Phagocytes, functional defects

Phagocyte function defects Neutrophils deficient in H2O2... 

Primary defects in neutrophils expose individuals to recurring infections. These defects may be due to a variety of causes such as neutrophil adhesion defects, defects in phagocyte function, and other causes. 

Defective phagocytosis by neutrophils in CGD can be demonstrated by the classical nitroblue terazolium test by the absence of dark-blue staining of the cytoplasm, in contrast, normal neutrophils with efficient phagocytic function exhibit dark-blue cytoplasmic staining (84). Flow cytometry is also a powerful tool for the study of CGD (85). 

Thus a variety of biochemical defects can compromise the phagocytic function of neutrophils (see Table 8). 

V7. Vazquez Doval, J., and Sanchez Ibarrola, A., Defective mononuclear phagocyte function in systemic lupus erythematosus Relationship of FcRII (CD32) with intermediate cytoskeletal filaments. J. Inv. Allergol. Clin. Immunol. 3, 86-91 (1993). 

Although not readily quantifiable, abnormalities may exist in granulocyte function, as well as in cell numbers. Defects in phagocyte function may be caused by underlying disease (e.g., leukemia) or its treatment (e.g., corticosteroids, antineoplastic agents, and radiation). ... 

The role of complement factors with respect to opsonization and phagocytic function has led to the development of a number of new tests which take into consideration criteria other than counting ingested particles under the microscope (Yl, W5, LI). However, even when a defective opsonization has been recognized, the question of the biochemical level of the opsonic defect remains to be elucidated. 

As larger amounts of complexes are infused into experimental animals, the rate of clearance slows and vascular lesions appear, presumably as a result of overload (B9, HI, H2). Similar phenomena may occur in man, and impaired clearance has been demonstrated in several diseases associated with manifestations of immune complex deposition including systemic lupus erythematosus (F9, H8, K9, L19, P2), primary biliary cirrhosis (G19), Sjogren s syndrome (H9), and dermatitis herpetiformis (L6). Impaired clearance may be a result of circulatory overload by immune complexes, or a primary defect in mononuclear phagocytic system function may contribute or predispose to immune complex deposition (A15, A16, HI). However, impaired clearance, as currently measured, is neither a prerequisite nor a consistent consequence of immune complex disease. 

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