Thanai Pongdee, MD

Pongdee also discussed the changing treatment landscape for indolent systemic mastocytosis and questions that will need to be answered in the field. 

Looking Deeper Into ISM and KIT Mutations, with Thanai Pongdee, MD

Indolent systemic mastocytosis (ISM) is a rare, clonal mast cell disease caused by 

 D816V mutations. Patients typically experience chronic debilitating symptoms including allergic type symptoms, gastrointestinal symptoms, and fatigue, and it often takes years for a correct diagnosis to be made.

Thanai Pongdee, MD, allergist-immunologist at Mayo Clinic, is actively engaged in ISM research and coauthored a number of abstracts that were presented at the 

2025 American Academy of Allergy, Asthma, and Immunology (AAAAI)/World Allergy Organization (WAO) Joint Congress

, February 28-March 3, in San Diego, California.

One abstract Pongdee presented focused on using more sensitive duplex sequencing (DS) to detect 

mutations that were undetectable by droplet digital PCR (ddPCR) in patients that received avapritinib in the PIONEER (NCT03731260), and associations with response.

 Pongdee and colleagues found that 70% of participants with undetectable 

 D816V by ddPCR had KIT mutations, including non-D816V mutations, detected by DS.

spoke with Pongdee to learn more about the findings from the analysis. He also discussed the changing treatment landscape of ISM and questions that remain to be answered past the introduction of novel therapies.

“Once drugs are approved, then what? What's the course of disease after that? We really don't know that, so that'll be interesting to watch over time, and [effects on] some of the longer-term issues with mastocytosis, [including higher risk of] osteoporosis or bone disease,” Pongdee said. “Can these drugs affect or alter the course?”

Pongdee’s disclosures include GSK, Blueprint Medicines, and Sanofi.

Systemic mastocytosis. Mayo Clinic. Updated November 20, 2020. Accessed March 11, 2025. 

https://www.mayoclinic.org/diseases-conditions/systemic-mastocytosis/symptoms-causes/syc-20352859

Pongdee T, Vachhani P, Tashi T, et al. Responses to Avapritinib in Patients Without Detectable KIT Mutations by ddPCR in Peripheral Blood Highlight Diagnostic Challenges and Opportunities in Indolent Systemic Mastocytosis. Presented at: 2025 AAAAI/WAO Joint Congress, February 28-March 3. Abstract 965

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Pongdee discussed research presented at the AAAAI/WAO Joint Congress that focused on improving diagnosis of indolent systemic mastocytosis.

Improving Care for ISM With Better Diagnoses, Disease Characterization, with Thanai Pongdee, MD

Indolent Systemic Mastocytosis (ISM) is a rare, clonal mast cell disease driven by KIT D816V mutations and characterized by chronic debilitating symptoms including allergic type symptoms, gastrointestinal symptoms, and fatigue.

Thanai Pongdee, MD, allergist-immunologist at Mayo Clinic, is involved with a number of studies aiming to improve care for patients with ISM, many of which were presented at the 2025 American Academy of Allergy, Asthma, and Immunology (AAAAI)/World Allergy Organization (WAO) Joint Congress, February 28-March 3, in San Diego, California.

® spoke with Pongdee to learn more about the studies he investigated, including one on characterizing the symptom burden on patients with ISM and another on using large-language models to potentially help diagnose ISM. He stressed the importance of such research for ISM, which clinicians may be unfamiliar with and can be difficult to diagnose.

“A lot of the work we’ve done is really looking at the symptom burden for those patients and bringing that knowledge to other healthcare providers beyond our specialty because the diagnosis may be quite difficult to make and earlier intervention would definitely be helpful,” Pongdee said. “You can imagine being tired, having skin issues, those are pretty common symptoms in the general population, so how do you highlight someone who maybe might be a little different, that maybe we need to investigate a little further. How do we best do that?”

Pongdee T, Powell D, Weis T, et al. Assessing Real-world Natural History of Indolent Systemic Mastocytosis: Retrospective Matched Cohort Study from Mayo Clinic Electronic Health Records. Presented at: 2025 AAAAI/WAO Joint Congress, February 28-March 3. Abstract 955.

Yi CA, Mills H, Naqvi SA, et al. Utility of Large Language Models to Quantify Diagnostic Delays in Systemic Mastocytosis: A Multi-Center Real World Study. Presented at: 2025 AAAAI/WAO Joint Congress, February 28-March 3. Abstract 544.

Thanai Pongdee, MD

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