[Frequency of systemic manifestations in patients with primary Sjögren's syndrome in Argentina]

Association of Inflammatory Cytokine Levels with Extra Glandular Manifestations, Fatigue, and Disease Activity in Primary Sjögren's Syndrome in Saudi Patients: A Cross-Sectional Study

BACKGROUND

Primary Sjögren's syndrome (pSS) is an autoimmune disease that can cause fatigue and extraglandular manifestations (EGMs). pSS is associated with cytokine network dysregulation, which may be related to the immune-mediated destruction of exocrine glands.

OBJECTIVE

We determined cytokine levels and their relationship to EGMs, the European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI), and fatigue in Saudi patients with pSS.

METHODS

This study was a cross-sectional, single-center study. We included forty-one patients and 71 controls. Serum samples were collected from random healthy people and pSS patients who were followed in the rheumatology and pulmonary clinics of King Saud University Medical City in Riyadh, Saudi Arabia. Levels of the frequently studied cytokines were measured using Luminex xMAP technology. Each ESSDAI score and EGM were recorded, and the Arabic version of the fatigue severity scale (FSS) was applied to assess fatigue. The main outcome measures were cytokine levels in pSS Saudi patients using/not using immune-suppressive medications (ISMs).

RESULTS

Thirty-six (87.8%) patients had one or more EGMs, and the mean ESSDAI score was 9.95 ± 7.73. There was a significant decrease in TNFα and IL-21 levels in the pSS group compared to those in the control group (p = 0.034 and p < 0.001, respectively), whereas IL-12 levels were significantly elevated in the pSS group (p = 0.002). Cytokine levels in patients who used ISMs were the same as those in patients who did not use medications. Decreased IL-1β (p = 0.014), IL-2 (p = 0.035), IL-6 (p = 0.014), and IL-35 (p = 0.010) levels were observed in patients who had EGMs. Patients who had low disease activity exhibited low IL-10 (p = 0.018) and high IFN-α (p = 0.049), IFN-β (p = 0.049), IL-1β (p = 0.006), and IL-35 (p = 0.032) levels compared to patients with high disease activity. A negative association between a positive fatigue score and IL-1β (p = 0.010), IL-2 (p = 0.037), IFN-α (p = 0.025), TNFα (p = 0.030), IL-17 (p = 0.029), IL-12 (p = 0.046), and IL-21 (p = 0.005) levels was found.

CONCLUSIONS

Cytokine profiles correlate with EGMs, ESSDAI, and fatigue. Patients with controlled disease activity have a normal cytokine profile that is similar to that of controls.

Primary Sjögren's syndrome: Extraglandular manifestations and hydroxychloroquine therapy

The use of hydroxychloroquine (HCQ) in Primary Sjögren's Syndrome (pSS) has been assessed in different studies over the last years, with conflicting results regarding its efficacy in sicca syndrome and extraglandular manifestations (EGM). The goal of this study was to compare the incidence rate of EGM in pSS patients with and without HCQ therapy.We performed a multicenter retrospective study, including patients with pSS (European classification criteria) with at least 1 year of follow-up. Subjects with concomitant fibromyalgia, autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis were excluded. Demographics and pSS characteristics were recorded. The EGM were defined by EULAR-SS disease activity index (ESSDAI). Patients were divided into two groups according to their use or not of HCQ therapy. We evaluated the use of HCQ and its relationship to EGM. HCQ therapy was defined as the continuous use of the drug for at least 3 months. A descriptive analysis of demographics and pSS characteristics was performed. We compared the incidence of EGM between groups defined by HCQ therapy using chi² test or Fisher's exact test. A total of 221 patients were included (97.3% women), mean age, 55.7 years (SD 14). Mean age at diagnosis, 48.8 years (SD 15); median disease duration, 60 months (IQR 35-84). One hundred and seventy patients (77%) received HCQ. About half of the patients had at least one EGM during the course of the disease, 20% of them developed an EGM before the onset of the sicca syndrome and 26% simultaneously with dryness symptom. Overall, EGM were less frequent in those on HCQ therapy (36.5% vs 63.5%, p < 0.001). Considering each EGM individually, the following manifestations were more frequent in the non-treated group: arthritis (p < 0.001), fatigue (p < 0.001), purpura (p = 0.01), Raynaud phenomenon (p = 0.003), and hypergammaglobulinemia (p = 0.006). Immunosuppressive treatment was indicated on 28 patients (12.7%), 13 of which were receiving also HCQ. The first reason for those treatments was the presence of arthritis in 12/28 patients (42.8%), and the drug used in all the cases was methotrexate. Only three patients required immunosuppressive therapy with cyclophosphamide, due to the presence of glomerulonephritis, vasculitis, and interstitial lung disease. None of the patients received biologic therapy. The lower incidence of EGM was observed in patients on HCQ therapy supports its efficacy in pSS. However, further large scale prospective studies are needed to confirm these findings.