Research Of Systemic Lupus Erythematosus And Secondary Sj(?)gren's Syndrome In Children

Background:Systemic Lupus Erythematosus(SLE)and Sj(?)gren's syndrome(SS)are both typical autoimmune diseases that can affect people of all ages,while in children SLE is more common.Although SLE and SS are two different diseases,they share clinical and laboratory features to some extent and can coexist in one patient.It is reported that about 8.3%-30.0%of SLE patients are associated with SS,and SLE-SS patients may be more similar to pSS in terms of phenotypes.This study aims to investigate the clinical,laboratory and immunological features of Chinese pediatric SLE patients associated with SS,as well as its similarities to and differences from SLE children without SS.In addition,we explore how the recent '2018 Clinical practice guidance for Sj(?)gren's syndrome in pediatric patients' apply to this population.Methods:This was a retrospective research of SLE children who went to the Department of Pediatrics,Peking Union Medical College Hospital for inpatient care between January 2009 and July 2019.Diagnosis of SLE was made according to existing criteria;If one patient meets the following two items and rule out other diseases leading to dryness,the diagnosis of SS can be made:1.objective evidence of ocular involvement or salivary gland involvement,or abnormal MRI or ultrasound result;2,the presence of anti-RO/SS A and/or anti-LA/SSB antibodies,Labial salivary gland biopsy exhibiting focal lymphocytic sialadenitis,confirmed systemic rheumatic disease or positive anti-SSA(Ro)and/or anti-SSB(La)or[positive rheumatoid factor and ANA?1:320.Demographic,clinical,laboratory and immunological characteristics in SLE patients associated with SS(SLE-SS)were compared with those without SS(SLE-no SS).Descriptive statistics were used.We then applied 'the 2018 Clinical practice guidance for Sj(?)gren's syndrome in pediatric patients in this study to explore how it apply to Chinese children SLE-SS population.Results:1.A total of 383 patients(65 males and 318 females)with a diagnosis of SLE were finally involved and SS was identified in 58 SLE patients(15.14%).Compared to the SLE-no SS group,patients with SLE-SS had a higher frequency of anti-Ro/SSA or anti-La/SSB,rheumatoid factors,and IgG(P<0.001),but a significantly lower frequency of renal involvement(P=0.003).There was no statisticdifference in disease activity between the two groups;2.Fifty-eight children(9 males and 49 females)were diagnosed as sSS,eighteen of whom had complaints of dryness.The children were grouped according to whether had sicca symptoms,and no statistically significant differences were seen in the age of onset,gender or clinical symptoms between the two groups,while children with sicca symptoms were more prone to hyperglobulinemia(P=0.045).According to the 2018 Clinical practice guidance,56 of the 58 children(96.55%)could be classified as "definite SS",while the remaining two were classified as "probable SS".Conclusion:The presence of SS in SLE patients defines a subset with distinctive demographic,clinical,and laboratory characteristics.Our study was consistent with the 2018 Clinical practice guidance for Sj(?)gren's syndrome in pediatric patients.It is important to develop appropriate diagnostic criteria for pediatric Sj(?)gren's syndrome.Since sicca symptoms are infrequent in pediatric patients,their existing as an inclusion item may lead to missed diagnosis.Patients who do not meet existing criteria still need pay attention to gland manifestations and follow up regularly to examine serological indicators.More research is needed to determine and standardize the reference range of diagnostic tests in children,as well as whether new alternative tests can be added to existing criteria.