FcγRIII 在体内有FcγRIIIa和FcγRIIIb两种亚型，和IgG的结合力分别为中度和低亲和力。 FcγRIIIa几乎在所有白细胞中表达，主要负责NK细胞的ADCC作用和巨噬细胞对抗体-抗原免疫复合物的清除。

CD64 (C luster of D ifferentiation 64) is a type of integral membrane glycoprotein known as an Fc receptor that binds monomeric IgG-type antibodies with high affinity. [1] It is more commonly known as Fc-gamma receptor 1 (FcγRI).

2013年2月28日 · Receptors for the Fc portion of IgG (FcγRs) are mandatory for the induction of various IgG-dependent models of autoimmunity, inflammation, anaphylaxis, and cancer immunotherapy. A few FcγRs have the ability to bind monomeric IgG: high-affinity mouse mFcγRI, mFcγRIV, and human hFcγRI.

2013年2月28日 · Our results unravel novel capabilities of human FcγRI that confirm the role of high-affinity IgG receptors in vivo. Receptors for the Fc portion of IgG (FcγRs) are expressed in humans and mice and mediate most biologic activities of IgG antibodies. FcγRI (CD64), FcγRIIB (CD32B), and FcγRIIIA (CD16A) exist in both species.

FcγRI (CD64) is the only high-affinity Fcγ receptor found on monocytes, macrophages, eosinophils, neutrophils and dendritic cells. It binds immunoglobulin G (IgG) antibody-antigen complexes at its Fc region to trigger key immune responses. CD64 contains three immunoglobulin-fold extracellular domains (D1, D2 and D3) and a membrane-spanning region.

The high-affinity human IgG receptor FcγRI (CD64) promotes IgG-mediated inflammation, anaphylaxis, and antitumor immunotherapy. Blood. 2013;121:1563–1573. doi: 10.1182/blood-2012-07-442541.

The Fc gamma receptor I (FcγRI or CD64) is the only human Fc receptor with a high affinity for monomeric IgG. It plays a crucial role in immunity, as it mediates cellular effector functions of antibodies including phagocytosis, antigen presentation, and cytokine production.

2023年5月1日 · CD64是免疫球蛋白IgG的Fc段受体1，属免疫球蛋白超家族的成员，主要分布在巨噬细胞、单核细胞及树突状细胞表面，其表达受细胞因子的调控，起连接体液免疫和细胞免疫的桥梁作用。

CD64指数（CD64 index）在患败血症的新生儿中明显升高，联合中性粒细胞绝对计数可将敏感性提高至95%，阴性预测值提高至90%。 CD64指数升高水平与败血症的严重程度和器官衰竭程度密切相关，对败血症患者的治疗及预后也具有一定的指导作用。

CD64是能识别免疫球蛋白、对IgG单体具有高亲和力、介导体液免疫和细胞免疫、对感染性疾病具有早期诊断价值的IgG Fc片段受体1 (FcγRⅠ)。 正常情况下,CD64主要表达于巨噬细胞、单核细胞及树突状细胞表面,中性粒细胞表面几乎不表达CD64。