Dual latent tuberculosis screening with tuberculin skin tests and QuantiFERON-TB assays before TNF-α inhibitor initiation in children in Spain

Disseminated Mycobacterial Infection With Reactive Polyarthritis (Poncet's Disease) During Immune-suppressive Treatment Including Ustekinumab for Pediatric Crohn's Disease

BACKGROUND

The incidence of pediatric inflammatory bowel disease is increasing. tumor necrosis factor alpha inhibitors medicines improved the prognosis of affected subjects. Nonetheless, a proportion of patients do not respond or lose response to treatment. Newer biologics, like ustekinumab, have been approved for adults. The pediatric off-label use of these drugs is increasing, despite limited safety evidence. We report a case of disseminated mycobacterial infection (MI) presenting with reactive polyarthritis (Poncet's disease, PD) in a girl with Crohn's disease receiving various immunosuppressants, including ustekinumab.

CASE REPORT

A 12-year-old girl with Crohn's disease was admitted for acute-onset migratory polyarthritis of large and small joints and opioid-resistant pain. She had recently received adalimumab and methotrexate and was currently under treatment with ustekinumab. She was vaccinated with Bacillus Calmette-Guérin and screened for tuberculosis before starting immunosuppressants. Interferon-gamma release assay, Mantoux test and chest computed tomography scan were negative. Disseminated MI with PD was diagnosed following positive cultures for Mycobacterium tuberculosis complex in blood and intestinal biopsies (with negative in synovial fluid and gastric aspirate). Whole-exome sequencing did not identify any genetic susceptibility to MI. Antituberculosis treatment eradicated MI.

CONCLUSIONS

Children with inflammatory bowel disease receiving combination immunosuppressive treatments including tumor necrosis factor alpha inhibitors and anti-IL-12/23 agents are at higher risk for MI. Disseminated MI should be considered and ruled out in these patients when presenting with pulmonary, extrapulmonary or unusual clinical manifestations, like PD. The collection of multiple specimens (including intestinal biopsies) for mycobacterial culture is recommended when mycobacterial disease is suspected.

Disseminated tuberculosis after anti-TNF alpha treatment: Do not blindly trust the IGRA test

INTRODUCTION

Interferon gamma release assay (IGRA) is used to detect latent tuberculosis prior to biological treatments in the context of suspected inflammatory rheumatism.

METHODS

We report the case of a 50-year-old woman with negative IGRA test before adalimumab introduction for presumed axial spondyloarthritis.

RESULTS

The worsening of symptoms under treatment led to further investigations and the diagnostic of disseminated tuberculosis (TB) was later established with miliary and multiple bone locations such as spondylitis and sacroilitis. The patient's history revealed past exposure to tuberculosis. This observation illustrates the limitations of IGRA in such situation due to its variable performance for active TB diagnosis.

CONCLUSION

Misdiagnosis is frequent in bone tuberculosis due to non-specific signs. We draw the attention to the importance of a global risk assessment prior to the introduction of biological treatment for suspected chronic inflammatory rheumatism and recall the risk factors for false-negative IGRA. An extended treatment course may be necessary after exposure to anti-TNF-alpha.

The Value of the Second QuantiFERON-TB Gold-Plus Antigen Tube at Diagnosis and at Treatment Completion in Spanish Children With Tuberculosis

We studied 295 children (tuberculosis disease, n = 159; latent tuberculosis infection, n = 136) with positive QuantiFERON-TB Gold-Plus assay results. No significant differences between first and second antigen tube interferon-gamma responses were detected, irrespective of patient and disease characteristics at diagnosis. Of patients with a repeat assay after treatment completion (n = 65), only 16.9% converted to negative results.

Host, technical, and environmental factors affecting QuantiFERON-TB Gold In-Tube performance in children below 5 years of age

Interferon-gamma release assays performance can be impaired by host-related, technical and environmental factors, but data in young children are limited. We performed a cross-sectional study of children < 5 years-of-age at risk of tuberculosis (TB), using QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. The impact of the following was evaluated: (i) host-related [age; hematological parameters; erythrocyte sedimentation rate (ESR); C-reactive protein (CRP); and tobacco smoke exposure (TSE) based on serum cotinine concentrations], (ii) technical (pre-analytical delay) and (iii) environmental factors (annual season; monthly temperatures). Of 204 children, 35 (17.2%) were diagnosed with latent TB infection or TB disease. QFT-GIT results were indeterminate in 14 (6.9%) patients. In multivariate analysis, younger age and higher ESR were associated with lower positive control responses (beta: 0.247, p = 0.002 and - 0.204, p = 0.007, respectively), and increasing age was associated with lower rates of indeterminate QFT-GIT results [OR (95% CI) 0.948 (0.903-0.996) per month, p = 0.035]. In children with positive QFT-GIT results, average monthly temperatures correlated with antigen responses (r = 0.453, p = 0.020); also, antigen responses were lower in winter than in other seasons (p = 0.027). Serum cotinine concentrations determined in a subgroup of patients (n = 41) indicated TSE in 36 (88%), positive control responses being lower in children with TSE (p = 0.034). In children < 5 years-of-age, young age, elevated ESR, temperature, annual season and TSE can affect the performance of QFT-GIT assays.