Haemophagocytic lymphohistiocytosis (HLH) (sometimes referred to as a ‘cytokine storm syndrome’) is a rare and devastating disease caused by over-activation of the immune system. HLH is caused by another underlying condition, for example, genetic defects, infections, cancers, inflammatory diseases (such as Adult-Onset Still’s Disease), pregnancy and some medications. We do not know why some people get HLH while others do not. Although HLH is rare, the number of people being diagnosed with this disease is rising but unfortunately many patients go undiagnosed. Even with a clear diagnosis, about 50% of patients die.
Through our work running HLH clinical services (Best Practice/Patient Choice award winners, 2024), we know we need better diagnostic tests/treatments for HLH especially since fast diagnosis and treatment are very important to prevent serious complications and even death. There are no specific tests for HLH meaning that diagnosis can be difficult, and current HLH treatment involves suppressing the immune system which can lead to further problems. We lack simple tests that can identify HLH from other similar diseases such as sepsis so we can diagnose and treat HLH patients quickly and correctly.
We have collected the UK’s biggest library of blood samples from patients with HLH linked to our clinical service. We plan to compare these samples with those from healthy people and other diseases and use machine learning technology to identify important differences. Our early research shows that we can use markers in the blood to identify patients with HLH. We now need to test these markers in patients with other diseases that can mimic HLH such as Adult-Onset Still’s Disease. This research will help us to understand why HLH affects some people and not others and may lead to novel diagnostic tests and avenues for treatment.
