Mitochondrial DNA (mtDNA) mutations have been causally linked with cardiomyopathies, both dilated (DCM) and hypertrophic. We identified the T12297C mutation in the mtDNA-tRNA(Leu(CUN)) of a 36-year-old male patient diagnosed with DCM. The mutation was heteroplasmic, with high amount (88%) of mutant DNA in the myocardium, and was absent in normal (n = 120) and disease (n = 150) controls. It affects a highly conserved nucleotide (adjacent to the anticodon triplet) that allows the phospho-ribose backbone to turn and form the loop. The potential pathological role of T12297C mutation is further supported by its recent identification in another unrelated Italian family with DCM associated with endocardial fibroelastosis. In the variable loop of the same tRNA, our patient also carried the A12308G transition that is debated as pathological mutation or neutral polymorphism in progressive external ophthalmoplegia: the two defects could exert a synergistic effect on the tRNA structure and function. The endomyocardial biopsy study showed abnormal ring-like mitochondria and occasional cytochrome c oxydase negative myocytes. Overall, the heteroplasmy, the highly conserved position of the mutated nucleotide, the absence of the mutation in large series of diseased and normal controls, and the cardiac mitochondrial changes support a causative link of the mutation with the disease.

Adult↗

PubMed2001

Evidence-based diagnosis of familial non-X-linked dilated cardiomyopathy. Prevalence, inheritance and characteristics.

AIMS: To assess the prevalence of familial non-X-linked dilated cardiomyopathy, to diagnose early asymptomatic cases evaluate inheritance and characterize clinical phenotypes. METHODS AND RESULTS: We screened 472 relatives of 104 consecutive patients diagnosed with dilated cardiomyopathy; males with X-linked dilated cardiomyopathy were excluded based on systematic immunohistochemical and molecular analysis. Relatives underwent clinical examination, electrocardiography, echocardiography and serum creatine-phosphokinase determination. Twenty-six index patients (25%) had familial disease: four youths (< or = 20 years) had rapidly progressive outcome and underwent emergency transplantation. In a sib-pair, the onset was with atrioventricular block. Inheritance was autosomal dominant in 15, undetermined in seven (four sib-pairs); mitochondrial DNA pathological mutations were found in four. The screening identified 23 newly diagnosed relatives in the familial group. Transplantation (P = 0.04) and atrial fibrillation (P = 0.04) were more frequent, and left bundle branch block (P = 0.04) less frequent in index patients with familial than in those with non-familial disease. Several non-affected relatives had instrumental abnormalities potentially useful as pre-clinical markers: their prevalence was similar in both groups. CONCLUSIONS: The prevalence of familial, non X-linked dilated cardiomyopathy was 25%. The immediate benefits of screening family members of index patients was early diagnosis in unaware symptomless affected relatives.

Adult↗

PubMed2000

Prevalence and characteristics of dystrophin defects in adult male patients with dilated cardiomyopathy.

OBJECTIVES: To assess the prevalence of dystrophin defects in dilated cardiomyopathy (DCM) in male patients and to formulate investigation strategies for their identification. BACKGROUND: Dystrophin defects presenting with predominant or exclusive cardiac involvement may be clinically indistinguishable from "idiopathic" DCM. Diagnosis may be missed, unless specifically investigated. METHODS: Clinical and biochemical evaluation, right ventricular endomyocardial biopsy (EMB), light and electron microscopic and immunohistochemical studies of biopsy samples, six multiplex and two single polymerase chain reactions for 38 exons and automated sequencing of exon 9 and muscle promoter-exon 1 were undertaken in 201 consecutive male patients presenting with DCM, with (n = 14) and without (n = 187) increased serum creatine phosphokinase (sCPK). RESULTS: Dystrophin defects were identified in 13 of the 201 patients (6.5%, age 16-50). Family history was positive in four patients. Serum CPK levels were increased in 11 of 13 patients. Light microscopy examination of EMB was uninformative; ultrastructural study showed multiple membrane defects. Dystrophin immunostain was abnormal. Eight patients, all older than 20, had deletions affecting midrod domain, normal or mildly increased CPK and better outcome than the five remaining cases all younger than 20, with more than five-fold increase of sCPK. Two of these latter had proximal and rod-domain deletions. Sisters of two patients were diagnosed as noncarriers with microsatellite analysis. CONCLUSIONS: Although the overall prevalence of dystrophin defects in our consecutive DCM male series is low (6.5%), immunohistochemical and molecular studies are essential to identify protein and gene defects; screening studies are justified to define prevalence, clinical profile and genotype-phenotype correlation.

Adolescent↗

PubMed2000

Enteroviral infection causing fatal myocarditis and subclinical myopathy.

UNLABELLED: Enteroviral RNA detection in myocarditis and dilated cardiomyopathy is rare. Enteroviral particles and RNA have recently been identified in patient's skeletal muscle, suggesting that skeletal more than heart muscle hosts the virus in chronic infection. Enteroviral RNA and virus-like particles were found in the myocardium and in the skeletal muscle of two patients with fatal myocarditis: a 39 year old man who died five days after the onset of febrile flu; and a 49 year old woman, assisted for 50 days with a left ventricular assist device, who then died from cerebral haemorrhage. Automated sequencing, alignment, and sequence comparison confirmed the enteroviral origin of polymerase chain reaction products and excluded contamination. These findings agree with prior observations of enteroviral localisation in the skeletal muscle of patients with dilated cardiomyopathy, and further support the hypothesis that skeletal rather than heart muscle may host the virus and serve as a reservoir in cardiomyopathies related to chronic infection. KEYWORDS: enterovirus; myocarditis; viral particles; skeletal muscle

Adult↗

PubMed2000

Central precocious puberty: clinical and imaging aspects.

We review briefly the definition of central precocious puberty (CPP), and discuss early puberty and very early puberty. The association of hypothalamic hamartoma and empty sella with CPP is described. The contribution of new imaging techniques - CT, MRI and ultrasound in the differential diagnosis of CPP is discussed.

Brain Diseases↗

PubMed1999

Bronchiolitis obliterans with organizing pneumonia (BOOP), presenting as a ring-shaped opacity at HRCT (the atoll sign). A case report.

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Cryptogenic Organizing Pneumonia↗

PubMed1998

Evidence that amyloidogenic light chains undergo antigen-driven selection.

AL amyloidosis is characterized by fibrillar tissue deposits (amyloid) composed of monoclonal light chains secreted by small numbers of indolent bone marrow plasma cells whose ontogenesis is unknown. To address this issue and to provide insights into the processes that accompanied pathogenic light chain formation, we isolated the complete variable (V) regions of 14 light (VL) and 3 heavy (VH) chains secreted by amyloid clones at diagnosis (10 Bence Jones and 4 with complete Igs, 9 lambda and 5 kappa) by using an inverse polymerase chain reaction-based approach free of primer-induced biases. Amyloid V regions were found to be highly mutated compared with the closest germline genes in the databases or those isolated from the patients' DNA, and mutations were not associated with intraclonal diversification. Apparently high usage of the lambdaIII family germline gene V lambdaIII.1 was observed (4 of 9 lambda light chains). Analysis of the nature and distribution of somatic mutations in amyloid V regions showed that there was statistical evidence of antigen selection in 8 of 14 clones (7 in VL and 1 in VH). These results indicate that a substantial proportion of the amyloid clones developed from B cells selected for improved antigen binding properties and that pathogenic light chains show evidence of this selection.

Aged↗

PubMed1998

Mitochondrial DNA mutations and mitochondrial abnormalities in dilated cardiomyopathy.

Mitochondrial (mt)DNA defects, both deletions and tRNA point mutations, have been associated with cardiomyopathies. The aim of the study was to determine the prevalence of pathological mtDNA mutations and to assess associated defects of mitochondrial enzyme activity in dilated cardiomyopathy (DCM) patients with ultrastructural abnormalities of cardiac mitochondria. In a large cohort of 601 DCM patients we performed conventional light and electron microscopy on endomyocardial biopsy samples. Cases with giant organelles, angulated, tubular, and concentric cristae, and crystalloid or osmiophilic inclusion bodies were selected for mtDNA analysis. Mutation screening techniques, automated DNA sequencing, restriction enzyme digestion, and densitometric assays were performed to identify mtDNA mutations, assess heteroplasmy, and quantify the amount of mutant in myocardial and blood DNA. Of 601 patients (16 to 63 years; mean, 43.5 +/- 12.7 years), 85 had ultrastructural evidence of giant organelles, with abnormal cristae and inclusion bodies; 19 of 85 (22.35%) had heteroplasmic mtDNA mutations (9 tRNA, 5 rRNA, and 4 missense, one in two patients) that were not found in 111 normal controls and in 32 DCM patients without the above ultrastructural mitochondrial abnormalities. In all cases, the amount of mutant was higher in heart than in blood. In hearts of patients that later underwent transplantation, cytochrome c oxidase (Cox) activity was significantly lower in cases with mutations than in those without or controls (P = 0.0008). NADH dehydrogenase activity was only slightly reduced in cases with mutations (P = 0.0388), whereas succinic dehydrogenase activity did not significantly differ between DCM patients with mtDNA mutations and those without or controls. The present study represents the first attempt to detect a morphological, easily identifiable marker to guide mtDNA mutation screening. Pathological mtDNA mutations are associated with ultrastructurally abnormal mitochondria, and reduced Cox activity in a small subgroup of non-otherwise-defined, idiopathic DCMs, in which mtDNA defects may constitute the basis for, or contribute to, the development of congestive heart failure.

Adolescent↗

PubMed1998

Coexistence of mitochondrial DNA and beta myosin heavy chain mutations in hypertrophic cardiomyopathy with late congestive heart failure.

OBJECTIVE: To investigate the possible coexistence of mitochondrial DNA (mtDNA) mutations in patients with beta myosin heavy chain (beta MHC) linked hypertrophic cardiomyopathy (HCM) who develop congestive heart failure. DESIGN: Molecular analysis of beta MHC and mtDNA gene defects in patients with HCM. SETTING: Cardiovascular molecular diagnostic and heart transplantation reference centre in north Italy. PATIENTS: Four patients with HCM who underwent heart transplantation for end stage heart failure, and after pedigree analysis of 60 relatives, eight additional affected patients and 27 unaffected relatives. A total of 111 unrelated healthy adult volunteers served as controls. Disease controls included an additional 27 patients with HCM and 102 with dilated cardiomyopathy. INTERVENTION: Molecular analysis of DNA from myocardial and skeletal muscle tissue and from peripheral blood specimens. MAIN OUTCOME MEASURES: Screening for mutations in beta MHC (exons 3-23) and mtDNA tRNA (n = 22) genes with denaturing gradient gel electrophoresis or single strand conformational polymorphism followed by automated DNA sequencing. RESULTS: One proband (kindred A) (plus seven affected relatives) had arginine 249 glutamine (Arg249Gln) beta MHC and heteroplasmic mtDNA tRNAIle A4300G mutations. Another unrelated patient (kindred B) with sporadic HCM had identical mutations. The remaining two patients (kindred C), a mother and son, had a novel beta MHC mutation (lysine 450 glutamic acid) (Lys450Glu) and a heteroplasmic missense (T9957C, phenylalanine (Phe)-->leucine (Leu)) mtDNA mutation in subunit III of the cytochrome C oxidase gene. The amount of mutant mtDNA was higher in the myocardium than in skeletal muscle or peripheral blood and in affected patients than in asymptomatic relatives. Mutations were absent in the controls. Pathological and biochemical characteristics of patients with mutations Arg249Gln plus A4300G (kindreds A and B) were identical, but different from those of the two patients with Lys450Glu plus T9957C(Phe-->Leu) mutations (kindred C). Cytochrome C oxidase activity and histoenzymatic staining were severely decreased in the two patients in kindreds A and B, but were unaffected in the two in kindred C. CONCLUSIONS: beta MHC gene and mtDNA mutations may coexist in patients with HCM and end stage congestive heart failure. Although beta MHC gene mutations seem to be the true determinants of HCM, both mtDNA mutations in these patients have known prerequisites for pathogenicity. Coexistence of other genetic abnormalities in beta MHC linked HCM, such as mtDNA mutations, may contribute to variable phenotypic expression and explain the heterogeneous behaviour of HCM.

Adult↗

PubMed1997

Enteroviral RNA and virus-like particles in the skeletal muscle of patients with idiopathic dilated cardiomyopathy.

The role of chronic viral infection in the etiopathogenesis of idiopathic dilated cardiomyopathy (IDC) has generated considerable research. Enteroviruses were the favorite candidates as etiologic agents of IDC. However, enteroviruses were rarely demonstrated in affected hearts. We investigated whether enteroviral infection persists in the heart and in extracardiac sites, particularly in skeletal muscle, in patients with IDC. Blood and myocardial and skeletal muscle samples were collected at cardiac transplantation from 31 IDC patients, 24 non-IDC heart disease patients, and 3 heart donors. Samples underwent ultrastructural studies and ribonucleic acid (RNA) extraction. RNA was reverse-transcribed, and 2 nested fragments (bps 179 and 126) were amplified in the highly conserved 5' noncoding region of enteroviral genomic RNA. Enteroviral RNA was found in the skeletal muscle of 12 cases, whereas only 4 hearts (2 of which with positive skeletal muscle) were positive. Of the 24 controls, 2 were positive (1 muscle and heart, 1 muscle only). Automated sequencing confirmed the enteroviral nature of the amplified products. Ultrastructural study showed enterovirus-like particles in 4 of the enterovirus-positive muscles, and myopathic changes in all enterovirus-positive cases. Skeletal muscle hosts chronic enteroviral infection in more than one third of patients with sporadic IDC. Two hypotheses may explain this link. Myocardial damage may derive directly from recurrent subclinical heart infections caused by enteroviruses harbored in skeletal muscle. Alternatively, enterovirus-related myopathy may trigger an autoimmune response to antigens shared by muscle and myocardium. Further studies are needed to assess the importance of these, non-mutually exclusive mechanisms in IDC pathogenesis.

Adult↗

PubMed1997

Ten-year experience with endomyocardial biopsy in myocarditis presenting with congestive heart failure: frequency, pathologic characteristics, treatment and follow-up.

The present study summarizes our ten-year (1985-1995) experience with endomyocardial biopsy (EMB) in patients with idiopathic congestive heart failure (CHF), with specific reference to frequency of myocarditis, treatment policy, relative benefits, and follow-up. Of the 601 patients who constituted our series, 38 were clinically suspected of having myocarditis on the bases of a very recent onset of congestive heart failure and/or of arrhythmias and/or of conduction disturbances, and of a close-to-recent history of flu-like febrile illness. Corresponding EMBs showed myocarditis in 16 of the 38 cases (42.1%). A further 10 EMBs, from patients with a recent onset of congestive heart failure without prior infection episodes, showed myocarditis. Therefore, biopsy-proven myocarditis occurred in 26 of the 601 patients (4.3%). Of the 26 cases, 21 were lymphocytic, 1 was necrotizing granulomatous, 1 was eosinophilic and occurred in a patient who later developed overt zoonosis, 1 had some giant cells within endocardial inflammatory infiltrates, and 2 were borderline forms. In active myocarditis, inflammatory cells mostly constituted of T-lymphocytes (CD45RO+) with sparse macrophages (CD68+) and a few B cells (CD20+). B-lymphocytes and macrophages, along with activated T-lymphocytes, all expressed MHC class II HLA DR molecules, which were also expressed "de novo" by activated endothelial calls of capillaries and of small intramural vessels. HLA DR revealed itself as a very useful marker for the detection of activated inflammatory and endothelial cells. We also noted an increase in the number of perivascular and interstitial mast cells. Ultrastructural study was helpful for the characterization of myocyte damage and of interactions between inflammatory cells and myocytes. In 4 cases (1 of whom was later revealed as HIV positive, and subsequently died of AIDS), we found microreticulotubular structures in endothelial cells of small vessel and capillaries; in 7 cases, there were myocyte changes similar to those described in polymyositis; in 1 case, we observed subplasmalemmal buddings, but no viral particles; in 6 cases, there was extensive myocyte damage with myofibrillar lysis and focal adipous metaplasia; the remaining 6 cases showed myocyte damage of differing extent and severity; in the borderline forms, such damage coexisted with interstitial fibrosis. One of the 21 lymphocytic myocardites was not treated because during hospital screening the patient proved to be HIV positive; of the remaining 20 active myocardites, 11 were treated with a 6-month tapered steroid and azathioprine protocol (one was treated for 24 months), while 9 were not treated. The corresponding follow-up was: 6 deaths (congestive heart failure), 2 cardiac transplants and 3 survivals (1 with pace-maker) in the treated group, and 3 deaths (2 of congestive heart failure and 1 of sudden death), 1 cardiac transplant and 5 survivals (1 on the waiting list for transplantation) in the non-treated group. One of the 2 patients with borderline myocarditis died of congestive heart failure, and 1 is alive. Of the 22 patients with clinical diagnosis of myocarditis and negative biopsy, 7 died of congestive heart failure (2 on the waiting list for transplantation), 4 underwent cardiac transplantation, and 11 are alive (1 is awaiting transplantation). Of the 20 patients currently alive, 1 was originally in NYHA class III, 15 were in class II and 4 were in class I. Of the 20 overall patients who died, 12 were originally in NYHA class IV, 6 in class III, 2 in class II; of the 8 patients who underwent transplantation, 6 were originally in NYHA class IV and 2 in class III. Our overall experience shows that the frequency of myocarditis diagnosed according to Dallas criteria is high in patients with clinical diagnosis of myocarditis, while it is extremely low in dilated cardiomyopathy patients. This finding suggests that, although non-specific, recent onset of symptoms and prior febrile infe

Adolescent↗

PubMed1997

Acute rejection and heart infection rates in FK 506- versus cyclosporine A-treated heart transplant recipients: an endomyocardial biopsy pathologic study.

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Adult↗