Gould S J, Isaacson P G
Department of Histopathology, Middlesex School of Medicine, University College London, U.K.
J Pathol. 1993 Feb;169(2):229-34. doi: 10.1002/path.1711690209.
Bronchus-associated lymphoid tissue (BALT) has been defined as the organized lymphoid tissue of the lung. Although well described in a variety of animal species, documentation of its presence and development in human lung is limited. Because the tissue to volume ratio in adult lungs is so low, a systematic search for BALT would involve so many sections as to be impractical. In this study, therefore, we have studied post-mortem specimens of fetal (n = 102) and infant (n = 17) lungs, which have a much higher tissue to volume ratio. Fetal death was due to various causes but all but two infants died from sudden infant death syndrome. In the fetal lungs, the presence of BALT was almost invariably associated with chorioamnionitis or intrauterine pneumonia, being present in 24 of 51 of these cases (47 per cent). The earliest ill-defined lymphoid aggregate was seen at 16 weeks' gestation, while lymphoepithelium, a hallmark of mucosa-associated lymphoid tissue, could be identified at 20 weeks. In 51 fetuses without infection, BALT was found in only five cases (10 per cent). BALT was identified in 13/17 (77 per cent) of infant lungs and well-developed lymphoepithelium was evident in four cases. This study shows that BALT may be present in the human fetal and infant lung, but that its appearance is probably dependent on antigenic stimulation.
支气管相关淋巴组织（BALT）被定义为肺内有组织的淋巴组织。尽管在多种动物物种中已有详细描述，但关于其在人肺中的存在和发育的文献却很有限。由于成人肺组织与体积的比例很低，系统地寻找BALT需要切取大量切片，不太实际。因此，在本研究中，我们研究了胎儿（n = 102）和婴儿（n = 17）肺的尸检标本，其组织与体积的比例要高得多。胎儿死亡原因各异，但除两名婴儿外，其他均死于婴儿猝死综合征。在胎儿肺中，BALT的存在几乎总是与绒毛膜羊膜炎或宫内肺炎相关，在51例此类病例中有24例（47%）存在BALT。最早的界限不清的淋巴聚集物在妊娠16周时可见，而黏膜相关淋巴组织的标志——淋巴上皮在20周时可被识别。在51例无感染的胎儿中，仅5例（10%）发现有BALT。在17例婴儿肺中有13例（77%）识别出BALT，4例可见发育良好的淋巴上皮。本研究表明，BALT可能存在于人类胎儿和婴儿肺中，但其出现可能依赖于抗原刺激。
