title: HIV and intestinal parasite co-infections among a Chinese population: an immunological profile.
abstract: BACKGROUND
  Parasite infections often result in a switch of the human body's predominant immune reaction from T-helper 1 (Th1)-type to Th2-type. Hence, parasite infections are widely expected to accelerate the progression of human immunodeficiency virus (HIV) infections to acquired immunodeficiency syndrome (AIDS). In the People's Republic of China, both parasitic diseases and AIDS are epidemic in certain rural areas, and co-infections are relatively common. However, no population-based studies have yet investigated the frequency of HIV and parasite co-infections, and its effects on immune responses. We studied (1) the immune status of an HIV-infected population, and (2) the effect of co-infection of HIV and intestinal parasites on selected parameters of the human immune system.
  
  
  METHODS
  A total of 309 HIV-infected individuals were recruited and compared to an age-matched and sex-matched control group of 315 local HIV-negative individuals. Questionnaires were administered to all participants to obtain information on sociodemographic characteristics, sanitation habits, family income, and recent clinical manifestations. Two consecutive stool samples and 10 ml samples of venous blood were also collected from each individual for the diagnosis of parasite infections and quantitative measurements of selected cytokines and CD4+ T-lymphocytes, respectively.
  
  
  RESULTS
  During the study period, 79 HIV-infected individuals were not under highly active antiretroviral therapy (HAART) and were thus included in our analysis; the prevalence of intestinal helminth infections was 6.3% and that of protozoa was 22.8%. The most common protozoan infections were Blastocystis hominis (B. hominis) (13.9%) and Cryptosporidium spp. (10.1%). The prevalence of Cryptosporidium spp. in HIV-infected individuals was significantly higher than that in HIV negative individuals (P < 0.05). Compared to the non-co-infected population, no significant difference was found for any of the measured immunological indicators (P > 0.05). However, the following trends were observed: IFN-γ levels were lower, but the IL-4 level was higher, in the population co-infected with HIV and helminths. In the population co-infected with HIV and B. hominis, the IL-2 level was higher. The population co-infected with HIV and Cryptosporidium spp. had markedly lower CD4+ T-lymphocyte counts.
  
  
  CONCLUSIONS
  According to the immunologic profile, co-infection with helminths is disadvantageous to HIV-infected individuals. It was associated with a shift in the Th1/Th2 balance in the same direction as that caused by the virus itself, which might indicate an acceleration of the progress from an HIV infection to AIDS. Co-infection with Cryptosporidium spp. was not associated with a significant change in immune factors but co-infection with Cryptosporidium spp. was associated with a reduced level of CD4 + T-lymphocytes, confirming the opportunistic nature of such infections. Co-infection with B. hominis, on the other hand, was associated with an antagonistic shift in the immunological profile compared to an HIV infection.
authors: National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (China CDC); WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis; Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, People's Republic of China. chenjiaxu1962@163.com.
authors: Li-Guang
authors: LG
authors: Tian
authors: Tian-Ping
authors: TP
authors: Wang
authors: Shan
authors: S
authors: Lv
authors: Feng-Feng
authors: FF
authors: Wang
authors: Jian
authors: J
authors: Guo
authors: Xiao-Mei
authors: XM
authors: Yin
authors: Yu-Chun
authors: YC
authors: Cai
authors: Mary Kathryn
authors: MK
authors: Dickey
authors: Peter
authors: P
authors: Steinmann
authors: Jia-Xu
authors: JX
authors: Chen
references: Science. 1994 Jul 8;265(5169):244-8
references: 8023142
references: Rev Inst Med Trop Sao Paulo. 1972 Nov-Dec;14(6):397-400
references: 4675644
references: J Egypt Soc Parasitol. 1999;29(3):951-61
references: 12561933
references: Am J Trop Med Hyg. 1998 Apr;58(4):431-5
references: 9574787
references: Trop Med Int Health. 2002 Jun;7(6):479-88
references: 12031069
references: J Clin Invest. 1994 Feb;93(2):768-75
references: 8113410
references: Am J Trop Med Hyg. 1991 Oct;45(4):518-21
references: 1951861
references: Clin Microbiol Rev. 1991 Jan;4(1):61-79
references: 2004348
references: Infect Dis Clin North Am. 2007 Mar;21(1):1-17, vii
references: 17502227
references: Clin Infect Dis. 2007 Nov 1;45(9):1208-13
references: 17918086
references: Am J Trop Med Hyg. 2003 Aug;69(2):213-6
references: 13677378
references: J Infect Dis. 1999 Aug;180(2):559-63
references: 10395883
references: Ann Trop Med Parasitol. 1992 Apr;86(2):129-36
references: 1417203
references: Clin Infect Dis. 2007 Nov 1;45(9):1214-20
references: 17918087
references: West J Med. 1989 Nov;151(5):518-9
references: 2603418
references: Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2008 Oct 30;26(5):376-81
references: 19157305
references: Am J Med Sci. 1994 Aug;308(2):96-101
references: 8042662
references: Retrovirology. 2006 Dec 01;3:87
references: 17140434
references: AIDS. 1994 Jun;8(6):757-62
references: 8086133
references: J Exp Med. 1994 Aug 1;180(2):489-95
references: 8046328
references: Infect Dis Poverty. 2013 Jan 24;2(1):2
references: 23849678
references: Mil Med. 2002 Aug;167(8):643-6
references: 12188234
references: Lancet. 2002 Jun 22;359(9324):2177-87
references: 12090997
references: Braz J Infect Dis. 2001 Dec;5(6):339-44
references: 12010598
references: J Assoc Physicians India. 2000 Apr;48(4):404-6
references: 11273176
references: Science. 1993 Dec 10;262(5140):1721-4
references: 7903123
references: Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2007 Aug;25(4):259-73
references: 18038794
references: Int J Parasitol. 2010 Aug 15;40(10):1137-44
references: 20430032
references: Acta Trop. 2003 May;86(2-3):315-33
references: 12745148
references: Parasit Vectors. 2009 Jul 09;2(1):31
references: 19589143
references: Immunol Today. 1993 Mar;14(3):107-11
references: 8096699
references: Acta Microbiol Immunol Hung. 1999;46(1):33-40
references: 10331066
references: Parasit Vectors. 2012 Feb 13;5:36
references: 22330320
references: J Infect. 1997 Jul;35(1):63-6
references: 9279726
references: J Infect Dis. 2000 Dec;182(6):1804-8
references: 11069260
references: Jpn J Infect Dis. 2007 Jul;60(4):209-10
references: 17642535
references: Southeast Asian J Trop Med Public Health. 2005 Jul;36(4):841-5
references: 16295534
references: Medicina (B Aires). 1994;54(4):307-10
references: 7715428
references: Jpn J Infect Dis. 2002 Jun;55(3):83-4
references: 12195048
references: Trends Parasitol. 2008 Apr;24(4):184-9
references: 18329342
references: J Infect Dis. 1998 Feb;177(2):437-45
references: 9466533
references: Science. 1994 Jul 8;265(5169):248-52
references: 8023143
references: J Infect Dis. 1992 Jun;165(6):1012-9
references: 1533867
references: Parasitology. 2001;122 Suppl:S61-4
references: 11442197
references: Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 2005 Oct 30;23(5 Suppl):332-40
references: 16562464