Biomaterial Database

[Activation of the alternative complement pathway in pleural fluid of patients with pneumonia]. 1982

M T Aguado, and A Celada

It has been reported that the opsonic activity of pleural fluid is decreased in patients with pneumonia complicated by infected effusions (empyema) compared to those with sterile (metapneumonic) effusions. In this paper some parameters of complement activity in 12 patients with empyema and in 13 patients with metapneumonic effusions were compared. The hemolytic activity of the alternative pathway and of Factor B in empyemas (15 +/- 10% and 25+15%, respectively) was less than that measured in metapneumonic effusions (55 +/- 38% and 71 +/- 21%; p less than 0.01). Both parameters showed a significant correlation (r=0.76; p less than 0.01). The Ba fragment, a catabolic product of Factor B, was increased in empyema (125 +/- 59%) compared to that in metapneumonic effusions (49 +/- 24%; p less than 0.01). The levels of C3, protein of both, alternative and classical pathways, were decreased in empyema (17 +/- 29%) when compared with the levels in metapneumonic pleural effusion (42 +/- 20%; p less than 0.01). The levels of this protein were correlated with the activity of alternative complement pathway (r=0.68; p less than 0.01), as well as with those of Factor B (r=0.75; p less than 0.01). Finally, the hemolytic activity of C4, as a representative element of the classical pathway, has also shown to be decreased in empyema (6 +/- 6%) compared to metapneumonic fluids (27 +/- 28%; p less than 0.01). Significant correlations between the hemolytic activity of C4 and levels of C3 (r=0.75; p less than 0.01), the hemolytic activity of the alternative pathway (r=0.63; p less than 0.01) and the levels of Factor B (r=0.73; p less than 0.01) were demonstrated. This last suggest a simultaneous activation of both, classical and alternative pathways of complement. The complement decrease and particularly, the activation of the alternative pathway in patients with empyema could be a determinant factor of the deficient bacterial opsonization. This can explain the survival of bacteria in an empyema despite the large number of neutrophils present.

UI	MeSH Term	Description	Entries
D009895	Opsonin Proteins	Proteins that bind to particles and cells to increase susceptibility to PHAGOCYTOSIS, especially ANTIBODIES bound to EPITOPES that attach to FC RECEPTORS. COMPLEMENT C3B may also participate.	Opsonin,Opsonin Protein,Opsonins,Protein, Opsonin
D010996	Pleural Effusion	Presence of fluid in the pleural cavity resulting from excessive transudation or exudation from the pleural surfaces. It is a sign of disease and not a diagnosis in itself.	Effusion, Pleural,Effusions, Pleural,Pleural Effusions
D011014	Pneumonia	Infection of the lung often accompanied by inflammation.	Experimental Lung Inflammation,Lobar Pneumonia,Lung Inflammation,Pneumonia, Lobar,Pneumonitis,Pulmonary Inflammation,Experimental Lung Inflammations,Inflammation, Experimental Lung,Inflammation, Lung,Inflammation, Pulmonary,Inflammations, Lung,Inflammations, Pulmonary,Lobar Pneumonias,Lung Inflammation, Experimental,Lung Inflammations,Lung Inflammations, Experimental,Pneumonias,Pneumonias, Lobar,Pneumonitides,Pulmonary Inflammations
D011415	Complement Factor B	A glycine-rich, heat-labile serum glycoprotein that contains a component of the C3 CONVERTASE ALTERNATE PATHWAY (C3bBb). Bb, a serine protease, is generated when factor B is cleaved by COMPLEMENT FACTOR D into Ba and Bb.	C3 Proactivator,C3PA,Complement 3 Proactivator,Factor B,Properdin Factor B,Bb Fragment of Factor B,Complement Factor B Fragment, Bb,Complement Factor B, Alternative Pathway,Complement Factor B-Derived Fragment Bb,Complement Factor Ba,Complement Factor Bb,Complement Protein B,Complement Protein Factor B,Properdin Factor Ba,Properdin Factor Bb,Properdin Factor Bf,Properdin Factor Bf F1,Bb, Complement Factor,Complement Factor B Derived Fragment Bb,Factor B, Complement,Factor B, Properdin,Factor Ba, Complement,Factor Ba, Properdin,Factor Bb, Complement,Factor Bb, Properdin,Factor Bf, Properdin,Proactivator, C3,Proactivator, Complement 3,Protein B, Complement
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003170	Complement Pathway, Alternative	Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D003181	Complement C4	A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.	C4 Complement,C4 Complement Component,Complement 4,Complement C4, Precursor,Complement Component 4,Pro-C4,Pro-complement 4,C4, Complement,Complement Component, C4,Complement, C4,Component 4, Complement,Component, C4 Complement,Pro C4,Pro complement 4
D004653	Empyema	Presence of pus in a hollow organ or body cavity.
D006461	Hemolysis	The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.	Haemolysis,Extravascular Hemolysis,Intravascular Hemolysis,Extravascular Hemolyses,Haemolyses,Hemolyses, Extravascular,Hemolyses, Intravascular,Hemolysis, Extravascular,Hemolysis, Intravascular,Intravascular Hemolyses