Researchers at UCSF and Chan Zuckerberg Biohub have discovered a novel biomarker for an autoimmune disease that affects patients with testicular cancer. The disease, known as “testicular cancer-associated paraneoplastic encephalitis,” can cause severe neurological symptoms. The symptoms include loss of limb control, eye movement, and in some cases, speech. The disease begins with testicular cancer, which in some cases causes the immune system to attack the brain. Affected patients are often misdiagnosed and appropriate treatment is delayed.
The inventors identified a highly specific and unique biomarker for the disease using programmable phage display. Using this powerful tool, the researchers evaluated cerebrospinal fluid from a 37-year-old patient who had a history of testicular cancer and debilitating neurological symptoms, including vertigo, imbalance and slurred speech. The enhanced phage technology identified autoantibodies targeting Kelch-like protein 11 (KLHL11) found in the testes and parts of the brain. These results were correlated and validated with additional patient samples.