Polymorphic neutrophils

The immune system is divided into two defense mechanisms nonspecific, or innate, and specific, or adaptive, mechanisms fhat recognize and respond to foreign substances. Some of the important cellular components of nonspecific and specific immunity are described in Table 9.2. The nonspecific immune sysfem is the first line of defense againsf infectious organisms. Its cellular components are the phagocytic cells such as the monocytes, macrophages, and polymorphic neutrophils (PMNs). 

These polymorphs are divided into three subgroups by virtue of the staining properties of their cytoplasmic contents when treated with dye mixtures. Thus, eosinophils stain with acid dyes such as eosin and appear red in stained blood films, basophils stain with basic dyes and appear blue whilst neutrophils stain with both types of dye and their cytoplasm appears purple. The differences between the cytoplasmic contents in these cells types is much more fundamental than is suggested by these simple staining properties. The granules of basophils, neutrophils and eosinophils contain distinct molecular constituents that confer upon the cells their specialised functions during infection and inflammation. 

The full name of these cells is neutrophilic polymorphonuclear leukocytes, but the terms neutrophil and, less-commonly now, polymorph are generally used to describe this cell (Fig. 1.1a). In fact, most preparations of neutrophils contain about 95-97% neutrophils, the remainder being largely eosinophils, because the commonly-used separation techniques do not efficiently separate these cell types. Neutrophils are the most abundant white cell in the blood, accounting for 40-65% of white blood cells, and are found at concentrations usually in the range 3-5 x 106 cells/ml blood. This number can increase dramatically (up to tenfold) in cases of infection. They have a relatively short half-life in the circulation (estimated at about 8-20 h), but this may be extended to up to several days if the cells leave the circulation and enter tissues - although it is difficult to measure the lifespan of a tissue neutrophil. Because of the large numbers of neutrophils in the circulation and their relatively short lifespan, vast numbers of neutrophils enter and... 

Figure 1.1. Electron micrographs of leukocytes (a) neutrophil, showing polymorphic nucleus and numerous cytoplasmic granules (b) eosinophil, showing distinctive granules with crystalline core (c) monocyte, with horseshoe-shaped nucleus (d) small lymphocyte. Magnification x7000.

LE cells are neutrophil polymorphs, which have phagocytosed the basophilic nuclear material of leucocytes, which has been altered by interaction with antinuclear antibodies. The development of ANA requires a lower intake of hydralazine and occurs more quickly in slow acetylators than in rapid acetylators, and rapid acetylators have significantly lower titers of ANA than slow acetylators. There is also a significant correlation between the cumulative dose of hydralazine and the development of ANA, but as indicated above, patients who develop LE do not have a significantly different cumulative intake of hydralazine from those patients who do not develop the syndrome. 

Sodium azide/hydrogen peroxide solution blocks endogenous peroxidase enzyme activity This is important m cervical smears where large numbers of neutrophil polymorphs and red blood cells are present. Although often not essential when analyzing cultured cells or biopsies, incubation m this solution is equally effective with these sample types. 

Fever, cardiac murmur and vegetations are not invariably present in patients with infective endocarditis, and blood cultures are indicated in unexplained stroke particularly if there is raised erythrocyte sedimentation rate, mild anemia, neutrophil leukocytosis or a history of intravenous drug abuse. The cerebrospinal fluid (CSF) can be normal, but > 100 X 10 cells/l polymorphs is said to suggest endocarditis, although similar counts have been described in intracerebral hemorrhage and in hemorrhagic transformation of an infarct, but not in ischemic stroke (Powers 1986). 

Stroke-related inflammation in the brain appears to largely result from a selective migration and infiltration of systemic (i.e., circulating) leukocytes to the focus of cerebral ischemia. These cells are predominantly those of the innate immune system, at least initially. Activated neutrophil polymorphs begin to infiltrate as early as 4h after stroke, initially being... 

Yang J, Qiao FIL, Dong ZM (2005) Polymorphisms of IL-13 and IL-4-IL-13-SNPs inpatients with penicillin allergies. Eur J Clin Pharmacol 61 803-809 Yee SB, Bourdi M, Masson MJ, Pohl LR (2007) Hepatoprotective role of endogenous interleukin-13 in a murine model of acetaminophen-induced liver disease. Chem Res Toxicol 20 734—744 You Q, Cheng L, Reilly TP, Wegmann D, Ju C (2006) Role of neutrophils in a mouse model of halothane-induced liver injury. Hepatology 44 1421-1431... 

Neutrophils are polymorph nuclear cells that are critical for defense against bacterial and fungal infections. Neutrophils are traditionally known to express only a very limited number of chemokine receptors and the recruitment of these phagocytes to the side of infection is mainly directed by the CXC chemokine subfamily, in particular CXCRl and CXCR2 [11-13]. However, the expression pattern of the chemokine receptors on the neutrophil is subjected to change. Hartl et al. (2008) described that neutrophils while infiltrating at the pulmonary and synovial site of inflammation... 

Kefalas, P., Allport, J.R., Donnelly, L.E., Rendell, N.B., Murray, S., Taylor, G.W., Lo, G., Yadollah-Farsani, M. and MacDermot, J. (1997) Arginine specific mono(ADP-ribosyl)-transferase activity in human neutrophil polymorphs. A possible link with the assembly of filamentous actin and chemotaxis. Adv. Exp. Med. Biol 419, 241-244. 

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