A blood test to detect immune deficiency
As many as 1 in 300 people may suffer from a weakened immune system, making them more susceptible to frequent infections and complications from diseases. Yet patients can shuttle between doctors for years before being diagnosed. Moreover, an estimated 70% of cases go undiagnosed because existing tools are inadequate.
A team from the lab of Professor Kathrin de la Rosa, Group Leader of Cancer & Immunology/Immune Mechanisms and Human Antibodies, which is a guest lab at the Max Delbrück Center, in collaboration with researchers from the Berlin Institute of Health at Charité, have developed a tool to enable quicker and more accurate diagnoses. The research is described in “Nature Communications.”
“Doctors need diagnostics that are fast, cheap and widely accessible,” says Dr. Clara Vázquez García, a lead author of the study and a postdoc in the de la Rosa lab, which is formally affiliated with the Centre for Individualised Infection Medicine in Hannover, a joint initiative of Hannover Medical School and the Helmholtz Centre for Infection Research. “Our method requires just one milliliter of blood and costs only around 30 euros.”
Better diagnoses
Physicians typically diagnose immune deficiency using a combination of health history and laboratory tests, including immune cell counts, antibody levels, and response to vaccines. Patients may also be referred for more costly procedures like genetic testing, which still miss about 70% of immune deficiencies because many of them do not have clearly defined genetic causes.
The idea behind the tool arose when Vázquez García and colleagues were studying the DNA of B cells, the antibody-producing cells of the immune system. During an infection, B cells switch the type of antibody they produce – switching from early, general-purpose antibodies to those that provide longer-term protection, for example. This involves cutting and repairing B cell DNA to reshuffle antibody-encoding genes, leaving behind so-called “genomic scars.”
When the team analyzed these scars in cell lines, they observed clear differences between healthy B cells and those with DNA repair defects, suggesting that they might serve as a benchmark of how well a person’s immune system is functioning. They developed SWIBRID (SWItch-joint Breakpoint Repertoire Identification) – a method that uses DNA sequencing and artificial intelligence to analyze B cell genomic scars.
In their study of a cohort of 68 patients, the researchers reported that SWIBRID identified immune deficiency with 99% accuracy and DNA repair disorders – a more severe disorder that increases susceptibility to complications like cancers – with 84% accuracy.
“People with immune deficiency generally have a higher risk of cancer, but until now doctors could not distinguish which patients were most at risk,” Vázquez García says, “Our method was able to distinguish severe from less severe cases. This stratification could enable personalized prevention and treatment.”
Toward clinical application
The team now hopes to bring SWIBRID to market. Under project “immPRINT,” they were recently accepted into the 2026 Nucleate Activator cohort – a program that provides business skills training.
The team is also exploring applications in other immune-related disorders and have begun testing new patient cohorts in partnership with clinics, Vázquez García says. “We want to get SWIBRID on the market as soon as possible because we really believe this can help people.”
Text: Anita Waltho
Further information
- Clara Vázquez García wins Helmholtz Doctoral Award
- Five Berlin-based leading minds honored
- Innovations to improve personalized medicine
Literature
Clara Vázquez García, Benedikt Obermayer, Baerbel Keller, et. al. (2025) “Recombination junctions from antibody isotype switching classify immune and DNA repair dysfunction,” Nature Communications DOI: 10.1038/s41467-025-67206-5
Contacts
Dr. Clara Vázquez García
Immune Mechanisms and Human Antibodies
Max Delbrück Center
Clara.VazquezGarcia@mdc-berlin.de
Gunjan Sinha
Editor, Communications
Max Delbrück Center
+49 30 9406-2118
Gunjan.Sinha@mdc-berlin.de or presse@mdc-berlin.de
- Max Delbrück Center
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The Max Delbrück Center for Molecular Medicine in the Helmholtz Association lays the foundation for the medicine of tomorrow through our discoveries of today. At locations in Berlin-Buch, Berlin-Mitte, Heidelberg, and Mannheim, interdisciplinary teams investigate the complexity of disease at the systems level – from molecules and cells to organs and entire organisms. Together with academic, clinical, and industry partners, and as part of global networks, we turn biological insights into innovations for early detection, personalized therapies, and disease prevention. Founded in 1992, the Max Delbrück Center is home to a vibrant, international research community of around 1,800 people from over 70 countries. We are 90 percent funded by the German federal government and 10 percent by the state of Berlin.
