fibrin and Respiratory-Tract-Infections

Topics: Acute Kidney Injury; Adolescent; Adult; Child; Child, Preschool; Diarrhea; Female; Fibrin; Humans; Hypocalcemia; Infant; Infant, Newborn; Kidney; Kidney Tubules; Male; Microscopy, Electron; Muscles; Muscular Diseases; Myofibrils; Myoglobinuria; Necrosis; Phosphorus; Respiratory Distress Syndrome, Newborn; Respiratory Tract Infections; Staining and Labeling; Tetany; Thrombosis

Fibronectin (FN) is able to bind fibrin and FN-fibrin complexes and is found in the plasma of some patients suffering from inflammatory disease. The present study was undertaken to determine whether soluble supra-molecular FN-fibrin complexes were present in the plasma of children with recurrent respiratory infections (RRI).. The frequency of occurrence and relative amounts of the supra-molecular FN-fibrin forms, concentrations of immunoglobulins and numbers of natural killer cells (NK) were determined in the plasma of children with recurrent respiratory infections. The frequencies of these parameters were compared with their frequencies in the plasma of children with acute respiratory infections and plasma from healthy children.. SDS-agarose immunoblotting of patients' plasma revealed the presence of several additional FN-fibrin bands, with decreasing electrophoretic mobilities and increasing molecular masses of 750 kDa, 1000 kDa, 1300 kDa, 1600 kDa and 1900 kDa. Such FN-fibrin complexes occurred with higher frequency and in larger amounts in the plasma of children with RRI and acute infection than they did in plasma from normal children. Moreover, bands above 1000 kDa were absent in most young healthy individuals. The occurrence of FN-fibrin complexes did not correlate with either immunoglobulin concentrations, or with the number of NK cells.. The occurrence of plasma supra-molecular FN-fibrin complexes is associated with acute and recurrent respiratory infections of children.

Topics: Child; Female; Fibrin; Fibrin Fibrinogen Degradation Products; Fibronectins; Humans; Immunoblotting; Immunoglobulins; Killer Cells, Natural; Male; Molecular Weight; Plasma; Recurrence; Respiratory Tract Infections

Topics: Blood Platelets; Cell Adhesion; Fibrin; Gram-Positive Bacterial Infections; Gram-Positive Cocci; Host-Pathogen Interactions; Humans; Immune Evasion; Platelet Activation; Respiratory Tract Infections; Thrombospondin 1; Virulence

Platelets and coagulation are involved in bacterial colonisation of the host. Streptocococcus pneumoniae (pneumococcus) are important etiologic agents of respiratory tract infections in humans. The formation of pneumococci-platelet associations may facilitate haematogenous dissemination of pneumococci by providing an adhesive surface on damaged endothelium. However, the formation of platelet-pneumococci associations and the factors involved in this process have not been described so far. The formation of platelet-pneumococci associates was analysed and quantified using flow cytometry. Binding of pneumococci to platelets was significantly increased after activation of platelets with thrombin, while platelet activation by ADP or collagen did not promote formation of platelet-pneumococci associates. In addition to be a platelet agonist, thrombin cleaves fibrinogen, which results in the generation of fibrin. The simultaneous formation of fibrin and activation of platelets was shown to be a prerequisite for a high number of platelet-pneumococci associates. Moreover, exogenously added human thrombospondin-1 (TSP-1) significantly enhanced the association of pneumococci with activated platelets. Soluble fibrin and TSP-1 are key co-factors of platelet-pneumococci-association. Similar results were recently demonstrated for S. aureus-platelet adhesion. Consequently, we hypothesise that the described mechanism of platelet-bacteria-association might represent a general and important strategy of Gram-positive bacteria during development of invasive diseases.

Topics: Adenosine Diphosphate; Blood Platelets; Cell Adhesion; Cells, Cultured; Fibrin; Fibrinogen; Host-Pathogen Interactions; Humans; Platelet Activation; Respiratory Tract Infections; Streptococcal Infections; Streptococcus pneumoniae; Thrombin; Thrombospondin 1

Topics: Adolescent; Adult; Aged; Candidiasis; Child; Child, Preschool; Deglutition Disorders; Epithelial Cells; Esophagitis; Female; Fibrin; Heart; Herpes Simplex; Humans; Lung; Male; Middle Aged; Necrosis; Pneumonia; Respiratory Tract Infections; Simplexvirus; Trachea

Topics: Adolescent; Child; Child, Preschool; Female; Fibrin; Glomerulonephritis; Hematuria; Humans; Hypersensitivity; Immunoglobulin A; Immunoglobulin G; Immunosuppression Therapy; Male; Proteinuria; Purpura; Respiratory Tract Infections; Serum Globulins