaquone may prevent the onset of PJP.

[Analysis of anti-SARS-CoV-2 IgG antibody titers after mRNA booster vaccination in patients with nonmalignant hematological disorders].

In our facility, anti-SARS-CoV-2 mRNA vaccines were given to 21 patients, including 8 with aplastic anemia (AA), 3 with pure red cell aplasia (PRCA), and 10 with immune thrombocytopenic purpura (ITP), and IgG antibody titers were assessed one month after vaccinations. After receiving both a second vaccine and a booster shot, all patients with AA/PRCA treated with cyclosporine A aside from one, had IgG titers that were lower than the median levels of healthy controls. Even if prednisolone (PSL) doses did not go over 10 mg/day, ITP patients receiving PSL therapy were unable to achieve adequate levels of IgG after booster immunizations.

[Outcomes of COVID-19 due to omicron variant infection complicated with hematological disorders].

When the omicron variant became the most dominant severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) variant causing coronavirus disease 2019 (COVID-19) in Japan, 11 patients with hematological diseases infected with this new variant were treated at our institution. Among them, four of the five patients who had been treated with chemotherapy progressed to moderate-II COVID-19, and two of them died. In contrast, five of the six patients who did not receive the treatment remained at mild to moderate-I stage of COVID-19, except for a single case progressing to moderate-II COVID-19. While all four patients infused with anti-coronavirus monoclonal antibodies within 8 days after the onset survived, the other two patients, being withheld from treatment or treated later, died. In these two cases, anti-SARS-Cov-2 immunoglobulin G antibodies remained at low titers. Although the omicron variant is considered a less harmful SARS-Cov-2 variant, patients with hematological disorders, particularly those who are immunosuppressed caused by chemotherapy, should be continuously cared for as they remain at a higher risk of severe COVID-19 due to insufficient or delayed anti-viral humoral immunity development. Thus, the rapid introduction of antiviral monoclonal antibodies together with anti-viral reagents may rescue these patients.

Age-Stratified Seroprevalence of SARS-CoV-2 Antibodies before and during the Vaccination Era, Japan, February 2020-March 2022.

Japan has reported a relatively small number of COVID-19 cases. Because not all infected persons receive diagnostic tests for COVID-19, the reported number must be lower than the actual number of infections. We assessed SARS-CoV-2 seroprevalence by analyzing >60,000 samples collected in Japan (Tokyo Metropolitan Area and Hokkaido Prefecture) during February 2020-March 2022. The results showed that ≈3.8% of the population had become seropositive by January 2021. The seroprevalence increased with the administration of vaccinations; however, among the elderly, seroprevalence was not as high as the vaccination rate. Among children, who were not eligible for vaccination, infection was spread during the epidemic waves caused by the SARS-CoV-2 Delta and Omicron variants. Nevertheless, seroprevalence for unvaccinated children <5 years of age was as low as 10% as of March 2022. Our study underscores the low incidence of SARS-CoV-2 infection in Japan and the effects of vaccination on immunity at the population level.

Preceding bortezomib administration for a certain period reduces the risk of lenalidomide-induced skin rash.

WHAT IS KNOWN AND OBJECTIVE: It was previously reported that the incidence of lenalidomide (LEN)-induced skin rash is reduced by administration of bortezomib (BOR) prior to LEN administration in patients with multiple myeloma (MM). Therefore, we investigated whether LEN-induced skin rash is affected by the duration of BOR administration and the dosing interval between BOR and LEN administration. METHOD: A retrospective investigation was conducted among MM patients who received BOR treatment prior to LEN treatment in Eiju General Hospital from May 2010 to December 2020. We investigated whether the BOR administration duration and interval duration from the completion of BOR administration to the initial LEN administration affect the development of LEN-induced skin rash. RESULT AND DISCUSSION: Twenty-eight of the 81 patients exhibited LEN-induced skin rash (34.6%). The administered duration, but not the interval, was significantly longer in the group without skin rash. Cut-off values were set for the duration of administration and interval, which were 35 days and 30 days, respectively. Multivariate analysis was performed on patients which are administered duration of more than 35 days and intervals of less than 30 days, and those who are not applicable. A significant difference was observed in the incidence of skin rash for each factor. WHAT IS NEW AND CONCLUSION: The risk of reduced LEN-induced skin rash is affected not only by the presence of prior BOR administration, but also by the duration of BOR and the interval from the completion of BOR to the initial LEN administration.

[Rapid response of secondary plasma cell leukemia after carfilzomib and dexamethasone therapy].

An 83-year-old man was admitted to our hospital due to a recurrence of multiple myeloma, accompanied by the appearance of plasma cells in the peripheral blood (PB). Subsequently, he was diagnosed with secondary plasma cell leukemia (sPCL). A chemotherapy regimen of carfilzomib and dexamethasone (Cd) combination therapy was selected, and 15 days later, plasma cells completely disappeared from the PB. Cd therapy was continued, and the free kappa chain levels normalized. Three months later, M-protein could not be detected using serum electrophoresis. This is a valuable report wherein Cd combination therapy was successful in treating sPCL.

[Complete response with tirabrutinib for relapsed and refractory Bing-Neel syndrome].

A 62-year-old female patient was diagnosed with Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL) 8 years ago, which was resolved with rituximab (R) monotherapy. Five years ago, she experienced numbness of the lower limbs, followed by diminished lower limb muscle strength and hearing disturbance. PET-CT scans showed accumulations along the peripheral nerves of the upper and lower limbs together with clonal B lymphocytes in the cerebrospinal fluid, thus a diagnosis of relapse with Bing-Neel syndrome (BNS). After a temporal remission by high-dose cytarabine or bendamustine plus R regimens as salvage treatments, WM/LPL recurred for the third time accompanied by gait disturbances due to muscle weakness and urinary retention. Thus, tirabrultinib was started as a subsequent therapy, which significantly improved the neurological condition together with abnormal findings of magnetic resonance imaging or cerebrospinal fluids. This case is valuable since few relapsed BNS was reported in the literature with successful tirabrutinib treatment.

[SARS-CoV2 anti-spike IgG response following COVID-19 mRNA vaccination (BNT162b2) in patients with hematological disorders].

This is a prospective study conducted to determine the level of anti-spike IgG to SARS-CoV-2 2-6 weeks following the BNT162b2 vaccination in 125 patients with hematological disorders. Compared with healthy controls, patients with malignant lymphoma had lower rates of seropositivity and lower levels of antibody titer. Furthermore, patients who received rituximab (R)-containing chemotherapy had lower antibody titers than those who were not treated with R or who had completed R-containing chemotherapy more than 9 months earlier. Despite having 71% IgG-seropositivity, patients with multiple myeloma had lower antibody titers than the control group. Furthermore, patients receiving daratumumab-containing chemotherapy had lower antibody titers than those not receiving treatment. Moreover, patients with acute myeloid leukemia or myelodysplastic syndrome had lower antibody titers than the control group. Overall, the number of peripheral blood lymphocytes was significantly correlated with IgG titers, with seropositive patients having more peripheral blood lymphocytes than seronegative patients. Patients with severe immunosuppression, such as those with hematological disorders, often have impaired seroconversion with COVID-19 vaccination that should be taken into consideration by clinicians.

[Novel germline SAMD9 mutation in an elderly patient with myelodysplastic syndrome].

An 80-year-old Japanese male patient presented to our hospital with complaints of fatigue. His peripheral blood tests revealed pancytopenia with predominant lymphocytes and without blasts. The bone marrow (BM) aspiration was unsuccessful due to a dry tap, and the subsequent BM biopsy revealed hypocellular marrow with fibrosis. He was diagnosed with myelodysplastic syndrome (MDS) with excess blasts (EB)-2 based on CD34-positive cells. The chromosome analysis of the BM revealed monosomy 7, and the SAMD9 W22* mutation was detected (variant allele frequency [VAF] of 51.22%) using next-generation sequencing. An identical mutation was observed in the buccal mucosa (VAF of 50%), which was confirmed as a germline mutation. The SAMD9 gene mutation is reported as one of the causative genes for MIRAGE syndrome and child-onset MDS. The present case was considered a loss-of-function mutation due to the near full-length SAMD9 deletion. This is the first adult case of MDS with SAMD9 W22* as a germline mutation.

Phase II clinical trial of personalized VCD-VTD sequential therapy using the Vulnerable Elders Survey-13 (VES-13) for transplant-ineligible patients with newly diagnosed multiple myeloma.

The Vulnerable Elders Survey-13 (VES-13) is a well-studied simplified frailty screening tool for elderly patients in the oncology setting. We conducted a prospective clinical trial to evaluate the efficacy and safety of dose-adjusted treatment based on the VES-13 in transplant-ineligible patients with newly diagnosed multiple myeloma (MM). In the Fit group (VES-13 <3), patients were treated with 4 cycles of standard-dose VCD (bortezomib, cyclophosphamide, and dexamethasone) followed by 4 cycles of standard-dose VTD (bortezomib, thalidomide, and dexamethasone). In the Frail group (VES-13 ≥3), patients were treated with 4 cycles of reduced-dose VCD followed by 4 cycles of reduced-dose VTD. The median age was 75 years (66-86 years), and 34% of the cases were classified as PS 3. Among the Fit group (n=16), the overall response rate (ORR) was 87.5%. Among the Frail group (n=31), the ORR was 87.1%. There were no significant differences in progression-free survival (PFS) and overall survival (OS) between the Fit and Frail groups (3-year PFS: 68.8% vs 53.3%, P = 0.658; 3-year OS: 70.0% vs 77.6%, P = 0.919). Personalized VCD-VTD sequential therapy based on the VES-13 was associated with high response rates and showed acceptable safety in elderly frail patients with MM. The study is registered as UMIN000011235.

Simple desensitization protocol for multiple myeloma patients with lenalidomide-induced skin rash: Case series.

WHAT IS KNOWN AND OBJECTIVE: Skin rash is one of the typical side effects of lenalidomide (LEN) treatment. Desensitization therapies have been reported to be effective in patients with severe skin rash caused by LEN. However, they have proved impractical due to the complexity of the protocols. CASE SUMMARIES: We present 5 patients who developed severe LEN-induced skin rash. The five patients received our simple, slow desensitization protocol, and all were re-administered LEN with no adverse reaction. WHAT IS NEW AND CONCLUSION: Our simpler and slow desensitization protocol, which desensitizes the patients without reducing the effect of LEN, includes drug holidays, similar to the usual LEN dosing schedule, and moreover is recommended as a treatment option especially for elderly patients with no housemate to help with medical management.

Determination of the concentration of gilteritinib in human plasma using HPLC.

Gilteritinib, an oral inhibitor of FMS-like tyrosine kinase 3 (FLT3), is a standard treatment for FLT3-mutated acute myeloid leukemia. We developed a simple HPLC-UV-based method for determining the concentration of gilteritinib in human plasma. The analysis requires the extraction of a 200-µL plasma sample and the precipitation of proteins by solid-phase extraction. Gilteritinib was isocratically separated within 10 min using a mobile phase of acetonitrile:0.5% monopotassium phosphate (KH2 PO4 , pH 3.5, 28:72, v/v) on a Capcell Pack C18 MG II (250 × 4.6 mm) column at a flow rate of 1.0 mL/min and monitored at 250 nm. The calibration curve was found to be linear within a plasma concentration range of 25-2500 ng/mL, with the coefficient of determination (r2 ) being 0.9997. The coefficients of intra-day and inter-day validation were 2.3-3.7 and 1.3-5.2%, respectively. The accuracy and recovery of the assay were -9.6 to 0.1 and >81.8%, respectively. This HPLC-UV method for determining the plasma concentration of gilteritinib is simple and can be effectively applied to routine drug monitoring.

[Practical guidance for the management of patients with hematological disorders during the coronavirus disease 2019 pandemic in Japan].

During the nosocomial coronavirus disease 2019 (COVID-19) outbreak, patients with hematological disorders showed poorer survival and aggressive course of respiratory failure than patients with other disorders. Two patients with immune thrombocytopenia who were being treated with prednisolone experienced severe respiratory failure related to COVID-19 and finally died. Patients who were yet to achieve remission and those receiving chemotherapy with steroids had a higher risk of death, and the mortality rate was higher in patients with lymphoid malignancies, including lymphoma and myeloma, than in those with myeloid malignancies. We describe the case of a myeloma patient in whom high-dose steroid administration was able to achieve considerable resolution of respiratory failure. In patients with unsuccessful seroconversion of anti-SARS-CoV-2 IgG antibodies, recurrence or re-infection of COVID-19 should be closely monitored.

[Practical management of the patients with hematological diseases during the COVID-19 pandemic in Japan].

PCR assay cannot always detect the SARS-CoV2 virus, which might be due to differences in the sensitivities of each sampling site. Under these circumstances, immunochromatography may serve as an alternative method to detect anti-SARS-CoV-2 IgG antibodies that can demonstrate a history of infection. In patients with severe COVID-19 infection, 14 of 19 serum samples were shown to be positive, whereas 6 of 10 samples from patients with asymptomatic or mild cases were negative for IgG antibodies. Two patients with immune thrombocytopenia, who were treated with prednisolone, experienced aggressive behavior of COVID-19-related respiratory failure and eventually died. Patients who were before an achievement of remission and those who received steroid-based chemotherapy possessed a higher risk of death, and more deaths were observed in patients with lymphoid malignancies including lymphoma and myeloma compared with those with myeloid malignancies. As for daily medical care in hematological department, a stricter cohorting strategy using repeat PCR tests or isolation to a private room should be adopted in order to prevent viral spread to the environment.

[Severe thrombocytopenia after COVID-19 mRNA vaccination].

The Japanese Society of Hematology recently published on acute exacerbation of immune-mediated thrombocytopenia (ITP) after mRNA-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. In addition, there is a growing concern for the development of the newly diagnosed ITP after SARS-CoV-2 vaccination. Herein, we report two cases of severe thrombocytopenia associated with bleeding tendencies at 4 and 14 days after BNT162b2 mRNA vaccination. Platelet counts returned to normal following platelet transfusion or treatment with intravenous immunoglobulin and dexamethasone. To our knowledge at the time of the draft of this manuscript, nine cases of SARS-CoV-2 vaccine-induced ITP have been reported. Although most patients showed favorable clinical courses similar to that of our cases, critical thrombocytopenia can lead to unfavorable outcomes. A national survey may be required to examine the causal relationship between SARS-CoV-2 vaccination and the emergence of the newly diagnosed ITP and clinical outcomes of vaccine-induced thrombocytopenia.