Inhibitory Effects of Polymyxin B and Human LL-37 on the Flagellin Expression in Vibrio vulnificus.

Vibrio vulnificus, an opportunistic human pathogen responsible for primary septicemia, initiates pathogenesis by attachment to the intestinal epithelial cells for which the motility by the polar flagellum plays an essential role. The proteomic analysis of outer membrane proteins showed that the treatment with the 1/2 minimum inhibitory concentration (MIC) of polymyxin B (a bacterial antimicrobial peptide) led to the reduced production of flagellin (a major component of the polar flagellum). Furthermore, the bacterial motility was inhibited in the presence of 1/2 MIC of polymyxin B. V. vulnificus has six flagellin genes organized into the flaFBA and flaCDE loci. The flaA was found to be expressed higher than flaC, and its expression was significantly decreased by polymyxin B. As well as polymyxin B, the 1/2 MIC of LL-37 (a human intestinal antimicrobial peptide) reduced the expression of flaA. In addition, among four fragments of LL-37, KI-18 and FK-13 containing F17KRIVQRIKDELR29 could lead to the decreased expression of flaA. Because the motility closely relates to virulence of V. vulnificus, the findings obtained herein indicate that LL-37 may reduce the bacterial virulence through inhibition of the motility via the polar flagellum.

Therapeutic options for CTLA-4 insufficiency.

BACKGROUND: Heterozygous germline mutations in cytotoxic T lymphocyte-associated antigen-4 (CTLA4) impair the immunomodulatory function of regulatory T cells. Affected individuals are prone to life-threatening autoimmune and lymphoproliferative complications. A number of therapeutic options are currently being used with variable effectiveness. OBJECTIVE: Our aim was to characterize the responsiveness of patients with CTLA-4 insufficiency to specific therapies and provide recommendations for the diagnostic workup and therapy at an organ-specific level. METHODS: Clinical features, laboratory findings, and response to treatment were reviewed retrospectively in an international cohort of 173 carriers of CTLA4 mutation. Patients were followed between 2014 and 2020 for a total of 2624 months from diagnosis. Clinical manifestations were grouped on the basis of organ-specific involvement. Medication use and response were recorded and evaluated. RESULTS: Among the 173 CTLA4 mutation carriers, 123 (71%) had been treated for immune complications. Abatacept, rituximab, sirolimus, and corticosteroids ameliorated disease severity, especially in cases of cytopenias and lymphocytic organ infiltration of the gut, lungs, and central nervous system. Immunoglobulin replacement was effective in prevention of infection. Only 4 of 16 patients (25%) with cytopenia who underwent splenectomy had a sustained clinical response. Cure was achieved with stem cell transplantation in 13 of 18 patients (72%). As a result of the aforementioned methods, organ-specific treatment pathways were developed. CONCLUSION: Systemic immunosuppressants and abatacept may provide partial control but require ongoing administration. Allogeneic hematopoietic stem cell transplantation offers a possible cure for patients with CTLA-4 insufficiency.

Bortezomib-containing therapy in Japanese children with relapsed acute lymphoblastic leukemia.

Outcomes of children treated for relapsed acute lymphoblastic leukemia (ALL) remain poor. Bortezomib (BZM), a proteasome inhibitor, has shown promising activity against lymphoid malignancies. We conducted a phase I study to evaluate the safety and tolerability of multidrug chemotherapy including BZM in Japanese children with relapsed ALL. Three of five children with relapsed ALL enrolled in the study between November 2014 and April 2016 were evaluated. BZM (1.3 mg/m2) was administered on days 8, 11, 15, and 18 of multidrug induction chemotherapy. Pharmacokinetic studies were performed. Age at study entry was 5, 7, and 7 years old, respectively. Two patients had hyperdiploid B-precursor ALL, and one had T cell ALL. Although all patients experienced grade 3-4 hematologic toxicity and grade 3 elevation of aminotransferases, no dose-limiting toxicities were observed. The maximum tolerated dose was defined as 1.3 mg/m2. Peripheral neuropathy and respiratory complications were not observed. Complete remission was achieved in all three patients. The mean maximum plasma concentration and area under the concentration-time curve was 74.0 ng/mL and 73.9 ng h/mL, respectively. Thus, adding BZM to 5-drug induction chemotherapy appears safe and well-tolerated in Japanese children with relapsed ALL.

Duplication of ALK F1245 missense mutation due to acquired uniparental disomy associated with aggressive progression in a patient with relapsed neuroblastoma.

Recent genome-wide analysis of neuroblastoma (NBL) revealed amplification and heterozygous mutation of anaplastic lymphoma kinase (ALK) are responsible for oncogenicity, frequently observed during relapses. A 3-year-old girl with relapsed high-risk NBL had a heterozygous ALK F1245L mutation at diagnosis, which became homozygous due to uniparental disomy (UPD) of the entire chromosome 2, confirmed by single nucleotide polymorphism array and variant allele frequency of this mutation. The ALK inhibitor, crizotinib, failed to control the tumor and the patient died of the disease. Further genomic analysis using targeted capture sequencing for 381 genes related to pediatric cancers identified more alterations acquired at relapse, such as TSC complex subunit 2 and protein tyrosine phosphatase receptor type D. In addition to these several acquired mutations, this extremely rare duplication of ALK mutation might explain the aggressive clinical course after relapse, because acquired UPD, resulting in the duplication of an oncogenic mutation, has been reported for various neoplasms. Although a clinical benefit of ALK inhibitors in patients with NBL has not been confirmed yet, a treatment based on the ALK mutation status will be promising in future using more potent next-generation ALK inhibitors.

[Transplantation-associated thrombotic microangiopathy confirmed by renal biopsy].

An eight-year-old girl with myelodysplastic syndrome (refractory cytopenia) received a bone marrow transplant (BMT) from an unrelated donor because of immunosuppressive therapy failure. Following administration of foscarnet for cytomegalovirus reactivation at day40 post-BMT, serum creatinine increased, and proteinuria, hematuria, and hypertension gradually exacerbated and became prolonged. However, neither schistocytosis nor other organ damage was evident. At six months post-BMT, renal biopsy revealed diffuse glomerular damage with glomerular lobulation, a double contour of the glomerular basement membrane, erythrocyte congestion and thrombi in the glomerular endocapillaries, and mesangiolysis, confirming the diagnosis of transplantation-associated thrombotic microangiopathy (TA-TMA). We initiated strict controls regarding fluid balance, salt intake, and blood pressure. The patient's renal function improved 10 months post-BMT. TA-TMA often presents as non-specific symptoms, making diagnosis difficult. In cases of post-transplant renal damage, TA-TMA should be differentiated regardless of whether specific symptoms such as hemolytic anemia and other organ failure are evident, and a renal biopsy should, therefore, be considered.

Chemotherapy for a child with relapsed acute myeloid leukemia complicated with persistent hepatitis C virus infection.

An 8-year-old Mongolian female was diagnosed with acute myeloid leukemia (AML) and treated at a hospital in Mongolia according to the BFM-AML2004 SR protocol. Although complete remission (CR) was achieved, chemotherapy was interrupted because of shortage of drugs. The patient moved to Japan 7 months after diagnosis. Screening for viral infection revealed the presence of hepatitis C virus (HCV) antibody and RNA. At 11 months after initial diagnosis, the patient experienced bone marrow relapse and a RUNX1-RUNX1T1 fusion transcript was detected. Considering the inadequate intensity of initial treatment and the persistent HCV infection, chemotherapy was preferred and initiated over hematopoietic cell transplantation. After the first course of induction therapy, a second CR was confirmed and the chimeric transcript disappeared. The viral load mildly increased during myelosuppression and transient elevation of liver enzymes was observed along with hematological recovery. HCV infection remained stable, without progression to reactivation of hepatitis C. Given the high risk of second relapse and liver fibrosis and sclerosis following chronic HCV infection, treatment against HCV may be indicated during second remission.

Infantile fibrosarcoma treated with postoperative vincristine and dactinomycin.

Infantile fibrosarcoma is a non-rhabdomyosarcoma soft-tissue sarcoma that occurs in infancy and which has a relatively good prognosis. A vincristine and dactinomycin (VA) regimen has been shown to be effective, although the duration of chemotherapy has not been well defined. We describe the case of a 4-month-old boy with a mass at the left dorsum of the foot who was diagnosed with infantile fibrosarcoma after resection of the tumor, the margin of which was macroscopically positive. VA treatment was carried out with careful monitoring of response and adverse effects. Pancytopenia was seen during the second cycle, and therapy was reduced thereafter. The treatment was continued for 38 weeks (12 cycles). There was no functional impairment, and no evidence of recurrence at 18 months after therapy.

Severe 6-mercaptopurine-induced hematotoxicity in childhood an ALL patient with homozygous NUDT15 missence variants.

Thiopurine S-methyltransferase (TPMT) and nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15) variants are considered to be genes responsible for severe myelotoxicity induced by 6-mercaptopurine (6MP). We report a 4-year-old girl with acute lymphoblastic leukemia, who developed the complication of severe 6MP-induced myelotoxicity due to homozygous NUDT15 variant alleles. In early consolidation therapy containing 6MP, her course was complicated by severe neutropenia (Grade 4) and chemotherapy had to be discontinued for 33 days. The 6MP dose was subsequently adjusted based on the white blood cell count. The ratios of the prescribed 6MP dose over the protocol dose in early consolidation, central nervous system (CNS) prophylaxis, re-induction, interim maintenance and maintenance therapy were 63%, 27%, 4%, 26% and 7%, respectively. Suspension of therapy was required during early consolidation, CNS prophylaxis and interim maintenance therapy. We investigated candidate genes for 6MP-associated myelotoxicity and found homozygous NUDT15 variant alleles and a heterozygous inosine triphosphate pyrophosphatase (ITPA) variant allele. In patients with homozygous NUDT15 variants, drastic reduction (less than 10%) of the 6MP dose from the protocol dose might be required not only during maintenance therapy, but also during other treatment courses containing 6MP. Screening of candidate genes at diagnosis is recommended in order to avoid serious adverse events.

Cervical ultrasound and computed tomography of Kawasaki disease: Comparison with lymphadenitis.

BACKGROUND: Differentiating Kawasaki disease (KD) from cervical lymphadenitis (CL) is clinically difficult but essential given that treatment and outcome differ significantly. Research on differentiation between KD and CL using ultrasound (US) and computed tomography (CT) is limited. The purpose of this study was to identify cervical US and CT findings that may differentiate KD from CL. METHODS: We retrospectively reviewed cervical US of 25 KD patients and 25 CL patients, and CT of 14 KD patients, and 14 CL patients. Two radiologists analyzed specific imaging features on US (lymph node size, shape, echogenicity, margins, laterality, necrosis, and presence of normal hilum) and on CT (size and location of enlarged nodes, laterality, perinodal infiltration, and retropharyngeal edema). RESULTS: On US, patients with KD more frequently had lymph nodes with a "cluster of grapes" appearance (KD vs CL: 64% vs 32%, P < 0.05) and less frequently had poorly circumscribed margins (0% vs 36%, P < 0.01), necrosis (0% vs 32%, P < 0.01), or non-visualization of the hilum (4% vs 36%, P < 0.01). On CT, KD patients more frequently had retropharyngeal edema (100% vs 29%, P < 0.001) and less frequently had level 4 lymphadenopathy (14% vs 79%, P < 0.01) than CL patients. CONCLUSIONS: Ultrasound is mainly useful for excluding purulent lymphadenopathy while CT is a useful diagnostic tool for differentiating KD from CL, especially in patients with incomplete KD, who present with prominent cervical lymphadenopathy and other equivocal principal findings.

Feasibility of HLA-haploidentical hematopoietic stem cell transplantation with post-transplantation cyclophosphamide for advanced pediatric malignancies.

BACKGROUND: Patients with advanced malignancies in non-complete remission (CR) have a dismal prognosis after HLA-matched hematopoietic stem cell transplantation (HSCT). T-cell-replete HLA-haploidentical HSCT has remarkable anti-leukemia/tumor effects on these patients, but also a high risk of severe/extensive graft-versus-host disease (GHVD). Post-transplantation cyclophosphamide (PTCY) is regarded as a GVHD-specific immunosuppressant in adults, but its feasibility is unknown in children. METHODS: We performed a prospective feasibility study of PTCY at 50 mg/kg on day 3 for children with advanced leukemias or malignant solid tumors: refractory to chemotherapy or relapsed after conventional allogeneic HSCT. Conditioning consisted of fludarabine (180 mg/m2) and melphalan (140-210 mg/m2). RESULTS: Long-term engraftments were achieved in 11 patients (73.3%) after bone marrow transplantation (BMT, n = 13) or peripheral blood (PB) stem cell transplantation (n = 2). The incidence of severe acute GHVD was 25.0% and that of extensive chronic GVHD 0.0% after evaluable BMT. CR was achieved in 6/15 and partial response in 4/15 as the best response. Finally, 11/15 experienced disease progression/relapse, 2/15 suffered treatment-related mortality without evidence of disease, and 2/15 are alive in continuous CR. CONCLUSIONS: PTCY is feasible in children; however, for a better outcome in such patients with advanced malignancies, some modifications are anticipated.