Department of Internal Medicine, Center for Rheumatic Diseases, Dohgo Spa Hospital, 21-21 Otsu Dohgo-Himezuka, Matsuyama, Ehime 790-0858, Japan.
Mod Rheumatol. 2012 Sep;22(5):750-7. doi: 10.1007/s10165-011-0587-4. Epub 2012 Jan 12.
The expression level of CD64 on neutrophils can be used to differentiate between an infection and a disease flare in rheumatoid arthritis (RA) patients. However, the CD64 expression is elevated by both bacteria and viruses, so it cannot be used to distinguish the type of infection. We herein investigated the results of a simultaneous quantitative analysis of the expression of CD64 and CD35 on neutrophils to determine whether these molecules can be used to distinguish between bacterial and viral infections in RA patients.
We collected blood from 22 RA patients with pathogen-proven infections (15 bacterial and 7 viral infections). Blood samples were stained with QuantiBRITE CD64PE/CD45PerCP and CD35PE, and the mean fluorescence intensities were assessed by a flow cytometer. The mean numbers of molecules were calculated using QuantiBrite PE beads.
We calculated the ratio of CD64 to the CD35 level (CD35/CD64), and used a cut-off value of 2.8 for the CD35/CD64 ratio. At this value, the sensitivity for diagnosing a bacterial infection was 87%, and the specificity was 86%.
Simultaneous quantitative analysis of CD64 and CD35 expression on neutrophils might be useful to distinguish between bacterial and viral infections in RA patients.
中性粒细胞表面 CD64 的表达水平可用于区分类风湿关节炎（RA）患者的感染与疾病活动。然而，CD64 的表达既受细菌又受病毒的影响，因此无法用于区分感染类型。本研究通过同时定量分析中性粒细胞 CD64 和 CD35 的表达，来确定这些分子是否可用于区分 RA 患者的细菌和病毒感染。
我们收集了 22 例病原体已证实的感染（15 例细菌感染和 7 例病毒感染）的 RA 患者的血液。用 QuantiBRITE CD64PE/CD45PerCP 和 CD35PE 对血液样本进行染色，并通过流式细胞仪评估平均荧光强度。使用 QuantiBrite PE 珠计算分子的平均数量。
我们计算了 CD64 与 CD35 水平的比值（CD35/CD64），并将 CD35/CD64 比值的截断值设定为 2.8。在此值下，诊断细菌感染的灵敏度为 87%，特异性为 86%。
同时定量分析中性粒细胞 CD64 和 CD35 的表达可能有助于区分 RA 患者的细菌和病毒感染。
