To investigate the characteristics of patients with primary Sjögren syndrome (pSS) who have autoimmune cytopenia.
We analyzed 113 participants from the Korean Initiative of Primary Sjögren Syndrome, a prospective pSS cohort. Autoimmune cytopenia was defined as autoimmune origin neutropenia, anemia, and/or thrombocytopenia without vitamin or iron deficiency, or drug-induced cytopenia. To identify the association between autoimmune cytopenia and the clinical characteristics of pSS, extraglandular manifestations were analyzed according to the European League Against Rheumatism Sjögren's syndrome disease activity index (ESSDAI) definition. Xerophthalmia was assessed with the Ocular Surface Disease Index, Schirmer I test, ocular stain score (OSS), and tear film breakup time.
The median total ESSDAI score was 2 (interquartile range 1-6). About a quarter of patients had no systemic activity. Autoimmune cytopenia was observed in 23.9% of patients (n = 27). Moderate biological features were more frequently observed in patients with autoimmune cytopenia than in patients without [10 (37%) and 11 (12.8%), respectively, p = 0.016]. Articular involvement was exhibited in 1 patient with autoimmune cytopenia, but in 23 patients (27.4%) without autoimmune cytopenia (p = 0.013). Higher OSS (p = 0.002) and lower mean Schirmer I test (p = 0.029) were observed in patients with autoimmune cytopenia than in those without. Neutrophils and lymphocytes negatively correlated with OSS (ρ = -0.204, p = 0.041 and ρ = -0.230, p = 0.020, respectively).
Autoimmune cytopenia is closely associated with severe ocular surface damage in pSS. Therefore, assessment of xerophthalmia by ophthalmologists may be mandatory, particularly in patients with pSS with cytopenia, even if patients do not complain of eye dryness.