Lymphoid Tissue BALT

From the lungs of 34 patients (aged 59 23 years) who had died of non-lung associated diseases and with no history of respiratory tract diseases, no BALT could be identified (Pabst and Gehrke 1990). Hiller et al. (1998) in a study of 27 further lungs of patients over 20 years of age in only 3 cases found small BALT structures. Lun kova et al. (1998) reported similar findings. 

BALT is significantly more frequent in smokers and recent ex-smokers ( 2 years) as compared to never-smokers and longer term ex-smokers ( 2 years) (P 0.01) in age and sample-matched groups (Richmond et al. 1992). Endobronchial biopsies of second- and third-generation bronchi taken from 44 non-smoking elite cross-country skiers showed small BALT in 64% of skiers but in only 25 % of their control subjects (Sue-Chu et al. 1998). 

In the Wistar rat, lymphoid aggregates of the bronchi and bronchioles varied from small collections of mononuclear cells limited to the lamina propria of the airway to large nodules that extended through the muscularis and merged into the peribronchial connective tissue or the walls of adjacent alveoli (Chamberlain et al. 1973). 

Scanning electron microscopic photographs of rabbit bronchial epithelium showed islands of lym-poepithehum varying from a few to a few hundred cells surrounded by a carpet of ciliated epithelium (Bienenstock and Johnston 1976). The flattened cells devoid of dlia consistently possessed small membrane projections, subsequently identified as microvilli by transmission electron microscopy. The lymphoepithelial cells generally contained mitochondria, but endoplasmic reticulum, pinocytotic vesicles, and phagosomes were not a feature. 

In the BALT of perfused male Sprague-Dawley rats, expression of eNOS (NOS-3) was markedly suppressed under entotoxin challenge, while cellu- 

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Tschernig T, Pabst R Bronchus-associated lymphoid tissue (BALT) is not present in the normal adult lung but in different diseases. Pathobiology 2000 68 1-8. 

Breel, M., Van der Ende, M., Sminia, T. and Kraal, G. (1988). Subpopulations of lymphoid and non-lymphoid cells in bronchus-associated lymphoid tissue (BALT) of the mouse. Immunolc 63, 657-662. 

Nohr, D. and Weihe, E. (1991). The neuroimmune link in the bronchus-associated lymphoid tissue BALT) of cat and rat peptides and neural markers. Brain Behav. Immun. 5, 84-101. 

Richmond I, Pritchard GE, Ashcroft T, et al. Bronchus associated lymphoid tissue (BALT) in human lungs Its distribution in smokers and nonsmokers. Thorax. 1993 48 1130-1134. 

Delventhal S, Hensel A, Petzoldt K, et al. Effects of microbial stimulation on the number, size and activity of bronchus-associated lymphoid tissue (BALT) structures in the pig. Int J Exp Pathol 1992 73(3) 351-357. 

Delventhal S, Brandis A, Ostertag H, et al. Low incidence of bronchus-associated lymphoid tissue (BALT) in chronically inflamed human lungs. Virchows Arch B Cell Pathol Include Mol Pathol 1992 62(4) 271-274. 

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