FAQs

1. What kind of test is it?

LIOFeron® TB/LTBI is an immunological test diagnosing infection with latent tuberculosis, more

scientifically called Latent Tuberculosis Infection (LTBI).

2  Can LIOFeron® TB/LTBI also diagnose active TB?

Yes, but this test similar to all other IGRA tests, it cannot differentiate between active TB and LTBI.

3  Have clinical studies been done with LIOFeron® TB/LTBI?

Yes, it has been evaluated in several  independent TB hospitals. Two clincial studies habeen published, one each in adults and children,  showing excellent results and high concordance to Quantiferon TB Gold Plus of Qiegen GmbH. Since, LIOFERON has in TUBE B a properietary antigen alanine dehydrogenase which is a proven antigen for CD8 T cells, it might correct but different results to Quantiferon TB Gold Plus.

4  What if the QuantiFERON TB Gold Plus and LIOFeron® TB/LTBI results are different?

I such cases, one has to consider results of further tests, such as microscopy, culture, PCR tests, skintest and clinical symptoms. One should never consider Quantiferon TB Gold Plus  to be the gold standard. There is no Gold Standard for LTBI.

5  Which antigens Tube is more important for LTBI diagnosis by LIOFeron® TB/LTBI?

The tube A containing EESAT 6, CFP10 and TB 7,7  proteins. It is important to note that since  TB7.7 is missing in Quantiferon TB Gold Plus , LIOFERON might show higher sensitivity than Quantiferon TB Gold Plus. Hence, LIOFERON result positive but QFT TB Gold Plus negative does not mean that LIOFERON results are wrong.

6  Can we use Instruments, ELISA readers of different manufacturers?

Yes, the current version of LIOFeron® TB/LTBI can be used on any open system.

7- Is there any software to automatically analyse the results of LIOFeron® TB/LTBI?

Yes, we have developed a STAND-ALONE SOFTWARE called LIOFERON®, which can automatically

analyse the results. The latest version of the software has options for direct import of raw data from several ELISA readers or automatic ELISA Platforms such as DS2. If you provide the exported raw data in .csv/ txt format, we can develop a script for direct import from your ELISA reader.

You can download the LIOFERON software at LIOFERON-SOFTWARE

8  Do we need additional reagents while using the LIOFeron® TB/LTBI kit?

No, all reagents and components are provided with the LIOFeron® TB/LTBI kit (Blood stimulation tubes and ELISA plates).

9  Can we collect blood directly in the LIOFeron® TB/LTBI kit tubes?

• Blood can be collected directly in the blood stimulation tubes since these contain Li-Heparin. In standard practice world-wide, the blood is first collected in proper BLOOD COLLECTION TUBES containing Li-Heparin and then dispensed into the tubes provided in the LIOFeron®️ TB/LTBI kit according to the instructions of use:

Or

 blood which is taken with injectors, butterfly sets, etc. can be directly added to the LIOFeron TB/LTBI HUMAN BLOOD STIMULATION TUBES provided in the kit followed by incubation because the LIOFERON Blood collection tubes contain Li-Heparin anticoagulant.

10  Are the LIOFeron® TB/LTBI kit tubes, screw-cap blood stimulation tubes?

No, you have to pull the caps to open and press tightly to close the caps. There are are two stages while closing. Please press tightly to ensure proper closing.

11  Do we need a CO2 incubator?

Not necessary, but you can use one, if available.

12  What is the reason for using IGRA tests in endemic countries, where there is a very high proportion of LTBI?

Such tests are helpful if clinical symptoms indicate active TB, since a positive result of an IGRA test shall confirm infection with MTB to a high degree.

13  Are such IGRA tests useful for population screening with TB-prevalence in mind?

No, such IGRA tests are not specific for active TB and hence, cannot be used for determining prevalence of active TB in a population.

Such IGRA tests are highly useful for screening LTBI populations for determining the prevalence of latent infections with TB pathogen, for eample, prior to the treatment with anti-TNF blockers or any other immun suppresive drug which might induce the growth of the TB pathogen

LIOFeron® is a trade mark of LIONEX GmbH, Braunschweig, Germany