A Novel IgM-capture enzyme-linked immunosorbent assay using recombinant Vag8 fusion protein for the accurate and early diagnosis of Bordetella pertussis infection.

An ELISA that measures anti-PT IgG antibody has been used widely for the serodiagnosis of pertussis; however, the IgG-based ELISA is inadequate for patients during the acute phase of the disease because of the slow response of anti-PT IgG antibodies. To solve this problem, we developed a novel IgM-capture ELISA that measures serum anti-Bordetella pertussis Vag8 IgM levels for the accurate and early diagnosis of pertussis. First, we confirmed that Vag8 was highly expressed in all B. pertussis isolates tested (n = 30), but little or none in other Bordetella species, and that DTaP vaccines did not induce anti-Vag8 IgG antibodies in mice (i.e. the antibody level could be unaffected by the vaccination). To determine the immune response to Vag8 in B. pertussis infection, anti-Vag8 IgM levels were compared between 38 patients (acute phase of pertussis) and 29 healthy individuals using the anti-Vag8 IgM-capture ELISA. The results revealed that the anti-Vag8 IgM levels were significantly higher in the patients compared with the healthy individuals (P < 0.001). ROC analysis also showed that the anti-Vag8 IgM-capture ELISA has higher diagnostic accuracy (AUC, 0.92) than a commercial anti-PT IgG ELISA kit. Moreover, it was shown that anti-Vag8 IgM antibodies were induced earlier than anti-PT IgG antibodies on sequential patients' sera. These data indicate that our novel anti-Vag8 IgM-capture ELISA is a potentially useful tool for making the accurate and early diagnosis of B. pertussis infection.

[Systemic organ invasion accompanied by immunophenotypic change observed in extraosseous plasmacytoma].

We report a 57-year-old man who was diagnosed based on morphological findings as having extraosseous plasmacytoma of the left lower eyelid. Tumor cells were positive not only for CD38 and CD138, but also for CD19 and surface immunoglobulin lambda chain. He obtained a complete remission with irradiation and VAD therapy, but the disease relapsed one year later in the testis and popliteal fossa. Because tumor cells appeared to be blastoid, CHOP therapy was administered, and the patient achieved a temporary remission. Cytoplasmic lambda chain-positive and CD19-negative tumors eventually recurred at multiple sites including the central nervous system but not in the bone marrow. Treatment with the BD regimen and lenalidomide failed, and he died four years after the initial diagnosis.

Predictive biomarker of mortality in children with infectious diseases: a nationwide data analysis.

Biomarkers play a crucial role in the early identification of high-risk children with infectious diseases. Despite their importance, few studies evaluated biomarkers' capabilities in predicting mortality. The aim of this study was to evaluate the biomarkers' predictive capabilities for mortality in children with infectious diseases. From an inpatient database covering ≥200 acute-care hospitals in Japan, we included children who underwent blood culture, and received antimicrobial treatment between 2012 and 2021. Biomarkers' results from the day of the initial blood culture were used. Biomarker discriminative capabilities were assessed using the area under receiver operating characteristic curves (AUCs). Of 11,365 eligible children with presumed infection, 1,378 (12.1%) required mechanical ventilation or vasoactive agents within 2 days of blood culture, and 100 (0.9%) died during admission. Of all children, 10,348 (91.1%) had community-onset infections and 1,017 (8.9%) had hospital-onset infections. C-reactive protein and white blood cell demonstrated limited discriminatory capabilities with AUCs of 0.44 [95% confidence interval (CI): 0.38-0.51] and 0.45 (95% CI: 0.39-0.52). In contrast, pH, prothrombin time-international normalized ratio, and procalcitonin exhibited strong discriminatory capabilities with AUCs of 0.77 (95% CI: 0.65-0.90), 0.77 (95% CI: 0.70-0.84) and 0.76 (95% CI: 0.29-1.00). In conclusions, our real-world data analysis suggested that C-reactive protein and white blood cell may not be reliable indicators for predicting mortality in children with presumed infection. These findings could warrant future studies exploring promising biomarkers, including those from blood gas analyses, coagulation studies and procalcitonin.

[Detection of BCR-ABL1 chimeric gene-positive neutrophils in a patient with mixed phenotype acute leukemia].

We experienced two patients with mixed phenotype acute leukemia with t(9;22)(q34;q11.2); BCR-ABL1 according to the WHO classification 2008. The type of BCR/ABL1 was major in both patients, and the chimeric gene was also detected in neutrophils from peripheral blood by the fluorescence in situ hybridization technique. Patient 1 was a 59-year-old Japanese woman, and patient 2 a 45-year-old Japanese man. They had both developed leukemia suddenly. Their leukemic blasts expressed B cell and myeloid cell antigens, but concomitantly in patient 1 (biphenotypic) and separately in patient 2 (biclonal). Percentages of BCR-ABL1-positive neutrophils were 98% and 89%, respectively. Both patients received an imatinib (600 mg/day)-combined Hyper-CVAD regimen as induction therapy, followed by treatment with dasatinib (140 mg/day). MEC therapy was also applied between these two treatments in patient 2. At present, patient 1 has obtained complete molecular remission quantitatively and qualitatively, and patient 2 only quantitatively. Considering their acute onsets with no prior history of chronic myelocytic leukemia (CML), they were both diagnosed as having acute leukemia with Ph1, but not blastic crisis of CML. In this tyrosine kinase inhibitor era, it has become more difficult to differentiate these two types of Ph1-positive leukemia development.

Pneumococcal Serotype-specific Opsonophagocytic Activity in Interleukin-1 Receptor-associated Kinase 4-deficient Patients.

BACKGROUND: The antibody response after pneumococcal vaccines and their effectiveness against invasive pneumococcal disease (IPD) in patients with interleukin-1 receptor-associated kinase 4 (IRAK4) deficiency have not been fully evaluated. Here, we evaluated pneumococcal serotype-specific opsonophagocytic activity (OPA) in IRAK4-deficient patients along with their clinical course. METHODS: We investigated 6 IRAK4-deficient patients in Japan, whose attending physicians could be contacted. We performed OPA measurements using stored and more recent serum samples obtained from these patients. RESULTS: All patients had received pneumococcal vaccination. Among the 3 patients who had IPD, 2 had an episode of pneumococcal meningitis and the other developed pneumococcal bacteremia 3 years after the occurrence of pneumococcal meningitis. Only one episode of invasive bacterial infection was caused by a Streptococcus pneumoniae vaccine-type strain. An increased opsonization index was found in the sera after vaccination for all IRAK-deficient patients, including when the 23-valent pneumococcal polysaccharide vaccine was used. CONCLUSIONS: A significant increase in levels of OPA against most of the pneumococcal vaccine antigens was observed for all IRAK4-deficient patients. However, IPD could not be prevented by pneumococcal vaccination alone. Therefore, adequate prophylaxis should be provided with antibiotics at least until 8 years of age, along with regular immunoglobulin therapy, particularly during the infantile period.

[A case of ulcerative colitis with preexisting idiopathic thrombocytopenic purpura].

A 53-year-old man was diagnosed as having idiopathic thrombocytopenic purpura (ITP). Hematochezia appeared under steroid therapy for ITP after the diagnosis of ITP 18 months. Colonoscopic study demonstrated inflamed rectal mucosa but there was no evidence of infectious colitis. The colonoscopic and pathological findings were compatible with ulcerative colitis (UC). There have been a few reports of patients with UC complicated by ITP, but in all except one report, UC preceded ITP. This is the third case in which ITP preceded UC and the first case in which the proctitis type of UC was complicated by ITP in Japan.

Successful Corticosteroid Treatment for Purpura Fulminans Associated with Quinolone.

Purpura fulminans (PF) is a life-threatening syndrome comprising progressive hemorrhagic necrosis due to disseminated intravascular coagulation and dermal vascular thrombosis that leads to purpura and tissue necrosis. Various therapies have been used to arrest the progression of this disease, however, there is no established treatment because of the variety of underlying causes. We herein present an adult case of PF associated with leukocytoclastic vasculitis triggered by antibiotic (levofloxacin) intake. As a result of our rapid and accurate identification of the underlying cause, corticosteroid therapy successfully repressed the inflammatory process. As far as we know, this is the first report of levofloxacin-associated PF.

Chronic myelogenous leukemia in chronic phase transforming into acute leukemia under treatment with dasatinib 4 months after diagnosis.

We report a 64-year-old woman morphologically diagnosed with chronic myelogenous leukemia in the chronic phase. Despite having achieved a complete hematological response following treatment with dasatinib, she developed lymphoblastic crisis 4 months later. Blastic cells were in a CD45-negative and SSC-low fraction, and positive for CD10, CD19, CD34, and HLA-DR expression and rearrangement in the immunoglobulin heavy chain gene. Chemotherapy using the HyperCVAD/MA regimen led to a complete cytogenetic response, and after cord blood transplantation, she obtained a complete molecular remission. However, the crisis recurred 6 months later. Another salvage therapy using L-AdVP regimen followed by nilotinib led to a complete molecular remission. Retrospective analyses using flow cytometry and polymerase chain reaction revealed a minimal blastic crisis clone present in the initial marrow in chronic phase. This case is informative as it suggests that sudden blastic crisis may occur from an undetectable blastic clone present at initial diagnosis and that leukemic stem cells may survive cytotoxic chemotherapy that eliminates most of the blastic cells.

Prevalence and genetic characterization of pertactin-deficient Bordetella pertussis in Japan.

The adhesin pertactin (Prn) is one of the major virulence factors of Bordetella pertussis, the etiological agent of whooping cough. However, a significant prevalence of Prn-deficient (Prn(-)) B. pertussis was observed in Japan. The Prn(-) isolate was first discovered in 1997, and 33 (27%) Prn(-) isolates were identified among 121 B. pertussis isolates collected from 1990 to 2009. Sequence analysis revealed that all the Prn(-) isolates harbor exclusively the vaccine-type prn1 allele and that loss of Prn expression is caused by 2 different mutations: an 84-bp deletion of the prn signal sequence (prn1ΔSS, n = 24) and an IS481 insertion in prn1 (prn1::IS481, n = 9). The frequency of Prn(-) isolates, notably those harboring prn1ΔSS, significantly increased since the early 2000s, and Prn(-) isolates were subsequently found nationwide. Multilocus variable-number tandem repeat analysis (MLVA) revealed that 24 (73%) of 33 Prn(-) isolates belong to MLVA-186, and 6 and 3 Prn(-) isolates belong to MLVA-194 and MLVA-226, respectively. The 3 MLVA types are phylogenetically closely related, suggesting that the 2 Prn(-) clinical strains (harboring prn1ΔSS and prn1::IS481) have clonally expanded in Japan. Growth competition assays in vitro also demonstrated that Prn(-) isolates have a higher growth potential than the Prn(+) back-mutants from which they were derived. Our observations suggested that human host factors (genetic factors and immune status) that select for Prn(-) strains have arisen and that Prn expression is not essential for fitness under these conditions.

Cloning and characterization of a novel RING-B-box-coiled-coil protein with apoptotic function.

We have identified a novel RING-B-box-coiled-coil (RBCC) protein (MAIR for macrophage-derived apoptosis-inducing RBCC protein) that consists of an N-terminal RING finger, followed by a B-box zinc finger, a coiled-coil domain, and a B30.2 domain. MAIR mRNA was expressed widely in mouse tissues and was induced by macrophage colony-stimulating factor in murine peritoneal and bone marrow macrophages. MAIR protein initially showed a granular distribution predominantly in the cytoplasm. The addition of zinc to transfectants containing MAIR cDNA as part of a heavy metal-inducible vector caused apoptosis of the cells characterized by cell fragmentation; a reduction in mitochondrial membrane potential; activation of caspase-7, -8, and -9, but not caspase-3; and DNA degradation. We also found that the RING finger and coiled-coil domains were required for MAIR activity by analysis with deletion mutants.