Department of Medical Physics, Royal Perth Hospital, Western Australia, 6001,
Valendar F Turner, John Papadimitriou, Barry Page, David Causer, Helman Alfonso, Sam Mhlongo, Todd Miller, Christian Fiala
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TB, "HIV" antibody tests and AIDS
In his rapid response, "Re: Re: Re: Questions for Peter Flegg", 28 September 204 Nicholas Bennett wrote: "I have not seen or heard of any studies showing that TB increases the risk of HIV seropositivity".
In 1994, Kashala, Essex and their colleagues showed that antibodies to carbohydrate-containing antigens such as lipoarabinomannan and phenolic glycolipid that constitute the cell wall of Mycobacterium leprae, a bacterium which 'shares several antigenic determinants with other mycobacterial species', cause 'significant cross-reactivities with HIV-1 pol and gag proteins'.
Namely, "Of the 57 leprosy sera tested, 41 (71.9%) were positive for HIV-1 by Abbott ELISA, 39 (68.4%) by Organon ELISA, and 37 (64.9%) by both ELISAs-positive by Abbott ELISA, 10 (25.6%) of 39 were HIV-positive by Organon ELISA, and 9 (23.1%) of 39 by both….WB were indeterminate in 46 (83.6%) of 55 leprosy patients and 19 (3.9%) of 482 HIV-negative pregnant women. Of interest, indeterminate patterns were also found in a higher proportion of leprosy contacts (25/39; 64.1%), probably reflecting a high prevalence of subclinical M.leprae infection among leprosy contacts. More importantly, HIV-1 ELISA-negative sera from leprosy patients (85%) and their contacts (56.7%) had a much greater likelihood of a positive reaction on immunoblot than did that of normal individuals (2.5%), again suggesting a high rate of subclinical M.leprae infection among the contacts."
The WB were said to be "indeterminate", because they did not fulfil their criteria for a positive WB, which were: "reactivity with two of the envelope bands (gp160/120 and gp41)". However, looking at figure 1 where the "indeterminate" WB strips are published, it is obvious that all the WB will be considered positive by the criteria used anywhere else, including Australia, which has the stringent in the world.
Kashala, Essex et al concluded: "Despite a lower HIV-1 prevalence among leprosy patients and their contacts, we had a very high rate of HIV-1 false-positive ELISA and WB results…Our observations of cross-reactivity between LAM, and to a lesser extent PGL-I, with HIV-1 antigens suggest that HIV-1 ELISA and WB results should be interpreted with caution when screening individuals infected with M. tuberculosis or other mycobacterial species. ELISA and WB may not be sufficient for HIV diagnosis in AIDS-endemic areas of Central Africa where the prevalence of mycobacterial diseases is quite high".1
It is important to note that (i) “Using sputum AFB as a reference, positive anti-LAM was found in 66.9% of 139 AFB- positive PTB, 34.4% of 61 AFB-negative PTB and 23.5% of 800 non-TB patients and in 8% of 50 healthy individuals”;2 (ii) one third of the global population is infected with M. tuberculosis; (iii) this burden falls disproportionably on the developing world which also has the highest prevalence of AIDS. (AFB=acid fast bacillus; PTB=pulmonary tuberculosis).
In 1987 researchers from Canada noticed that in the vast majority of patients of African or Haitian origin who were developing the then AIDS defining diseases, TB was present "prior to infection with HIV or development of overt AIDS". This led them to "hypothesise that infection with M.tuberculosis prior to exposure to HIV (including heterosexual contact) is a common predisposing factor to infection with the AIDS virus and development of AIDS in Africans and Haitians".3 In other words the effect, TB, preceded the cause, HIV.
In a paper published in 1996 by researchers from Italy and the US, including Anthony Fauci, discussing their findings the authors wrote: "The observed higher rate of HIV disease progression as well as susceptibility to infection upon exposure to HIV in individuals in sub-Saharan Africa might be due, at least in part, to the chronic and persistent immune activation with ongoing immune responses to parasites and other infections. In this regard, it is interesting to note that MTB [Mycobacterium tuberculosis] disease is one of the most common infections in African patients who die from AIDS, suggesting a possible role for MTB in the pathogenesis of AIDS in this population…These findings highlight the importance of prophylactic therapy against MTB in HIV-infected individuals, which may help to control not only the spread of tuberculosis, but also the enhanced replication of HIV that is associated with MTB disease" 4 (italics ours).
Would Nicholas Bennett tell us:
1. If patients infected with mycobacteria and their contacts have "a very high rate of HIV-1 false-positive ELISA and WB results", how does he know what percent, if any, of the TB patients are infected with "HIV";
2. If, as Fauci et al conclude, MTB has a role in the pathogenesis of AIDS, what is the role of "HIV" in this syndrome? And what is the role of "HIV" in TB?;
(a) MTB disease is one of the most common infections in African patients who die from AIDS;
(b) MTB plays a role in the pathogenesis of AIDS;
Then given that MTB disease has been endemic in Africa long before the AIDS era, why is African AIDS claimed to be caused by "HIV"? Why, the prevent and treat African AIDS do HIV/AIDS experts advocate antiretroviral rather than anti-bacterial drugs?
1. Kashala O, Marlink R, Ilunga M, Diese M, Gormus B, Xu K, et al. Infection with human immunodeficiency virus type 1 (HIV-1) and human T cell lymphotropic viruses among leprosy patients and contacts: correlation between HIV-1 cross-reactivity and antibodies to lipoarabinomannan. J Infect Dis 1994;169:296-304.
2. Tessema TA, Bjune G, Hamasur B, Svenson S, Syre H, Bjorvatn B. Circulating antibodies to lipoarabinomannan in relation to sputum microscopy, clinical features and urinary anti-lipoarabinomannan detection in pulmonary tuberculosis. Scand J Infect Dis 2002;34:97-103.
3. Lamoureux G, Davignon L, Turcotte R, Laverière M, Mankiewicz E, Walker MC. Is Prior Mycobacterium Infection a Common Predisposing Factor to AIDS in Haitians and Africans. Annales de l'Institut Pasteur Immunologie 1987;138:521-529.
4. Goletti D, Weissman D, Jackson RW, Graham NM, Vlahov D, Klein RS, et al. Effect of Mycobacterium tuberculosis on HIV replication. Role of immune activation. J Immunol 1996;157:1271-8.
Competing interests: None declared