Central nervous system aspergillosis with negative serum fungal biomarkers after sequential teclistamab and talquetamab for multiple myeloma: a case report and review of the literature
This case report describes a rare instance of central nervous system aspergillosis with negative serum fungal biomarkers in a multiple myeloma patient treated sequentially with teclistamab and talquetamab, highlighting the critical need for tissue diagnosis and heightened clinical suspicion for invasive mould infections in patients receiving bispecific antibodies, particularly those requiring corticosteroids for neurotoxicity.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
When the body's immune system is turned off to treat a specific disease, the door is left open for other invaders. This is a fundamental trade-off in modern medicine, particularly when treating blood cancers like multiple myeloma. In recent years, doctors have gained powerful new tools called bispecific antibodies. These are laboratory-made proteins designed to act like a bridge, grabbing onto a cancer cell on one side and a healthy immune cell on the other, forcing the immune system to attack the tumor. While this approach has saved lives, it comes with a significant cost: the treatment often leaves patients vulnerable to severe infections. Among these, fungal infections are a rare but deadly threat. Unlike bacteria, which can often be identified by simple blood tests, fungi can hide deep inside the body, making them difficult to spot until they have caused serious damage. Understanding how these infections behave in patients receiving these advanced cancer therapies is critical, because missing the diagnosis can be fatal.
A team of researchers recently documented a striking and difficult case that highlights the dangers of these hidden infections. They followed a 70-year-old woman who had been battling multiple myeloma for nearly a decade. After many rounds of standard treatment, she received a new therapy involving two different bispecific antibodies given one after the other. The first drug, which targets a specific protein on the cancer cells, caused her immune system to react violently, leading to confusion and cognitive decline before she could receive her second dose. Doctors treated this reaction with strong steroids to calm the immune system down. Once her mind cleared, she was switched to a second, different antibody therapy. Shortly after starting this second treatment, she began to cough and became confused again.
At first, the medical team suspected a bacterial infection in her lungs. Scans showed holes, or cavities, in her lung tissue, which often look like bacterial abscesses. However, antibiotics did not help. The doctors then turned to a different set of tests designed to detect fungi in the blood. These tests looked for specific chemical markers that fungi release, but the results came back negative every single time over several months. Despite the clean blood tests, a needle biopsy of her lung tissue revealed the truth: she had an invasive mold infection called aspergillosis. The doctors started her on a powerful antifungal medication, and the lung infection began to respond.
The story became more complex when the patient failed to return to her normal level of strength and mobility. Because she had previously suffered from confusion caused by the first drug, the medical team initially worried that her current weakness was just a lingering side effect of that treatment. They hesitated to look for a new cause. However, her condition continued to worsen, prompting a scan of her brain. The images showed a small, ring-shaped lesion in the back of her brain. A biopsy of this area confirmed that the mold had traveled from her lungs to her brain, causing a central nervous system infection. This was a rare occurrence, as fungal infections of the brain are not commonly seen in patients with this type of cancer.
The researchers reviewed the medical literature to see if others had experienced similar events. They found very few reports of this specific type of fungal infection occurring in patients treated with these new antibody therapies. In the few cases where blood tests were reported, those tests had been positive, unlike this patient's. This discrepancy is the most important lesson from the case. The study shows that a negative blood test for fungal markers does not guarantee a patient is free of infection, especially when they are undergoing this specific type of cancer treatment. The infection can be present and growing even when the blood tests remain silent.
The authors suggest that this case changes how doctors should think about monitoring patients. When a patient receiving these antibody therapies develops new neurological symptoms or lung problems, doctors should not rely solely on blood tests to rule out a fungal infection. If the symptoms persist or worsen, a tissue biopsy is necessary to get a definitive answer. Furthermore, the study points out that patients who require high doses of steroids to manage immune reactions during this therapy may be at higher risk. The researchers propose that these specific patients might need preventative antifungal medication, a step that is not currently standard practice for everyone. While this single case does not prove that such a strategy will work for everyone, it provides a strong reason to investigate it further. The goal is to ensure that when these powerful new cancer treatments are used, the hidden dangers they carry can be caught early, before they become fatal.
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