| Hypertrophic cardiomyopathy is a sarcomere disease of myocardium, it can be caused by several genes and it is an autosomal-dominant inherited disease characterized by heterogeneity of clinical coures and genotype.Myocardial hypertrophy and disarray are common in this disorder.The pathophysiology of hypertrophic cardiomyopathy is complex,with a number of different processes contributing to the symptoms and natural history.It consists of abnormal diastolic function, myocardial ischemia,outflow tract obstruction,mitral regurgitation, arrhythmias.The clinical course is heterogeneous.Many patients remain asymptomatic throughout life,some represent chest distress,palpitation, others develop severe heart failure,syncope,malignant ventricular arrhythmia or atrial fibrillation with embolism,and some die suddenly, often at a young age and in the absence of previous symptoms.The overall annual mortality rate associated with HCM is only 1%, and about 10%develop severe dilated cardiomyopathy.The prevalence of the disease is estimated to be as high as 0.2%in the general population. Previous echocardiographic screening studies in China have estimated that the prevalence of HCM is about 0.16%,suggesting that at least 1 million cases exist in China.However,it is generally acknowledged that in most cardiology practices relatively few patients with HCM are diagnosed,and many patients miss clinical recognition,including some at high risk for sudden death.So,it is important for internists and general practitioners to be aware of the clinical features of the disease and there is considerable significance for those patients'prognosis if early diagnosis and early treatment are fulfilled.Cardiac troponin I(cTnI),a regulatory protein unique to heart muscle which regulate its function,has compacted correlation with cardiac function.It is released to the bloodstream after myocardial necrosis.The exposed cTnI can activate the immune system resulting in the production of cTnI autoantibodies and reside in the circulation for long term.As reported that cTnI autoantibodies can be detected in the serum of myocardial infarction patients.Experimental animal studies show that cTnI autoantibodies can active the calcium channel of L-form chronically and elevate the level of intracellular Ca2+,suggesting that autoantibodie of cTnI could be involved in myocardial damage.From the last century,autoantibodies are suspected to be involved in the pathogenesis of DCM,for the first,D(o|¨)rffel et al.demonstrated clinical and hemodynamic improvement after a short course of immunoadsorption that led to a decline in immunoglobulin levels, otherwise,Haim S et al found that IgG antibodies to cTnI are increased in a significant number of patients with both ICM and idiopathic DCM,all those may point to the involvement of autoantibodies in the pathogenesis of DCM although the concret mechanism of action has not been resolved.To study if the autoantibody of cTnI participate the etiopathogenisis of HCM we evaluate the serum anti-cTnI antibody levels among those patients.Aims:1 To analyse the Patients with Hypertrophic Cardiomyopathy in the region of Nanjing.2 To evaluate the serum cTnI autoantibodies level in the Hypertrophic Cardiomyopathy patients.Methods:1 Enrolled the testees of 121 referred patients with HCM evaluated at the First Affiliated Hospital of Nanjing Medical University,Jiangsu province,China,from July of 2000 to April of 2007.The diagnosis is based on the check of echocardiogram,i.e.echocardiogram shows myocardial hypertrophy more than 13mm and precluded high blood pressure or other disease that could result in ventricular hypertrophy.2 A sandwich ELISA method detecting cTnI autoantibodies was established with human cTnI and mouse anti-human IgG.Test the effect of this method by detecting mouse anti-human antibodies of different concentrations.All the serum cTnI autoantibodies of the testees (Hypertrophic Cardiomyopathy group and healthy control group)were measured by ELISA.Set the mean±3SD obtained from the healthy control to define positive for each group.Results:1 Among those 121 patients with HCM,96(79.3%)were diagnosed by the trigger of clinical symptom,others(20.7%)are not based on clinical symptom,of the total,10(8.3%)are because of abnormal ECG results of routine medical examination,15(12.4%)are by Family screening.The majority of the patients were male(60%).The age of onset was mainly concentrated between 30 and 60 years old.Among 105 patients' available ECG records and 56 Holter ECG results,we recognized arrhythmia in 54(51.4%)patients.26 of those patients presented left ventricular outflow tract gradient(LVOTG)≥30mmHg.Among the 26 patients;Among patients without any clinical symptoms,contrast to younger,the older are more easily got diagnosis clue by ECG examination and Family screening(15%vs 10%),especially by ECG examination(23%vs7%, p=0.02).2 The mean value of the serum cardiac troponin I autoantibodies of the healthy control group was 0.53±0.19(max 0.89,min 0.28),the positive value is 1.10.And the hypertrophic Cardiomyopathy group was 0.81±0.36(max 2.00,min 0.27),13(15.5%)samples of HCM patients are positive.Purificate the serum sample of high autoantibody with Protein A then evaluate again,we found the serum anti-cTnI antibody levels breakdown significant with times and stay at a level in the end,While elute the material from Protein A and evaluate the antibody levels,the result step up highly.By SDS-PAGE,the material of the elution's molecular weight concentrated around 25KD and 25KD,just like the molecular weight of light chain and heavy chain of IgG.Conclusions:1 Among 121 patients with HCM,96(79.3%)are diagnosed with the presentation of cardiac symptoms.81.8%cardiac hypertrophy affects the interventricular septum.The age of onset was mainly concentrated between 30 and 60 years old.A subset of 53 highrisk patients(43.8%) were identified.2 The method of ELISA which evaluates the serum cTnI autoantibodies level is stable,and 13(15.5%)HCM patients in our study showed high titer of antibody.
|
PDF Full Text Request