Chaz Langelier Lab

1. A More Accurate Way to Diagnose Respiratory Tract Infections (April 06, 2023): Lower respiratory tract infections (LRTI), such as pneumonia, bronchiolitis and even RSV, have long been a leading cause of death in children worldwide. Even in countries where the death toll is not high, LRTIs are incredibly common. For example, a recent study out of the Philippines found that 45% of children developed a LRTI at least once before their first birthday. Read more...

2. Cracking the Puzzle of Lower Respiratory Tract Infection in Children (April 5, 2023): Lower respiratory tract infection (LRTI), which includes conditions such as pneumonia, has long been the leading cause of death from communicable agents and a leading cause of death in children worldwide. But despite its prevalence, LRTI is tricky for doctors to treat effectively because the current diagnostic approach often fails to conclusively determine whether an infection is present at all, and if so, what pathogen is causing it. Read more...

3. What's the Point of PCR Tests Anymore? (February 16, 2023): If you had COVID-19 symptoms in 2020, you probably would have masked up and braved a visit to a laboratory, doctor’s office, or clinic to get a polymerase chain reaction (PCR) test. A health care worker would have shoved a swab up your nose, and then you would have waited a day or two, if not more, to get your results. Now, you’d likely use an at-home test, which spits out results in just 15 minutes. It’s easier, faster, and reliable, even against the latest variants. Read more...

4. A Culture of [Blood] Cultures-Why hasn't rapid sequencing for serious infections and sepsis become standard of care? (December 17, 2022): In 2014, Sharon Peacock, a professor of microbiology at the University of Cambridge, wrote an important piece in Nature, first page shown below, advocating sequencing as a standard of care to rapidly determine the causative pathogen and direct appropriate therapy—since the sequence can reveal mutations that confer resistance to antibiotics. She wrote: “Microbial sequencing should be done as close to the patient as possible.” To achieve the best outcome, the need for speed to crack the case and initiate the right treatment cannot be emphasized enough. Read more...

5. Boosting accuracy, reducing false positives of PCR COVID-19 tests (December 14, 2022​): PCR swab tests that look for viral RNA have become the gold standard for identifying infection with the SARS-CoV-2 virus, but their results aren’t 100% accurate. This week in  mSystems,  an open-access journal of the American Society for Microbiology, researchers report that testing for levels of certain immune-related genes in an infected individual, in addition to looking for genetic material of the virus itself, could increase diagnostic accuracy. Read more...

6. Boosting accuracy, reducing false positives of PCR COVID-19 tests (December 12, 2022​): PCR swab tests that look for viral RNA have become the gold standard for identifying infection with the SARS-CoV-2 virus, but their results aren't 100% accurate. Researchers report that testing for levels of certain immune-related genes in an infected individual, in addition to looking for genetic material of the virus itself, could increase diagnostic accuracy. Read more...

7. We Still Don't Have At-Home Testing For the Flu—But COVID-19 Has Changed the Stakes (December 7, 2022): Most of us are used to a certain routine by now for when we feel sick. If we feel a little feverish, or start coughing, we reach for an at-home testing kit that tells us, with a quick nasal swab and after 15 minutes, whether we have COVID-19 or not. The tests are easy to use, and for now, paid for by insurance if you’ve got it. If you don’t have insurance, you can still get the kits for free from some community health centers. Read more..

8. Integrated Host-Microbe Metagenomics Assay Nearly Nails Diagnosis Of Sepsis (November 3, 2022): Diagnosing sepsis is a longstanding challenge in medicine because the clinical signs and symptoms are nonspecific and, in the absence of a gold standard for identifying patients with the disease, the focus has remained largely on identifying the culprit pathogen, says Chaz Langelier, M.D., Ph.D., associate professor of medicine in the division of infectious diseases at the University of California, San Francisco (UCSF), and a Chan Zuckerberg Biohub investigator. But an assay developed by UCSF researchers that deploys metagenomic next-generation sequencing (mNGS) of both pathogens and host immune response could be a real gamechanger. Read more...

9. Machine Learning Enables Diagnosis of Sepsis, the Elusive Global Killer (October 26, 2022): Sepsis, the overreaction of the immune system in response to an infection, causes an estimated 20% of deaths globally and as many as 20 to 50% of U.S. hospital deaths each year. Despite its prevalence and severity, however, the condition is difficult to diagnose and treat effectively. The disease can cause decreased blood flow to vital organs, inflammation throughout the body, and abnormal blood clotting. Therefore, if sepsis isn’t recognized and treated quickly, it can lead to shock, organ failure, and death. But it can be difficult to identify which pathogen is causing sepsis, or whether an infection is in the bloodstream or elsewhere in the body. And in many patients with symptoms that resemble sepsis, it can be challenging to determine whether they truly have an infection at all. Read more...

10. Machine Learning Enables ‘Almost Perfect’ Diagnosis of an Elusive Global Killer (October 25, 2022): Sepsis, the overreaction of the immune system in response to an infection, causes an estimated 20% of deaths globally and as many as 20 to 50% of U.S. hospital deaths each year. Despite its prevalence and severity, however, the condition is difficult to diagnose and treat effectively. The disease can cause decreased blood flow to vital organs, inflammation throughout the body, and abnormal blood clotting. Read more...

11. New COVID-19 Testing Approach Measures Patients’ Immune Response for Better Diagnosis (December 7, 2020): Researchers from UC San Francisco and the Chan Zuckerberg Biohub (CZ Biohub) have developed a new approach for COVID-19 testing that detects a distinct pattern of immune gene expression in infected individuals. This type of test could be used as a check against possible errors generated by the standard tests that directly detect the SARS-CoV-2 virus, the scientists said. Read more...

12. The Importance of Diagnostics in Tackling the COVID-19 Pandemic (October 28, 2020): Large-scale testing and contact tracing are central to efforts to control the pandemic. This relies on diagnostic tests that can rapidly, accurately and reliably detect SARS-CoV-2. In December 2019, the novel coronavirus SARS-CoV-2 first emerged in China and it has since rapidly spread around the world. The disease it causes, COVID-19, has resulted in over one million deaths and put extreme pressure on health systems and economies. “Until a vaccine is developed, our main approach is going to be testing and preventing transmission of the virus,” says Chaz Langelier, associate medical director at UCSF. Read more...

13. Illuminating the Blueprint of Disease (December 4, 2020): The cells of patients with infectious diseases harbor patterns of gene expression that can reveal far more about the illness than conventional diagnostic tests. Chaz Langelier ’00 is decoding these patterns with a technique called metagenomic sequencing at the University of California, San Francisco (UCSF), where he is a practicing physician and associate professor of medicine. Read more...

14. How Covid Sends Some Bodies to War With Themselves (January 28, 2021): Back in April, as the pandemic was cresting over New York, Iris Navarro-Millán, a physician at Weill Cornell Medicine in Manhattan, treated a Covid-19 patient, a Hispanic woman in her 60s, who would prove to be a turning point in how she approached the disease. The woman was just a little short of breath when Navarro-Millán first saw her; a day later, she deteriorated so rapidly that she was rushed to intensive care, put on a ventilator and hooked up to a dialysis machine for her failing kidneys. Read more...

15. Diagnosing and Tracking COVID-19 and other Respiratory Infections (June 13, 2020, recorded on May 27th, 2020): The US has lagged behind other countries in testing for COVID-19. Dr. Chaz Langelier, UCSF Infectious Disease experts, talks about why we were late to start testing and the importance of widespread testing for a disease that spreads through asymptotic or pre-symptomatic individuals. He also talks about lower respiratory tract infections (LRTI), the leading cause of death due to infection. Currently, the cause of most LRTI remains unknown due to limitations of current tests. Watch the video...

16. An Update on Covid-19 Testing, Treatments, and Vaccines (July 30, 2020): In this UCSF Medical Grand Rounds (July 30, 2020), we get updates on three key issues in the Covid-19 pandemic. Chaz Langelier reviews testing, including test shortages, false positives and negatives, and the meaning of persistent PCR positivity. Annie Luetkemeyer offers an update on treatments, including remdesivir, dexamethasone, convalescent plasma and antibodies, interferon, hydroxychloroquine, and the prospects for oral therapies. Finally, Joel Ernst reviews the latest information about vaccines, including trials of the Moderna and Oxford vaccines, our growing understanding of Covid-19 immunity, the ethics of challenge trials, and determination of priority groups once a vaccine is approved. The session is hosted by UCSF Department of Medicine chair Bob Wachter. Watch the video...

17. The Epidemiology, Science & Clinical Manifestations of COVID-19: A UCSF Update (April 2, 2020): In this UCSF Medical Grand Rounds presentation (April 2, 2020), nine UCSF experts provide an update on what we’ve learned about the epidemiology, virology, clinical manifestations, pathophysiology, and treatments for COVID-19 in the last few weeks. They also highlight some of the strategies that UCSF has taken to address COVID, and discuss reasons that San Francisco is having a very different experience than harder hit areas like New York. The session is hosted by UCSF Department of Medicine chair, Bob Wachter. Watch the video...