39.關於肺泡蛋白沉著症（pulmonary alveolar proteinosis，PAP）的敘述，下列何者錯誤？
(A)肺泡內堆積PAS（Periodic acid-Schiff）陽性物質
(B)肺功能呈現阻塞性通氣障礙
(C)肺泡巨噬細胞功能障礙
(D)可能與吸入有毒物質有關，如矽酸鹽（Silica）

Pulmonary alveolar proteinosis (PAP) :
1. 肺泡內 eosinophilic, periodic acid-Schiff (PAS)-positive 物質的累積
2. 遠端氣道發展成restrictive肺功能障礙進而造成呼吸衰竭甚至死亡
3. Two general categories of PAP exist:
      a) autoimmune
      b) non-autoimmune.
           (1)hereditary
           (2)secondary.
 4.病理生理：
More than 90% of PAP cases are caused by defective granulocyte macrophage colony-stimulating factor (GM-CSF) signaling due to high levels of circulating autoantibodies that prevent GM-CSF binding to its receptor (autoimmune PAP).
Three main etiologies of secondary PAP have been identified: (1) lung infections, including Pneumocystis carinii pneumonia in patients with and without AIDS; (2) hematologic malignan- cies and other immune-altering conditions; and (3) exposure to inhaled chemicals and minerals. Several toxic insults to the lung (e.g., silica, NO2, ozone, and ONOO-) can result in alveolar proteinosis.

From：Manual of clinical Problems in Pulmonary Medicine 7ed.