By Nancy Lapid
(Reuters) – Happy New Year Health Rounds Readers! We kick off our first newsletter of 2025 with potentially good news for parents of children with asthma. We also report on a study looking to better understand why protection lasts longer from some vaccines than others.
Nasal swab identifies asthma subtypes
Using nasal swabs to identify a child’s asthma subtype may lead to more precise medication prescribing and development of better treatments for what have been harder to diagnose types of the respiratory condition, researchers reported on Thursday in JAMA.
Asthma is a highly variable disease with different endotypes, or mechanisms of action, that respond differently to various treatments, study leader Dr. Juan Celedon of UPMC Children’s Hospital of Pittsburgh said in a statement.
Confirmation of endotype usually involves genetic analysis of lung tissue samples obtained under general anesthesia. Doctors are often reluctant to perform invasive diagnostic procedures on children, especially those with milder asthma.
In their study, researchers applied genetic analyses to nasal-lining cells obtained with swabs from 459 asthma patients, ages 6 to 20. The majority were from racial and ethnic minority groups in which rates of severe asthma are higher than average.
The results showed that an asthma endotype called T2-high, which has been thought to be the most common one in that age group, was in fact less common than so-called T2-low asthma endotypes.
“We have better treatments for T2-high disease, in part, because better markers have propelled research on this endotype,” said Celedon. “But now that we have a simple nasal swab test to detect other endotypes, we can start to move the needle on developing biologics for (T2-low) disease.”
Researchers find clues to vaccine durability
Researchers are a step closer to understanding why some vaccines offer protection for decades while others must be boosted periodically, according to a report published on Thursday in Nature Immunology.
Blood cells called megakaryocytes, known for their production of clot-forming platelets, are also playing a role in vaccine durability, they have discovered.
The researchers studied blood samples from 244 people who had received any of seven different vaccines a few days earlier, such as for seasonal influenza, yellow fever, malaria or COVID-19. They identified a molecular signature associated with the strength of antibody responses to the vaccines months later.
The signature was mostly detected in tiny bits of megakaryocyte RNA carried inside platelets. When the platelets break off from megakaryocytes and enter the bloodstream, they often take small pieces of RNA from the megakaryocytes with them, the researchers explained.
Signs of megakaryocyte activation were associated with longer-lasting antibody production. Conversely, when the researchers blocked key megakaryocyte molecules, survival of antibody-producing cells was diminished.
“The question of why some vaccines induce durable immunity while others do not has been one of the great mysteries in vaccine science,” study leader Bali Pulendran of Stanford University said in a statement.
Megakaryocytes appear to be providing a “nurturing, pro-survival environment in the bone marrow” for antibody-producing cells, Pulendran said.
The researchers hope to learn why some vaccines might spur higher levels of megakaryocyte activation. Those findings could aid the development of vaccines that more effectively activate megakaryocytes and lead to more durable antibody responses.
(Reporting by Nancy Lapid; editing by Bill Berkrot)
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