Immune thrombocytopenia (ITP) is an autoimmune hemorrhagic disease. It is considered that production of platelet auto-antibodies was one of the pathogenesis of ITP, first-line therapy including corticosteroid and immunoglobulin could reduce destruction of platelets by inhibiting production of auto-antibodies and blocking Fc-receptor of reticuloendothelial system, but some of the patients were refractory to first-line therapy and have persistent duration of the disease, having worse prognosis and developing into chronic/refractory ITP(C/RITP) . Platelet membrane glycoprotein like GPIIb/IIIa and GPIbα are the most common antigen targets, but first-line therapy was less effective to patients whose anti-GPIbα antibodies are positive. Further studies revealed that the way causing platelet destruction by anti-GPIIb/IIIa antibodies and anti-GPIbα antibodies are different: the former is mainly dependent to Fc-pathway, and the latter mainly cleared platelet by Fc-independent way. Results above indicated that detection of type of platelet auto-antibodies maybe potential to treatment and prognosis of ITP. This article summarizes relationship between platelet specific antibodies and the onset, clinical manifestation, treatment and prognosis of ITP.
Antibodies ; immunology ; Autoimmune Diseases ; Blood Platelets ; immunology ; Humans ; Platelet Membrane Glycoproteins ; Prognosis ; Thrombocytopenia ; immunology ; therapy

We selected 12 antigens corresponding to commonly used autoantibodies in clinical practice to prepare antigen microarray. We chose NBT/BCIP color reaction as the end detection strategy to develop a new autoantibody protein chip detection system. Using this system, we optimized the best spotting solution, spotting concentration of the 12 antigens and the dilution of serum. We prepared a protein chip that could detect 12 autoantibodies simultaneously using the optimized antigen concentration. We established a new method to determine the cutoff of each autoantibodies by evaluation of 678 positive and 120 negative serum of clinical sample. We also evaluated the sensitivity and specificity of our new detection system. The optimal spotting solution was 0.1% TBST, the dilution of serum was 1:4 and the best spotting concentration of the 12 antigens were ANA 520 microg/mL, Ro-60/SSa 465 microg/mL, La/SSb 530 microg/mL, Jo-1 530 microg/mL, Scl-70 525 microg/mL, Sm 520 microg/mL, Ro-52/SSa 615 microg/mL, RF 340 microg/mL, CCP 465 microg/mL, ulRNP 410 microg/mL, CENP-B 490 microg/mL and dsDNA 580 microg/mL respectively. It had higher coincidence rate compared to current clinical used methods. We have developed a 12 antigens protein chip for the detection of autoantibodies based on the NBT/BCIP color reaction system. This system was fast, convenient, efficient, and cost-effective.
Autoantibodies ; blood ; immunology ; Autoimmune Diseases ; blood ; immunology ; Humans ; Protein Array Analysis ; instrumentation ; methods ; Sensitivity and Specificity

OBJECTIVETo identify the candidate auto-antigen of rheumatic heart disease as a molecular marker for this disease.

METHODSThe total RNA of the heart tissue of patients with rheumatic heart disease was extracted and reverse-transcribed into long cDNA to construct the phage expression library. The library was screened using the serum from patients with active rheumatic fever, and the positive clone was identified and analyzed by bioinformatics and expressed in vitro. The expressed products were evaluated with Western blotting and its cross-reactivity was assessed.

RESULTSThe phage expression library of the heart tissue of patients with rheumatic heart disease was constructed, with the titer of the primary library of 3.3×10(6) pfu/ml, recombinant rate of 99%, and 81% of the inserted segments were larger than 1 kb. An auto-antigen RHDAG1 was identified by screening, which was homologous to keratin 18. RHDAG1 was detected in the serum of patients with active rheumatic fever and of those with rheumatic heart disease, but not in the serum of healthy subjects.

CONCLUSIONPhage display library can be an effective strategy to screen the auto-antigens of rheumatic heart disease. The auto-antigen RHDAG1 can be a candidate molecular biomarker of rheumatic heart disease and/or rheumatic fever.

Autoantibodies ; blood ; immunology ; Autoantigens ; immunology ; isolation & purification ; Autoimmune Diseases ; blood ; immunology ; Humans ; Peptide Library ; Rheumatic Heart Disease ; immunology

Objective To explore the clinical characteristics of autoimmune disease with dual seropositive antibodies of leucine-rich glioma inactivated 1(LGI1)and contactin-associated protein 2(Caspr2).Methods The clinical data of seven patients with dual seropositive LGI1 and Caspr2 antibodies who were admitted to the Neurology Department of Peking Union Medical College Hospital from July 2014 to December 2017 were retrospectively analyzed.Results Central,peripheral and autonomic nervous systems were all involved in the seven cases;100%(7/7)presented with insomnia,myokymia,neuropahic pain and hyperhydrosis;71%(5/7)showed memory decline or psychiatric and behavioral symptoms;57%(4/7)had urinary hesitation or constipation;and 43%(3/7)had seizure.Electromyography showed 100%(6/6) of the patients had prolonged afterdischarges following normal M waves and/or abnormal spontaneous firing.Electroencephalography revealed slow waves or basic rhythm slowing in 71%(5/7)of patients.Electrocardiography showed sinus tachycardia,axis deviation,and prolonged QT intervals in 71%(5/7)of patients.One patient died from arrhythmia before immunotherapy.One died from pulmonary infection after immunotherapy.Improvement with immunotherapy was documented in the other five cases.No relapse was noted during the 1-2-year follow-up.Conclusions Autoimmune disease with dual seropositive antibodies of LGI1 and Caspr2 can diffusely affect the central,peripheral,and autonomic nervous systems.The possibility of this disease should be considered in patients with acute and subacute onset of neuropsychiatric symptoms,especially in patients with accompanying insomnia,myokymia,and hyperhydrosis.
Autoantibodies ; blood ; Autoimmune Diseases ; immunology ; Humans ; Membrane Proteins ; immunology ; Nerve Tissue Proteins ; immunology ; Proteins ; immunology ; Retrospective Studies

IgG4-related disease (IgG4-RD) is a novel and rare autoimmune disease entity. Elevated serum IgG4 level is strongly suggestive of IgG4-RD. But it is still unknown whether serum IgG4 elevation commonly occurs in other autoimmune diseases. In this study, the serum IgG4 levels were detected by an established enzyme-linked immunosorbent assay (ELISA) in a variety of autoimmune diseases including systemic lupus erythematosus (SLE), Sjogren's syndrome (SS), polymyositis or dermatomyositis (PM/DM) and IgG4-RD. To evaluate the reliability of this ELISA system, some of our samples were sent to a lab in Kanazawa Medical University, Japan, and detected by using the nephelometric assay. The results showed that our findings were consistent with theirs. Moreover, it was found that the serum IgG4 levels were 0.23±0.16 g/L in 53 healthy controls, 0.16±0.15 g/L in 103 SLE patients, 0.22±0.18 g/L in 41 SS patients and 0.40±0.32 g/L in 21 PM/DM patients. No significant difference in the serum IgG4 level was observed among these groups (P>0.05). The serum IgG4 levels of two cases of IgG4-RD were 1.63 and 4.65 g/L respectively, and both decreased markedly after treatment with glucocorticoids. These data indicated that this established ELISA system can be used for detecting serum IgG4 levels. Elevated serum IgG4 levels help diagnose IgG4-RD and evaluate the curative effect of this condition rather than other autoimmune diseases.
Autoimmune Diseases ; blood ; diagnosis ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Immunoglobulin G ; blood

BACKGROUND: The indirect basophil activation test using flow cytometry is a promising tool for autoimmune urticaria diagnosis. We aimed to identify better donor basophils (from atopic vs. non-atopic donors and interleukin-3 primed vs. unprimed basophils) and improve basophil identification and activation markers (eotaxin CC chemokine receptor-3 [CCR3] vs. CD123 and CD63 vs. CD203c). METHODS: Donor basophils were obtained from non-atopic and atopic group O donors. Positive control sera were artificially prepared to simulate autoimmune urticaria patients' sera. Patient sera were obtained from nine children with chronic urticaria. Assay sensitivity was compared among each variation by using positive control sera (n=21), applying cutoff values defined from negative control sera (n=20). RESULTS: For basophil identification, a combination of CCR3 and CD123 markers revealed a higher correlation with automated complete blood count (r=0.530) compared with that observed using CD123 (r=0.498) or CCR3 alone (r=0.195). Three activation markers on the atopic donor basophils attained 100% assay sensitivity: CD203c on unprimed basophils, CD63+CD203+ or CD63 alone on primed basophils; however, these markers on the non-atopic donor basophils attained lower assay sensitivity. CONCLUSIONS: For basophil identification markers, a combination of CD123 and CCR3 is recommended, while CD123 alone may be used as an alternative. Donor basophils should be obtained from an atopic donor. For basophil activation markers, either CD203c alone on unprimed basophils or CD203c and CD63 on primed basophils are recommended, while CD63 alone on primed basophils may be used as an alternative.
Autoimmune Diseases/blood/*diagnosis/immunology ; Basophils/*immunology/metabolism ; Biomarkers/blood ; Child ; Flow Cytometry ; Humans ; Interleukin-3 Receptor alpha Subunit/blood ; Male ; Receptors, CCR3/blood ; Urticaria/blood/*diagnosis/immunology

Autoantibodies ; blood ; Autoimmune Diseases ; complications ; Hepatitis C, Chronic ; complications ; immunology ; Humans

OBJECTIVETo assess the seroprevalence and diagnostic value of aquaporin-4 antibody (AQP4-Ab) in patients with inflammatory central nervous system demyelinating diseases.

METHODSSeventy-two patients with neuromyelitis optica (NMO), 68 with multiple sclerosis (MS), 4 with optic neuritis (ON), and 41 with transverse myelitis (TM) were included in this study. The TM group comprised 19 patients with non-longitudinally extensive transverse myelitis (nLETM), 14 with monophasic longitudinally extensive transverse myelitis (mLETM), and 8 with recurrent longitudinally extensive transverse myelitis (rLETM). The serum levels of AQP4-Ab was detected by indirect immunofluorence assay in these patients.

RESULTSAQP4-Ab was detected in 72.2% (52/72) patients with NMO, 5.9% (4/68) patients with MS, 25.0% (1/4) patients with ON, and 17.1% (7/41) patients with TM, showing a significant difference in the positivity between NMO and MS groups (P<0.01). AQP4-Ab seropositivity rate was 5.3% (1/19) in nLETM patients, 62.5% (5/8) in rLETM patients and 7.1% (1/14) in mLETM patients, significantly higher in rLETM than in nLETM (P<0.01) and mLETM groups (P<0.05), but no statistical difference was found between rLETM and NMO groups.

CONCLUSIONSA high seroprevalence of AQP4-Ab is observed in patients with NMO and rLETM, which support the hypothesis that NMO and rLETM belong to NMO spectrum disorders. AQP4-Ab can serve as a useful index for diagnosing NMO and differential diagnosis from MS. More attention and effective immunosuppressive treatments should be given to patients positive for AQP4-Ab.

Aquaporin 4 ; immunology ; Autoantibodies ; blood ; Demyelinating Autoimmune Diseases, CNS ; diagnosis ; immunology ; Female ; Humans ; Male ; Multiple Sclerosis ; diagnosis ; immunology ; Neuromyelitis Optica ; diagnosis ; immunology ; Seroepidemiologic Studies

OBJECTIVETo investigate the relation between insulin resistance and glutamic acid decarboxylase antibody (GAD-Ab) titers in latent autoimmune diabetes in adults (LADA).

METHODSThe patients with phenotypic type 2 diabetes were screened for GAD-Ab positivity, and the 141 positive patients were divided into two subgroups according to the GAD-Ab titer, namely the high-titer group (LADA-1 subtype) and low-titer group (LADA-2 subgroup). The clinical features and insulin resistance were compared between the two groups. Insulin resistance was calculated by HOMA 2 software, and GAD-Ab and C peptide were determined with radioligand and radioimmune assay, respectively.

RESULTSCompared with low-titer LADA patients, the patients with high titers had younger age of onset, lower BMI, higher HbA1c level, and worse fasting and postprandial C peptide levels. The insulin resistance index by HOMA 2 was significantly lower in LADA-1 group than in LADA-2 group (1.6-/+1.1 vs 2.1-/+1.1, P=0.001). The HOMA2-IR index showed a negative correlation to GAD-Ab titer.

CONCLUSIONThe degree of insulin resistance is correlated to GAD-Ab titers in LADA, and low titer patients have higher insulin resistance level.

Adult ; Aged ; Autoantibodies ; blood ; Autoimmune Diseases ; diagnosis ; immunology ; Diabetes Mellitus, Type 2 ; diagnosis ; immunology ; Female ; Glutamate Decarboxylase ; immunology ; Humans ; Insulin Resistance ; Islets of Langerhans ; immunology ; physiology ; Male ; Middle Aged

BACKGROUND/AIMS: To diagnose autoimmune pancreatitis (AIP), serum IgG and IgG4 concentration are significant serologic markers. The purpose of this study was to assess the utility of serum IgG and IgG4 for the diagnosis of AIP. METHODS: We divided enrolled patients into 2 groups: autoimmune pancreatitis and other pancreatic disease. We measured serum IgG and IgG4 levels in patients including 12 AIP and 23 other pancreatic disease. RESULTS: Among AIP patients, 10 cases (83%) showed elevated IgG4 levels of more than 135 mg/dL and 4 cases (33%) showed elevated IgG levels of more than 1,800 mg/dL, the current cutoff value applied in Japan. Only one patient showed elevated serum IgG level, despite having normal IgG4 level. Sensitivity and specificity for AIP of elevated serum IgG4 (>135 mg/dL) were 91% and 92%, and for elevated serum IgG (>1,800 mg/dL) 67% and 92%, respectively. The optimal cut-off level of IgG4 using receiver operation characteristic (ROC) was 127 mg/dL, at which the sensitivity and specificity were 83% and 96%, respectively, for the diagnosis of AIP. Serum IgG at 1,520 mg/dL showed the sensitivity and specificity of 83% and 87%, respectively. CONCLUSONS: The measurement of serum IgG and IgG4 are helpful to diagnose AIP. Serum IgG and IgG4 are complementary to each other in the diagnosis of AIP.
Adult ; Aged ; Autoimmune Diseases/*diagnosis/immunology ; Biological Markers/blood ; Diagnosis, Differential ; Female ; Humans ; Immunoglobulin G/*blood ; Male ; Middle Aged ; Pancreatitis, Chronic/*diagnosis/etiology/immunology ; ROC Curve ; Sensitivity and Specificity