3.1 The Diagnostic Significance of anti-Ro-52 in SS
3.1.1 Difference of positive rate between anti-Ro-52 and anti-SSB in SS patients
To study the superiority of the positive rate of anti-Ro-52 expression in patients with Sjogren's syndrome (SS), 22 related literature were selected. The number of anti-Ro-52 positive patients, the total number of anti-Ro-52 group patients, the number of anti-SSB positive patients in the control group, and the total number of control group patients in the study samples were collected and recorded. After the software processing, 13 studies intersected with the invalid line, of which 2 studies (Ben Eli H 2020, Wahren M 1997) were biased towards anti-SSB, and the remaining 9 studies were biased towards the side beneficial to anti-Ro-52 although they intersected with the invalid line.
The total sample size of the research group was 1019, and that of anti-Ro-52 positive patients was 555. The overall positive rate was 54.47%, which was higher than 36.16% in the control group[5,6]. The overall forest plots analysis results did not intersect with the invalid line and were located on the right side of the invalid line (RR = 1.52 [1.39,1.67]), showing that the positive expression rate of anti-Ro-52 in SS patients was significantly higher than that of traditional detection item anti-SSB[7,8], and had statistical significance (95% CI, P < 0.00001)(Figure 3-1)
3.1.2 Distribution of clinical manifestations in anti-Ro-52 positive SS patients
Five studies(Tengnér P 1998, Halse AK 2000, Halse A 1999, Sujau I 2014, Fujimoto M 1997) mentioned the clinical characteristics of anti-Ro-52(+) SS patients and counted the number of specific samples of each phenotype. It is worth noting that patients classified as severe Sjogren's syndrome (severe SS) only appear in anti-Ro-52(+) patients, and the incidence rate is as high as 35% (in this literature, SS patients with severe organ failure or long-term pain symptoms or arthritis or myositis are defined as severe SS patients), while all anti-Ro-52 negative patients are defined as moderate SS. These results indicate that anti-Ro-52 can be used as a potential indicator of severe disease or poor prognosis in patients with SS, and provide some guidance for the medication and treatment of patients.
For all SS patients with anti-Ro-52(+), pulmonary fibrosis is the most prominent complication, with an incidence rate as high as 70%, which is much higher than that of arthritis and thyroid involvement, and more serious complications such as renal crisis or heart involvement are rarely mentioned in the literature screened in this study, indicating that the overall prognosis of SS patients with anti-Ro-52(+) is relatively considerable. However, we need to pay attention to the maintenance and treatment of the respiratory system to improve the prognosis of patients. (Figure 3-2)
3.1.3 Age Distribution of anti-Ro-52(+) SS patients
As shown in Figure 3-3, three pieces of literature mentioned the age information of anti-Ro-52(+) SS patients at the time of diagnosis. Most anti-Ro-52(+) SS patients were diagnosed before 45 years old, and only a small number of patients were diagnosed after 45 years old. It can be inferred that anti-Ro-52(+) SS patients may have more serious symptoms, which speeds up the process of diagnosis and further consolidates the results of the previous histogram, These results suggest that anti-Ro-52 may be an indicator of poor prognosis in SS patients.(Figure 3-3)
3.1.4 The result of funnel plot analysis
For funnel plot analysis, more than 9 articles need to be included for being statistically significant. A total of 22 articles were included in this study. The sample size and analysis results of each article were analyzed by using Revman software. As shown in Figure 3-3, 20 papers are distributed in the middle top of the funnel chart, which indicates that most of the studies have a large sample size and high accuracy. The funnel plot showed a symmetrical distribution, indicating that there was no publication bias, the level of included literature was high, and the results of data analysis were reliable.(Figure 3-4)
3.2 The Diagnostic Significance of anti-CENP-B in SS
3.2.1 Difference of positive rate between anti-CENP-B and anti-SSB in SS patients
As a popular antinuclear antibody to detect autoimmune diseases, the expression of anti-CENP-B in SS patients also has certain characteristics. In this group, we included 9 studies with corresponding data, recorded the number of SS patients with positive expression of anti-CENP-B, the total number of patients studied, the number of patients with positive expression of anti-SSB in the control group, and the total number of patients in the control group, and input the data into Revman for forest map analysis. As shown in Figure 3-4, the results of four studies intersect with the invalid line, three of which are in favor of the side against SSB, and only one study is slightly in favor of the side of anti-CENP-B.
The total sample size of the group was 781, the positive rate of the experimental group was 21.51%, and the positive rate of the control group was 23.16%. After meta-analysis, the result intersected with the invalid line (CI 0.97 [0.81,1.17]), and there was no significant statistical difference (P = 0.77), indicating that anti-CENP-B had no obvious advantage over traditional anti-SSB detection in the positive rate of expression[14, 15]. (Figure 3-5)
3.2.2 The result of funnel plot analysis
The research group has included 9 pieces of literature, as shown in Figure 3-6. Most of the literature is distributed in the middle and lower part of the funnel map, indicating that the sample size of most studies is small and the accuracy is not good. However, the 9 studies are symmetrical distribution relative to the axis in funnel map, without obvious deviation, indicating that the group has no published bias, and the overall analysis results are more feasible. But we should optimize the quality of the selected research, and eliminate the research with low precision and poor quality.(Figure 3-6)
3.3 The Diagnostic Significance of AMA in SS
In the AMA group, we included six studies, none of which intersected the invalid line, and all of them were on the left side of the invalid line, that is, the results of all studies were biased to the side of ana. The total sample size of this research group was 564. The positive rate of AMA was 15.25%, and that of ANA was 76.24%. The overall meta-analysis results of the AMA group as a whole did not intersect with the invalid line and located on the left, indicating that the positive rate of ANA in SS patients was significantly higher than that of AMA, and the results were statistically significant(CI 0.20 [0.16,0.25], P < 0.00001). Therefore, AMA was not superior to ANA in the diagnosis of SS patients. However, studies have shown that for SS patients with autoimmune liver disease, AMA titer is significantly increased, and the content is significantly higher than Ana, which has a certain guiding significance for the diagnosis and differential diagnosis of autoimmune hepatitis. (Figure 3-7)
3.4 The Diagnostic Significance of anti-Ro-52 in SSc
3.4.1 Difference of positive rate between anti-Ro-52 and anti-SSB/anti-Scl-70 in SSc
To study the role of anti-Ro-52 in the diagnosis of SSc patients, 24 eligible studies were selected. The total sample size of our group was 5850, the number of anti-Ro-52 positive SSc patients was 1590, the overall positive rate was 27.18%, while in the control group, there were only 569 anti-SSB/anti-Scl-70 positive SSc patients, the positive rate was only 9.73%. Therefore, the positive rate of the experimental group was significantly higher than that of the control group, which was conducive to the further analysis of its statistical significance by using forest plots.
After processing by Revman software, as shown in Figure 3-8, 9 of 24 studies intersected with the invalid line, and only 1 of these 9 studies (Liu C 2019) slightly biased to the anti-SSB side, and the remaining 23 literature results were all favorable for anti-Ro-52 antibody[18,19]. In the overall meta-analysis results, the total RR value did not intersect with the invalid line and was located on the right side of the invalid line (r = 2.79 [2.56,3.04]), indicating that the positive rate of anti-Ro-52 expression in SSc patients was significantly higher than that in traditional antinuclear antibody detection items anti-SSB and anti-Scl-70, and the results were statistically significant (P < 0.00001). It can be seen that anti-Ro-52 is superior to anti-SSB/anti-Scl-70 in positive rate in the detection of SSC[20,21,22], which can be used as a new indicator of SSC detection.(Figure 3-8)
3.4.2 Distribution of clinical manifestations of anti-Ro-52(+) SSc patients
In the literature on the relationship between anti-Ro-52 and SSc patients, a total of 6 pieces of literature have data support for the clinical manifestations and incidence of anti-Ro-52 positive patients[23, 24]. Among all the common clinical complications, Raynaud's phenomenon and gastrointestinal involvement were the most common, with an average incidence of 62.65% and 50.43% respectively. The second is telangiectasia (42.57%) and pulmonary fibrosis and pulmonary hypertension (47.55%). The average incidence of this symptom is not only high, but also mentioned in almost every literature, and the variance is less than 0.2, indicating that the results of each literature fluctuate less, and the incidence is relatively stable and reliable. The incidence of hand deformity and arthritis is about 30%, only a few literature mentioned this symptom, and the symptoms in SSc patients are not serious. The average incidence of disease crises such as renal crisis and cardiac involvement was less than 3%, indicating that the prognosis of anti-Ro-52 positive SSc patients was better, and the probability of death factors was very low. However, as with SS patients, the incidence of pulmonary complications in anti-Ro-52 positive SSc patients is higher, which has a certain role in the treatment of symptoms. At the same time, the vascular complications of anti-Ro-52 positive SSc patients are also very common, which should be paid attention to during the medical treatment.(Table 3-1)
3.4.3 Distribution of disease types in anti-Ro-52(+) SSc patients
Systemic sclerosis (SSc) can be divided into localized sclerosis(lcSSc) and diffuse sclerosis(dcSSc). In SSc patients with positive expression of anti-Ro-52, the incidence of lcSSc and dcSSc is also different. Among the relevant literature screened out in this study, 6 pieces of literature have expounded relevant views and provided corresponding data, as shown in Table 3-2. Among them, 61.21% of anti-Ro-52 positive SSc patients are lcSSc, only 38.45% of anti-Ro-52 positive SSc patients are dcSSc, and 1.55% of patients are defined as sine scleroderma, i.e. systemic sclerosis without skin sclerosis symptoms. It can be seen that when the anti-Ro-52 expression is positive, lcSSc is dominant, but compared with the overall SSc patients, the proportion of lcSSc (68.42%) is not significantly reduced, so anti-Ro-52 is not enough to provide a guarantee for a good prognosis. (Table 3-2)
3.4.4 The result of funnel plot analysis
A total of 24 pieces of related literature were included in this research group. As shown in Figure 3-9, 22 literature were located in the upper and middle parts of the funnel chart, which means the research with large sample size and high accuracy. Two pieces of literature were located in the lower and middle parts of the chart, which means the accuracy is poor compared with other literature. The funnel plot is symmetrical, but slightly skewed to the right, indicating that there is a slight publication bias, but the overall accuracy of the literature is good and the quality is high, so the overall research results are highly reliable.(Figure 3-9)
3.5 The Diagnostic Significance of anti-CENP-B in SSc
3.5.1 Difference of positive rate between anti-CENP-B and anti-SSB/anti-Scl-70 in SSc
In the study group of the therapeutic significance of anti-CENP-B for SSc patients, 42 articles met our research requirements, and the total sample size reached 8273 cases. Among them, 3218 cases were anti-CENP-B positive, and the overall positive rate was 38.90%. The positive rate of the control group was only 22.86%. The positive rate of the experimental group was significantly higher than that of the control group, It provides basic data support for the subsequent meta-analysis of forest plots drawing.
After the data processing of Revman software, 14 of the 42 studies intersected with the invalid line, and the results of 7 works of literature were biased to the side of anti-SSB and anti-Scl-70. The results of the four studies were in the middle of the invalid line, and there was no difference between the experimental group and the control group. The remaining 31 results were all in favor of the anti-CENP-B side. The overall results of the meta-analysis showed that RR was 1.71 [1.63,1.79], which did not intersect with the invalid line and was on the right side of the invalid line, indicating that the positive rate of anti-CENP-B expression in SSc patients was significantly higher than that of anti-SSB and anti-Scl-70, and the results were statistically significant (P < 0.00001). Therefore, anti-CENP-B is superior to anti-SSB and anti-Scl-70 in the detection positive rate[32, 33, 34], which can be used as a new basis for the diagnosis of SSc patients.(Figure 3-10)
3.5.2 Distribution of clinical manifestations in anti-CENP-B(+) SSc patients
In the literature screened by our group, we selected 10 articles with relevant data support to make statistics and comparisons on the occurrence probability of clinical manifestations of anti-CENP-B positive SSc patients. As shown in Table 3-3, gastrointestinal involvement had the highest incidence of symptoms (46.44%), followed by telangiectasia (45.25%) and Raynaud's phenomenon (44.23%)[36, 37]. However, the data of different studies on these two phenomena were quite different, so the reliability was not high. Pulmonary fibrosis and pulmonary hypertension are still the most common complications mentioned in most articles, but the incidence rate is only 33.48%. Compared with anti-Ro-52 positive SSc patients, the incidence of disease crisis was higher in anti-CENP-B positive SSc patients (renal crisis 1.55% vs. 7.88%, cardiac involvement 2.98% vs. 13.18%). Therefore, the positive expression of anti-CENP-B may indicate the poor prognosis of SSc patients[38, 39].
Our group also analyzed the age of diagnosis and course of disease of SSc patients with positive anti-CENP-B. The age of diagnosis was 45.0 years old, which was not significantly different from the average age of diagnosis of SSc patients of 40.1 years old. The course of the disease was 15.6 years, which was significantly longer than the average course of 3.5 years. In other circumstances the symptoms of anti-CENP-B positive patients are not obvious, leading to delayed treatment, delayed age of diagnosis, and prolonged course of disease. (Table 3-3)
3.5.3 Distribution of disease types in anti-CENP-B(+) SSc patients
In the study of our group, there are 9 literature that mentioned the classification characteristics of anti-CENP-B(+) SSc patients and provided relevant data. The lcSSc patients accounted for 85.13%, which was much higher than the overall lcSSC accounted for 68.42%. It explained the characteristics of delayed diagnosis and the long course of disease in patients with positive anti-CENP-B expression. Because the symptoms of most mild lcSSc are not obvious, it is common to cause misdiagnosis. The patients choose to see a doctor when the symptoms become too serious, thus delaying the best treatment opportunity, resulting in the increased incidence of disease crisis, poor prognosis, and increased mortality. Therefore, anti-CENP-B can be used as an important indicator for early diagnosis of SSC, to prevent missed diagnosis and misdiagnosis, and to take timely measures for relevant patients, which can effectively avoid the deterioration of the disease and improve the prognosis of patients.(Table 3-4)
3.5.4 The result of funnel plot analysis
As shown in Figure 3-11, most of the 42 papers in our group are distributed at the top of the middle of the funnel plot, which is of large sample size and high precision. Only 5 papers are distributed at the right side of the middle of the funnel plot, which is smaller than most of the studies, but all of them are close to the middle line. The funnel plot is symmetrical, and there is no obvious deviation, which indicates that there is no publication bias, the overall research accuracy is high, the quality of literature is good, and the research results are reliable.(Figure 3-11)
3.6 The Diagnostic Significance of AMA in SSc
The positive rate of AMA and ANA were compared in 7 selected literature. Four of the results intersect with the invalid line, three of them are biased to the side of AMA, and one is biased to the side of ANA. All the results that do not intersect with the invalid line are on the left. The total sample size reached 1191 cases, the positive rate of AMA was 4.03%, and the positive rate of ANA was 82.92%. After forest plots analysis, the RR value was 0.04 [0.03,0.06], which was located on the left side of the invalid line. Therefore, the positive rate of AMA was far lower than that of ANA, and the result was statistically significant (P < 0.00001).(Figure 3-12)
3.7 Comparison of disease type distribution between Ro-52(+) and CENP-B(+) SSc
As shown in Figure 3-13, the proportion of lcSSc in anti-CENP-B(+) SSc patients is significantly higher than that in the anti-Ro-52 positive group. Based on the above analysis, anti-Ro-52 positive as an indicator of poor prognosis may tend to lead to more severe dcSSc, while anti-CENP-B is more likely to lead to mild lcSSc, leading to missed diagnosis and misdiagnosis, delaying the diagnosis time, prolonging the course of the disease, and affecting the prognosis of patients.(Figure 3-13)
3.8 Coexistence of antibodies in SSc patients
In SSc patients, the coexistence probability of anti-Ro-52 and anti-Ro-60, anti-CENP-B, and anti-SSB is more than 30%, which provides a good basis for improving the accuracy of SSC detection and the judgment of clinical manifestations. Through the combination of traditional detection indicators and new indicators, the diagnostic efficiency of SSC can be improved and the prognosis of patients can be improved.(Table 3-5)
3.9 The Effect of EBV infection on anti-Ro-52(+) SS and SSc patients
3.9.1 The Effect of EBV infection on anti-Ro-52(+) SS patients
For SS patients with positive anti-Ro-52 expression, EBV infection will greatly increase the risk of SS transforming into Hodgkin's lymphoma. The virus infiltration site is usually the gland with abnormal monoclonal amplification of B cells. In the past 20 years, nearly 14% of SS patients developed into malignant lymphomas. The mechanism of EBV infection-related SS patients may be related to excessive T cell costimulation, impaired specific T cell response to EBV, cross-reaction of anti-EBV antibody, inhibition of B cell apoptosis, and other factors. The detection rate of EB-DNA in salivary glands of anti-Ro-52(+) SS patients was significantly increased (78%), while the detection rate of EB-DNA in salivary glands of normal people was only 13%.
3.9.2 The Effect of EBV infection on anti-Ro-52(+) SSc patients
EBV infection contributes to the deterioration of the disease in anti-Ro-52(+) SSc patients. The main mechanism is that EBV can infect dermal fibroblasts, regulating the innate immune response of infected fibroblasts and inducing them to transform into a typical Pro fibrotic phenotype. EBV viral transcripts and proteins play an important role in this process. For example, EBV proteins like ZEBRA, BFRF1, and BFLF2 are more significantly expressed in non-lcSSc patients, which can induce chronic inflammation and fibrosis of the skin. Studies have shown that EBV cleavage antigen is detected in scleroderma skin vessels, suggesting that endothelial cells may be the target of EBV infection in scleroderma skin. Compared with healthy EBV carriers, the load of EBV-DNA in peripheral blood, plasma, and circulating monocytes of scleroderma patients are significantly increased. These results suggest that the upregulation of EB-DNA loading may be a potential biomarker for scleroderma vasculopathy.