A Cohort Study on Deficiency of ADA2 from China

Area of Science:

• Genetics
• Immunology
• Rheumatology

Background:

• Deficiency of adenosine deaminase 2 (DADA2) is an autoinflammatory disorder.
• Genetic variants in ADA2 cause DADA2.
• DADA2 has not been well-characterized in the Chinese population.

Purpose of the Study:

• To characterize DADA2 cases in China.
• To analyze clinical features, genotypes, and treatment responses in Chinese DADA2 patients.

Main Methods:

• Retrospective analysis of 30 DADA2 patients identified via whole exome sequencing.
• Data collected from 17 rheumatology centers across China.
• Analysis of clinical characteristics, laboratory findings, genotype, and treatment outcomes.

Main Results:

• Median age at presentation was 4.3 years, and diagnosis at 7.8 years.
• Common manifestations include systemic inflammation (92.9%) and vasculitis (86.7%).
• TNF inhibitors (TNFi) and hematopoietic stem cell transplantation (HSCT) led to clinical remission in treated patients.

Conclusions:

• Early diagnosis of DADA2 through genetic testing and ADA2 enzymatic activity assays is crucial.
• TNFi is a first-line treatment for vascular DADA2 phenotypes.
• HSCT is a potential option for hematological DADA2 or TNFi-refractory cases.