How to Perform Cryptococcus Antigen Testing

Detection of antigen in serum and cerebrospinal fluid (CSF) has been a significant advance in the diagnosis of cryptococcosis, with a sensitivity and specificity for cryptococcal meningitis exceeding 95%.

Cryptococcal antigen為陰性，血液或腦脊髓液發現Positive，可能感染新型隱球菌，會通報危險值。 血清會先經protease之處理，可降低偽陽性反應的可能性，增加實驗之特異性。 偽陽性 : 1.Trichosporon beigelii會產生多醣體抗原的交互反應，造成陽性之結果；2.當檢體溶血，血球內的物質釋放出來與試劑產生反應或當檢體有雜質顆粒時，會使結果判讀成有凝集。

利用測定血清、脊髓液或其他體液中Cryptococcus neoformans的莢膜多醣體抗原 ( capsular polysaccharide antigen )可協助CNM的診斷。 陽性結果顯示檢體中存在隱球菌抗原，但這並非隱球菌感染的診斷標準。 需要重複檢測和進行確認試驗才能確診。 此測定法具有偵測極限 (LOD)。 陰性結果不能用於排除隱球菌感染。 資料來源：Dynamiker Cryptococcal Antigen Lateral Flow Assay試劑說明書。

The College of American Pathologists (CAP) requires that Cryptococcal antigen detection testing performed on CSF specimens be confirmed by culture (CAP MIC.42005).

We searched MEDLINE and Embase for studies where CrAg detection in serum/cerebrospinal fluid (CSF) and CSF fungal culture were done on adults living with human immunodeficiency virus (HIV) who had suspected cryptococcal meningitis (CM).

CSF檢體常用於診斷腦膜炎新型隱球菌感染及治療效果評估。

A false-negative cryptococcal antigen (CrAg) in cerebrospinal fluid (CSF) is one of the potential confounders in the diagnosis of cryptococcal meningitis in CSF samples during routine clinical care.