Latent Tuberculosis is Highly Prevalent in Sub-Saharan Africans in Dublin - a Study Intended to Establish Normal CD4 Reference Ranges in this Population

Authors

  • Killian Bates School of Medicine, Trinity College, University of Dublin, Ireland

Keywords:

Medicine

Abstract

Objectives: To establish the normal reference range for CD4 lymphocyte cells in human immunodeficiency virus (HIV) negative sub-Saharan Africans attending the Genito-Urinary and Infectious Diseases (GUIDE) Outpatient Clinic at St. James’s Hospital in Dublin. To correlate CD4 Count with lymphocyte count. Design: This was a prospective observational study. Methods: Volunteers were recruited among new sub-Saharan African patients attending the GUIDE Outpatient Clinic at St. James’s Hospital, Dublin. Recruitment took place over an eight-week period between July and August 2003. The study objectives and methods were explained to volunteers, and informed consent for participation was obtained. History and relevant physical examination, together with measurement of haematological parameters, screening for sexually transmitted infections (STIs) and examination of stool and urine samples were performed to exclude confounding co-morbidities. A chest radiograph and Mantoux skin test was performed to exclude pulmonary tuberculosis (TB). Results: Seventeen participants were recruited. Two (12%) were excluded on the basis of HIV infection. Ten men and five women form the CD4 study group. Of the fifteen suitable patients recruited, the range of CD4 count is 532–1537 x 106/L. The reference range used by the laboratory at St. James’s, based on CD4 counts in largely Caucasian populations, is 380 – 1500 x 106/L. Despite a high level of coincidental findings in the cohort, the range of CD4 counts measured falls within the range currently used by the laboratory. Women had significantly higher CD4 cell counts than men (median = 1245 and 899 respectively. P < 0.01), as has been previously described. There was a strong linear relationship between CD4 cell count and absolute lymphocyte count (r2=0.5). Twelve of thirteen patients (92%) screened had evidence of latent pulmonary tuberculosis (TB), on the basis of a positive Mantoux reaction without radiographic evidence of TB. Two of fifteen (13%) HIV-negative patients defaulted before the result of their tuberculin skin test could be read. Only one patient in the entire cohort had a negative reaction to tuberculin challenge. We have referred 92% of this cohort for tuberculosis chemotherapy. Conclusions: The range of CD4 lymphocyte counts measured in this cohort falls within that used by the central pathology laboratory at St. James’s Hospital, and by clinicians at GUIDE. This is the range that is used to guide clinical care among HIV-positive patients at GUIDE. A high rate of latent TB exists in this cohort.

Author Biography

Killian Bates, School of Medicine, Trinity College, University of Dublin, Ireland

6th year Medicine, TCD

References

1. World Health Organization Tuberculosis Fact Sheet No 104 Revised August 2002 Available from: URL: http://www.who.int/mediacentre/factsheets/who104/en/ 2. WHO Report 2003: Global Tuberculosis Control - Surveillance, Planning, Financing 7th Annual WHO Report on Global TB Control Available from: URL: http://www.who.int/gtb/publications/globrep/download .html
3. Sinka K, Mortimer J, Evans B, Morgan D. Impact of the HIV epidemic in Sub-Saharan Africa on the pattern of HIV in the UK. AIDS 2003; 17: 1683 – 169.
4. ERHA Service Plan 2003 Eastern Regional Health Authority Available from: URL: http://www.erha.ie/news/uploads/560- Service%20Plan%202003.pdf
5. Feely E, O’Sullivan P, O’Flanagan D. Report on the epidemiology of TB in Ireland 2000 National Disease Surveillance Centre. Available from: URL:http://www.ndsc.ie/Publications/Tuberculosis/d4 61.PDF
6. Yeni P, Hammer S, Carpenter C, Cooper D, et al. Antiretroviral Treatment for Adult HIV Infection in 2002. Updated Recommendations of the International AIDS Society-USA Panel. JAMA. 2002;288:222-235. 7. Collins S, Fisher M, Johnson M, Khoo S, et al. British HIV Association guidelines for the treatment of HIV-infected adults with antiretroviral therapy July 2003 Available from: URL: http://www.bhiva.org
8. Messele T, Abdulkadir M, Fontanet AL, Petros B, et al. Reduced naïve and increased activated CD4 and CD8 cells in healthy adult Ethiopians compared with their Dutch counterparts. Clin Exp Immunol. 1999 Mar; 115(3): 443 – 50.
9. Howard RR, Fasano CS, Frey L, Miller CH. Reference intervals of CD3, CD4, CD8, CD4 / CD8, and absolute CD4 values in asian and non-asian populations. Cytometry. 1996 Sept 15; 26(3): 231-2. 10. Shahabuddin S. Quantitative differences in CD8+ Lymphocytes, CD4/CD8 Ratio, NK Cells and HLA-
DR(+)-activated T cells of racially different male populations. Clin Immunol Immunopathol. 1995 May; 75(2): 168–70.
11. Office of the Refugee Applications Commissioner, 79 – 83 Lower Mount Street, Dublin 2, Ireland Monthly Statistics Available from: URL: http://www.orac.ie/Pages/Statistics.htm
12. Maini MK, Gilson RJC, Chavda N, Gill S, et al. Reference ranges and sources of variability of CD4 counts in HIV-seronegative women and men. Genitourin Med. 1996; 72:27-31.
13. AIDS Strategy 2000: Report of the National AIDS Strategy Committee Department of Health and Children of Ireland. Available from Government publications statistics office Sun Alliance House Molesworth Street Dublin 2. URL: http://www.doh.ie/pdfdocs/aids_strategy.pdf
14. Joint Tuberculosis Committee of the British Thoracic Society: Control and prevention of tuberculosis in the United Kingdom: Code of Practice 2000. Thorax 2000; 55:887-901.
15. Clancy J, Kelly P. Tuberculosis and Mycobacterial Diseases: Proceedings of the 6th Tuberculosis Conference, 2002 Peamount Hospital, Newcastle, Co. Dublin (Unpublished)
16. British Medical Association British National Formulary 45th edition March 2003 section 5.1.9 pg 284 Available from: URL:http://www.bnf.org
17. Pang SC, Harrison RH, Brearley J, Jegathesan V, et al. Preventive therapy for tuberculosis in Western Australia. Int J Tuberc Lung Dis. 2000; 12:984–988. 18. Eidlitz-Markus T, Zeharia A, Baum G, Mimouni M, et al. Use of the Urine Color Test to Monitor Compliance With Isoniazid Treatment of Latent Tuberculosis Infection. Chest. Mar 2003; 123: 736 - 739.
19. Frieden TR, Sterling TR, Munsiff SS, Watt CJ, et al. Seminar: Tuberculosis. Lancet. September 13, 2003; 362:887-899.
20. Diagnostic Standards and Classification of Tuberculosis in Adults and Children. This Official Statement of the American Thoracic Society and the Centers for Disease Control and Prevention was adopted by the ATS Board of Directors, July 1999. This Statement was endorsed by the Council of the Infectious Disease Society of America, September 1999. Am. J. Respir. Crit. Care Med. 2000; (161): 1376- 1395.
21. Centers for Disease Control and Prevention. The role of BCG vaccine in the prevention and control of tuberculosis in the United States: a joint statement by the Advisory Council for the Elimination of Tuberculosis and the Advisory Committee on Immunization Practices. MMWR Morb Mortal Wkly Rep. 1996; 45(No. RR-4):[13 – 14] Available from: URL: http://www.cdc.gov/mmwr/PDF/rr/rr4504.pdf
22. Centers for Disease Control and Prevention. Screening for tuberculosis and tuberculosis infection in high-risk populations: recommendations of the Advisory Council for Elimination of Tuberculosis. MMWR Morb Mortal Wkly Rep. 1995; 44(RR-11):18-34.
23. Tripathy SP. Fifteen-year follow-up of the Indian BCG prevention trial. In: International Union Against Tuberculosis - Proceedings of the XXVIth IUAT World Conference on Tuberculosis and Respiratory Diseases. Singapore: Professional Postgraduate Services International, 1987:69–72.
24. International Health Regulations (1969) adopted by the Twenty-second world health assembly in 1969 and amended by the Twenty-sixth world health assembly in 1973 and the Thirty-fourth World Health Assembly in 1981. 3rd Annotated Edition WHO Geneva 1983 reprinted 1995 Available from: URL: http://www.who.int/csr/ihr/current/en/

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Published

2004-01-01

How to Cite

Bates, K. (2004). Latent Tuberculosis is Highly Prevalent in Sub-Saharan Africans in Dublin - a Study Intended to Establish Normal CD4 Reference Ranges in this Population. Trinity Student Medical Journal , 5(1), Page 72–78. Retrieved from https://ojs.tchpc.tcd.ie/index.php/tsmj/article/view/1948