الملخص الإنجليزي
Primary Sjogren's syndrome (pSS) is an autoimmune chronic
inflammatory disease with unique clinical presentation and variable
outcomes. It affects the exocrine glands including the salivary and
lacrimal glands, leading to the sicca syndrome, which is characterized by
dryness of the mouth (xerostomia), and eyes (xeropthalmia). Also, extra glandular organ manifestations may develop in some patients. Those
patients may later develop devastating symptoms. Initial indicative clinical
features and/or diagnostic markers of extra-glandular pSS are under investigated, which delay diagnosis, and management. We used a
clustering approach to evaluate and identify clinical manifestations and/or
biological markers (features) in Omani patients that may distinguish pSS
subtypes. This study was based on data for patients attending the
rheumatology clinic at SQUH diagnosed with only pSS (97).
Demographic, clinical, and laboratory data were retrospectively collected
from the SQUH information system. The studied cohort included 89
females (91.8%) and 8 males (8.1%), i.e., about 9:1 ratio. The average of
pSS patients' age at diagnosis is 38.2 years ± (10.4). Compared to other
populations, Anti-nuclear and Anti-SSA antibodies are more prevalent
(94.9%, 80.60%), while vasculitis and subjective oral sicca are less
prevalent (6.1%, 54.5%). To identify the potential pSS clusters, K-means
clustering was used. Features which were associated with the best
performance were identified. Silhouette and Calinski –Harabasz (CH)
scores were used for internal evaluation and for external evaluation, a
clinician reviewed the common features between each subtype. Using K means clustering, two clusters showed the best results, and 6 features
were identified (i.e., eye and mouth dryness, fatigue, CNS disorders, eye
symptoms, and age at diagnosis). The internal evaluation showed
satisfactory scores, 0.364, and 55.16, respectively. The identified clinical
and biological features that distinguish between the two pSS subtypes
may enable early diagnosis of subtypes and facilitate better targeted
management.
