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dc.contributor.author | Bipath, Priyesh![]() |
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dc.contributor.author | Levay, Peter Ferenc![]() |
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dc.contributor.author | Viljoen, Margaretha![]() |
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dc.date.accessioned | 2016-08-15T12:03:51Z | |
dc.date.available | 2016-08-15T12:03:51Z | |
dc.date.issued | 2016-02-17 | |
dc.description | MV was the project leader. PB developed and validated the GC-MS method for the analysis of tryptophan and performed the biochemical and immunological analyses. MV and PB were responsible for the project design, analyses of the results and writing of the manuscript. PL was involved in the sourcing of patients and the clinical examination of all patients. | en_ZA |
dc.description | The authors wish to thank the participants and staff of the Immunology Clinic at Kalafong Hospital and the South African National Blood Service at the Pretoria West satellite site. | en_ZA |
dc.description.abstract | BACKGROUND : The essential amino acid tryptophan cannot be synthesised in the body and must be acquired through dietary intake. Oxidation of tryptophan, due to immune induction of the enzyme indoleamine 2,3- dioxygenase (IDO), is considered to be the main cause of tryptophan depletion in HIV infection and AIDS. We examined plasma tryptophan levels in a low-income sub-Saharan HIV-infected population and compared it to that of developed countries. Tryptophan levels were further examined in context of the general nutritional and inflammatory status. METHODS : This cross-sectional study included 105 HIV-positive patients recruited from the Kalafong Hospital in Pretoria, South Africa, and 60 HIV-negative controls. RESULTS : Patient tryptophan levels were in general markedly lower than those reported for developed countries. In contrast to reports from developed countries that showed tryptophan levels on average to be 18.8 % lower than their control values, tryptophan levels in our study were 44.1 % lower than our controls (24.4 ± 4.1 vs. 43.6 ± 11.9 μmol/l; p < 0.001). Tryptophan levels correlated with both CD4 counts (r = 0.341; p = 0.004) and with proinflammatory activity as indicated by neopterin levels (r = −0.399; p = 0.0001). Nutritional indicators such as albumin and haemoglobin correlated positively with tryptophan and negatively with the pro-inflammatory indicators neopterin, interleukin 6 and C-reactive protein. The most probable causes of the lower tryptophan levels seen in our population are food insecurity and higher levels of inflammatory activity. CONCLUSIONS : We contend that inflammation-induced tryptophan depletion forms part of a much wider effect of pro-inflammatory activity on the nutritional profile of HIV-infected patients. | en_ZA |
dc.description.department | Internal Medicine | en_ZA |
dc.description.department | Physiology | en_ZA |
dc.description.department | Psychiatry | en_ZA |
dc.description.librarian | am2016 | en_ZA |
dc.description.sponsorship | This research was supported by grant funding received from the Medical Research Council of South Africa and the South African Sugar Association (SASA Project 213). | en_ZA |
dc.description.uri | http://www.jhpn.net/index.php/jhpn | en_ZA |
dc.identifier.citation | Bipath, P, Levay, PF & Viljoen, M 2016, 'Tryptophan depletion in context of the inflammatory and general nutritional status of a low-income South African HIV-infected population', Journal of Health, Population and Nutrition, vol. 35, pp. 1-7. | en_ZA |
dc.identifier.issn | 1606-0997 (print) | |
dc.identifier.issn | 2072-1315 (online) | |
dc.identifier.other | 10.1186/s41043-016-0042-4 | |
dc.identifier.uri | http://hdl.handle.net/2263/56298 | |
dc.language.iso | en | en_ZA |
dc.publisher | BioMed Central | en_ZA |
dc.rights | © 2016 Bipath et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License | en_ZA |
dc.subject | Tryptophan | en_ZA |
dc.subject | HIV/AIDS | en_ZA |
dc.subject | Malnutrition | en_ZA |
dc.subject | Sub-Saharan | en_ZA |
dc.subject | Pro-inflammatory activity | en_ZA |
dc.title | Tryptophan depletion in context of the inflammatory and general nutritional status of a low-income South African HIV-infected population | en_ZA |
dc.type | Article | en_ZA |