Shu-Xia Huang, Tian-Yu Cao, Zhan-Shuo Xiao , Hai-Bo Yin?

1. Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China

2. Beijing University of Chinese Medicine, Beijing 100029, China

Keywords:Sjogren's syndrome Traditional Chinese Medicine Hydroxychloroquine sulfate Meta analysis Randomized controlled trial

ABSTRACT Objective: To systematically evaluate the efficacy and safety of traditional Chinese medicine combined with hydroxychloroquine sulfate in the treatment of Sjogren's Syndrome(SS).Methods: Two researchers searched the databases of Chinese National Knowledge Infrastructure(CNKI), Wanfang Database,Weipu Database, Chinese Biomedical Literature Database, PubMed Database, Web of science Database and The Cochrane Library Database(the retrieval period is from the establishment of the database to October 2020) and screened the literatures independently.The data were extracted for bias risk assessment, and then meta?analysis was performed using Revman 5.3 software. Results: A total of 19 articles involving 1185 patients were included, including 617 cases in the treatment group and 568 cases in the control group. Combined data analysis showed that the total effective rate of traditional Chinese medicine combined with hydroxychloroquine sulfate in the treatment of Sjogren's syndrome was significantly higher than that of hydroxychloroquine sulfate alone [R R=1.34,95%CI(1.24,1.44),P<0.00001].The improvement of salivary gland[SMD=0.66,95%CI(0.47,0.85),P＜0.00001], tear secretion function [MD=2.56,95%CI(1.29,3.83),P＜0.0001] and reducing CRP[MD=?3.53,95%CI(?3.93,?3.14),P<0.00001], ESR [MD=?5.80,95%CI(?8.48,?3.13),P<0.00001]were better than those of the control group. However, there was no significant difference in the reduction of IgG and the incidence of adverse reactions between the two groups. Conclusion: Traditional Chinese medicine combined with hydroxychloroquine sulfate in the treatment of SS is superior to the control group in total effective rate, improvement of salivary gland and tear secretion function, and reduction of CRP and ESR, and we didn’t see the significantly increase on the adverse event.However, due to the small sample size and low quality of the included studies, the conclusion needs to be verified by larger sample and higher quality randomized controlled trials.?Corresponding author: YIN Hai?bo, Chief Physician, Doctoral Supervisor.E?mail: yinhbxs@126.com.

1. Introduction

Sj?gren's Syndrome's syndrome (SS) is a chronic inflammatory autoimmune disease characterized by invasion of exocrine glands and lymphocyte proliferation. It is considered the second most common rheumatic immune disease after Rheumatoid Arthritis.Its pathogenesis is not clear, at present, it is mainly considered to be related to heredity, immune disorder, infection, environmental factors and so on[1].The main clinical manifestations are dry keratitis, xerostomia, and it can cause Musculoskeletal, blood,digestive system damage too[2]. The prevalence of the disease is about 0.33%?0.77% in China. At present, western medicine treatment mainly includes local symptomatic treatment,and hormone, immunosuppressant or biological agents are used for systemic involvement. Hydroxychloroquine sulfate (HCQ) is a commonly used immunosuppressant for Sjogren's syndrome with systemic involvement, which can improve patients' symptoms and laboratory indicators, but long?term use may cause eye damage [3].

Traditional Chinese medicine(TCM) has a unique view and treatment for Sj?gren's syndrome. There is no record of similar diseases in ancient Chinese medicine. Modern Professor Lu Zhizheng was the first to create the name of "dry bi" , according to TCM, the basic pathogenesis of the disease is deficiency,stasis, dryness and Arthralgia[4].Relevant evidence?based studies have shown that traditional chinese medicine in the treatment of Sjogren's syndrome has more obvious advantages in improving the symptoms of patients, while there are still deficiencies in improving laboratory indicators[5]. In recent years, more and more studies have reported the effectiveness of combined Chinese medicine and HCQ in the treatment of SS. The purpose of this study is to evaluate the effectiveness of combined Chinese medicine and Hcq in the treatment of SS by Meta?analysis, so as to better guide the treatment of SS in clinic.

2. Materials and methods

2.1 Inclusion and exclusion criteria

Inclusion of research type:Randomized controlled trial(RCT);blind method or not;language restricted to Chinese and English.Research objects: Sj?gren's syndrome patients whose diagnosis of met the international recognized standards such as the international classification of Sjogren's syndrome (diagnostic) standard of 2002 or the ACR / EULAR classification of Sjogren's syndrome standard of 2016.Interventions: Control group: use hydroxychloroquine sulfate alone or combined with basic treatment;treatment group:on the basis of the control group,combined with traditional Chinese medicine treatment (Chinese medicine is limited to compound prescription,granules,Chinese patent medicine,injection and other preparations,excluding traditional Chinese medicine extract preparation such as total glucosides of paeony preparation,Tripterygium Glycosides tablets,etc..).

Exclusion criteria:①not a randomized controlled trials,self?control trials;②obvious defects in the experimental design, unclear criteria for diagnosis and efficacy evaluation, treatment group only using traditional Chinese medicine or control group including acupuncture and other traditional Chinese medicine therapy, using other Western medicine treatment such as methotrexate, hormone, etc.;③unable to obtain the full text of the meeting summary or incomplete data;④the most comprehensive report is reserved for the repeated published research.Outcome measures:The outcome of clinical trials should be determined according to at least one of the following criteria.The total effective rate (the curative effect was determined according to the standard formulated in the guiding principles for clinical research of new Chinese Medicine),adverse reaction rate, salivary flow rate,Schirmer test, erythrocyte sedimentation rate (ESR), C?reactive protein (CRP) and immunoglobulin G (IgG).

2.2 Search strategy

2.3 Literature screening and data extraction

Two researchers independently screened the literature, extracted the data and cross checked. In case of disagreement, the third researcher was invited to discuss. Data extraction information includes: ①basic information of included literature: author, year of publication,research site,etc.; ② baseline characteristics of research objects;③ specific program and course of intervention measures; ④ key information of bias risk assessment; ⑤ main data of outcome indicators concerned.

2.4 Literature Bias Risk Assessment

Two researchers used the risk bias assessment tools in the Cochrane manual to evaluate RCT from the following:random method;allocation concealment;blind method;integrity of the outcome data; selective reports; other biases.The evaluation results were integrated after verification by two researchers.

2.5 Statistical analysis

Revman3.5 software was used for statistical analysis.The relative risk (RR) and 95% confidence interval (95% CI) were used for for counting data such as the total effective rate and adverse reaction rate. If the adverse reaction rate was 0, the RR value could not be calculated, and the relative risk difference (RD) was used instead.Measurement data such as salivary flow rate, filter paper test, CRP,ESR and IgG were continuous variables, so they were expressed by mean difference (MD) or standard mean difference (SMD)and 95% confidence interval. Heterogeneity test was performed for the included RCTs.If I2≤50% and P≥0.10,it indicates that the heterogeneity is acceptable and the fixed effect model will be used;if I2> 50% or P < 0.10, it indicates that there is high statistical heterogeneity among the studies. After excluding the sources of clinical and methodological heterogeneity, random effect model analysis, subgroup analysis and sensitivity analysis will be used to reduce the heterogeneity between studies. Funnel plot will be made to analyze the possibility of publication bias at the same time.

3. Results

3.1 Literature screening process and results

1708 articles were retrieved from various databases.19 RCTs [6-24]were included after screening which involving 1185 patients as 617 in the treatment group and 568 in the control group. The detailed process and results of literature screening are shown in Figure 1.

Figure 1 Flow chart of literature screening

3.2 Basic characteristics and bias risk assessment results of included studies

The basic characteristics of the included literatures are shown in Table 1. A total of 19 articles [6-24] involving 1185 patients were included, including 617 cases in the treatment group and 568 cases in the control group. The results of bias risk showed that: 8 RCTs[3-9] used random number table method, 1 RCT [10] used random number generated by rectangular distribution function and then sorted according to the order of inclusion, 1 RCT [11] used spss19.0 for random allocation, and the remaining 8 studies [12-19] did not mention specific random methods; 1 study [11] reported allocation concealment; 1 study [11] reported blind method; 1 study [18] lost 3 cases It is unclear whether all studies selectively report results and whether there are other sources of bias. The bias risk assessment results are shown in Table 2 and Figure 2.

Figure 2 Risk assessment of included literature bias

Table 1 Basic characteristics of included literatures

Table 2 Bias risk assessment results of included studies

3.3 Meta analysis results

3.3.1 Evaluation of the total effective rate

A total of 14 studies [7-9, 11-13, 16-18, 20-24] reported the total effective rate, including 900 patients. Heterogeneity test showed that I2= 20%, P = 0.23. Fixed effect model analysis was used and the result showed that the difference of total effective rate between the two groups was statistically significant [RR = 1.34, 95% CI (1.24,1.44), P < 0.00001].

Once upon a time there was a miller1. He lived contentedly2 with his wife. They had money and land, and their prosperity increased from year to year. But misfortune comes overnight. Just as their wealth had increased, so did it decrease from year to year, until finally the miller scarcely owned even the mill where he lived. He was in great distress4, and when he lay down after a day s work, he found no rest, but tossed and turned in his bed, filled with worries.

Figure 3 Comparison of the total effective rate of traditional Chinese medicine combined with HCQ and single HCQ in the treatment of Sjogren's syndrome

3.3.2 Evaluation of salivary flow rate

Eight studies [9,10,13,14,20,21,23,24] reported salivary flow rate. Due to the different methods of measuring salivary flow rate between groups, some of them used non irritative salivary flow measurement method and some used irritative salivary flow measurement method,so SMD analysis was used. Heterogeneity test results showed that the homogeneity was good (I2= 0%, P = 0.79). Fixed effect model analysis was used and the result showed that there was a significant difference in the improvement of salivary flow rate between the two groups [SMD = 0.66, 95% CI (0.47, 0.85), P < 0.00001].

Figure 4 Comparison of improvement of salivary flow rate between traditional Chinese medicine combined with HCQ and single use of HCQ

3.3.3 Evaluation of the efficacy of Schirmer testA total of 8 studies [6,9,10,16,20,21,23,24] reported the Schirmer trial,involving 476 patients. Heterogeneity test results showed that there was heterogeneity (I2= 97%, P < 0.00001). Sensitivity analysis showed that excluding any study could not significantly reduce the inter study heterogeneity, so random effect model analysis was used.The results showed that there was a statistically significant difference in the improvement of Schirmer test between the two groups [MD =2.56, 95% CI (1.29, 3.83), P < 0.0001].

Figure 5 Comparison of the improvement effect of traditional Chinese medicine combined with HCQ and single HCQ on Schirmer test

3.3.4 The curative effect on reducing CRP level

There were 11 studies[6,8,9,11,14,17,18,20-23]reported CRP.Heterogeneity test results showed that there was heterogeneity(I2= 93%, P < 0.00001). The sensitivity analysis showed that the heterogeneity decreased significantly (I2= 41%, P = 0.08) after excluding one of the studies [6], so the fixed effect model meta?analysis was used for the remaining 10 studies The results showed that the difference of CRP improvement between the two groups was statistically significant [MD = ?3.53, 95% CI (? 3.93, ? 3.14), P <0.00001].

Figure 6 Comparison of the effect of traditional Chinese medicine combined with HCQ and HCQ alone in reducing CRP

3.3.5 Evaluation of the effect of reducing ESR

A total of 15 studies [6,8,9,11,14-24] reported ESR, including 910 patients. There was heterogeneity among the studies (I2= 89%,P < 0.00001). The sensitivity analysis failed to find the study that affected the heterogeneity. Using the random effect model analysis,the results showed that the treatment group [MD = ?5.80, 95% CI (?8.48, ? 3.13), P < 0.00001]. The baseline level of ESR was higher than 50 mm / h in 9 studies, 30?50 mm / h in 5 studies and less than 30 mm / h in 1 study. Subgroup analysis according to the baseline level showed that: ESR > 50mm / h before treatment, the difference between the treatment group and the control group was statistically significant [MD = ?8.63, 95% CI (? 11.23, ? 6.02), P < 0.00001];ESR before treatment was significantly higher than that in the control group [MD = ?8.63, 95% CI (? 11.23, ? 6.02), P < 0.00001]The difference between the treatment group and the control group was statistically significant [MD = ?4.91, 95% CI (? 5.85, ? 3.98), P< 0.00001]. There was only one study with ESR < 30mm / h before treatment (MD = ?0.53).

Figure 7 Comparison of the efficacy of traditional Chinese medicine combined with HCQ and HCQ alone in reducing ESR

3.3.6 Evaluation of curative effect on reducing blood IgG level

A total of 11 studies [6,8,14, 17-24] I2= 92%, P < 0.00001, sensitivity analysis showed that after excluding one of the studies [8], the heterogeneity decreased by 38% (I2= 54%, P = 0.02). After discussion by the researchers, the source of heterogeneity could not be found, so after excluding the study, random effect model analysis was used, the results showed that there was no significant difference between the two groups [RR = ?0.24, 95% CI (? 1.60, 1.13), P =0.73].

Figure 8 Comparison of therapeutic effects of traditional Chinese medicine combined with HCQ and HCQ alone in reducing serum IgG level

3.3.7 Adverse reactions

A total of 11 studies [6,10,12-14,16,19,20-22,23] reported adverse reactions, of which 3 studies [19,22,23] showed no adverse reactions in the treatment group and the control group. One study [20] mentioned 4 patients with diarrhea and weak stool, but did not specify which group. One study only described the specific adverse reactions in the control Group [16]. Common adverse reactions mainly include gastrointestinal adverse reactions, rash, abnormal liver function,blurred vision. Finally, 10 studies were included. The results of meta?analysis using fixed effect model showed that there was no significant difference in adverse reactions between the two groups[RD = ?0.03, 95% CI (? 0.07, 0.01), P = 0.14].

Figure 9 Comparison of adverse reaction rate between traditional Chinese medicine combined with HCQ and single HCQ in the treatment of Sjogren's syndrome

3.3.8 Publication biasPublication bias analysis was performed for the total effective rate,and funnel plot was drawn (Figure. 10). Funnel plot showed that each point did not pile up on both sides of the midline, suggesting that there was a certain publication bias. The reason may be related to less effective studies and unpublished negative results.

Figure 10 Funnel chart of total effective rate of two groups

4. Discussion

Traditional Chinese medicine treatment of Sjogren's syndrome has greater flexibility by considerating the location, condition, season of onset or other aspects as well as combining with the characteristics of each stage of the disease[20].Relevant animal experimental studies have also proved that TCM can reduce the immune response through inhibiting epithelial cells, B cells, T cells, etc.In a word, it can reduce the immune response from multiple targets and pathways to improve the condition of SS patients[25].It has been reported that the improvement of salivary gland function of traditional Chinese medicine may be related to its effect on AQPs, especially regulating AQP5 protein closely related to salivary secretion and inhibiting the release of tumor necrosis factor?α (TNF?α) and interleukin?1 β (IL?1 β) [26,27].On the other hand, traditional Chinese medicine may reduce the immune inflammatory response by down regulating the expression of inflammatory factors such as interleukin?1 (IL?1),TNF?α, nuclear factor kappa B (NF?κ b) and toll like receptor 4(TLR4), so as to promote tear secretion and play a role in relieving dry eye symptoms [28,29]. The increase of ESR and CRP is closely related to inflammatory reaction, and is often used as one of the indicators to evaluate disease activity in autoimmune diseases [30].Other studies have shown that the serum IgG level is positively correlated with the disease activity index of Sjogren's syndrome(ESSDAI), so reducing the levels of ESR, CRP and IgG can improve the condition to a certain extent [31]. In recent years, some scholars have systematically evaluated the efficacy of traditional Chinese medicine in the treatment of SS, and the results show that traditional Chinese medicine has certain efficacy in improving the above symptoms and indicators, and is not easy to cause adverse reactions[32-34]. In conclusion, whether clinical or experimental studies,traditional Chinese medicine treatment of Sjogren's syndrome has a potential role.

This study systematically evaluated the efficacy of TCM combined with hydroxychloroquine sulfate in the treatment of Sjogren's syndrome. The results of meta?analysis showed that there were statistically significant differences in the total effective rate, salivary flow rate, Schirmer test, ESR and CRP between the treatment group and the control group after the treatment of TCM combined with hydroxychloroquine sulfate, indicating that the patients in the treatment group included in the study had significant differences in salivary gland, lacrimal gland secretion function and inflammatory index.There was no significant difference in IgG and adverse reactions between the two groups. In terms of safety, the adverse reactions of blurred vision and abnormal liver function in the included studies were all from the control group. There was no similar adverse reaction report in the treatment group, and there was no evidence to prove that the combination of traditional Chinese medicine can increase the side effects of patients. In conclusion,these evidences provide a certain reference value for the treatment of Sjogren's syndrome.

However, this study still has the following limitations: ①the methodological quality of the included literature is generally low, 8 studies have not explained the allocation method in detail and some sources of heterogeneity can not be explained, so the analysis results should be carefully evaluated in combination with clinical practice;② the sample size of the included studies is small which affects the accuracy of the results, and the course of treatment and dosage of each study are inconsistent which may cause bias; ③The grey literature was not searched; ④publication bias may exist.

To sum up, the current research evidence shows that traditional Chinese medicine combined with hydroxychloroquine sulfate in the treatment of SS is superior to hydroxychloroquine sulfate alone in improving salivary flow rate, Schirmer test, ESR and CRP index,and can significantly improve the total effective rate, but there is no significant difference in improving IgG index and adverse reactions between the two groups. Based on the above limitations, the future research direction is to carry out multi center, large sample, high?quality research, develop a unified evaluation standard, and evaluate the results in various aspects for further verification.