A tuberculosis prediction score based on diagnostic models may enable prompt treatment decisions in HIV-infected children with suspected TB and a high risk for mortality, according to research published in Pediatrics. Implementing the score would likely have significant public health benefits, the researchers noted.
“To our knowledge, this is the first study in which a diagnostic score is developed exclusively in children infected with HIV by using methods recommended for diagnostic prediction models,” Olivier Marcy, MD, PhD, a clinical epidemiologist at the University of Bordeaux in France, and colleagues wrote. “Previous pediatric TB diagnostic scores and algorithms were mostly based on expert opinion and often lacked validation.”
Marcy and colleagues noted that diagnostic challenges are greater in children infected with HIV, and that immunodeficiency reduces sensitivity of immunologic tests for TB infection. According to the researchers, of the 40,000 TB-related deaths in children infected with HIV, 90% occurred in those not receiving TB treatment.
In their study, called PAANTHER, the researchers tested scores based on clinical assessment, chest radiography, QuantiFERON Gold In-Tube (QFT) TB testing, abdominal ultrasonography and sample collection for microbiology. They enrolled HIV-infected children with suspected TB who were aged 13 years or younger in eight hospitals in Burkina Faso, Cambodia, Cameroon and Vietnam from April 2011 to December 2014.
Using the results of the tests, the researchers created four TB diagnostic models using logistic regression: 1) all predictors included; 2) QFT excluded; 3) abdominal ultrasonography excluded; and 4) QFT and abdominal ultrasonography excluded.
Among 438 children enrolled in the study, 251 (57.3%) had TB, including 55 (12.6%) with culture- or Xpert MTB/RIF assay-confirmed TB, according to the researchers. In the final four models, they included the Xpert MTB/RIF assay, fever lasting more than 2 weeks, unremitting cough, hemoptysis and weight loss in the past 4 weeks, contact with a patient who had smear-positive TB, tachycardia, military TB, alveolar opacities and lymph nodes on the chest radiograph. They combined these with data from abdominal lymph nodes on the ultrasound and QFT results.
Marcy and colleagues concluded that the score developed from the second model — based on clinical assessment of symptoms, Xpert MTB/RIF testing, chest radiography and abdominal ultrasonography — had a sensitivity of approximately 90% and a specificity of 61.2%, far exceeding the specificity of scores developed in previous studies.
“With its high sensitivity, our score should enable standardized treatment initiation in most HIV-infected children with tuberculosis,” the researchers wrote.
In a related editorial, Silvia S. Chiang, MD, assistant professor of pediatrics at Brown University, and Andrea T. Cruz, MD, MPH, research chief for pediatric emergency medicine at Baylor College of Medicine, noted the decision tool’s potential improved diagnostic sensitivity over microbiologic assays.
“When used at the primary care level by frontline providers, this tool may facilitate the diagnosis and timely treatment of TB in children coinfected with HIV and TB and, in doing so, may save lives.” – by Joe Gramigna
Disclosures: The authors report no relevant financial disclosures.