Analysis of clinical characteristics and risk factors in primary Sjögren's syndrome with infection

ObjectiveTo explore the clinical characteristics and related risk factors in patients with primary Sjögren's syndrome(pSS) with infection.

MethodsIn this retrospective study, 197 patients with pSS were divided into infection group(n=52) and non-infection group(n=145), the characteristics of their infections including the infection sites and pathogens were investigated.The suspicious risk factors of infection in patients with pSS were assessed by bivariate logistic regression analysis, univariate factor analysis and multivariate factor analysis.

ResultsIn this study, infection incidence in pSS in this study was 26.4%(52/197).The most common sites of infection were the respiratory tract(52.7%) and the urinary tract(21.8%), followed by skin and soft tissue(12.7%), septicemia(5.5%), central nervous system(3.6%), digestive tract(1.8%) and reproductive system(1.8%).Bacteria are the most common pathogens of infection(67.3%), followed by viruses(25%), fungi(7.7%), mycoplasma(7.7%), with four cases of mixed infection.Gram-negative bacilli such as Escherichia coli and Klebsiella are the most common bacterial infections, which have the high resistance to antibiotics especially quinolones and cephalosporins.The age, course of disease, serum cholesterol, triglyceride, C reactive protein, EULAR Sjögren's syndrome disease activity index(ESSDAI), EULAR Sjögren's syndrome patient reported index(ESSPRI) score, degree of dryness and degree of fatigue, incidence of lung involvement and the utilization rate of glucocorticoid in the infection group were all higher than those in the non-infection group(P < 0.05 to P < 0.01), and the total protein and albumin level in the infection group were lower than those in the non-infection group(P < 0.01).The infection rate of pSS patient in highly active group was significantly higher than that in the stable group and the mildly active group(P < 0.05).Logistic univariate regression analysis showed that old age, high ESSDAI score, high ESSPRI score, high fatigue degree, high dryness degree, low serum total protein, low albumin, high serum cholesterol, high triglyceride, high C reactive protein, pulmonary involvement were risk factors for pSS complicated with infection(P < 0.05 to P < 0.01).Logistic multivariate regression analysis showed that high ESSDAI score, high dryness degree, high serum triglyceride and pulmonary involvement were independent risk factors for pSS complicated with infection(P < 0.05 to P < 0.01).

ConclusionsThe incidence of infection in pSS is high, respiratory and urinary tract are the most common sites of infection in pSS patients.The most common infection pathogens are Escherichia coli and Klebsiella.Moreover, high ESSDAI score, high degree of dryness, high serum triglyceride and pulmonary involvement are the independent risk factors for pSS complicated with infection, which should be attached importance to in clinical works.