Ultrasensitive malaria detection system for Anopheles mosquito field surveillance using droplet digital PCR.

Malaria remains a significant global public health concern, with a recent increase in the number of zoonotic malaria cases in Southeast Asian countries. However, limited reports on the vector for zoonotic malaria exist owing to difficulties in detecting parasite DNA in Anopheles mosquito vectors. Herein, we demonstrate for the first time that several Anopheles mosquitoes contain simian malaria parasite DNA using droplet digital PCR (ddPCR), a highly sensitive PCR method. An entomological survey was conducted to identify simian malaria vector species at Phra Phothisat Temple (PPT), central Thailand, recognized for a high prevalence of simian malaria in wild cynomolgus macaques. A total of 152 mosquitoes from six anopheline species were collected and first analyzed by a standard 18S rRNA nested-PCR analysis for malaria parasite which yielded negative results in all collected mosquitoes. Later, ddPCR was used and could detect simian malaria parasite DNA, i.e. Plasmodium cynomolgi, in 25 collected mosquitoes. And this is the first report of simian malaria parasite DNA detection in Anopheles sawadwongporni. This finding proves that ddPCR is a powerful tool for detecting simian malarial parasite DNA in Anopheles mosquitoes and can expand our understanding of the zoonotic potential of malaria transmission between monkeys and humans.

Clinical factors for central nervous system progression and survival in primary vitreoretinal lymphoma.

Primary vitreoretinal lymphoma (PVRL) is a rare subtype of malignant lymphoma with a poor prognosis because of high frequency of central nervous system (CNS) progression. Identification of factors associated with CNS progression is essential to improve the prognosis of patients with PVRL. We conducted a retrospective study of 54 patients diagnosed with PVRL and treated at our hospital to identify factors associated with CNS progression and prognosis. All patients were treated with intravitreal methotrexate (MTX) injections in the affected eyes until lesion resolution. Twenty-four patients were treated with systemic administration of high-dose MTX (systemic HD-MTX) every other week for a total of five cycles following intravitreal MTX injection. Of 24 patients, 20 completed five cycles of systemic HD-MTX. The 5-year cumulative incidence of CNS progression and overall survival (OS) rate were 78.0% and 69.0% respectively. By univariate and multivariate analyses, bilateral disease and the detection of B-cell clonality confirmed by flow cytometric analysis were risk factors associated with CNS progression. Moreover, systemic HD-MTX completion reduced the risk of CNS progression and was identified as a factor affecting OS. In this study, factors for CNS progression identified may potentially contribute to the optimized therapeutic stratification to improve the survival of patients with PVRL.

[Diagnosis and management of EBV-positive lymphoproliferative disorders].

Epstein-Barr virus (EBV) has the ability to immortalize not only B cells but also T and natural killer (NK) cells. The virus may also contribute to the onset of EBV-positive lymphoproliferative disorders (EBV-LPDs) by inducing the introduction of gene mutations. It is known that B cell EBV-LPDs (B-EBV-LPDs) develop with preexisting immunodeficiency, but the onset mechanism of T cell and NK cell EBV-LPDs (T-EBV-LPDs and NK-EBV-LPDs), also known as chronic active EBV disease and associated diseases, is unclear. The diagnosis of both EBV-LPDs requires the quantitative examination of EBV-DNA in the peripheral blood. Eliminating the cause of immunodeficiency or administering rituximab is effective in treating B-EBV-LPDs, but some B-EBV-LPDs and T-EBV-LPDs/NK-EBV-LPDs are resistant to pharmacotherapy. Therefore, further research is needed to explicate the pathophysiology of EBV-LPDs and develop a drug for its treatment.

Updated guidelines for chronic active Epstein-Barr virus disease.

Chronic active Epstein-Barr virus disease (CAEBV), formerly named chronic active Epstein-Barr virus infection, is characterized by systemic inflammation and clonal proliferation of Epstein-Barr virus (EBV)-infected T or NK cells. As CAEBV is a potentially life-threatening illness, appropriate diagnosis and therapeutic interventions are necessary for favorable clinical outcomes. Substantial evidence regarding the pathogenesis and treatment of CAEBV has been accumulated since previous guidelines for the diagnosis of CAEBV were proposed. To reflect this evidence, we updated the guidelines for the diagnosis and treatment of CAEBV to improve clinical management of the disease. The details of the updated guidelines are presented in this report. Diagnosis of CAEBV now requires confirmation of a high copy number of EBV genome and EBV-infected T or NK cells. An EBV DNA load ≥ 10,000 IU/mL in whole blood is proposed as the diagnostic cutoff value for CAEBV in this updated guideline. A standard treatment approach for CAEBV has not been established, and hematopoietic stem cell transplantation (HSCT) is considered the only curative treatment. Chemotherapy can be administered to control disease activity before HSCT.

Leukemic-phase mucosa-associated lymphoid tissue lymphoma.

A 78-year-old man presenting with leukocytosis was admitted to our hospital. The patient was asymptomatic and showed no lymphadenopathy. Peripheral blood flow cytometry revealed a leukemic-phase B-cell lymphoma with medium-to-large abnormal cells with reticulum. Positron emission tomography/computed tomography revealed abnormal uptake in the right orbit, bone marrow, and spleen. We performed immunological staining and fluorescence in situ hybridization on tissues extracted from the right orbit and bone marrow, which led to the diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma. Polymerase chain reaction analysis of immunoglobulin heavy chain rearrangements in the right orbital mass and bone marrow suggested that they were identical clones. Based on these collective findings, the diagnosis of leukemic-phase MALT lymphoma was confirmed, with sites of involvement including the bone marrow, peripheral blood, right orbit, and spleen. This is a highly rare case of leukemic MALT lymphoma.

Aortitis after administration of pegfilgrastim to a healthy donor for peripheral blood stem cell collection.

A 45-year-old man who was a sibling donor for allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was administered 7.2 mg of pegfilgrastim for stem cell collection. Peripheral blood stem cells were collected 4 days after administration of pegfilgrastim (Day 4) and 4.32 × 106 /kg of CD34-positive cells per recipient body weight were obtained. Fever of 38 ℃ or higher and left submandibular pain appeared on Day 6. Ultrasonography and contrast-enhanced computed tomography (CT) showed wall thickening of the carotid artery and the abdominal aorta. We carefully excluded the possibilities of cardiovascular and autoimmune diseases by thorough examination, and ultimately diagnosed pegfilgrastim-induced aortitis. The patient's fever resolved rapidly after treatment with prednisolone (PSL) 1 mg/kg. We began to taper PSL after eight days. Sixty-one days after starting PSL, we confirmed that abdominal aortic wall thickening had improved by contrast-enhanced CT. We continued to taper off PSL and stopped 141 days later with no relapse thereafter. This is the first case report of pegfilgrastim-induced aortitis in an allo-PBSCT donor. Careful monitoring is warranted when administering pegfilgrastim to donors even without past medical history.

Diagnostic and disease severity determination criteria for hydroa vacciniforme lymphoproliferative disorders and severe mosquito bite allergy.

Hydroa vacciniforme lymphoproliferative disorder (HV-LPD) and severe mosquito bite allergy (SMBA) are both cutaneous forms of Epstein-Barr virus (EBV)-associated T/natural killer (NK) cell LPDs and are closely related to chronic active EBV disease (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). HV-LPD is further divided into classic HV, a benign subtype mediated by EBV-positive γδT cells, and systemic HV, another life-threatening subtype mainly associated with EBV-positive αßT or γδT cells. The vast majority of patients with SMBA have increased numbers of EBV-infected NK cells in the blood. Clinical symptoms of HV-LPD and SMBA often overlap in the same patient and may progress to more serious disease conditions equivalent to the systemic form of CAEBV. To define the disease spectrum of HV-LPD and SMBA, we propose the diagnostic criteria and the determination criteria for disease severity. The proposed diagnostic criteria are consistent with those for CAEBV and EBV-HLH in the guidelines for the management for CAEBV and related disorders 2023.

Clinical significance of anti-Epstein-Barr virus antibodies in systemic chronic active Epstein-Barr virus disease.

Systemic chronic active Epstein-Barr virus disease (sCAEBV) is a rare and fatal neoplasm, involving clonally proliferating Epstein-Barr virus (EBV)-infected T cells or natural killer cells. Patients with sCAEBV have abnormal titers of anti-EBV antibodies in their peripheral blood, but their significance is unknown. We retrospectively investigated titers and their relationship with the clinical features of sCAEBV using the data collected by the Japanese nationwide survey. Eighty-four patients with sCAEBV were analyzed. The anti-EBV nuclear antigen (EBNA) antibody, targeting EBNA-expressing EBV-positive cells, was found in 87.5% of children (<15 years old), 73.7% of adolescents and young adults (15-39 years old), and 100% of adults (≥40 years old). Anti-EBNA antibody titers were significantly lower and anti-VCA-IgG antibody titers significantly higher in patients with sCAEBV than those in healthy controls (p < 0.0001). Patients with high anti-VCA-IgG and anti-early antigen-IgG antibody (antibodies against the viral particles) levels had significantly better 3-year overall survival rates than those with low titers, suggesting that patients with sCAEBV have a reduced immune response to EBV-infected cells.

Quantitative evaluation of treatment response to lenalidomide by applying fluorescence in situ hybridization for peripheral blood granulocytes in a patient with 5q- syndrome.

The introduction of lenalidomide has significantly improved clinical outcomes in myelodysplastic syndrome (MDS) with isolated interstitial deletion of the long arm of chromosome 5 (del(5q)) (5q- syndrome). These days, MDS with isolated del(5q) includes cases with one additional chromosome abnormality other than monosomy 7 or del(7q), and so we need a better way to monitor tumor cells in each patient than the clinical parameters used to date. An 82-year-old woman with MDS with isolated del(5q) was treated with lenalidomide daily for 21 days in a 4-week cycle. Fluorescence in situ hybridization with CSF1R located at 5q was applied to the peripheral blood samples. Because mature lymphocytes are not involved in the MDS clone, based on the nuclear morphology, polymorphonuclear cells (PMNs) and round-shaped nuclear cells (RSNs) were separately evaluated during treatment. After a single course of treatment, the number of PMNs with del(5q) decreased; by the end of the second course of treatment, both PMNs and RSNs with del(5q) had disappeared. The dynamics of 5q- PMNs is a simple but rapid and reliable indicator to confirm the effect of lenalidomide in MDS with del(5q).

The Plasma Level of Interleukin-1ß Can Be a Biomarker of Angiopathy in Systemic Chronic Active Epstein-Barr Virus Infection.

Systemic chronic active Epstein-Barr virus infection (sCAEBV) is an EBV-positive T- or NK-cell neoplasm revealing persistent systemic inflammation. Twenty-five percent of sCAEBV patients accompany angiopathy. It is crucial to clarify the mechanisms of angiopathy development in sCAEBV because angiopathy is one of the main causes of death. Interleukin-1ß (IL-1ß) is reported to be involved in angiopathy onset. We investigated if IL-1ß plays a role as the inducer of angiopathy of sCAEBV. We detected elevated IL-1ß levels in four out of 17 sCAEBV patient's plasma. Interestingly, three out of the four had clinically associated angiopathy. None of the other patients with undetectable level of IL-1ß had angiopathy. In all patients with high plasma levels of IL-1ß and vascular lesions, EBV-infected cells were CD4-positive T cells. In one patient with high plasma IL-1ß, the level of IL-1ß mRNA of the monocytes was 17.2 times higher than the level of the same patient's EBV-infected cells in peripheral blood. In Ea.hy926 cells, which are the models of vascular endothelial cells, IL-1ß inhibited the proliferation and induced the surface coagulation activity. IL-1ß is a potent biomarker and a potent therapeutic target to treat sCAEBV accompanying angiopathy.

Registry data analysis of hematopoietic stem cell transplantation on systemic chronic active Epstein-Barr virus infection patients in Japan.

The effects of allogeneic hematopoietic stem cell transplantation (allo-HSCT) on systemic chronic active Epstein-Barr virus infection (sCAEBV) are yet to be analyzed in a large number of patients. Using the Japanese registry database, Transplant Registry Unification Management Program, we investigated the outcomes of 102 sCAEBV patients who underwent allo-HSCT. The median age at HSCT was 21 years, and the three-year overall survival (3-year OS) rate was 72.5%. Of the 90 patients whose viral load after allo-HSCT was evaluated, 56 (62.2%) achieved a virological complete response, defined by the complete resolution of disease activity with a significant decrease in EBV-DNA in peripheral blood. The multivariate Cox proportional hazard model indicated that advanced age, in adolescents and young adults (AYA) (age, 15-39) and adults (age, ≥40 years) was a risk factor of poor OS. The hazard ratios (HRs) of the AYA and adult groups were 10.87 (95% confidence interval [CI]: 1.98-59.56, p = .006) and 15.93 (95% CI: 2.45-103.8, p = .004), respectively. Disease activity (HR 5.74), elevated soluble IL-2 receptor (sIL-2R) (≥ median, 691 U/mL) at HSCT (HR 6.93), and conditioning without radiotherapy (HR 3.53) were also independently associated with poor survival. Notably, 79% of radiotherapy doses were less than 6 Gy. Regardless of the presence of hemophagocytic lymphohistiocytosis, the group with a high sIL-2R level (≥2000 U/mL) showed a poorer prognosis. Although allo-HSCT is the only curative therapy for sCAEBV, treatment strategies need to be improved for high-risk patients, especially those with high levels of sIL-2R.

[Haploidentical stem cell transplantation for acute myeloid leukemia associated with adult-onset Shwachman-Diamond syndrome].

A 21-year-old man presented with bone marrow failure, short stature, fatty degeneration of the pancreas on CT images, and Shwachman-Bodian-Diamond syndrome (SBDS) gene abnormalities (exon 2: c.258+2T>C and deletion of exon 3). Thus, the patient was diagnosed with Shwachman-Diamond syndrome (SDS). In the clinical course, the patient developed acute myeloid leukemia (AML). Hematopoietic stem cell transplantation from the human-leukocytic-antigen-haploidentical father of the patient was performed. The patient was conditioned with 150 mg/m2 fludarabine, 6.4 mg/kg busulfan, and 4 Gy total body irradiation. Graft-versus-host disease prophylaxis included tacrolimus, micophenolate mofetil, and posttransplant cyclophosphamide. Although the patient achieved a complete remission on day 21, AML relapsed on day 434 after the transplantation. He died of sepsis. The prognosis of patients with SDS and AML is poor. Adult-onset cases must be recognized, and transplantation should be performed during bone marrow failure.

Challenges in the diagnosis and management of vitreoretinal lymphoma - Clinical and basic approaches.

Vitreoretinal lymphoma (VRL) is a subtype of diffuse large B-cell lymphoma and is sight- and life-threatening in the vast majority of patients. Lymphoma cells infiltrate the vitreous body and/or subretinal space and exhibit clinical signs of vitreous opacities and creamy white subretinal lesions. Although the intraocular signs can serve as clues to suspect VRL, they are nonspecific and may be misdiagnosed as uveitis. Histopathological evidence of malignant cells on vitreous biopsy, for instance, is the gold standard for diagnosis of VRL; however, cytological examination of the vitreous often results in a low success rate owing to the small quantity and poor quality of tissues and cells in the sample. Recent advancements in immunological, molecular, and gene analyses using intraocular samples have made it possible to accurately diagnose VRL. As for the management of VRL, local treatments with irradiation and/or intravitreal injections of anti-tumor agents (methotrexate or rituximab) are effective in suppressing intraocular VRL lesions. However, the effect of systemic chemotherapy, with or without brain irradiation, on preventing central nervous system involvements remains controversial. In this review article, we discuss the following concepts based on previous literature and our unpublished results: current ocular imaging examinations such as optical coherence tomography and fundus autofluorescence; immunological, molecular, and gene expression characterization of intraocular biopsies with special attention to flow cytometry; immunoglobulin gene rearrangement assays that use the polymerase chain reaction test; cytokine assays; gene mutations (MYD88, CD79B); and current local and systemic treatments of VRL.

NK-cell post-transplant lymphoproliferative disease successfully treated by second allogenic hematopoietic stem cell transplantation in chronic active Epstein-Barr virus infection.

Chronic active Epstein-Barr virus infection (CAEBV) is a systemic T- or NK-lymphoproliferative disorder (LPD) caused by EBV. Allogenic hematopoietic stem cell transplantation (HSCT) is the only curative therapy for CAEBV, but relapse sometimes occurs. Relapse is generally attributed to proliferation of recipient-derived CAEBV cells. We herein report a case of donor-derived CAEBV-like NK-cell post-transplant lymphoproliferative disease (PTLD) in a 41-year-old female after the first allogenic HSCT for CAEBV from an HLA-matched sibling donor. A second HSCT from an HLA-matched unrelated donor successfully controlled the disease, but EBV infection of cells derived from the second donor continued to be detected. Although the mechanisms underlying CAEBV and CAEBV-like NK-cell PTLD have not yet been elucidated in detail, the findings of the present case imply that host genetic factors, including familial factors, may be important in disease development.

Interferon-γ Produced by EBV-Positive Neoplastic NK-Cells Induces Differentiation into Macrophages and Procoagulant Activity of Monocytes, Which Leads to HLH.

Epstein-Barr virus (EBV)-positive T- or NK-cell neoplasms show progressive systemic inflammation and abnormal blood coagulation causing hemophagocytic lymphohistiocytosis (HLH). It was reported that inflammatory cytokines were produced and secreted by EBV-positive neoplastic T- or NK-cells. These cytokines can induce the differentiation of monocytes into macrophages leading to HLH. To clarify which products of EBV-positive neoplastic T- or NK-cells have effects on monocytes, we performed a co-culture assay of monocytes with the supernatants of EBV-positive T- or NK-cell lines. The expression of differentiation markers, the phagocytosis ability, and the mRNA expression of the inflammatory cytokines of THP-1, a monocytic cell line, clearly increased after culturing with the supernatants from EBV-NK-cell lines. Co-culturing with the supernatants promoted the expression of CD80 and CD206 as well as M1 and M2 macrophage markers in human monocytes. Co-culturing with the supernatants of EBV-NK-cell lines significantly enhanced the procoagulant activity and the tissue factor expression of monocytes. Interferon (IFN)-γ was elevated extremely not only in the supernatant of EBV-NK-cell lines but also in the plasma of EBV-positive NK-cell neoplasms patients accompanying HLH. Finally, we confirmed that IFN-γ directly enhanced the differentiation into M1-like macrophages and the procoagulant activity of monocytes. Our findings suggest that IFN-γ may potentially serve as a therapeutic target to regulate HLH in EBV-positive NK-cell neoplasms.

[The road to treating chronic active Epstein-Barr viral infection].

Chronic active Epstein-Barr virus (CAEBV) infection is a progressive disease characterized by persistent inflammatory symptoms accompanied by clonally proliferating EBV-positive T or NK cells. The optimal medical treatment for CAEBV to eradicate EBV-infected T or NK cells has not yet been established, with allogeneic hematopoietic stem cell transplantation as the only strategy currently available. Patients with CAEBV have been reported mainly from limited area of Japan and East Asia. However, CAEBV is drawing a global attention, and the number of reports is increasing worldwide after its definition was added to the EBV-positive T- or NK-cell neoplasms in the 2017 World Health Organization classification. We had previously discovered that STAT3 was constitutively activated in EBV-infected tumor cells in CAEBV inducing the immortalization and production of inflammatory cytokines. Based on these findings, an investigator-initiated clinical research of a JAK1/2 inhibitor ruxolitinib for CAEBV infection was initiated in January 2019. Japanese researchers have been expected to elucidate pathological mechanisms and to establish an effective treatment.

Antineoplastic and anti-inflammatory effects of bortezomib on systemic chronic active EBV infection.

Systemic chronic active Epstein-Barr virus (EBV; sCAEBV) infection, T- and natural killer (NK)-cell type (sCAEBV), is a fatal disorder accompanied by persisting inflammation harboring clonal proliferation of EBV-infected T or NK cells. Today's chemotherapy is insufficient to resolve disease activity and to rid infected cells of sCAEBV. The currently established treatment strategy for eradicating infected cells is allogeneic hematopoietic stem cell transplantation. In this study, we focused on the effects of proteasome inhibitor bortezomib on the disease. Bortezomib suppressed survival and induced apoptosis of EBV+ T- or NK-cell lines and peripheral mononuclear cells containing EBV-infected T or NK cells of sCAEBV patients. Bortezomib enhanced binding immunoglobulin protein/78-kDa glucose-regulated protein (Bip/GRP78) expression induced by endoplasmic reticulum stress and activated apoptosis-promoting molecules JNK and p38 in the cell lines. Bortezomib suppressed the activation of survival-promoting molecule NF-κB, which was constitutively activated in EBV+ T- or NK-cell lines. Furthermore, quantitative reverse transcription-polymerase chain reaction demonstrated that bortezomib suppressed messenger RNA expression of proinflammatory cytokines tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) in EBV+ T or NK cells from the patients. Finally, we examined the effects of bortezomib using xenograft models of sCAEBV generated by IV injection of patients' cells. The intraperitoneal administration of bortezomib significantly reduced EBV-DNA load in peripheral blood and the infiltration of EBV-infected cells in the models' livers. Moreover, the serum concentration of TNF-α and IFN-γ decreased after bortezomib treatment to the models. Our findings will be translated into the treatment of sCAEBV not only to reduce the number of tumor cells but also to suppress inflammation.