Background The WHO recently recommended the new Xpert MTB/RIF Ultra assay (Ultra) instead of the Xpert MTB/RIF assay because Ultra has improved sensitivity. We report the diagnostic accuracy of Ultra for tuberculous adenitis in a tuberculosis and HIV endemic setting.
Methods We obtained fine-needle aspirates (FNA) and lymph node tissue by core-needle biopsy in adult patients with peripheral lymphadenopathy of > 20 mm. Ultra and mycobacterial culture were performed on FNA and tissue specimens, with histological examination of tissue specimens. We assessed the diagnostic accuracy of Ultra against a composite reference standard (CRS) of ‘definite tuberculosis’ (presence of acid-fast bacilli (AFBs) or culture positive on FNA or lymph node tissue) or ‘probable tuberculosis’ (macroscopic caseation or granulomas on histology or tuberculosis proven from another site, and no other identified cause for lymphadenopathy).
Results We prospectively evaluated 99 participants of whom 50 were HIV positive: 21 had ‘definite tuberculosis’, 15 ‘probable tuberculosis’ and 63 did not have tuberculosis (of whom 38% had lymphoma and 19% disseminated malignancy). Using the CRS, the sensitivity of Ultra on FNA was 70% (95% CI 51-85) and on tissue was 67% (95% CI 45-84); specificity on FNA was 100% (95% CI 92-100) and on tissue 96% (95% CI 88-99).
Conclusions Ultra performed on FNA or tissue of a lymph node had reasonable sensitivity and high specificity. Ultra on FNA would be an appropriate initial investigation for lymphadenopathy in tuberculosis endemic areas.

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On 27 Dec, 2019
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On 19 Dec, 2019
Received 11 Dec, 2019
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On 05 Dec, 2019
On 05 Dec, 2019
Received 05 Dec, 2019
On 25 Nov, 2019
On 24 Nov, 2019
On 24 Nov, 2019
Posted 27 Aug, 2019
Received 05 Nov, 2019
On 05 Nov, 2019
On 28 Oct, 2019
Received 18 Sep, 2019
Invitations sent on 06 Sep, 2019
On 06 Sep, 2019
On 19 Aug, 2019
On 18 Aug, 2019
On 14 Aug, 2019
On 27 Dec, 2019
On 26 Dec, 2019
On 25 Dec, 2019
On 25 Dec, 2019
On 19 Dec, 2019
Received 11 Dec, 2019
Invitations sent on 05 Dec, 2019
On 05 Dec, 2019
On 05 Dec, 2019
Received 05 Dec, 2019
On 25 Nov, 2019
On 24 Nov, 2019
On 24 Nov, 2019
Posted 27 Aug, 2019
Received 05 Nov, 2019
On 05 Nov, 2019
On 28 Oct, 2019
Received 18 Sep, 2019
Invitations sent on 06 Sep, 2019
On 06 Sep, 2019
On 19 Aug, 2019
On 18 Aug, 2019
On 14 Aug, 2019
Background The WHO recently recommended the new Xpert MTB/RIF Ultra assay (Ultra) instead of the Xpert MTB/RIF assay because Ultra has improved sensitivity. We report the diagnostic accuracy of Ultra for tuberculous adenitis in a tuberculosis and HIV endemic setting.
Methods We obtained fine-needle aspirates (FNA) and lymph node tissue by core-needle biopsy in adult patients with peripheral lymphadenopathy of > 20 mm. Ultra and mycobacterial culture were performed on FNA and tissue specimens, with histological examination of tissue specimens. We assessed the diagnostic accuracy of Ultra against a composite reference standard (CRS) of ‘definite tuberculosis’ (presence of acid-fast bacilli (AFBs) or culture positive on FNA or lymph node tissue) or ‘probable tuberculosis’ (macroscopic caseation or granulomas on histology or tuberculosis proven from another site, and no other identified cause for lymphadenopathy).
Results We prospectively evaluated 99 participants of whom 50 were HIV positive: 21 had ‘definite tuberculosis’, 15 ‘probable tuberculosis’ and 63 did not have tuberculosis (of whom 38% had lymphoma and 19% disseminated malignancy). Using the CRS, the sensitivity of Ultra on FNA was 70% (95% CI 51-85) and on tissue was 67% (95% CI 45-84); specificity on FNA was 100% (95% CI 92-100) and on tissue 96% (95% CI 88-99).
Conclusions Ultra performed on FNA or tissue of a lymph node had reasonable sensitivity and high specificity. Ultra on FNA would be an appropriate initial investigation for lymphadenopathy in tuberculosis endemic areas.

Figure 1

Figure 2
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