Characteristics of paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome and its influence on tuberculosis treatment outcomes in persons living with HIV

OBJECTIVE

The influence of tuberculosis (TB)-immune reconstitution inflammatory syndrome (IRIS) on TB treatment outcomes and its risk factors were investigated among people with human immunodeficiency virus (HIV) and co-infected with TB.

METHODS

Newly diagnosed, culture-confirmed, pulmonary TB patients with HIV and enrolled in a clinical trial (NCT00933790) were retrospectively analysed for IRIS occurrence. Risk factors and TB outcomes (up to 18 months after initiation of anti-TB treatment [ATT]) were compared between people who experienced IRIS (IRIS group) and those who did not (non-IRIS group).

RESULTS

TB-IRIS occurred in 82 of 292 (28%) participants. Significant baseline risk factors predisposing to TB-IRIS occurrence in univariate analysis were: lower CD4⁺ T-cell count, CD4/CD8 ratio, haemoglobin levels, presence of extra-pulmonary TB focus, and higher HIV viral load; the last two retained significance in the multivariate analysis. After 2 months of ATT commencement, sputum smear conversion was documented in 45 of 80 (56.2%) vs. 124 of 194 (63.9%) (p=0.23), culture conversion was in 75 of 80 (93.7%) vs. 178 of 194 (91.7%) (p=0.57) and the median decline in viral load (log₁₀copies/mm³) was 2.7 in the IRIS vs. 1.1 in the non-IRIS groups (p<0.0001), respectively. An unfavourable response to TB therapy was detected in 17 of 82 (20.7%) and 28 of 210 (13.3%) in the IRIS and non-IRIS groups, respectively (p=0.14).

CONCLUSIONS

TB-IRIS frequently occurred in people with advanced HIV infection and in those who presented with extra-pulmonary TB lesions, without influencing subsequent TB treatment outcomes.

Anti-tuberculosis (TB) chemotherapy dynamically rescues Th1 and CD8+ T effector levels in Han Chinese pulmonary TB patients

CD4+/CD8+ T cells play a major role in conferring immune protection against tuberculosis (TB), but it remains unknown how the immune responses of CD4+/CD8+ T cells exactly correlate with the clinical variables and disease statuses during anti-TB chemotherapy. To address this, several major immune parameters of CD4+/CD8+ T cells in peripheral blood derived from pulmonary TB patients and healthy volunteers were evaluated. We observed that active TB infection induced lower CD3+ T cell and CD4+ T cell levels but higher CD8+T cell levels, while anti-TB chemotherapy reversed these effects. Also, anti-TB treatment induced enhanced production of IL-2 and IFN-γ but reduced expression of IL-10 and IL-6. Moreover, the dynamic changes of CD3, CD4, and CD8 levels did not show a significant association with sputum smear positivity. However, the frequencies of IL-2+CD4+ or IL-10 + CD4+ T effector subpopulation or IL-1β production in peripheral blood showed significant difference between patients positive for sputum smear and patients negative for sputum smear after anti-TB treatment. These findings implicated that recovery of Th1/CD8+T cell effector levels might be critical immunological events in pulmonary TB patients after treatment and further suggested the importance of these immunological parameters as potential biomarkers for prediction of TB progress and prognosis.

Comparison of Histological, Microbiological, and Molecular Methods in Diagnosis of Patients with TBLN Having Different Anti-TB Treatment Background

OBJECTIVE

The influence of anti-tuberculosis (TB) treatment history on tuberculous lymphadenitis (TBLN) diagnosis is unclear. Therefore, this study aims to evaluate the diagnostic methods, including histology, microbiology, and molecular tests, used for TBLN.

METHODS

In this study, suspected patients with TBLN and having different anti-TB treatment background were enrolled. All the samples were tested simultaneously by histology, Ziehl-Neelsen (ZN) staining, mycobacterial culture (culture), Xpert MTB/RIF (xpert), real-time PCR, and high-resolution melting curve PCR (HRM). Thereafter, the performance of these methods on samples with different anti-TB treatment background was assessed.

RESULTS

In our study, 89 patients were prospectively included 82 patients with TBLN and 7 with other diseases. The overall sensitivities of Xpert, real-time PCR, histology, ZN staining, and culture were 86.6%, 69.5%, 58.5%, 43.9%, and 22.0%, respectively. The anti-TB treatment history revealed dramatic influences on the sensitivity of culture (P < 0.0001). In fact, the treatment that lasted over 3 months also influenced the sensitivity of Xpert (P < 0.05). However, the treatment history did not affect the performance of remaining tests (P > 0.05). For rifampicin drug susceptibility test (DST), the anti-TB treatment showed only significant influence on the success rate of culture DST (P = 0.001), but not on those of Xpert and HRM tests (P > 0.05).

CONCLUSION

Other tests as well as culture should be considered for patients with TBLN having retreatment history or over 1-month treatment to avoid false negative results.