Ultrasound-Assessed Lesion Morphology and Drug-Coated Balloon Treatment for de novo Dysfunctional Arteriovenous Fistula in Hemodialysis Patients.

AIM: This study aimed to evaluate the effect of ultrasound-assessed lesion morphology on the outcomes of drug-coated balloon (DCB) versus plain old balloon angioplasty (POBA) treatment for de novo dysfunctional arteriovenous fistulas (AVF) lesions. METHODS: This single-center retrospective study enrolled 114 consecutive patients (mean age, 73 ± 10 years; male, 69%) with de novo dysfunctional AVF lesions who underwent percutaneous transluminal angioplasty (PTA) using DCB (n = 48) and POBA (n = 66). The morphology of the stenotic lesions, evaluated using ultrasonography, was classified into intimal hyperplasia and shrinking types. The outcome measure was 12-month primary patency. Factors associated with loss of primary patency were evaluated using Cox proportional hazards models. RESULTS: The baseline characteristics were not significantly different between the 2 treatment groups. The 12-month primary patency rate was significantly higher in the DCB group than in the POBA group (66.8 ± 7.1% versus 35.9 ± 6.3%, P = .006). The 12-month primary patency rate in the lesions with intimal hyperplasia type was not significantly different (DCB: 70.3 ± 9.5% versus POBA: 45.9 ± 8.0%; P = .310), whereas that in the shrinking type was significantly higher in the DCB group than in the POBA group (61.9 ± 10.6% versus 15.2 ± 8.1%; P < .001). The interaction analysis demonstrated that lesion morphology had a significantly different hazard ratio (HR) for restenosis between the POBA and DCB groups (P for interaction = .031). The multivariate analysis revealed that DCB usage (adjusted hazard ratio [aHR], 0.49; 95% confidence interval [CI]: [0.28, 0.87]; P = .015), ultrasound-assessed lesion morphology (shrinking type: aHR, 1.77; 95% CI: [1.07, 2.93]; P = .026), and location of stenosis (aHR, 2.26; 95% CI: 1.15, 4.46; P = .018) were significantly associated with AVF patency after PTA. CONCLUSION: This study revealed that lesion morphology evaluated using ultrasonography had a differential impact on DCB and POBA outcomes. The therapeutic effect of DCB was unexpectedly confirmed in the shrinking type. CLINICAL IMPACT: The effectiveness of DCB in inhibiting smooth muscle cell proliferation in intimal hyperplasia lesions was expected based on the known mechanism of action of paclitaxel. However the therapeutic effect of DCB was unexpectedly confirmed in the shrinking type too. We may not need to hesitate usage of DCB for shrinking type.

Use of a fluoropolymer-based paclitaxel-eluting stent for arteriovenous graft outflow vein stenosis in hemodialysis patients.

We implanted a fluoropolymer-based paclitaxel-eluting stent (FP-PES) in four hemodialysis patients with refractory outflow venous stenosis of their arteriovenous graft. The mean observation period after FP-PES implantation was 11.5 ± 4.7 months (range, 7.0-18.0 months). After FP-PES implantation, the patients were evaluated by ultrasound every 3 months. No of the patients experienced neointimal hyperplasia in the stents during the observation period, and no reintervention was performed. FP-PESs could be an attractive alternative to percutaneous transluminal angioplasty for patients with refractory outflow venous stenosis of arteriovenous hemodialysis grafts.

Thrombotic thrombocytopenic purpura developed during the conservative treatment of anti-phospholipase A2 receptor antibody-positive idiopathic membranous nephropathy: a case report.

BACKGROUND: Idiopathic membranous nephropathy (MN) is one of the major glomerulonephritis that cause nephrotic syndrome. The phospholipase A2 receptor (PLA2R) has recently been identified as an endogenous antigen of idiopathic MN. Thrombotic thrombocytopenic purpura (TTP) is a disorder characterized by schistocytes, hemolytic anemia, thrombocytopenia, and organ dysfunction which occurs as a result of thrombi. Patients with acquired TTP have autoantibodies against a disintegrin and metalloprotease with thrombospondin type 1 motif 13 (ADAMTS13). These autoantibodies act as an inhibitor and cause ADAMTS13 deficiency. Idiopathic MN and acquired TTP are usually considered as independent autoimmune diseases. We experienced a patient who developed TTP during the conservative treatment of idiopathic MN, with the coexistence of ADAMTS13 inhibitor and anti-PLA2R antibody. CASE PRESENTATION: A 73-year-old man presented with thrombocytopenia, hemolytic anemia, disturbance of consciousness, and acute kidney injury after 4-year course of biopsy-proven idiopathic MN. ADAMTS13 activity was undetectable and the ADAMTS13 inhibitor was identified. Additionally, he was positive for anti-PLA2R antibody. The patient did not have any diseases that could cause secondary thrombotic microangiopathy, and he was diagnosed with acquired TTP. Steroid therapy and plasma exchange were initiated and the acquired TTP resolved. MN achieved remission 3 months after the anti-PLA2R antibody disappeared. CONCLUSIONS: This is the first reported case of acquired TTP developed during conservative treatment of idiopathic MN, with both ADAMTS13 inhibitor and anti-PLA2R antibody positive at the onset of the TTP. The present case suggests that idiopathic MN might be associated with the development of some cases of acquired TTP.

Genetic diversity of Theileria orientalis in tick vectors detected in Hokkaido and Okinawa, Japan.

In the present study, we investigated the possible tick vectors that can transmit Theileria orientalis in eastern Hokkaido, Japan. Questing ticks collected from three different districts, Taiki, Otofuke, and Shin-Hidaka, of Hokkaido included Ixodes persulcatus, Haemaphysalis megaspinosa, Haemaphysalis douglasi, and Ixodes ovatus, while all the ticks collected from Yonaguni island of Okinawa were identified as Haemaphysalis longicornis. When the ticks were screened by polymerase chain reaction (PCR) for T. orientalis, the parasite was commonly detected among all tick species. Genotype-specific PCR assays revealed that all tick species in Hokkaido were predominantly detected with type 2, while ticks collected from Okinawa (H. longicornis) were predominantly detected with type 1. Consistent with the genetic diversity of T. orientalis in ticks, genotyping PCR assays from cattle grazed in the same Hokkaido sampling locations identified type 2 as the most prevalent genotype. This study provides the first identification of I. persulcatus, H. megaspinosa, H. douglasi, and I. ovatus as possible tick vectors of T. orientalis, and finds that the variety of vectors apparently capable of transmitting T. orientalis is wider in Japan than expected. The authors suggest that tick control strategies should be modified in Hokkaido based on the seasonal activities of ticks identified in the present study.

Expression and immunological characterization of the heat shock protein-70 homologue from Babesia bigemina.

The Babesia bigemina heat shock protein-70 gene (BbigHSP-70) was cloned from cDNA by polymerase chain reaction (PCR) and sequenced. The length of the gene is 1947 bp and the predicted polypeptide is 649 amino acids long with a calculated molecular weight of 70.85 kDa. BbigHSP-70 has a signal peptide of 15 amino acids. Phylogenetic analysis of the amino acid sequence of BbigHSP-70 showed that B. bigemina was most closely related to B. caballi and B. bovis and lies within a phylogenetic cluster with Theileria. rBbigHSP-70 was expressed in E. coli as a soluble GST-fusion protein with a molecular mass of 96.8-kDa. The serum raised in mice against rBbigHSP-70 detected the native protein in B. bigemina, B. bovis, B. caballi, B. gibsoni, and B. microti lysates and also reacted with B. bigemina, B. bovis, and B. caballi merozoites in the IFAT. Mice vaccinated with rBbigHSP-70 showed lower parasitemia against the challenge infection with B. microti than GST-vaccinated and non-vaccinated controls. These results added a new member of Babesia heat shock proteins70 that is well conserved among intraerythrocytic protozoa and demonstrated its protective effects in an experimental model of rodent babesiosis.

Epidemiological survey of Theileria orientalis infection in grazing cattle in the eastern part of Hokkaido, Japan.

Theileria orientalis is one of the benign species of Theileria that is widely distributed in Japan and is sometimes responsible for serious economic losses in the livestock industry. In the present study, we surveyed the current status of T. orientalis infection in grazing cattle in the eastern areas of Hokkaido (Taiki, Otofuke, Shintoku, and Shin-Hidaka districts) using molecular methods, as well as traditional methods, of diagnosis. The genes encoding the major piroplasm surface protein (MPSP) and p23 of T. orientalis were identified using highly detectable polymerase chain reaction (PCR). Results of the MPSP-PCR assay indicated that grazing cattle in these districts, after about 1.5 months pasturage, showed high rates of infection, ranging from 10.0-64.8%. Although the main MPSP and p23 genotypes detected were the Ikeda- or Chitose-types, an MPSP gene closely relating to that found in Okinawa prefecture, and a p23 gene closely relating to the Australian (Warwick) Buffeli-type gene, were found in the cattle in Shintoku and Shin-Hidaka districts. The present survey indicated that there were at least five types of T. orientalis classified by their MPSP genes in Hokkaido, Japan, and that T. orientalis infection rates are still high in this region.

Babesia: the protective effects of killed Propionibacterium acnes on the infections of two rodent Babesia parasites in mice.

In the present study, we investigated the protective effects of killed Propionibacterium acnes on the infections of two rodent Babesia parasites in mice. Pre-treatment with "EqStim" (a commercially available immunostimulant containing killed P. acnes) showed significant resistance to both infections. To elucidate the immunological status in the mice, the concentrations of multiple cytokines were measured in serum collected from infected mice. After B. microti infection, the levels of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12p70, and tumor necrosis factor (TNF)-alpha in the treated group were significantly lower than in the control group. In contrast, after B. rodhaini infection, only IL-12p70 and TNF-alpha were detectable at significantly higher levels in the treated group than in the control group. The present findings indicated the protective effects of killed P. acnes on rodent babesiosis even with different immune responses between the B. microti and B. rodhaini infections. Killed P. acnes might be a powerful tool for the control of serious livestock babesiosis.