Human immunodeficiency virus (HIV), which can lead to acquired immune deficiency syndrome (AIDS) by attacking the immune system, is globally prevalent with approximately 38 million people living with HIV as of 2019 [1]. Common diagnostics used to detect whether a person is infected by HIV include antibody, p24 antigen, and polymerase chain reaction (PCR) tests [2]. Moreover, because an important characteristic of increased HIV replication is the progressive exhaustion of T-lymphocytes, the number of CD4+ T cells is one of the most common indicators of HIV-related treatment decisions [3]. However, the methods mentioned above require specialized instruments that have economic and time-related costs.

GP73, a new Golgi membrane protein discovered by Kladney in 2000 [4], is also known as Golgi membrane protein 1 (GOLM1) or Golgi phosphoprotein 2 (GOLPH2). GP73 can be expressed in a variety of cells, especially in epithelial cells, in human tissues [5]. A proprotein convertase (PC) cleavage site is located near residue 55 of GP73, and after cleavage by PC, the full-length GP73 is released from the Golgi apparatus and secreted into the serum [6]. Thus, GP73 can be detected by routine serum analysis, a process considerably simpler than flow cytometry, which is commonly used to detect CD4+ T cells [7]. Diagnostic values of GP73 protein have been reported for the serum of patients with primary hepatic carcinoma and chronic liver diseases [5, 6, 8].

In addition to serum, a previous study [9] has found that GP73 may exist in peripheral blood mononuclear cells where HIV replicates in vivo. A prospective single-center cohort study [7] found that GP73 was correlated with HIV indicators, including HIV RNA level and CD4+ T cell count, suggesting that the increase in GP73 levels correlated with the immune response and viral replication in HIV-1-infected patients. Thus, the relationship between GP73 and HIV is worth further exploration, although such studies are rare. This study aimed to explore the relationship between GP73 and HIV infection, and detect the association among the changes of GP73 and other HIV markers during treatment.