Chaojun Hu

Novel autoimmune hepatitis-specific autoantigens identified using protein microarray technology.

Autoimmune hepatitis (AIH) is a chronic necroinflammatory disease of the liver with a poorly understood etiology. Detection of nonorgan-specific and liver-related autoantibodies using immunoserological approaches has been widely used for diagnosis and prognosis. However, unambiguous and accurate detection of the disease requires the identification and characterization of disease-specific autoantigens. In the present study, we have profiled the autoantigen repertoire of patients with AIH versus those with other liver diseases, identifying and validating three novel and highly specific biomarkers for AIH. In phase I, we fabricated a human protein chip of 5011 nonredundant proteins and used it to quickly identify 11 candidate autoantigens with relative small serum collection. In phase II, we fabricated an AIH-specific protein chip and obtained autoimmunogenic profiles of serum samples from 44 AIH patients, 50 healthy controls, and 184 additional patients suffering from hepatitis B, hepatitis C, systemic lupus erythematosus, primary Sjogrens syndrome, rheumatoid arthritis, or primary biliary cirrhosis. With this two-phase approach, we identified three new antigens, RPS20, Alba-like, and dUTPase, as highly AIH-specific biomarkers, with sensitivities of 47.5% (RPS20), 45.5% (Alba-like), and 22.7% (dUTPase). These potential biomarkers were further validated with additional AIH samples in a double-blind design. Finally, we demonstrated that these new biomarkers could be readily applied to ELISA-based assays for use in clinical diagnosis/prognosis.

Clinical characteristics of immunoglobulin G4–related disease: a prospective study of 118 Chinese patients

OBJECTIVE To characterize the clinical features of IgG4-related disease (IgG4-RD) in China. METHODS A prospective cohort study of IgG4-RD was carried out in Peking Union Medical College Hospital between 2011 and 2013. Patients with newly diagnosed IgG4-RD were enrolled. RESULTS A total of 118 patients with IgG4-RD were enrolled, including 82 males and 36 females, aged 53.1 (s.d. 13.6) years. The most common symptom at onset was lacrimal gland swelling (38/32.2%). A range of organs were involved: 77 patients (65.3%) had lymphadenopathy, 76 (64.4%) had sialadenitis, 60 (50.8%) had dacryoadenitis, 45 (38.1%) had autoimmune pancreatitis, 32 (27.1%) had pulmonary involvement, 31 (26.3%) had periaortitis/retroperitoneal fibrosis, 29 (35.4% of male patients) had prostatitis and 29 (24.6%) had renal involvement. In addition, there were 21 (17.8%) cases of sclerosing cholangitis, 15 (12.7%) of sinusitis and 10 (8.5%) of inflammatory pseudotumour. Uncommon manifestations included mediastinal fibrosis, skin involvement, sclerosing thyroiditis, hypophysitis, orchitis and colitis. Multiple organ involvement was observed in 93 patients, whereas only 4.2% had only a single organ involved. A history of allergy was reported in 73 (61.9%) patients. The serum IgG4 level was elevated in 97.5% and was correlated with the number of organs involved. Most patients were treated with glucocorticoids alone or in combination with immunosuppressive drugs, and the majority usually improved within 3 months. CONCLUSION IgG4-RD is a systemic inflammatory and sclerosing disease. Parotid and lacrimal involvement (formerly called Mikuliczs disease), lymphadenopathy and pancreatitis are the most common manifestations. Patients with IgG4-RD showed favourable responses to treatment with glucocorticoids and immunosuppressive agents.

Association of genetic variations in the STAT4 and IRF7/KIAA1542 regions with systemic lupus erythematosus in a Northern Han Chinese population.

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease with complex genetic inheritance. Genome-wide association studies have identified SLE susceptibility variations at the IRF7/KIAA1542 locus and with STAT4 gene in European populations. We decided to investigate the association of single-nucleotide polymorphisms (SNPs) in the IRF7/KIAA1542 region (rs4963128, rs2246614, and rs702966) and in STAT4 (rs7574865 and rs7582694) with SLE disease in a Northern Han Chinese population of 748 patients and 750 healthy controls. Our study indicated a strong association between rs7574865 (odds ratio = 0.68; 95% confidence interval 0.59-0.79; p = 1.57 × 10(-6)) and SLE and between rs7574865 and the production of anti-Sm antibodies. Additionally, rs4963128 and rs2246614 were correlated with a variety of clinical subphenotypes, such as lupus nephritis, arthritis, and the production of anti-SSA/B autoantibodies, despite a lack of significant association between these two SNPs and SLE disease susceptibility in general.

MALDI-TOF MS combined with magnetic beads for detecting serum protein biomarkers and establishment of boosting decision tree model for diagnosis of systemic lupus erythematosus

OBJECTIVES To discover novel potential biomarkers and establish a diagnostic pattern for SLE by using proteomic technology. METHODS Serum proteomic spectra were generated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with weak cationic exchange magnetic beads. A training set of spectra, derived from analysing sera from 32 patients with SLE, 43 patients with other autoimmune diseases and 43 age- and sex-matched healthy volunteers, was used to train and develop a decision tree model with a machine learning algorithm called decision boosting. A blinded testing set, including 32 patients with SLE, 42 patients with other autoimmune diseases and 40 healthy people, was used to determine the accuracy of the model. RESULTS The diagnostic pattern with a panel of four potential protein biomarkers of mass-to-charge (m/z) ratio 4070.09, 7770.45, 28 045.1 and 3376.02 could accurately recognize 25 of 32 patients with SLE, 36 of 42 patients with other autoimmune diseases and 36 of 40 healthy people. CONCLUSIONS The preliminary data suggested a potential application of MALDI-TOF MS combined with magnetic beads as an effective technology to profile serum proteome, and with pattern analysis, a diagnostic model comprising four potential biomarkers was indicated to differentiate individuals with SLE from RA, SS, SSc and healthy controls rapidly and precisely.

Specific serum protein biomarkers of rheumatoid arthritis detected by MALDI-TOF-MS combined with magnetic beads.

OBJECTIVES To identify novel serum protein biomarkers and establish diagnostic pattern for rheumatoid arthritis (RA) by using proteomic technology. METHODS Serum proteomic spectra were generated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) combined with weak cationic exchange magnetic beads. A training set of spectra, derived from analyzing sera from 22 patients with RA, 26 patients with other autoimmune diseases and 25 age- and sex-matched healthy volunteers, was used to train and develop a decision tree model with a machine learning algorithm called decision boosting. A blinded testing set, including 21 patients with RA, 24 patients with other autoimmune diseases and 25 healthy people, was used to examine the accuracy of the model. RESULTS A decision tree model was established, consisting of four potential protein biomarkers whose m/z values were 4966.88, 5065.3, 5636.97 and 7766.87, respectively. In validation test, the decision tree model could differentiate RA from other autoimmune diseases and healthy people with the sensitivity of 85.71% and specificity of 87.76%, respectively. CONCLUSIONS The present data suggested that MALDI-TOF-MS combined with magnetic beads could screen and identify some novel serum protein biomarkers related to RA. The proteomic pattern based on the four candidate biomarkers is of value for laboratory diagnosis of RA.

Meta-Analysis: Diagnostic Accuracy of Anti-Carbamylated Protein Antibody for Rheumatoid Arthritis

Objective The anti-carbamylated protein (CarP) antibody is a novel biomarker that might help in the diagnosis of rheumatoid arthritis (RA). We aim to assess the diagnostic value of anti-CarP antibody for RA. Methods We systematically searched PubMed, Embase, the Cochrane Library, Web of Science, and Scopus for studies published by December 15, 2015. Studies in any language that evaluated the utility of the anti-CarP antibody in the diagnosis of RA in which healthy donors or patients without arthritis or arthralgia served as controls were included. Two investigators independently evaluated studies for inclusion, assessed study quality and abstracted data. A bivariate mixed-effects model was used to summarize the diagnostic indexes from 7 eligible studies. Results The pooled sensitivity, specificity, and positive and negative likelihood ratios for anti-CarP antibody were 42% (95% CI, 38% to 45%), 96% (95% CI, 95% to 97%), 10.2 (95% CI, 7.5 to 13.9), and 0.61 (95% CI, 0.57 to 0.65), respectively. The summary diagnostic odds ratio was 17 (95% CI, 12 to 24), and the area under summary receiver operator characteristic curve was 80% (95% CI, 77% to 84%). Conclusion Anti-CarP antibody has a moderate value in the diagnosis of RA with high specificity but relatively low sensitivity.

Exploring Serological Classification Tree Model of Active Pulmonary Tuberculosis by Magnetic Beads Pretreatment and MALDI‐TOF MS Analysis

Pulmonary tuberculosis (TB) is an infectious disease disturbing status of public health, and accurate diagnosis of TB would effectively help control the disturbance. Our study tried to establish a classification tree model that distinguished active TB from non‐TB individuals. We used matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF MS) combined with weak cationic exchange (WCX) magnetic beads to analyse 178 serum samples containing 75 patients with active TB and 103 non‐TB individuals (43 patients with common pulmonary diseases and 60 healthy controls). Samples were randomly divided into a training set and a test set. Statistical softwares were applied to construct this model. An amount of 48 differential expressed peaks (P < 0.05) were identified by the training set, and our model was set up by three of them, m/z 7626, 8561 and 8608. This model can discriminate patients with active TB from patients with non‐TB with a sensitivity of 98.3% and a specificity of 84.4%. The test set was used to verify the performance, which demonstrated good sensitivity and specificity: 85.7% and 83.3%, respectively. Differential expressed peaks between smear‐positive and smear‐negative active TB also have been analysed. It came out that m/z 8561 and 8608 not only acted as vital factors in the pathogenesis of active TB but also played an important role in regulating different active TB status. In conclusion, MALDI‐TOF MS combined with WCX magnetic beads was a powerful technology for constructing classification tree model, and the model we built could serve as a potential diagnostic tool for active TB.

Association of the PTPN22 gene (-1123G > C) polymorphism with rheumatoid arthritis in Chinese patients

This study aimed at examining the association of the single nucleotide polymorphism (SNP) in the protein tyrosine phosphatase gene (PTPN22) with the risk of rheumatoid arthritis (RA) in a Chinese population. A total of 200 RA patients and age and gender-matched healthy controls were recruited. Their genotypes and allelic frequency were determined by the TaqMan-MGB probe-based polymerase chain reaction (PCR). The frequencies of the CC genotype and C allele in RA patient group were significantly higher than that of controls (P < 0.01 or P < 0.05) with an odds ratio of 1.67, respectively. These data suggest, the CC genotype and C allele of the -1123G > C in the PTPN22 gene are associated with an increased risk for RA in Chinese population. Therefore, the CC genotype and C allele of the -1123G > C in the PTPN22 gene may be used as a genetic marker for the predisposition of RA in Chinese.

Establishing a serologic decision tree model of extrapulmonary tuberculosis by MALDI-TOF MS analysis.

Matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) combined with weak cationic exchange (WCX) magnetic beads was used to establish a decision tree model that distinguished extrapulmonary tuberculosis (EPTB) from non-EPTB individuals. Eight-one patients with EPTB and 112 non-EPTB individuals (72 disease controls and 40 healthy controls) were involved in this study. The model was set up by 5 of 19 differentially expressed peaks (P < 0.05), m/z 4100, 4310, 6093, 8605, and 14,019. This model can discriminate patients with EPTB from non-EPTB with a sensitivity of 97.7% and a specificity of 84.1%. The test set verified that this model had good sensitivity and specificity: 94.4% and 83.6%, respectively. In conclusion, MALDI-TOF MS combined with WCX magnetic beads is a powerful technology for constructing a decision tree model and the model we built could serve as a potential diagnostic tool for EPTB.

Novel systemic lupus erythematosus autoantigens identified by human protein microarray technology

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease affecting many organs. Many autoantibodies have been associated with the disease, but either in low specificity or low sensitivity of detection. In an aim to screen for better autoantibodies, we profiled the autoantibody repertoire in sera from 30 SLE patients versus 30 healthy controls using a protein microarray containing 5011 non-redundant human proteins, and identified four candidates. We then selected CLIC2 for further verification by ELISA in an extended cohort including 110 SLE, 121 non-AD, 118 RA, 117 SSc, and 105 pSS patients. The positive rate of anti-CLIC2 was 28.18% in SLE patients, significantly higher than those in non-AD, RA, and SSc patients. The presence of anti-CLIC2 in SLE had positive correlation with disease activity in terms of SLEDAI score and several indexes (p<0.05).