Leukopenia and systemic features in Sjögren's disease: a retrospective hospitalized cohort study

To evaluate the clinical characteristics of leukopenia in hospitalized patients with Sjögren's disease (SjD), particularly its association with systemic organ involvement, immunological activity, and disease duration.

This retrospective exploratory study of 200 hospitalized patients with SjD admitted to a tertiary medical center between 2017 and 2023. Patients were divided into leukopenia and normal white blood cell (WBC) groups according to WBC count. Demographic characteristics, hematologic parameters, inflammatory and immunological markers, and systemic organ involvement were compared between groups. Among patients with leukopenia, disease duration was further stratified into tertiles to explore duration-related patterns. Where data are available, multivariable logistic regression should be performed to explore whether leukopenia is associated with selected systemic manifestations after adjustment for disease duration and treatment exposure.

Leukopenia occurred in 67 of 200 patients (33.5%). Compared with patients with normal WBC counts, patients with leukopenia had lower hemoglobin and platelet counts. The proportions of interstitial lung disease (ILD), pulmonary hypertension/suspected pulmonary arterial hypertension, peripheral nervous system involvement, and skin, joint, and muscle involvement were not significantly different between the leukopenia and normal WBC groups. In the leukopenia group, however, the prevalence of ILD increased across disease-duration quartiles, from 14.8% in Q1 (≤ 3 years) to 40.7% in Q4 (> 11 years). IgG and erythrocyte sedimentation rate were higher in early-duration leukopenic patients and lower in later-duration strata, suggesting a possible change in inflammatory activity rather than proven immune exhaustion.

In this hospitalized SjD cohort, leukopenia was a common hematologic abnormality but was not significantly associated with most systemic manifestations in direct between-group comparisons. Within the leukopenic subgroup, a higher prevalence of ILD was observed across longer disease-duration strata, a hypothesis-generating finding rather than evidence of progression. These observations warrant validation in prospective longitudinal studies with standardized disease activity assessments, detailed treatment exposure records, and leukocyte subset analyses. Key Points • Leukopenia is common in Sjögren's disease, affecting approximately one-third of patients in this hospitalized cohort. • In leukopenic patients, longer disease duration is associated with a higher prevalence of ILD, an exploratory finding that warrants prospective validation rather than evidence of progression. • IgG and ESR levels decline across disease-duration strata in leukopenic patients, which may reflect duration- or treatment-related immune remodeling and not proven immune exhaustion.