Figures
Abstract
Background
Prior to being spread throughout broader China, multiple human immunodeficiency virus (HIV)-1 genotypes were originally discovered in the Yunnan Province. As the HIV-1 epidemic continues its spread in Yunnan, knowledge of the influence of gender, age, and ethnicity to instances of HIV reservoirs will benefit monitoring the spread of HIV.
Methods
The degree to which T cells are depleted during an HIV infection depends on the levels of immune activation. T-cell subsets were assessed in newly-diagnosed HIV/AIDS patients in Yunnan, and the influence of age, gender, and ethnicity were investigated. Patients that were newly diagnosed with the HIV-infection between the years 2015 and 2018 at the First Affiliated Hospital of Kunming Medical College were selected for this study (N = 408). The lymphocyte levels and T cell subsets were retrospectively measured in whole blood samples by FACS analysis.
Results
The median CD4 count was 224 ± 191 cells/μl. Significantly higher mean frequencies and absolute numbers were observed in CD3+, CD3+CD4+, CD3+CD8+, CD45+, and CD3+CD4+/CD45+ in females compared to males. Han patients showed a higher total number of CD3+T cells and the ratio of CD3+ /CD45+ cells compared to any other ethnic minority (P < 0.001). The numbers of CD3+ T-cells, CD3+CD8+ T cells, and CD45+ T cells were highest in the age group ≥ 60. Significant differences were observed in the counts of CD3+, CD3+CD8+, and CD45+ cells and the ratio of CD3+/CD45+ and CD3+CD4+/CD45+ cells between the ≤ 29 and 30–59 age groups.
Conclusion
This study has revealed that low levels of CD4+ T cells can be observed in newly-diagnosed HIV/AIDS patients in the Yunnan province. It has also been demonstrated that gender, age, and ethnicity have a significant association with the ratio of T-cell subsets that may contribute to virus progression and disease prognosis in individuals belonging to certain subsets of the population. This study has highlighted the importance of HIV/AIDS screening in at-risk populations to ensure timely and adequate clinical management in Yunnan.
Citation: Li Y, He C, He Z, Zhong M, Liu D, Liu R, et al. (2019) AIDS prevention and control in the Yunnan region by T cell subset assessment. PLoS ONE 14(4): e0214800. https://doi.org/10.1371/journal.pone.0214800
Editor: Zhefeng Meng, Fudan University, CHINA
Received: September 12, 2018; Accepted: March 20, 2019; Published: April 18, 2019
Copyright: © 2019 Li et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: This study was funded by the Applied Basic Research in Yunnan Province (joint project of Yunnan Provincial Department of Science and Technology and Kunming Medical University) (grant number: 2015FB040). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Introduction
In the absence of antiretroviral therapy (ART), infection with HIV weakens the host’s immune system, leading to acquired immune deficiency syndrome (AIDS). The time between infection and clinical diagnosis of AIDS varies between individuals and can be influenced by age, gender, ethnicity, and sexual orientation [1].
AIDS is a serious public health problem in China [2–4]. Located in the Southwest region of China, the Yunnan province borders Vietnam, Myanmar, and Laos and contains a large scale of cross-border populations. Yunnan is also close to the Golden Triangle: the largest drug-producing area in China [5–7]. In 1989, the first HIV type-1 (HIV-1) outbreak occurred in injection drug users in the Dehong prefecture of Yunnan [8]. Since that outbreak, Yunnan has become the gateway for HIV-1 epidemics in China and is the most severely-affected HIV/AIDS area nationwide [9–11]. Recent statistics suggest that almost 25% of new HIV cases in China originate from Yunnan [12–14], 92.6% of which are caused by unprotected sex [9,15,16]. Epidemiological surveillance is vital to the control of this epidemic.
The ability of HIV to establish long-lasting viral reservoirs in CD4 T cells initiates rebound viremia during ART treatment [17–19]. This represents a distinct aspect of HIV-1 pathogenesis and a critical factor that contributes to the inability to cure HIV-1 infection [20]. Viral persistence is attributed to latently-infected CD4 T cells that contain transcriptionally silent forms of the virus that are not susceptible to ART drugs or immune factors (1). Traditionally, resting CD4 T memory cells are regarded as the major T cell population that harbor latent HIV-1, which become infected at the time of activation, and viral latency occurs when these cells revert to a resting condition [21–23].
CD4 T cell counts are the primary prognostic marker for HIV-related diseases and is the main indicator for ART therapy [20]. When CD4 T cell numbers decline below 200 cells/ul, the immune system is compromised, resulting in a poor disease prognosis and lack of response to ART therapy [12,20,24–27]. However, not all CD4 T cells are identical, and emerging data suggests a role for specific T-cell subsets during virus progression [23,28–30]. The ratio of these T cells in HIV patients can be influenced by age, gender, and ethnicity The various T-cell subpopulations likely play an important role in modulating not only HIV-specific immunity, but the overall immune response during infection [23,28–30].
The worldwide use of ART therapy is expanding [12,25–27]. With this increase, it is important to identify differences in immunological progression by gender, age, and ethnicity, as specific populations may require subtype-specific monitoring and guidelines for treatment [1,31]. Such estimates of CD4+ T cell trajectories are essential for public health models as they can predict the course of an HIV epidemic [20,24,32]. In this study, to enhance the understanding of T cell characteristics and disease progression in newly diagnosed HIV/AIDS patients in Yunnan, a comprehensive study was conducted that included patient samples collected across the entire province from 2015 to 2018. The aim of this study was to provide a meaningful reference for AIDS prevention and control strategies in Yunnan.
Methods
Ethics approval
The study protocol was reviewed and approved by the Ethics committee of the first affiliated hospital of Kunming Medical University. Informed consent was obtained from all participants prior to enrollment. Patient records and information were de-identified prior to analysis.
Study population and detection of HIV infection
A retrospective study of HIV/AIDS cases in the Yunnan provinces was conducted. The survey subjects were newly diagnosed HIV-infected patients who had not received ART therapy. All patients were confirmed positive for HIV antibodies by standard laboratory detection methods, including Western blot analysis to detect HIV antibodies and nucleic acid as a supplementary test to detect the HIV load when necessary. All patient diagnoses were consistent with the national HIV/AIDS testing technical specifications.
Blood samples
For newly diagnosed HIV-infected patients, 2 mL of venous blood samples were obtained from each patient to measure T cell subsets, with all analysis completed within 4 h of sampling. Flow cytometric acquisition and analysis was performed using a FACSCan II flow cytometer (BD Biosciences, San Jose, CA). Absolute numbers of each lymphocyte subset were determined using CD3/CD4/CD8/CD45 BD Multitest reagents according to the manufacturer’s protocols (BD Biosciences).
Statistical analysis
SPSS22.0 software was used for statistical analyses. Continuous variables are presented as the mean ± Standard Deviation (SD). Two–two comparisons amongst the groups were performed using LSD methods. Two-tailed tests were used for statistical analysis. The threshold for statistical significance was a p-value < 0.05.
Results
Patient characteristics study
A total of 408 newly diagnosed with HIV/AIDS patients were assessed. Table 1 and Table 2 summarize the basic characteristics of the study population. Fig 1 depicts the mean and standard deviation of CD3+, CD3+CD4+, CD3+CD8+, CD45+, CD3+/CD45+,CD3+CD4+/CD45+, CD3+CD8+/CD45+, and CD3+CD4+CD8+/CD45+ in two box plots. The HIV patients were grouped according to age (1) 30–59 years, (2) ≤ 29 years, and (3) ≥ 60 years. The study sample was primarily male (65%, n = 267), 11.8% were ethnic minorities, and the mean CD4 T cell count was 224 cells/μL across all individuals.
The boxplots of CD3+, CD3+CD4+, CD3+CD8+, CD45+, CD3+/CD45+, CD3+CD4+/CD45+, CD3+CD8+/CD45+, and CD3+CD4+CD8+/CD45+.
T-lymphocyte subset analysis
Baseline CD4 counts are a significant predictor of the progression of HIV-associated diseases [20]. The mean baseline CD3+CD4+ T cell counts of HIV-infected individuals in the study population were 224 cells/μl. The CD4 T-cell counts of the patients ranged from 1 to 1079 cells/μl. Of these individuals, 97 patients (23.8%) had baseline CD4 cell counts >350 cells/μl, while 99 patients (24.3%) had baseline CD4 cell counts ranging from 200–350 cells/μl. 93 patients (22.8%) had baseline CD4 cell counts 100–200 cells/μl, and 119 patients (29.1%) had CD4 T cell levels <100 cells/μl (Fig 2). The low levels of CD4 T cells in these patients suggested a diagnosis of an advanced stage of HIV infection [33].
The bar graphs are presented by data of blood samples from newly diagnosed HIV-infected patients.
T cell subset frequencies in HIV+ men and women
Clinical studies indicate that female gender is associated with lower viral loads, higher CD4 counts, pronounced ART side effects, and a more rapid progression to AIDS, though this has not been shown in the Yunnan population [9,16,34–40]. When the mean absolute numbers of each T cell subset were assessed by gender (Fig 3), the mean percentage of CD3+CD8+/CD45+ T cells in men was higher than in women (P<0.001), while the mean frequencies and absolute numbers of CD3+, CD3+CD4+, CD3+CD8+, CD45+, and CD3+CD4+/CD45+ in female patients was higher than in male patients (P<0.01 or P<0.001), suggesting a functional skewing of the accompanying quantitative CD8 elevation. Since this would be predicted to fuel immune dysfunction in females infected with HIV in Yunnan [41], a combination of immunological strategies to supplement ART may be required to recover CD8 T-cell normalization and improve HIV symptoms in these patients.
FACs data are presented as the mean ± SD for the comparison of CD3/CD4/CD8/CD45 subsets between male and female patients.
T lymphocyte subset frequencies and ethnicity
In the context of HIV, ethnicity is associated with differences in CD4 T counts, the rate of CD4 decline, viral escape, and systemic immune activation [35,42–44]. As shown in Fig 4, the absolute number of CD3+ cells and the percentage of CD3+/CD45 and CD3+CD8+/CD45 cells were significantly higher in Han patients (1815 ± 987, 73.94 ± 11.61%, and 58.18 ± 15.42%) compared to ethnic minority patients (1417 ± 1130, 65.58 ± 14.55%, and 45.53 ± 16.02%) (P<0.001). The percentage of CD3+CD4+/CD45 cells was significantly higher in ethnic patients (19.67 ± 18.55%) compared to Han patients (13.04 ± 9.69%) (P<0.001). Although absolute numbers of Han patients had modestly higher numbers of CD3+CD8+, and minority patients had slightly higher numbers of CD3+, CD3+CD4+ and CD45+ T cells, the differences between the groups were not significant. These values may contribute to the hotspots of HIV-1 infection in Yunnan ethnic minorities including both Western and Northeast regions where the largest number of HIV sufferers occurs [45].
FACs data are presented as the mean ± SD for the comparison of CD3/CD4/CD8/CD45 subsets between Yunnan ethnic minorities.
T lymphocytes in patients of different ages
HIV disproportionately afflicts young people both in China and worldwide. All newly diagnosed HIV/AIDS patients were divided into three groups based on age: ≤29, 30–59, or ≥60 years. Fig 5 summarizes the lymphocyte subsets present in each of these three age groups. Statistically significant differences in the absolute numbers of CD3+, CD3+CD8+, CD45+ and in the percentage of CD3+/CD45+, CD3+CD4+/CD45+, CD3+CD8+/CD45+T cells were found between the three age groups. The numbers of CD3+ T cells, CD3+CD8+ T cells, and CD45+ T cells were highest in the age ≥60 group. Significant differences were observed in the counts of CD3+, CD3+CD8+, and CD45+, and the ratio of CD3+/CD45+ to CD3+CD4+/CD45+ cells between the ≤29 and 30–59 groups. Other parameters decreased as age increased, however the differences did not show statistical significance.
FACs data are presented as the mean ± SD for the comparison of CD3/CD4/CD8/CD45 subsets between different age groups.
The general linear model is composed of 7 factors: CD3+/CD45+, nationality, occupation, marital status, age, infection route, and degree of education. For the variable CD3+/CD45+, the influence of nationality and age showed a statistical significance(The P values were 0.01 and 0.025, respectively). In the general linear model of CD3+CD4+CD8+/CD45+, age and gender show an influence, and for the variable CD3+CD4+CD8+/CD45+, the influence of gender showed a statistical significance(The P values were 0.035), while age did not account for a significant influence(The P values were 0.198). These are shown in Table 3.
Discussion
The Yunnan Province is located in Southwest China. Owing to its special location near the Golden Triangle, the HIV epidemic in this region has primarily spread through the use of injection drugs for many years [5–7]. It was previously reported that the mean number of CD4+ T cells in newly diagnosed HIV/AIDS patients in China in 2010 was 334 ± 302 cells/μl [20,33]. Amongst the 408 newly HIV-diagnosed patients in Yunnan, the baseline CD3+CD4+ T cell counts were 224 ± 191 cells/μl, which are significantly lower than those of Xiamen and Taizhou [46]. This suggests that HIV-infected patients in the Yunnan district are more likely to be diagnosed during the late stages of HIV infection (due to the progressive decline of CD4 numbers) compared to those in Xiamen and Taizhou. In addition, the lower CD4 counts may explain the greater risk of disease development and risk of progression to AIDS, reported to occur more rapidly in Yunnan compared to other regions [10,47–49].
In this study, it was found that the absolute numbers of CD3+, CD3+CD4, CD3+ CD8+, and CD45+T cells in infected women are higher than those in infected men. These biologically-based gender differences may arise from differential gene expression associated with the X chromosome [1]. Lower absolute numbers of HIV-specific CD8+ T-cells would be expected to lead to differential responses to ART therapy within the province, given the evidence for the significance of cytotoxic T-lymphocytes (CTLs) in the response to ART therapy [41].
Advanced age is also a strong predictor of accelerated HIV-1 progression and increased AIDS-related mortality [50–52]. The number of CD3+CD4+ T cells in patients aged ≤29 years old was higher than those aged > 30 years, suggesting that the number of T-lymphocytes decreases with increasing age. However, compared to patients aged 30–59, the group aged ≥ 60 showed a renewed increase in CD3+CD4+ T cells, suggesting that CD4+T cell damage was more chronic in patients aged 30–59 after HIV infection. Knowledge of these parameters is important in Yunnan given that the population of HIV-infected adults is progressively aging, due to more effective treatments that lower the viral load and increase life expectancy [50–52].
It was observed that CD3+ and CD3+/CD45 T cell percentages in the Han population were significantly higher than those of the ethnic minorities. HIV infects CD4+ T lymphocytes through binding of its viral envelope to cell surface expressed CD4 and to its co-receptors CCR5 or CXCR4 [53]. A 32 base pair deletion of the CCR5 gene has been shown to significantly reduce HIV entry and to disrupt the progression to AIDS [53–56]. CCR2-64I (A/A genotype) and SDF1-3'A are also known to protect against HIV infection, while CX3CR1 expression is associated with an increased risk of HIV-1 infection [57]. Mutations in CCR2 (CCR2-64I) also prolong the survival of HIV-infected individuals [54,55]. SDF1-3'A homozygotes show a protective effect against the onset of AIDS [55,58]. Chen and coworkers observed a high allele frequency of HIV-resistance genes CCR2b-64I and SDF1-3'A in the Han, Yi, and Hani ethnic populations [59]. In this study, the Yi and Hani ethnic groups accounted for 44% of the minority populations, and the T cell percentages were higher in these infected ethnic minority groups relative to the Han group. This suggests that differences in HIV-resistance genotypes may also be an important factor involved in the delay to HIV progression.
The proportion of patients with late stage diagnoses remains high in China, making effective treatments and viral remission difficult to achieve [33]. The frequency of opportunistic infections in HIV/AIDS patients increases as the CD3+CD4+ lymphocyte count decreases [23]. From the data, an estimated date of HIV infection was calculated for the diagnosed HIV-infected cohort based on previously-published methods [60]. Approximately 52% of newly diagnosed patients in this retrospective study were predicted to have been infected for more than 7 years at the time of diagnosis. These patients have reached a later disease-stage and have become highly susceptible to opportunistic infections. Approximately 24% of patients in the study were predicted to have been infected for 5–7 years, with the remaining 24% of patients estimated to have been infected for less than 5 years. Since late diagnosis greatly increases the risk of HIV exposure and spread, early diagnosis efforts and CD4 cell count testing should be priorities amongst high-risk populations within the Yunnan province. Regular assessment and monitoring of newly identified HIV-positive individuals should be accompanied by timely CD4 testing and rapid initiation of treatment. The National Free Antiretroviral Therapy Program (NFATP) in China has addressed the problem of poor access to ART therapy and has greatly reduced mortality among patients. Prompt CD4 testing is a critical step for successful HIV treatment, making it vital to reducing the rates of HIV/AIDS in this region.
One limitation of this study should be noted. The Han ethnic group accounted for the majority of study participants (349/408; 86%), and samples only consisted of infected individuals in the Kunming area, and are thus not fully representative of Yunnan. Sample selection bias and the small sample size may therefore influence our findings. Further studies comparing our findings to a range of ethnic groups should be conducted.
In conclusion, it is shown that low levels of CD4+ T lymphocytes in patients newly diagnosed with HIV/AIDS are found in the Yunnan province. Furthermore, T-cell subsets in these HIV patients were shown to be influenced by gender, age, and ethnicity which may contribute to disease progression. From this information, the most at-risk populations can be predicted and this can be used to inform HIV surveillance and management strategies. Older members of the Han nationality and men over 60, for example, may be more susceptible to HIV than younger Yi women. Of course, this requires prospective research and some actual prediction models, which can hopefully be conducted in future studies. Routine screening for HIV/AIDS in these populations can ensure timely and adequate clinical management in Yunnan, improving patient quality of life and reducing HIV morbidity.
Supporting information
S1 File. Description of methodological quality control and data rigor.
This is a quality report on flow cytometry T lymphocyte subsets and it describe a technically sound piece of scientific research with data that supports the conclusions.
https://doi.org/10.1371/journal.pone.0214800.s001
(DOCX)
S1 Dataset. Original data.
This is the source of all the data.
https://doi.org/10.1371/journal.pone.0214800.s002
(XLSX)
References
- 1. Johnston RE, Heitzeg MM. Sex, age, race and intervention type in clinical studies of HIV cure: a systematic review. AIDS Res Hum Retroviruses. 2015; 31(1):85–97. pmid:25313793
- 2. Chen M, Jia MH, Ma YL, Luo HB, Chen HC, Yang CJ, et al. The changing HIV-1 genetic characteristics and transmitted drug resistance among recently infected population in Yunnan, China. Epidemiol Infect. 2018; 146(6):775–781. pmid:29534773
- 3. Chen M, Ma Y, Chen H, Luo H, Dai J, Song L, et al. Multiple introduction and naturally occuring drug resistance of HCV among HIV-infected intravenous frug users in Yunnan: An origin of China's HIV/HCV epidemics. PLoS One. 2015; 10(11):e0142543. pmid:26562015
- 4. Xu Y, Fu LR, Jia M, Dai G, Wang Q, Huang P, et al. HIV prevalence and associated factors among foreign brides from Burma in Yunnan Province, China. PLoS One. 2014; 9(12):e115599. pmid:25536087
- 5. Li J, Li L, Yang S, Li J, Zhang M, Yang C, et al. The identification of a novel HIV-1 CRF01_AE/B recombinant based on near full-length genomic analysis in Yunnan Province, China. AIDS Res Hum Retroviruses. 2016; 32(5):467–470. pmid:26678279
- 6. Li L, Chen L, Yang S, Liu Y, Li H, Bao Z, et al. Near full-length genomic characterization of a novel HIV type 1 subtype B/C recombinant strain from Yunnan, China. AIDS Res Hum Retroviruses. 2010; 26(6):711–716. pmid:20528150
- 7. Jia Y, Sun J, Fan L, Song D, Tian S, Yang Y, et al. Estimates of HIV prevalence in a highly endemic area of China: Dehong Prefecture, Yunnan Province. Int J Epidemiol. 2008;37(6): 1287–1296. pmid:18922804
- 8. Jia Z, Wang L, Chen RY, Li D, Wang L, Qin Q, et al. Tracking the evolution of HIV/AIDS in China from 1989–2009 to inform future prevention and control efforts. PLoS One. 2011;6(10): e25671. pmid:21998679
- 9. Zhu J, Yuan R, Hu D, Zhu Z, Wang N, Wang B. HIV prevalence and correlated factors of female sex workers and male clients in a border region of Yunnan Province, China. Int J STD AIDS. 2018;29(5): 424–434. pmid:28901213
- 10. Li YY, Jin YM, He LP, Bai JS, Liu J, Yu M, et al. Clinical analysis of HIV/AIDS patients with drug eruption in Yunnan, China. Sci Rep. 2016;6: 35938. pmid:27796328
- 11. Wang Y, Liang Y, Feng Y, Wang B, Li Y, Wu Z, et al. HIV-1 prevalence and subtype/recombinant distribution among travelers entering China from Vietnam at the HeKou port in the Yunnan province, China, between 2003 and 2012. J Med Virol. 2015;87(9): 1500–1509. pmid:25865741
- 12. Chow EP, Gao L, Koo FK, Chen L, Fu X, Jing J, et al. Qualitative exploration of HIV-related sexual behaviours and multiple partnerships among Chinese men who have sex with men living in a rural area of Yunnan Province, China. Sex Health. 2013;10(6): 533–540. pmid:24119339
- 13. Duan S, Guo HY, Pang L, Yuan JH, Jia MH, Xiang LF, et al. Analysis of the epidemiologic patterns of HIV transmission in Dehong prefecture, Yunnan province. Zhonghua Yu Fang Yi Xue Za Zhi. 2008;42(12): 866–869. (in Chinese) pmid:19141217
- 14. Xiao Y, Kristensen S, Sun J, Lu L, Vermund SH. Expansion of HIV/AIDS in China: lessons from Yunnan Province. Soc Sci Med. 2007;64(3): 665–675. pmid:17107739
- 15. Li Y, Miao J, Miao Z, Song Y, Wen M, Zhang Y, et al. Identification of a Novel HIV type 1 circulating recombinant form (CRF86_BC) among heterosexuals in Yunnan, China. AIDS Res Hum Retroviruses. 2017;33(3): 279–283. pmid:27593341
- 16. Su Y, Ding G, Reilly KH, Norris JL, Liu H, Li Z, et al. Loss to follow-up and HIV incidence in female sex workers in Kaiyuan, Yunnan Province China: a nine year longitudinal study. BMC Infect Dis. 2016;16(1): 526. pmid:27686152
- 17. Xuan Q, Liang S, Qin W, Yang S, Zhang AM, Zhao T, et al. High prevalence of HIV-1 transmitted drug resistance among therapy-naïve Burmese entering travelers at Dehong ports in Yunnan, China. BMC Infect Dis. 2018;18(1): 211. pmid:29739342
- 18. Yao S, Shi Y, Li P, Xu Y, Yang W, Zhang Y, et al. Study on drop-out from antiretroviral therapy among adult HIV-infected individuals in Dehong prefecture, Yunnan province. Zhonghua Liu Xing Bing Xue Za Zhi. 2015;36(7): 667–671. (in Chinese) pmid:26564690
- 19. He N, Duan S, Ding Y, Rou K, McGoogan JM, Jia M, et al. Antiretroviral therapy reduces HIV transmission in discordant couples in rural Yunnan, China. PLoS One. 2013;8(11): e77981. pmid:24236010
- 20. Ren L, Li J, Zhou S, Xia X, Xie Z, Liu P, et al. Prognosis of HIV patients receiving antiretroviral therapy according to CD4 counts: A long-term follow-up study in Yunnan, China. Sci Rep. 2017;7(1): 9595. pmid:28852017
- 21. Kaufmann GR, Cunningham P, Zaunders J, Law M, Vizzard J, Carr A, et al. Impact of early HIV-1 RNA and T-lymphocyte dynamics during primary HIV-1 infection on the subsequent course of HIV-1 RNA levels and CD4+ T-lymphocyte counts in the first year of HIV-1 infection. Sydney Primary HIV Infection Study Group. J Acquir Immune Defic Syndr. 1999;22(5): 437–444. pmid:10961604
- 22. Kilewo C, Karlsson K, Swai A, Massawe A, Lyamuya E, Mhalu F, et al. Mortality during the first 24 months after delivery in relation to CD4 T-lymphocyte levels and viral load in a cohort of breast-feeding HIV-1-infected women in Dar es Salaam, Tanzania. J Acquir Immune Defic Syndr. 2005;38(5):598–602. pmid:15793372
- 23. Kelleher AD, Zaunders JJ. Decimated or missing in action: CD4+ T cells as targets and effectors in the pathogenesis of primary HIV infection. Curr HIV/AIDS Rep. 2006;3(1): 5–12. pmid:16522253
- 24. Eshun-Wilson I, Taljaard JJ, Nachega JB. Sub-optimal CD4 T-lymphocyte responses among HIV infected patients who develop TB during the first year of ART. J AIDS Clin Res. 2012;3(135): 1000135. pmid:22442755
- 25. Li H, Zhong M, Guo W, Zhuang D, Li L, Liu Y, et al. Prevalence and mutation patterns of HIV drug resistance from 2010 to 2011 among ART-failure individuals in the Yunnan Province, China. PLoS One. 2013;8(8): e72630. pmid:24009694
- 26. Wen Y, Shi Y, Jiang C, Detels R, Wu D. HIV/AIDS patients' medical and psychosocial needs in the era of HAART: a cross-sectional study among HIV/AIDS patients receiving HAART in Yunnan, China. AIDS Care. 2013;25(7): 915–925. pmid:23061980
- 27. Hu XS, Zhao Y, Huang LL, Luo YX, Wu ZY. Antiretroviral treatment discontinuation and its influencing factors among HIV-infected patients who initiated ART from 2012 to 2015 in Wenshan prefecture, Yunnan Province. Zhonghua Yu Fang Yi Xue Za Zhi. 2017;51(11): 982–987. (in Chinese) pmid:29136742
- 28. Ye RH, Duan S, Xiang LF, Yang YC, Yang ZJ, Han WX, et al. Studies on the determinants and changes related to the natural CD4(+) T cell counts among antiretroviral treatment-naive HIV/AIDS patients in Dehong prefecture, Yunnan province. Zhonghua Liu Xing Bing Xue Za Zhi. 2011;32(9): 882–887. (in Chinese) pmid:22340875
- 29. D'Huys T, Claes S, Van Loy T, Schols D. CXCR7/ACKR3-targeting ligands interfere with X7 HIV-1 and HIV-2 entry and replication in human host cells. Heliyon. 2018;4(3): e00557. pmid:29560468
- 30. Joseph SB, Swanstrom R. The evolution of HIV-1 entry phenotypes as a guide to changing target cells. J Leukoc Biol. 2018;103(3): 421–431. pmid:29389021
- 31. Johnson M, Lemi BL, Tonny HL, David AD, Boru W, Ransom J. Late entry to HIV and AIDS care and treatment, Juba Teaching Hospital, Juba, South Sudan, 2013–2016. Afr J AIDS Res. 2018;17(2): 213–216. pmid:29745288
- 32. Rowley CF. Developments in CD4 and viral load monitoring in resource-limited settings. Clin Infect Dis. 2014;58(3): 407–412. pmid:24218101
- 33. Zhang Y, Lu L, Li HQ, Liu W, Tang ZR, Fang H, et al. Engaging HIV-infected patients in antiretroviral therapy services: CD4 cell count testing after HIV diagnosis from 2005 to 2009 in Yunnan and Guangxi, China. Chin Med J (Engl). 2011;124(10): 1488–1492. pmid:21740803
- 34. Xu J, Brown K, Ding G, Wang H, Zhang G, Reilly K, et al. Factors associated with HIV testing history and HIV-test result follow-up among female sex workers in two cities in Yunnan, China. Sex Transm Dis. 2011;38(2): 89–95. pmid:20838364
- 35. Wang JJ, Yang Q, Fan PY, Reilly KH, Ding GW, Wang N. Estimation of population-size changes and HIV prevalence among female sex workers from 2006 to 2009 in Kaiyuan, Yunnan, China. Biomed Environ Sci. 2012;25(4): 489–494. pmid:23026531
- 36. Xu JJ, Smith MK, Chu J, Ding GW, Chang DF, Sharp GB, et al. Dynamics of the HIV epidemic in southern China: sexual and drug-using behaviours among female sex workers and male clients in Yunnan. Int J STD AIDS. 2012;23(9): 670–675. pmid:23033525
- 37. Yao Y, Yang F, Chu J, Siame G, Lim HJ, Jin X, et al. Associations between drug use and risk behaviours for HIV and sexually transmitted infections among female sex workers in Yunnan, China. Int J STD AIDS. 2012;23(10): 698–703. pmid:23104743
- 38. Ding GW, Hsi JH, Liu HX, Su YY, Wang JJ, Bai J, et al. HIV-infected female sex workers' high risk behavior and attitude changes in Kaiyuan City, Yunnan Province, China. Biomed Environ Sci. 2014;27(6): 444–452. pmid:24961854
- 39. Wang J, Ding G, Zhu Z, Zhou C, Wang N. Analysis of HIV correlated factors in Chinese and Vietnamese female sex workers in Hekou, Yunnan Province, a Chinese border region. PLoS One. 2015;10(6): e0129430. pmid:26053040
- 40. Yang C, Ma Y, Chen H, Su Y, Chen M, Dong L, et al. Application of BED for HIV-1 incidence research in female sex workers (FSW) in Yunnan province. Zhonghua Yu Fang Yi Xue Za Zhi. 2015;49(1): 70–71. (in Chinese) pmid:25876501
- 41. Cao W, Mehraj V, Kaufmann DE, Li T, Routy JP. Elevation and persistence of CD8 T-cells in HIV infection: the Achilles heel in the ART era. J Int AIDS Soc. 2016;19(1): 20697. pmid:26945343
- 42. Luo X, Duan S, Duan Q, Pu Y, Yang Y, Ding Y, et al. Alcohol use and subsequent sex among HIV-infected patients in an ethnic minority area of Yunnan Province, China. PLoS One. 2013;8(4): e61660. pmid:23626712
- 43. Chen M, Yao ST, Ma YL, He X, Wang JB, Cheng CL, et al. Distribution of HIV-1 subtypes among different populations in Dehong prefecture, Yunnan province, in 2011. Zhonghua Liu Xing Bing Xue Za Zhi. 2012;33(9): 883–887. (in Chinese) pmid:23290795
- 44. Yang L, Chen M, Ma Y, Luo H, Yang C, Su Y, et al. The changing trends of HIV-1 prevalence and incidence from sentinel surveillance of five sub-populations in Yunnan, China, 2001–2010. BMC Public Health. 2015;15: 376. pmid:25886791
- 45. Peng ZH, Cheng YJ, Reilly KH, Wang L, Qin QQ, Ding ZW, et al. Spatial distribution of HIV/AIDS in Yunnan province, People's Republic of China. Geospat Health. 2011;5(2): 177–182. pmid:21590667
- 46. Qiu DH, Shen WW, Xu J, Gu MX. Analysis on CD4+ T cells count of HIV infected in Taizhou. Chinese J Health Lab Technol. 2008;18(10): 2051–2052. (in Chinese)
- 47. Duan X, Wang KR, Wang JB, Ye RH, Wang YK, Yang J, et al. HIV gene subtypes of newly reported HIV/AIDS cases in Dehong Dai and Jingpo autonomous prefecture of Yunnan province, 2016. Zhonghua Liu Xing Bing Xue Za Zhi. 2018;39(5):678–681. (in Chinese) pmid:29860817
- 48. Cai YN, Ma YL, Luo HB, Xiao MY, Niu J, Song LJ, et al. [Knowledge, related behavior and on AIDS/HIV infection among rural adults with Derung minority, in Yunnan province, 2016]. Zhonghua Liu Xing Bing Xue Za Zhi. 2018;39(4): 483–486. (in Chinese) pmid:29699042
- 49. Yang Y, Zhang Y, Cao Y, Tang R, Yang S, Li L, et al. Incidence and risk factors of HIV infection among sero-negative spouses of people living with HIV/AIDS in Dehong prefecture, Yunnan province. Zhonghua Liu Xing Bing Xue Za Zhi. 2016;37(4): 512–516. (in Chinese) pmid:27087216
- 50. Xia X, Lu L, Tee KK, Zhao W, Wu J, Yu J, et al. The unique HCV genotype distribution and the discovery of a novel subtype 6u among IDUs co-infected with HIV-1 in Yunnan, China. J Med Virol. 2008;80(7):1142–1152. pmid:18461611
- 51. Chen J, Yu B, Wang Y, Tang M, Hu Y, Cai T, et al. Expansion of HIV care and treatment in Yunnan Province, China: treatment outcomes with scale up of combination antiretroviral therapy. AIDS Care. 2014;26(5): 633–641. pmid:24116389
- 52. Gregoire Y, Germain M, Delage G. Factors associated with a second deferral among donors eligible for re-entry after a false-positive screening test for syphilis, HCV, HBV and HIV. Vox Sang. 2018;113(4): 339–344. pmid:29508402
- 53. Brelot A, Chakrabarti LA. CCR5 revisited: How mechanisms of HIV entry govern AIDS pathogenesis. J Mol Biol. 2018;430(17): 2557–2589. pmid:29932942
- 54. Smith MW, Dean M, Carrington M, Winkler C, Huttley GA, Lomb DA, et al. Contrasting genetic influence of CCR2 and CCR5 variants on HIV-1 infection and disease progression. Hemophilia Growth and Development Study (HGDS), Multicenter AIDS Cohort Study (MACS), Multicenter Hemophilia Cohort Study (MHCS), San Francisco City Cohort (SFCC), ALIVE Study. Science. 1997;277(5328): 959–965. pmid:9252328
- 55. Ye JJ, Wang FS, Peng L, Jin L, Ding M, Liu MX. Distribution of the HIV/AIDS associated CCR5Delta32, CCR2b-64I, SDF1-3'A allelesin Chinese Dai and Chingpaw populations from Dehong autonomous prefecture of Yunnan Province. Yi Chuan. 2003;25(6): 655–659. (in Chinese) pmid:15639953
- 56. Yang M, Zhi R, Lu L, Dong M, Wang Y, Tian F, et al. A CCR5 antagonist-based HIV entry inhibitor exhibited potent spermicidal activity: Potential application for contraception and prevention of HIV sexual transmission. Eur J Pharm Sci. 2018;117: 313–320. pmid:29496533
- 57. Faure S, Meyer L, Costagliola D, Vaneensberghe C, Genin E, Autran B, et al. Rapid progression to AIDS in HIV+ individuals with a structural variant of the chemokine receptor CX3CR1. Science. 2000;287(5461): 2274–2277. pmid:10731151
- 58. Winkler C, Modi W, Smith MW, Nelson GW, Wu X, Carrington M, et al. Genetic restriction of AIDS pathogenesis by an SDF-1 chemokine gene variant. ALIVE Study, Hemophilia Growth and Development Study (HGDS), Multicenter AIDS Cohort Study (MACS), Multicenter Hemophilia Cohort Study (MHCS), San Francisco City Cohort (SFCC). Science. 1998;279(5349): 389–393. pmid:9430590
- 59.
Chen JY. Study on polymorphism and prevalence of HIV infection in Yuxi Han, Yi and Hani people in Yunnan. (Masters Thesis). Southern Medical University. 2015. (in Chinese)
- 60. Hulgan T, Raffanti S, Kheshti A, Blackwell RB, Rebeiro PF, Barkanic G, et al. CD4 lymphocyte percentage predicts disease progression in HIV-infected patients initiating highly active antiretroviral therapy with CD4 lymphocyte counts >350 lymphocytes/mm3. J Infect Dis. 2005;192(6): 950–957. pmid:16107946