Autoimmune heart disease: role of sex hormones and autoantibodies in disease pathogenesis

Cardiovascular disease (CVD) and autoimmune diseases (ADs) are the first and third highest causes of death in the USA, respectively. Men have an increased incidence of the majority of CVDs, including atherosclerosis, myocarditis, dilated cardiomyopathy and heart failure. By contrast, nearly 80% of all ADs occur in women. However, in one category of ADs, rheumatic diseases, CVD is the main cause of death. Factors that link rheumatic ADs to CVD are inflammation and the presence of autoantibodies. In this review we will examine recent findings regarding sex differences in the immunopathogenesis of CVD and ADs, explore possible reasons for the increased occurrence of CVD within rheumatic ADs and discuss whether autoantibodies, including rheumatoid factor, could be involved in disease pathogenesis.     

Autoimmune heart disease: role of sex hormones and autoantibodies in disease pathogenesis

Cardiovascular disease (CVD) and autoimmune diseases (ADs) are the first and third highest causes of death in the USA, respectively. Men have an increased incidence of the majority of CVDs, including atherosclerosis, myocarditis, dilated cardiomyopathy and heart failure. By contrast, nearly 80% of all ADs occur in women. However, in one category of ADs, rheumatic diseases, CVD is the main cause of death. Factors that link rheumatic ADs to CVD are inflammation and the presence of autoantibodies. In this review we will examine recent findings regarding sex differences in the immunopathogenesis of CVD and ADs, explore possible reasons for the increased occurrence of CVD within rheumatic ADs and discuss whether autoantibodies, including rheumatoid factor, could be involved in disease pathogenesis.     

Atrioventricular canal defect in patients with RASopathies

Congenital heart defects affect 60-85% of patients with RASopathies. We analysed the clinical and molecular characteristics of atrioventricular canal defect in patients with mutations affecting genes coding for proteins with role in the RAS/MAPK pathway. Between 2002 and 2011, 101 patients with cardiac defect and a molecularly confirmed RASopathy were collected. Congenital heart defects within the spectrum of complete or partial (including cleft mitral valve) atrioventricular canal defect were diagnosed in 8/101 (8%) patients, including seven with a PTPN11 gene mutation, and one single subject with a RAF1 gene mutation. The only recurrent mutation was the missense PTPN11 c.124 A>G change (T42A) in PTPN11. Partial atrioventricular canal defect was found in six cases, complete in one, cleft mitral valve in one. In four subjects the defect was associated with other cardiac defects, including subvalvular aortic stenosis, mitral valve anomaly, pulmonary valve stenosis and hypertrophic cardiomyopathy. Maternal segregation of PTPN11 and RAF1 gene mutations occurred in two and one patients, respectively. Congenital heart defects in the affected relatives were discordant in the families with PTPN11 mutations, and concordant in that with RAF1 mutation. In conclusion, our data confirm previous reports indicating that atrioventricular canal defect represents a relatively common feature in Noonan syndrome. Among RASopathies, atrioventricular canal defect was observed to occur with higher prevalence among subjects with PTPN11 mutations, even though this association was not significant possibly because of low statistical power. Familial segregation of atrioventricular canal defect should be considered in the genetic counselling of families with RASopathies.     

Cardiac manifestations and gene mutations of patients with RASopathies in Taiwan

RASopathies are developmental diseases caused by mutations in rat sarcoma–mitogen‐activated protein kinase pathway genes. These disorders, such as Noonan syndrome (NS) and NS‐related disorders (NSRD), including cardio‐facio‐cutaneous (CFC) syndrome, Costello syndrome (CS), and NS with multiple lentigines (NSML; also known as LEOPARD syndrome), have a similar systemic phenotype. A wide spectrum of congenital heart disease and hypertrophic cardiomyopathy (HCMP) can exhibit major associated characteristics. A retrospective study was conducted at the Mackay Memorial Hospital, National Taiwan University Hospital, Buddhist Tzu‐Chi General Hospital, Chang‐Gung Memorial Hospital, Taichung Veterans General Hospital, and Chung Shan Medical University Hospital from January 2007 to December 2018. We reviewed the clinical records of 76 patients with a confirmed molecular diagnosis of RASopathies, including NS, CS, CFC syndrome, and NSML. We evaluated the demographic data and medical records with clinical phenotypes of cardiac structural anomalies using cross‐sectional and color Doppler echocardiography, electrocardiographic findings, and follow‐up data. A total of 47 (61.8%) patients had cardiac abnormalities. The prevalence of cardiac lesions according to each syndrome was 62.7, 50.0, 60.0, and 66.7% in patients with NS, CFC syndrome, CS, and NSML, respectively. An atrial septal defect was usually combined with other cardiac abnormalities, such as pulmonary stenosis (PS), HCMP, ventricular septal defect, or patent ductus arteriosus. Patients with NS most commonly showed PS. In patients with NSRD and cardiac abnormalities, HCMP (29.4%) was the most commonly observed cardiac lesion. PTPN11 was also the most frequently detected mutation in patients with NS and NSRD. Cardiac abnormalities were the most common symptoms observed in patients with RASopathies at the time of their first hospital visit. Performing precise analyses of genotype–cardiac phenotype correlations in a larger cohort will help us accurately diagnose RASopathy as soon as possible.     

Natural autoantibodies in sera of patients with Gaucher's disease

Gaucher's disease (GD) is associated with hyperactivity of the immune system, which manifests by polyclonal hypergammaglobulinemia and an increased incidence of monoclonal gammopathies in GD patients. We analyzed sera of 43 patients with GD for the presence of autoantibodies against 14 autoantigens. The results demonstrated a significant increase in the incidence of all autoantibodies tested, ranging from 11% for anti-RNP, pyruvate dehydrogenase (PDH), and DNA antibodies to 57% for rheumatoid factor. The autoantibodies were of all three isotypes, namely, IgG, IgM, and IgA. There was no correlation between the levels of immunoglobulins in the serum and the titer of autoantibodies found. Immunization of naive mice with a pool of purified anti-DNA antibodies form GD patients did not result in induction of experimental systemic lupus erythematosus (SLE), suggesting that they may represent natural autoantibodies that are not pathogenic. In conclusion, we found high titers of natural, polyspecific, nonpathogenic autoantibodies in the sera of GD patients.     

Autoimmune phenomena and disease in cancer patients treated with immune checkpoint inhibitors

The discovery and approved treatment with immune checkpoint inhibitors (ICIs) for a variety of cancers has changed dramatically the morbidity and mortality rates for these patients.Despite the obvious benefits, their use is associated with unique immune-related adverse effects (irAEs), including autoimmune conditions such as: inflammatory arthritis, myositis, vasculitis and Sicca syndrome.The appearance of ICIs-induced autoimmune irAE requires from oncologists and rheumatologists a different approach to the identification and treatment of these conditions, which may differ from the classic and traditional approach to rheumatologic diseases. It should be taken into consideration that ICIs therapy in patients with preexisting autoimmunity could be possible, but with a cost of causing disease exacerbation.In this extensive review, we present the autoimmune irAEs, mostly as phenomena, but also as classic autoimmune diseases as well as therapeutic options for the side effects.     

Levels of cytokines and thyroid autoantibodies in Omani patients with Graves' disease

An altered balance of pro- and anti-inflammatory cytokines is thought to play an important role in the pathogenesis of autoimmune thyroiditis. The aim of the present study is to assess the cytokine and autoantibody profiles in Omani patients with Graves' disease (GD). Cytokines and autoantibodies including interleukin (IL)-2, IL-4, tumour necrosis factor (TNF)alpha, interferon (IFN)gamma, thyroid stimulating hormone receptor antibody (TRA) and thyroid peroxidase antibody (TPO) are measured in GD patients (n=59) before treatment (n=23) and after treatment (n=36) with 131I-labelled iodine, and compared with normal controls (n=20). Patients with GD showed comparable serum levels of IL-2 but significantly higher levels of IL-4, TNFalpha, IFNgamma, TRA and TPO, compared with the normal controls. There was also a significant increase in serum levels of IL-4 and TNFalpha, and a decrease in TRA in the treated group, compared to the untreated group. IL-4, TNFalpha, IFNgamma, TRA and TPO showed a high prevalence in Omani patients with GD. Thus, cytokines and autoantibodies may prove useful in the diagnosis of GD and in assessing prognosis.     

Anti-heart autoantibodies in ischaemic heart disease patients.

One hundred and ninety-nine ischaemic heart disease (IHD) patients were studied with regard to the prevalence of anti-heart autoantibodies (AHA). The incidence of AHA in IHD patients was 1%: one out of 102 patients who suffered acute myocardial infarction (AMI), one out of seventy-two patients who suffered from acute coronary insufficiency (ACI), and none out of twenty-five patients with other signs and symptoms of IHD, had AHA in their sera. An additional 2% of patients who suffered from AMI developed detectable antibody levels during a follow-up period of 15 days. In comparison,, 53% of patients (eight out of fifteen) who underwent heart surgery and who had no AHA prior to operation, developed these antibodies in their sera during 1-2 weeks following operation.     

Autoimmune haemolytic anaemia. VI. 51Chromium survival studies in patients with different kinds of warm autoantibodies

The results of ⁵¹Cr red cell survival and organ sequestration studies in seventysix patients with autoimmune haemolytic anaemia are described.

In patients with incomplete IgG and IgA warm autoantibodies increased red cell destruction to a varying degree and mainly spleen sequestration were found. In patients with IgM incomplete warm autoantibodies sequestration of red cells mainly in the liver was seen. Liver sequestration was also present in patients with cold agglutinins/haemolysis, sometimes accompanied by a significant spleen sequestration. In a number of patients with haemolytic autoantibodies, i.e. warm haemolysins and cold agglutinins/haemolysins, a biphasic ⁵¹Cr elimination curve was obtained. The cause of this type of survival curve is discussed.

In patients in whom a positive direct anticomplement test was the only serological abnormality a normal ⁵¹Cr red cell life-span was found.

     

Anti-beta1-adrenergic receptor autoantibodies in patients with chronic Chagas heart disease

Chronic Chagas heart disease (cChHD), a chronic manifestation of the Trypanosoma cruzi infection, is characterized by high antibody levels against the C-terminal region of the ribosomal P proteins (i.e. peptide R13, EEEDDDMGFGLFD) which bears similarity with the second extracellular loop of beta1-adrenergic receptor (beta1-AR, peptide H26R HWWRAESDEARRCYNDPKCCDFVTNR). Because it has not been demonstrated clearly that IgGs from cChHD patients bind to native human beta1-AR, the aim of this study was to investigate further the physical interaction between cChHD IgGs and the human beta1-AR. Immunofluorescence assays demonstrated the binding of these antibodies to the receptor expressed on stably transfected cells, together with a beta1-AR agonist-like effect. In addition, immunoadsorption of the serum samples from cChHD patients with a commercially available matrix, containing peptides representing the first and the second extracellular loop of the beta1-AR, completely abolished reactivity against the H26R peptide and the physiological response to the receptor. The follow-up of this specificity after in vitro immunoadsorption procedures suggests that this treatment might be used to diminish significantly the serum levels of anti-beta1-AR antibodies in patients with Chagas heart disease.     

自身免疫性肝病患者自身抗体检测及临床意义

目的 探讨自身免疫性肝病患者血清中出现的自身抗体等免疫学指标及临床意义.方法 对3 500例肝功能反复异常的患者采用间接免疫荧光法检测抗核抗体(ANA)、抗平滑肌抗体(SMA)、抗线粒体抗体(AMA).并对AMAM2型及抗可溶性肝抗原/肝胰抗原(抗SLA/LP)、抗肝肾微粒体抗体Ⅰ型(抗LKM-1)和抗肝特异性胞浆抗原Ⅰ型抗体(抗LC-1)等肝脏疾病相关的自身抗体进行检测.结果 3 500例患者中,自身免疫性肝炎患者29例,检出率为0.83%,其中符合Ⅰ型、Ⅱ型、Ⅲ型自身免疫性肝炎的比例占72.4%、10.3%和17.2%.原发性胆汁性肝硬化(PBC)患者58例,检出率为1.65%,血清中AMAM2型抗体阳性率为93.1%,其中19例AMAM2阳性患者进行肝穿病理检查时12例(63.7%)患者病理提示符合PBC诊断.结论 每种自身免疫性肝病都具有特征性自身抗体谱,注重自身抗体检测对明确诊断及鉴别诊断自身免疫性肝病具有重要的临床意义.     

Frequency of diabetes and thyroid autoantibodies in patients with autoimmune endocrine disease from Cameroon

BACKGROUND: Diabetes is a major cause of morbidity and mortality in both industrialized and developing countries. In Africa, there are little data on the prevalence and immunological features of patients with autoimmune endocrine diseases. AIM OF THE STUDY: The present hospital-based study was carried out to evaluate disease-associated autoantibodies in both type 1 diabetes and thyrotoxicosis attending the Central Hospital of Yaoundee in Cameroon. PATIENTS AND METHODS: Samples were collected from a total of 101 subjects, 47 of whom clinically had established type 1 diabetes (mean age 30.1 years +/- 7.6, mean disease duration 3.3 years), 18 had thyrotoxicosis (mean age 32.7 years +/- 7.6, mean disease duration 6.3 years +/- 2.8) and 36 normal subjects (mean age 26 years +/- 4.5). All subjects were tested for diabetes-associated glutamic acid decarboxylase (GAD) and tyrosine phosphatase (IA2) autoantibodies using antigen-specific radioimmunoassay as well as thyroiditis-associated thyroglobulin (Tg) and thyroid peroxidase (TPO) autoantibodies using commercially available kits. RESULTS: Of 47 patients with type 1 diabetes, 16 (34%) had GAD autoantibodies (Abs), 3 (6.4%) had IA2 Abs, and 2 (4.3%) had TPO Abs. Of 18 patients with thyrotoxicosis 4 (22.2%) had GAD Abs, 5 (27.8%) showed IA2 Abs, while 8 patients (44.4%) were TPO Abs positive. No patients in either group had Tg Abs. Among normal subjects, 2 (5.6%) showed GAD Abs, and one of these was also IA2 Abs positive, but none had thyroid autoantibodies. CONCLUSION: Adult-onset type 1 diabetic patients some years post-diagnosis from central Africa show GAD, IA2 or TPO Abs; and surprisingly, patients with thyrotoxicosis had a similar frequency of diabetes-associated autoantibodies. We conclude that, despite a different genetic and environmental background to European populations, islet cell autoimmunity is common in autoimmune endocrine patients in central Africa.     

Induction of immune complexes and autoantibodies to serotonin and dopamine in patients with Alzheimer's disease

Rats were exposed to systemic circulatory arrest for 10, 12, and 15 min. During the first 10 days after resuscitation exploratory activity of animals depended on the duration of systemic circulatory arrest and was determined by two opposite factors: high reactivity of the central nervous system contributing to intensification of exploratory activity, and impaired general state of survivors (inhibition of animal behavior).     

Clinical and molecular analysis of RASopathies in a group of Turkish patients

?im?ek‐Kiper PÖ, Alanay Y, Gülhan B, Lissewski C, Türky?lmaz D, Alehan D, Çetin M, Utine GE, Zenker M, Boduro?lu K. Clinical and molecular analysis of patients with RASopathies in Turkish patients. The ‘RASopathies’ are a group of disorders sharing many clinical features and a common pathophysiology. In this study, we aimed to clinically evaluate a group of Turkish patients and elucidate the underlying genetic etiology. Thirty‐one patients with a clinical diagnosis of one of the RASopathy syndromes were included in the study. Of these, 26 (83.8%) had a clinical diagnosis of Noonan syndrome, whereas 5 had a clinical diagnosis of either Costello, LEOPARD or cardio‐facio‐cutaneous syndromes. Twenty of 31 (64.5%) patients were found to be mutation positive. Mutations in PTPN11, SOS1 and SHOC2 genes were detected in patients with Noonan syndrome (57.6%). Mutations in MEK1, PTPN11, BRAF and HRAS genes were detected in the remaining. Pulmonary stenosis was the most common (61.5%) cardiac anomaly. Among Noonan syndrome patients with a confirmed mutation, mild intellectual disability tended to be more common in patients with PTPN11 mutation than in those with SOS1 mutation. Hematologic evaluation revealed coagulation defects in three Noonan syndrome patients with a mutation. This is currently the largest clinical and molecular study in Turkish RASopathy patients. Our findings indicate that molecular epidemiology and genotype–phenotype correlations in RASopathies are relatively independent from the ethnic population background.     

Autoimmune disease and malignant lymphoma associated with host-versus-graft disease in mice.

BALB/c mice neonatally injected with (BALB/c X C57BL/6)F1 hybrid spleen cells develop host-versus-graft disease (HVGD) with immunopathological features characteristic of either systemic lupus erythematosus (SLE), or immunoblastic lymphadenopathy (IBL) in man. HVGD mice manifest polyclonal hypergammaglobulinemia with various autoantibodies, generalized lymphadenopathy, hepatosplenomegaly, immune complex glomerulonephritis and evolve in the end to malignant lymphoma. The necessary prerequisite for HVGD induction between donor and host can be summarized as follows: Histoincompatibilities in the H-2 region between donor and host are needed; predominant F1 donor cells needed for HVGD induction are, if not sole, steroid resistant, nylon wool nonadherent and Thy-1 positive T cells; the role of donor T cells is not only to present H-2 complex to the host, but also to interact with and proliferate in the host; strain differences are found for the susceptibility of HVGD induction in the host. It has been found that HVGD evolves to a malignant lymphoma of host T cell origin. The HVGD mouse model may, therefore, contribute to the understanding of the cell to cell interactions at work in the pathogenesis of IBL, as well as SLE, in man.     

Anticentromere autoantibodies in patients without Raynaud's disease or systemic sclerosis

Anticentromere autoantibodies (ACA) are associated with Raynaud's disease and systemic sclerosis (SSc). ACA usually bind at least one of three major centromere proteins (CENPs), particularly CENP-B. We identified 16 patients with ACA who do not have Raynaud's disease or SSc. The objective of this study was to determine whether these 16 ACA differ in antigenic specificity from the ACA found in patients with Raynaud's disease or SSc. Binding of these serum ACA was tested using competition experiments with recombinant CENP-B, and native centromere proteins from HEp-2 cells and HeLa nuclear extracts in ELISAs, immunoblots, and indirect immunofluorescence assays. The ACA from these 16 patients are strikingly different from those obtained from patients who have Raynaud's disease or SSc. Only 5 of the 16 index sera (31.25%) bound CENP-B from two or more different sources by at least two methods. Six of these 16 sera (37.5%) did not bind CENP-B on ELISA, and 8 of 16 (43.75%) did not bind CENP-B on immunoblots. Three sera did not bind CENP-B either by ELISA or immunoblots. Of the 13 sera that bound CENP-B, their patterns of binding to CENP-B strongly suggested that they bind different epitopes within the CENP-B antigen. Independently of their binding to CENP-B, these sera reacted mainly with minor CENP antigens detected by HeLa nuclear extracts. We have identified unusual ACA not associated with Raynaud's disease or SSc.     

Anti-MOG autoantibodies in Italian multiple sclerosis patients: specificity, sensitivity and clinical association

There is considerable evidence that multiple sclerosis (MS) is an immune-mediated disease characterized by infiltration of inflammatory cells into the CNS and demyelination. Several myelin proteins may be encephalitogenic, including myelin basic protein, proteolipid protein and myelin oligodendrocyte glycoprotein (MOG), the latter being expressed on the external layer of myelin sheaths and hence accessible to antibody attack. We investigated MOG autoreactivity in serum and cerebrospinal fluid (CSF) by ELISA, employing the recombinant extracellular domain of MOG as antigen. We tested serum samples from 262 MS patients (175 relapsing-remitting, 43 primary progressive and 44 secondary progressive), 131 patients with other neurological diseases (OND) and 307 healthy controls. No patients or controls were receiving immunomodulating treatments. We found anti-MOG antibodies in the serum of 13.7% MS patients, mainly in those with secondary progressive MS (25%), in 13.7% of OND patients and in 6.2% of controls. We found a direct correlation (R(2) = 0.6, P = 0.002) between disease severity and anti-MOG titer only in patients with primary and secondary progressive MS. Anti-MOG antibodies were present in the CSF of 11.4% MS patients and 18.9% OND patients. Intrathecal synthesis of anti-MOG antibodies was demonstrated in four (4.5%) of MS patients and no OND patients. Anti-MOG antibodies are not specific for MS; however, they may characterize a subset of MS patients and this may be revealed by serial assays in relation to changing disease phase.     

Epitopes of calreticulin recognised by IgA autoantibodies from patients with hepatic and coeliac disease

Calreticulin (CRT) was identified as a frequent target of serum autoantibodies (Ab) in various diseases, but anti-CRT Ab of IgA isotype were described only in coeliac (CLD) and some hepatic diseases. Employing ELISA with recombinant CRT we found significantly higher (P<0.001) levels of IgA anti-CRT Ab in sera of patients with primary biliary cirrhosis (PBC) (77.6+/-8.9 AU/mean+/-SE), autoimmune hepatitis (AIH) (105.1+/-9.2 AU) and alcoholic liver cirrhosis (ALC) (193.5+/-21.0 AU) relative to healthy controls (38.6+/-2.0 AU). The levels of IgG anti-CRT Ab in sera of patients with PBC (59.5+/-3.4 AU), AIH (89.7+/-7.9 AU) and ALC (86.4+/-6.2 AU) were also significantly increased (P<0.001) when compared with controls (38.5+/-2.1 AU). Pepscan technique with decapeptides of CRT (each overlapping by eight amino acids) revealed antigenic epitopes of this molecule recognised by IgA Ab of almost all tested patients-KGKNVLINKD and QVKSGTIFDNFL. We also identified disease specific antigenic epitopes on CRT molecule, predominantly recognised by IgA Ab of patients suffering from a particular disease: GGYVKLFPNS and YVKLFPNSLD in AIH (83%, 92% of patients), GLQTSQDARF and EQRLKEEEED in CLD (both 75%) and ASKPEDWDER in ALC (67%). Identification of disease specific CRT epitopes contributes to clarification of autoreactivity against this molecule.