Also, the IGRA is more specific to TB rather than other types of mycobacterial infections and is unlikely to be positive as a result of having BCG vaccine in the past, a vaccine that protects against TB.

而且IGRA对于TB来说有更高的准确性，而不会对其它类型的分枝杆菌的感染出现反应，且IGRA并不会对于曾经接种过卡介苗的患者出现阳性反应；卡介苗是一种抵抗肺结核的疫苗。

If the underlying reason is an infection, like a bacterial or mycobacterial infection, then it's also possible for that infection to spread into the pleural space which is a walled off space - a bit like an enormous abscess.

如果原发病是感染，如细菌或分歧杆菌感染，那么感染也可能蔓延到胸膜腔，即一个被包绕的空间，有点像巨大的脓肿。