Pfizer公司(New York, NY, USA)和Monogram生物科學公司(South San Francisco, CA, USA)已經宣布了 一項非排他性合作項目，將Monogram公司的HIV共同受體趨化性檢測在全球范圍內推廣。該檢測是一項診斷工具，顯示趨向性，這是病毒進入人CD4細胞的途徑。

CD4或者T細胞是一種能夠保護機體免于感染的特定免疫細胞。HIV攻擊這些類型的細胞，并利用它們復制更多拷貝的HIV。在此過程中CD4細胞不能發揮保護機體的正常功能。開始的時候機體能夠制造更多T細胞，但是最終有功能的T細胞數量銳減。這就削弱了免疫系統，導致機體面臨各種感染的危險。

趨化性信息能夠幫助鑒別最有可能對CCR5拮抗劑產生反應的患者。這是一組被設計用于阻斷病毒通過CCR5共同受體進入體內的藥物。研究顯示80-85%剛診斷為HIV以及既往沒有接受HIV治療的患者，絕大多數是 therapy have the dominant CCR5趨向性病毒。在以前接受過抗逆轉錄藥物治療的患者中下降為50-60%。

Pfizer and Monogram Collaborate on HIV Tropism Assay
 
Pfizer Inc. (New York, NY, USA) and Monogram Biosciences (South San Francisco, CA, USA) have announced a non-exclusive collaboration to make Monogram’s HIV co-receptor tropism assay available for use on a global basis. The assay is a diagnostic tool to show tropism, the path taken by the virus to access human CD4 cells.

CD4 or T-cells are specialized immune cells that help protect the body from infection. HIV attacks these types of cells and uses them to make more copies of HIV. In doing so, the CD4 cell becomes unable to do its job of protecting the body. At first, the body can make more T-cells but eventually the number of working T-cells decreases. This weakens the immune system and leaves the body at risk for different types of infections.

Tropism information helps identify patients most likely to respond to CCR5 antagonists. These are a class of drugs designed to block viral entry through the CCR5 co-receptor. Studies have shown that 80-85% of patients newly diagnosed with HIV and previously untreated with HIV therapy have the dominant CCR5-tropic virus. This drops to 50-60% in patients who have been treated before with anti-retroviral medicines.