Parkinson��s disease-linked LRRK2 is expressed in circulating and tissue immune cells and upregulated following recognition of microbial structures

Sequence variants at or near the leucine-rich repeat kinase 2 (LRRK2) locus have been associated with susceptibility to three human conditions: Parkinson's disease (PD), Crohn's disease and leprosy. As all three disorders represent complex diseases with evidence of inflammation, we hypothesized a role for LRRK2 in immune cell functions. Here, we report that full-length Lrrk2 is a relatively common constituent of human peripheral blood mononuclear cells (PBMC) including affinity isolated, CD14(+) monocytes, CD19(+) B cells, and CD4(+) as well as CD8(+) T cells. Up to 26% of PBMC from healthy donors and up to 43% of CD14(+) monocytes were stained by anti-Lrrk2 antibodies using cell sorting. PBMC lysates contained full-length (>260 kDa) and higher molecular weight Lrrk2 species. The expression of LRRK2 in circulating leukocytes was confirmed by microscopy of human blood smears and in sections from normal midbrain and distal ileum. Lrrk2 reactivity was also detected in mesenteric lymph nodes and spleen (including in dendritic cells), but was absent in splenic mononuclear cells from lrrk2-null mice, as expected. In cultured bone marrow-derived macrophages from mice we made three observations: (i) a predominance of higher molecular weight lrrk2; (ii) the reduction of autophagy marker LC3-II in (R1441C)lrrk2-mutant cells (<31%); and (iii) a significant up-regulation of lrrk2 mRNA (>fourfold) and protein after exposure to several microbial structures including bacterial lipopolysaccharide and lentiviral particles. We conclude that Lrrk2 is a constituent of many cell types in the immune system. Following the recognition of microbial structures, stimulated macrophages respond with altered lrrk2 gene expression. In the same cells, lrrk2 appears to co-regulate autophagy. A pattern recognition receptor-type function for LRRK2 could explain its locus' association with Crohn's disease and leprosy risk. We speculate that the role of Lrrk2 in immune cells may also be relevant to the susceptibility of developing PD or its progression.     

Procalcitonin for the early prediction of renal parenchymal involvement in children with UTI: preliminary results

In order to establish the most reliable marker for distinguishing urinary tract infections (UTI) with and without renal parenchymal involvement (RPI), we recorded the clinical features and admission leukocyte count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum procalcitonin (PCT) in 57 children (including 43 girls) aged 2–108 months admitted with a first episode of UTI. RPI was evaluated by Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy within 7 days of admission. To establish cut-off points for ESR, CRP, and PCT, we used receiver operating characteristics curves and compared the area under the curve for ESR, CRP, and PCT. Twenty-seven children were diagnosed as having RPI based on positive renal scintigraphy. A body temperature of >38°C, a history of diarrhea, and poor oral intake were more common in patients with RPI. ESR, CRP, and PCT, but not leukocyte count, were significantly higher in patients with RPI (P < 0.001). PCT was more sensitive and specific for the diagnosis of upper versus lower UTI than ESR and CRP. Using a cut-off value of 0.85 ng/ml, PCT had the best performance, with sensitivity, specificity, and positive and negative predictive values of 89%, 97%, 96%, and 91% respectively. Serum PCT is a better marker than ESR, CRP, and leukocyte count for the early prediction of RPI in children with a first episode of UTI.     

Bile acids in combination with low pH induce oxidative stress and oxidative DNA damage: relevance to the pathogenesis of Barrett's oesophagus

BACKGROUND: Barrett's oesophagus is a premalignant condition associated with an increased risk for the development of oesophageal adenocarcinoma (ADCA). Previous studies indicated that oxidative damage contributes to the development of ADCA. OBJECTIVE: To test the hypothesis that bile acids and gastric acid, two components of refluxate, can induce oxidative stress and oxidative DNA damage. METHODS: Oxidative stress was evaluated by staining Barrett's oesophagus tissues with different degrees of dysplasia with 8-hydroxy-deoxyguanosine (8-OH-dG) antibody. The levels of 8-OH-dG were also evaluated ex vivo in Barrett's oesophagus tissues incubated for 10 min with control medium and medium acidified to pH 4 and supplemented with 0.5 mM bile acid cocktail. Furthermore, three oesophageal cell lines (Seg-1 cells, Barrett's oesophagus cells and HET-1A cells) were exposed to control media, media containing 0.1 mM bile acid cocktail, media acidified to pH 4, and media at pH 4 supplemented with 0.1 mM bile acid cocktail, and evaluated for induction of reactive oxygen species (ROS). RESULTS: Immunohistochemical analysis showed that 8-OH-dG is formed mainly in the epithelial cells in dysplastic Barrett's oesophagus. Importantly, incubation of Barrett's oesophagus tissues with the combination of bile acid cocktail and acid leads to increased formation of 8-OH-dG. An increase in ROS in oesophageal cells was detected after exposure to pH 4 and bile acid cocktail. CONCLUSIONS: Oxidative stress and oxidative DNA damage can be induced in oesophageal tissues and cells by short exposures to bile acids and low pH. These alterations may underlie the development of Barrett's oesophagus and tumour progression.     

Intrapleural fibrinolytic therapy for pleural infection

Pneumonia with secondary pleural infection causes considerable morbidity and mortality. Intrapleural instillation of fibrinolytic agents to dissolve fibrinous adhesions is intended to improve pleural fluid drainage and prevent pleural loculations. In the last 20 years their application in the every day clinical practice has dragged much of attention and several studies have supported their use in the management of parapneumonic pleural effusions (PPE) and pleural empyema (PE). However, recent published data cast doubt on the effectiveness of intrapleural fibrinolytic agents in promoting drainage of infected pleural effusions. Pending future clinical trials, fibrinolytic therapy may be used selectively in patients who fail drainage with appropriately sized, image-guided chest tubes if reasons exist to delay or avoid definitive surgical drainage. The scope of this article is to systematically review evidence for the efficacy of intrapleural fibrinolytic therapy in the treatment of PPE and PE with emphasis on controlled trials and present some of the future perspectives.     

Consequences of transfusion of platelet antibody: a case report and literature review

BACKGROUND: Passive transfer of platelet (PLT) antibody by blood transfusion can lead to severe thrombocytopenia, bleeding, and an acute transfusion reaction. CASE REPORT: A 49‐year‐old male on warfarin developed thrombocytopenic bleeding within 2 hours of transfusion with a single unit of fresh‐frozen plasma (FFP). The patient's PLT count on admission was 122 × 10⁹ per L. Two hours after transfusion, PLT count has decreased to 5 × 10⁹ per L. The patient's PLT antibody screen by solid‐phase enzyme‐linked immunosorbent assay was negative and his genotype was HPA‐1a/1b. The donor's genotype was HPA‐1b/1b and antibody screen revealed anti‐HPA‐1a. A lookback investigation identified another case of severe thrombocytopenia after FFP infusion 4 years previously. REVIEW OF LITERATURE: A literature review identified 19 cases of passive transfer of PLT antibody that resulted in thrombocytopenia. The PLT nadir of 7 × 10⁹ per L was reached within 6 hours after transfusion with a median time to PLT recovery of 5 days. Transfusion was accompanied by an acute transfusion reaction in 30 percent of recipients. Approximately 75 percent of recipients developed thrombocytopenic bleeding. All cases involved a female donor with a history of pregnancy. High‐plasma‐volume components accounted for the majority of cases while anti‐HPA‐1a was the most frequently implicated antibody. CONCLUSION: Unexplained posttransfusion thrombocytopenia should be investigated to rule out passive transfer of PLT antibodies. Implicated donors should be deferred from subsequent donations. Switching to predominantly male plasma for transfusion may lead to reduction in cases of thrombocytopenia due to passive transfer of PLT antibody. Rational use of blood products may further reduce incidence of this complication.     

Meta-iodobenzylguanidine, an inhibitor of arginine-dependent mono(ADP-ribosyl)ation, prevents neointimal hyperplasia

The association of ADP-ribosylation with cell proliferation and ischemia-reperfusion injury suggests that it may be a suitable target for therapeutic control of revascularization-induced injury. The purpose of this study was to investigate the inhibitory actions of ADP-ribosylation inhibitors on restenosis. In organ culture, the poly(ADP-ribose) polymerase (PARP) inhibitor 3,4-dihydro-5-methylisoquinolinone (PD128763) was unable to prevent neointimal hyperplasia, whereas the arginine-dependent mono(ADP-ribosyl)transferase (ART) inhibitor meta-iodobenzylguanidine (MIBG) was highly effective (EC(50) 21 microM). Treatment with 3-aminobenzamide (3AB), a less potent ART inhibitor, also produced a significant reduction in neointimal hyperplasia. Single doses (25 mM) of MIBG and 3AB were also applied within a fibrin coagulum directly to the adventitial surface of the porcine femoral artery after balloon catheter injury in vivo. MIBG reduced the neointimal index, measured 14 days after angioplasty, by 82%, whereas 3AB was ineffective. However, when extended to 45 days, the neointimal index was not significantly decreased by MIBG treatment relative to control. Assessment of MIBG release from the fibrin glue showed that the bulk of the compound was eluted within 3 days, suggesting that the vehicle was not suitable for long-term delivery. On the other hand, direct infusion of MIBG into vessels was able to reduce neointimal hyperplasia over 14 days in organ culture. These data support the conclusion that the cellular retention characteristics of MIBG contribute significantly to the efficacy of this compound. Based on these results, ART, but not PARP, may be a credible target for therapeutic treatment of restenosis.