Comorbid autoimmune disease in stiff-person syndrome spectrum disorder: a systematic review and meta-analysis.
Autoimmune comorbidities affect about half of patients with stiff-person syndrome spectrum disorder
Comorbid autoimmune disease in stiff-person syndrome spectrum disorder: a systematic review and meta-analysis.
Stiff-person syndrome spectrum disorder (SPSD) is a rare autoimmune disorder characterized by progressive muscle stiffness and painful spasms.
This meta-analysis aimed to estimate the pooled frequency of autoimmune comorbidities in SPSD and to examine differences across clinical subtypes and between GAD65 antibody-positive and -negative patients.
We searched PubMed, Embase, the Cochrane Library, Web of Science, and Scopus from inception to August 23, 2025.
over half had a second autoimmune disease alongside SPSD
The most common were diabetes (including T1D and LADA; 29.0%), autoimmune thyroid disease (25.1%), and hypothyroidism (12.0%), followed by pernicious anemia (10.3%), myasthenia gravis (9.3%), Graves' disease (7.3%), vitiligo (5.8%), and celiac disease (5.0%).
Sjögren's syndrome (2.4%), systemic lupus erythematosus (2.1%), and rheumatoid arthritis (1.9%) were relatively uncommon.
Frequencies varied across SPSD subtypes: PERM (79.5%), classic SPS (61.9%), and focal or segmental SPS (38.2%).
Autoimmune comorbidities are highly prevalent in SPSD, particularly in PERM, classic SPS, and GAD65-positive patients.
These findings guide screening and management to improve clinical outcomes and provide insights for future research into SPSD pathophysiology.