Elevated IL-8 and abnormal lymphocytes in pediatric primary Sjögren's syndrome: a single-center study

Cytokines and lymphocytes orchestrating the pathophysiological landscape have been well explored in adults but remains understudied in children. This study evaluated their potential as biomarkers in diagnosis of pediatric Sjögren's syndrome (pSS). We retrospectively analyzed 14 pediatric patients with pSS who attended our rheumatology clinic over 2 years. Plasma levels of IL-4, IL-5, TNF-α, IFN-γ, TNF-β, IL-6, IL-1β, IL-2, IL-10, IL-8, IL-22, IL-12p70, IL-17F, and IL-17A, as well as percentages and absolute counts of CD3 + , CD19 + , CD3-CD16 + /CD56 + , CD3 + CD4 + , and CD3 + CD8 + lymphocytes, were measured in 14 pSS patients and 12 healthy controls. IL-8 levels were elevated in pSS patients compared to controls. CD3 + CD8 + lymphocytes were increased, while CD3 + , CD3 + CD4 + , CD19 + , and CD3-CD16 + /CD56 + lymphocytes were decreased in pSS patients. IL-8 may be a potential indicator for the early diagnosis of pSS, together with T-, B-, and NK-cell abnormalities, may contribute to disease pathogenesis. Larger studies are needed to confirm these findings.