Attenuated response to purified protein derivative in patients with rheumatoid arthritis: study in a population with a high prevalence of tuberculosis
- PMID: 16100342
- PMCID: PMC1755642
- DOI: 10.1136/ard.2004.029041
Attenuated response to purified protein derivative in patients with rheumatoid arthritis: study in a population with a high prevalence of tuberculosis
Abstract
Background: The purified protein derivative (PPD) skin test is the only widely used method which detects latent tuberculosis infection (LTBI) and is dependent on a normal T cell function. In rheumatoid arthritis (RA) the T cell function is altered, which may result in an inability to develop an adequate PPD reaction.
Objectives: To evaluate the response to PPD in patients with RA and to compare it with that of control subjects.
Methods: 112 patients with RA and 96 healthy controls were studied. PPD 5 U was applied using the Mantoux method, and skin reaction was measured at 72 hours. The reaction was considered negative for PPD <5 mm.
Results: There were no significant differences in age, sex, history of bacille Calmette-Guerin vaccination, or tuberculosis contact between the two groups. The median size of the PPD induration in the patients with RA was significantly less than that in the control group (4.5 v 11.5 mm, p<0.01). 79 (70.6%) patients with RA compared with 25 (26%) of the control group had a negative reaction to PPD (p<0.01), a response not influenced by disease activity or duration of disease in the patients with RA.
Conclusion: A PPD skin test is not an appropriate test for recognising LTBI in patients with RA in our population.
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Comment in
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Attenuated response to purified protein derivative in patients with rheumatoid arthritis.Ann Rheum Dis. 2006 Jul;65(7):980. doi: 10.1136/ard.2005.050161. Ann Rheum Dis. 2006. PMID: 16769792 Free PMC article. No abstract available.
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QuantiFERON TB Gold Test: the new standard for screening of latent tuberculosis in patients with rheumatoid arthritis?Ann Rheum Dis. 2007 Feb;66(2):276. doi: 10.1136/ard.2006.061184. Epub 2006 Nov 24. Ann Rheum Dis. 2007. PMID: 17127686 Free PMC article. No abstract available.
