Epstein M M, Baumgarten A
Yale University, Department of Medicine, New Haven, Conn.
J Allergy Clin Immunol. 1991 Sep;88(3 Pt 1):356-60. doi: 10.1016/0091-6749(91)90097-8.
Secretory IgA is a dimeric immunoglobulin found in association with the J chain and secretory component (SC). It is secreted into saliva and other mucosal fluids and is involved in mucosal immunity. The absence of either SC or secretory IgA may be associated with recurrent sinopulmonary infections, diarrhea, and failure to thrive. We present a retrospective study of 1262 samples from 877 patients who were screened for salivary IgA, SC, and serum immunoglobulin levels. Forty-six patients (5.2%) of those tested were found to have absent salivary SC. Although only 19 of these patients (41.3%) could be retested, all were found to have SC on repeated testing. Of the patients whose initial samples of saliva exhibited no SC, 15% (6/46) had low or absent serum IGA (less than 10 mg/dl) in contrast to 8.6% (66/769) of patients whose saliva contained detectable SC, but this was not statistically significant (chi 2 = 1.93; p greater than 0.1). There was also no correlation between serum immunoglobulin levels and the absence of SC. Because of the rarity of salivary SC deficiency, routine screening is not valuable.
分泌型IgA是一种与J链和分泌成分（SC）相关的二聚体免疫球蛋白。它分泌到唾液和其他粘膜液中，并参与粘膜免疫。SC或分泌型IgA的缺乏可能与反复的鼻窦肺部感染、腹泻和发育不良有关。我们对877例患者的1262份样本进行了回顾性研究，这些患者接受了唾液IgA、SC和血清免疫球蛋白水平的筛查。在接受检测的患者中，有46例（5.2%）唾液SC缺失。尽管这些患者中只有19例（41.3%）能够再次接受检测，但所有患者在重复检测时均发现有SC。在唾液初始样本中未检测到SC的患者中，15%（6/46）血清IgA水平低或缺乏（低于10mg/dl），而唾液中可检测到SC的患者中这一比例为8.6%（66/769），但差异无统计学意义（卡方 = 1.93；p>0.1）。血清免疫球蛋白水平与SC缺失之间也没有相关性。由于唾液SC缺乏罕见，常规筛查没有价值。
