Quan S F, Witten M L, Grad R, Ray C G, Lemen R J
Department of Internal Medicine, University of Arizona, Tucson.
Pediatr Pulmonol. 1991;10(4):236-43. doi: 10.1002/ppul.1950100403.
We determined the effects of an immediately antecedent viral lower respiratory tract infection (LRI) on the severity of clinical illness, changes in lung function and airway histamine responsiveness produced by a subsequent LRI in 9-12 week old beagle puppies inoculated with canine adenovirus 2, followed in 2 weeks by inoculation with canine parainfluenza 2 virus (CAV2-CP12, n = 7). We compared their acute responses to puppies infected with CP12 alone (n = 5), CAV2 alone (n = 7), and no infection (control, n = 6). Puppies inoculated with either virus alone developed a LRI 3 to 6 days after inoculation which resolved by 12-14 days after inoculation. However, the illness was more severe in the CAV2 group. In the CAV2-CP12 group, CP12 infection following CAV2 infection resulted in a clinical illness nearly comparable to that observed with CAV2 alone. Whereas in control and CP12 puppies, lung resistance (RL) decreased and dynamic lung compliance (Cdyn) increased during the study due to normal growth, RL increased and Cdyn remained unchanged in the CAV2 group. In contrast, RL did not change and Cdyn increased in the CAV2-CP12 group. Airway histamine responsiveness in the CAV2-CP12 group increased during infection with CP12 and was similar to that observed with CAV2 alone. In contrast, infection with CP12 alone produced a small, but non-significant increase in histamine responsiveness. The duration of the increase in histamine responsiveness was not prolonged in the CAV2-CP12 group in comparison to CP12 or CAV2 alone. However, the length of clinical illness was extended in the CAV2-CP12 group in comparison to the other infected groups. These data suggest that an immediately antecedent viral LRI can potentiate the clinical and physiologic effects of a subsequent viral LRI.
我们研究了在9至12周龄的比格幼犬中，先前立即发生的病毒性下呼吸道感染（LRI）对随后LRI所导致的临床疾病严重程度、肺功能变化及气道组胺反应性的影响。这些幼犬先接种犬腺病毒2型，2周后再接种犬副流感2型病毒（CAV2-CP12，n = 7）。我们将它们的急性反应与单独感染CP12的幼犬（n = 5）、单独感染CAV2的幼犬（n = 7）以及未感染的幼犬（对照组，n = 6）进行了比较。单独接种任何一种病毒的幼犬在接种后3至6天出现LRI，接种后12至14天症状缓解。然而，CAV2组的疾病更为严重。在CAV2-CP12组中，CAV2感染后再感染CP12导致的临床疾病与单独感染CAV2时观察到的情况几乎相当。而在对照组和CP12幼犬中，由于正常生长，在研究期间肺阻力（RL）下降，动态肺顺应性（Cdyn）增加，CAV2组中RL增加而Cdyn保持不变。相比之下，CAV2-CP12组中RL没有变化而Cdyn增加。CAV2-CP12组在感染CP12期间气道组胺反应性增加，且与单独感染CAV2时观察到的情况相似。相比之下，单独感染CP12仅使组胺反应性有小幅但不显著的增加。与单独的CP12或CAV2相比，CAV2-CP12组中组胺反应性增加的持续时间并未延长。然而，与其他感染组相比，CAV2-CP12组的临床疾病持续时间延长。这些数据表明，先前立即发生的病毒性LRI可增强随后病毒性LRI的临床和生理效应。
