Addressing latent TB infection in the immunosuppressed31 October 2023
Dr Edoardo Carretto, the director of clinical microbiology at Santa Maria Nuova Hospital, located in Reggio Emilia, Italy, sheds light on the pivotal role of the T-SPOT.TB test from Revvity in combating cases of latent TB infection, and how it is leading the charge towards the constant reduction of TB cases within the province.
In the quest to support the World Health Organisation’s (WHO) ‘End TB Strategy’, which aims to reduce global TB incidence by 80% by 2030, the detection of latent TB infection (LTBI) is key.
As an active member of the local TB prevention and control programme for the region, Dr Edoardo Carretto is an advocate for the importance of screening for LTBI, particularly in the immunosuppressed population. This prompted the adoption of the WHO-recommended T-SPOT.TB test, an interferon-gamma release assay (IGRA).
Reliable by design
The T-SPOT.TB test is a sensitive blood test to detect LTBI. Through isolation, washing, and counting of the PBMCs, the accuracy of patient results is enhanced.
“Prior to using the T-SPOT.TB test, some of our results were equivocal mainly in immunosuppressed populations. With the normalisation of T cells in the T-SPOT.TB test, more than 80% of patients with previously ‘indeterminate’ results are now detected,” Carretto notes.
“The main advantages come with the automated workflow steps, which make previous labourintensive tasks, like cell isolation or spot counting, both easy and rapid.”
Commenting on the choice of the T-SPOT. TB test, Carretto says, “The T-SPOT.TB test has significantly improved our TB testing workflow, allowing the maximum efficiency in our Reggio Emilia lab. The main advantages come with the automated workflow steps, which make previous labour-intensive tasks, like cell isolation or spot counting, both easy and rapid. Now that the TB testing workflow is more technician-friendly, we have been able to process far more samples, and identify LTBI with greater accuracy and reliability.”
Having been actively engaged in the battle against TB, Carretto is optimistic about the future. Before the Covid-19 outbreak, in 2019, the TB rate in Italy was down to 5.5 per 100,000 population.
With an increased number of testing regimes such as that of Reggio Emilia, and further simplifications of the transformative T-SPOT.TB test workflow, the WHO’s target of an 80% reduction in new TB cases by 2030 could now be achieved.