Serial Testing of T-SPOT.TBAssays with Anti-Tuberculosis Therapy in Patients with Extrapulmonay Tuberculosis

A rare case series of HIV-negative patients with early relapsing cervical tuberculosis lymphadenitis

Most patients with early recurrent tuberculous lymphadenitis (RTL) can be overlooked due to the paucibacillary character of Mycobacterium tuberculosis complex (MTBC) causing difficulty in the differential diagnosis. Here, we present three cases with early RTL that occurred after completing pulmonary tuberculosis (TB) therapy with a cure, and that improved by early diagnosis and therapy. A 30-year-old migrant male, HIV-negative patient, who had used immunosuppressive drugs for Crohn's disease presented to the TB outpatient clinic with a new anterior cervical lymph node enlargement. Two months ago, his therapy for pulmonary TB and intra-abdominal tuberculous lymphadenitis (TL) was completed. Real-time polymerase chain reaction (RT-PCR) of purulent fine-needle aspiration (FNA) specimen from the anterior cervical lymphadenopathy (LAP) was detected positive for MTBC. Isoniazid (H) resistance was determined via the Seegene system. The 6 cm anterior cervical LAP regressed to a 1.6 cm LAP at the 4^th month of initial therapy with first-line antitubercular drugs. A 25-year-old female, the HIV-negative patient, was admitted to the TB outpatient clinic with a bulge on the submandibular area 3 months after the cessation of pulmonary multidrug-resistance TB therapy lasting 2 years. She had an index case but no comorbidity. The cytomorphology of FNA biopsy from the submandibular LAP reported granuloma with necrosis. RT-PCR of the purulent FNA specimen was positive for MTBC. H and rifampicin (R) resistances were found via the Seegene system. The right submandibular 2.9 cm LAP improved to a 1.7 cm LAP 6 months after the initiation of second-line antitubercular therapy. A 19-year-old male, the HIV-negative patient, presented to the TB outpatient clinic with a new bulge on the left supraclavicular area 9 months after cessation of pulmonary TB. He had no comorbidity and index case. RT-PCR of the purulent FNA specimen was positive for MTBC. H and R sensitivities were determined via the Seegene system. After the initial therapy with first-line antitubercular drugs for 2 months, the 1.5 cm left supraclavicular LAP improved to a 1.2 cm LAP.

Multiple Extrapulmonary Tuberculous Abscesses Developed Postpartum in a Non-HIV Patient Under Anti-tuberculosis Chemotherapy

Although abscess formation constitutes a recognized complication of tuberculous lymphadenitis, the concomitant development of multiple tuberculous abscesses in the course of tuberculous lymphadenitis has rarely been described in the literature among HIV-negative patients under appropriate chemotherapy. Adherence and sensitivity to the administered anti-tuberculosis chemotherapy have to be verified in such patients. We report a case of deteriorating tuberculous lymphadenitis, presenting with the development of multiple extrapulmonary abscesses (cervical, psoas, and retroperitoneal) in an HIV-negative patient who had complied with appropriate anti-tuberculosis chemotherapy for four months. Mycobacterium tuberculosis was the identified pathogen in specimens from the abscesses. Continuation of anti-tuberculosis medications and concurrent administration of antibiotics, along with CT-guided percutaneous drainage of the psoas abscess, resulted in gradual resolution of the patient's lesions. Interestingly, our patient had recent childbirth, indicating a potential association between the immunomodulatory processes during the postpartum period and the development of the so-called paradoxical reaction. Awareness of such complications should be raised, as a timely recognition and subsequent therapeutical treatment are essential for a favorable outcome.

Diagnostic usefulness of T-cell based assays for tuberculous meningitis in HIV-uninfected patients

OBJECTIVES

Early diagnosis and treatment of tuberculous meningitis (TBM) is essential for a positive outcome, but sensitive, specific, and rapid diagnostic tests for TBM are lacking. We evaluated the diagnostic utility of enzyme-linked immunosorbent spot (ELISPOT) assays in HIV-uninfected patients with suspected TBM.

METHODS

All HIV-uninfected patients with suspected TBM were prospectively enrolled at a tertiary care hospital in an intermediate TB-burden country, during a 6-year period. ELISPOT assays were performed on peripheral blood mononuclear cells (PBMC) and cerebrospinal fluid-mononuclear cells (CSF-MC).

RESULTS

Of the 276 evaluable patients, 90 (33%) were classified as having TBM (30 definite cases, 19 probable, and 41 possible), and 186 (67%) as having non-TBM. When comparing definite TBM versus non-TBM, the sensitivity and specificity of the PBMC ELISPOT assay (≥6 spots; manufacturer's recommended cut-off) for diagnosing TBM were 96% (95% CI, 82-100) and 58% (95% CI, 50-66), respectively. The CSF-MC ELISPOT assay (≥38 spots; receiver operating characteristic [ROC]-derived cut-off) was a useful rule-in test with specificity of 95% (96% CI, 90-98). Its sensitivity was 68% (95% CI, 45-86), which was superior those of AFB smear microscopy (14%; P < 0.001) and CSF Mycobacterium tuberculosis PCR (41%; P = 0.07). Combining this assay with M. tuberculosis PCR, clinical score, and both together increased sensitivity to 86%, 91%, and 95%, respectively, while retaining about 95% specificity.

CONCLUSIONS

The CSF-MC ELISPOT assay appears to be a rapid and accurate rule-in test for the diagnosis of TBM and a useful adjunct for diagnosing TBM in HIV-uninfected patients.

Kinetics of T-cell-based assays on cerebrospinal fluid and peripheral blood mononuclear cells in patients with tuberculous meningitis

BACKGROUND/AIMS

The goal of this study was to monitor tuberculosis (TB)-specific T-cell responses in cerebrospinal fluid-mononuclear cells (CSF-MCs) and peripheral blood mononuclear cells (PBMCs) in patients with tuberculous meningitis (TBM) over the course of anti-TB therapy.

METHODS

Adult patients (≥ 16 years) with TBM admitted to Asan Medical Center, Seoul, South Korea, were prospectively enrolled between April 2008 and April 2011. Serial blood or CSF samples were collected over the course of the anti-TB therapy, and analyzed using an enzyme-linked immunosorbent spot (ELISPOT) assay.

RESULTS

Serial ELISPOT assays were performed on PBMCs from 17 patients (seven definite, four probable, and six possible TBM) and CSF-MC from nine patients (all definite TBM). The median number of interferon-gamma (IFN-γ)-producing T-cells steadily increased during the first 6 months after commencement of anti-TB therapy in PBMCs. Serial CSF-MC ELISPOT assays revealed significant variability in immune responses during the first 6 weeks of anti-TB therapy, though early increases in CSF-MC ELISPOT results were associated with treatment failure or paradoxical response.

CONCLUSIONS

Serial analysis of PBMCs by ELISPOT during the course of treatment was ineffective for predicting clinical response. However, increases in TB-specific IFN-γ-producing T-cells in CSF-MC during the early phase of anti-TB therapy may be predictive of clinical failure.

Incidence and outcomes of paradoxical lymph node enlargement after anti-tuberculosis therapy in non-HIV patients

OBJECTIVES

Limited data are available regarding the incidence and outcomes of lymphadenopathy after completing tuberculosis (TB) treatment.

METHODS

We prospectively evaluated the incidence and outcomes of post-treatment lymphadenopathy in 154 patients with newly diagnosed lymph node TB (group 1) and in 12 patients previously treated for TB (group 2). We assessed the rates of microbiological recurrence, clinical recurrence, and post-treatment paradoxical response (PR) (defined as no microbiological recurrence with spontaneous improvement).

RESULTS

Post-treatment lymphadenopathy occurred in 24 (15.6%) patients of group 1 and in 12 patients of group 2. Re-biopsy was performed in 23 of these 36 patients. AFB stain was positive in four (17.4%) cases, and TB-PCR was positive in 11 (47.8%), but all samples were sterile (no microbiological recurrence). Granuloma was present in 12 (52.2%) histological specimens. Thirty-three (91.7%) of the 36 patients with lymphadenopathy improved spontaneously (post-treatment PR) and 3 (8.3%) were improved with retreatment (clinical recurrence). The overall incidence of post-treatment PR in patients with lymph node TB (group 1) was 8.6 per 100 person-years (95% CI, 5.8-12.7).

CONCLUSIONS

Lymphadenopathy after TB treatment was more likely to be associated with post-treatment PR rather than with microbiological recurrence, and it should be monitored until PR resolve.

Comparison of the QuantiFERON-TB Gold In-Tube test with the tuberculin skin test for detecting latent tuberculosis infection prior to hematopoietic stem cell transplantation

A total of 244 patients including 100 (41%) autologous hematopoietic stem cell transplant (HCT) recipients and 144 (59%) allogeneic HCT recipients were enrolled over a 28-month period. During the study period, no prophylaxis for latent tuberculosis (TB) infection was administrated. Of these, 201 (82%) had Bacillus Calmette-Guérin (BCG) scars or prior histories of BCG vaccination. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed simultaneously in all 244 patients. TST indurations were ≥ 5 mm in 39 of these patients (15%), and in 25 (10%) indurations were ≥ 10 mm. In addition, 40 (16%) had positive QFT-GIT outcomes, and 34 (14%) indeterminate outcomes. If the 34 patients with indeterminate QFT-GIT results were excluded from the overall agreement analysis, the agreement between the TST results (induration size ≥ 5 mm) and the QFT-GIT results in the 210 patients with clear QFT results was poor (κ = 0.08, 95% confidence interval [CI] -0.06 to 0.24), as it was for the patients with indurations ≥ 10 mm (κ = 0.15, 95% CI -0.004 to 0.31). During follow up, 2 patients developed TB after HCT. The incidence of TB in the patients with positive QFT-GIT outcomes was 2.80 per 100 person-years (95% CI 0.07-15.81), whereas among those with positive TST (≥ 5 mm) results, it was 0 per 100 person-years (95% CI 0-8.00). However, this finding should be cautiously interpreted because of the relatively short follow up and the fact that the sample size of the study cohort did not have adequate power. In conclusion, our data show that, although the frequencies of positive outcomes in the 2 TB screening tests were similar, the overall agreement between the TST and the QFT-GIT test was poor, regardless of BCG vaccination history.