Fingertip sweat shows whether tuberculosis patients are taking medication properly

Sweat from a fingertip can be used to test whether tuberculosis (TB) patients are taking their medication properly. Until now, this could only be done by pricking blood. Pulmonologist Onno Akkerman explains how he came up with this idea.

Reliable drug test

“In England, forensic medicine had developed a test to determine via sweat from a fingertip whether young people had taken drugs. This turned out to be reliable. I read about it and then thought, could this also work with tuberculosis medication? As TB center, we have been investigating for years whether there is a simple, reliable and patient-friendly way to determine whether patients are taking their medication. And also whether it has been properly absorbed into the body. I contacted the researchers in England with that question at the time.

Therapy adherence essential in TB

'There are about 10 million patients with TB around the world, making it the most common infectious disease worldwide. TB is always treated with multiple antibiotics. If patients do not always take their medication or do not complete their course of treatment, the treatment may not work. This can cause them to get sick again, thereby infecting other people. Therefore, it is essential to know that patients take their medication daily.

Burdensome checks

'For a long time, patients were even required to take their medication under the supervision of family or caregiver. Something that was very stressful both for them and for the practitioners. But you had to be there, also because you can't say, 'this patient doesn't need it and this one does.' There are blood tests to check compliance, but that's not very patient-friendly. Constant blood sampling is annoying. Also, some cultures have a lot of fear of having blood drawn.'

Sweat from fingertip

'In the English test, someone puts a fingertip on a glass for half a minute. You can then examine the sweat drops on the glass. Pricking is no longer necessary and it takes little effort. This test is probably easy to do even for young children.

Most commonly used TB drug

'We have now been able to investigate this for the most commonly used TB drug. We did this with mass spectrometry. This is a technique that can identify all the molecules and atoms of the sweat droplets. From the composition of those sweat droplets, we can clearly see whether the patient has taken his medication and also whether it has been properly absorbed into the body.'

Sweat test proves reliable

'For this drug, the test proved to be reliable. We are still in the research phase now, but of course this is a wonderful first result. I want to put it into practice as soon as possible. The UMCG is the only TB center in the world doing this research for TB-drugs. Together with Marieke Sturkenboom of the Department of Clinical Pharmacy and Pharmacology and Melanie Baily, a collegue from the University of Surrey, I will now investigate the reliability of this test for other TB medications as well.

Application in global TB care

'The goal is for this to become one of the options in patient care. As a practitioner, you can then choose the patient's preferred option. I really hope we can make an impact for global TB care with this. I was recently in South Africa, where tuberculosis is a much bigger problem than here. When you walk around there, you remember completely what you're doing this for.'