Myocardial lesions by Coxsackie virus B3 and cytomegalovirus infection in infants

Successful treatment of fulminant myocarditis with intra-aortic balloon pump counterpulsation combined with immunoglobulin and glucocorticoid in a young male adult

Background

Fulminant myocarditis (FM) is a serious non-specific inflammatory disease of the myocardium. FM tends to occur in adolescents and the course of the disease progresses rapidly. It is prone to cardiogenic shock (CGS) and multiple organ failure (MOF) with high mortality. We report a case of FM with CGS and MOF in a young male who was successfully treated with intra-aortic balloon pump counterpulsation (IABP) combined with intravenous immunoglobulin (IVIG) and glucocorticoid (GC).

Case summary

A 21-year-old previously healthy man presented with fever, headache, and chest tightness. He came to the hospital for emergency treatment. The laboratory data showed that the levels of serum cardiac troponin I (cTnI), N-terminal B-type natriuretic peptide (NT-proBNP), myocardial zymogram, and neutrophils increased. Echocardiography showed pericardial effusion and decreased left ventricular systolic function. ECG showed diffuse ST-segment elevation. He was clinically diagnosed with FM and admitted to the intensive care unit for treatment. Within 48 h of admission, the clinical course of the patient deteriorated rapidly, with CGS accompanied by MOF, high atrioventricular block (AVB), and ventricular tachycardia (VT). After using mechanical circulatory support (MCS) therapy with IABP, IVIG, GC, continuous renal replacement therapy (CRRT), and mechanical ventilation complicated with a temporary cardiac pacemaker, he recovered normal cardiac function. He made a full recovery and was discharged home on day 21.

Discussion

For patients with FM, early diagnosis, close monitoring, timely use of MCS devices, and active comprehensive treatment are very important. MCS devices such as IABP can become lifesaving tools for the treatment of FM.

Assessment of Coronary Inflammation by Pericoronary Fat Attenuation Index in Clinically Suspected Myocarditis with Infarct-Like Presentation

Background: The pathophysiology of angina-like symptoms in myocarditis is still unclear. Perivascular fat attenuation index (pFAI) by coronary computed tomography angiography (CCTA) is a non-invasive marker of coronary inflammation (CI) in atherosclerosis. We explored the presence of CI in clinically suspected myocarditis with infarct-like presentation. Methods: We retrospectively included 15 consecutive patients (67% male, age 30 ± 10 years) with clinically suspected infarct-like myocarditis who underwent CCTA to rule out coronary artery disease. Right coronary artery (RCA) pFAI mean value was compared with that of healthy volunteers. Results: Mean RCA pFAI value was −92.8 ± 8.4 HU, similar to that of healthy volunteers (−95.2 ± 6.0, p = 0.8). We found no correlation between RCA pFAI mean values and peak Troponin I (r = −0.43, p = 0.11) and C-reactive protein at diagnosis (r = −0.25, p = 0.42). Patients with higher pFAI values showed higher biventricular end-systolic volumes (ESV) (p = 0.038 for left and p = 0.024 for right ventricle) and lower right ventricular ejection fraction (RVEF) (p = 0.038) on cardiovascular magnetic resonance. Conclusions: In clinically suspected myocarditis with infarct-like presentation, RCA pFAI values are lower than those validated in atherosclerosis. The correlation between higher pFAI values, higher biventricular ESV and lower RVEF, may suggest a role of pFAI in predicting non-atherosclerotic CI (i.e., infective/immune-mediated “endothelialitis”).

Infectious myocarditis: the role of the cardiac vasculature

Infectious myocarditis is the result of an immune response to a microbial infection of the heart. The blood vessels of the heart, both the intramyocardial microvasculature and the large epicardial coronary arteries, play an important role in the pathogenesis of infectious myocarditis. First of all, in addition to cardiomyocytes, endothelial cells of the cardiac (micro)vasculature are direct targets for infection. Moreover, through the expression of adhesion molecules and antigen presenting Major Histocompatibility Complex molecules, the blood vessels assist in shaping the cellular immune response in infectious myocarditis. In addition, damage and dysfunction of the cardiac (micro)vasculature are associated with thrombus formation as well as aberrant regulation of vascular tone including coronary vasospasm. These in turn can cause cardiac perfusion abnormalities and even myocardial infarction. In this review, we will discuss the role of the cardiac (micro)vasculature in the pathogenesis of infectious myocarditis.

My approach to performing a perinatal or neonatal autopsy

An opportunity to determine the cause of death, factors that may have a role in it, and the extent and cause of malformations is provided by perinatal autopsy. The family may be assisted in finding closure after the death of their infant by the information obtained. Insight into classifying infants appearing normal into one of three groups, small, appropriate and large for gestational age, has been provided, as each group tends to have specific causes of death. In infants with congenital anomalies, patterns of malformation may lead us to the diagnosis. An accurate diagnosis is required to provide counselling for a subsequent pregnancy.

Probable intrafamilial transmission of coxsackievirus b3 with vertical transmission, severe early-onset neonatal hepatitis, and prolonged viral RNA shedding

Here we report a familial cluster of 3 cases of coxsackievirus B3 infection: a recent history of illness in a woman's 3-year-old son with a coxsackievirus B3-positive stool culture indicated that he probably infected his mother at home during her last week of pregnancy. Consequently, she delivered an infected neonate who developed severe hepatitis, disseminated intravascular coagulation, and bilateral intracranial hemorrhage. The neonate remained well for the first 2 days of life. On the third day, he developed fever (39 degrees C) and poor peripheral circulation. On the fourth day, he developed petechiae and bruises over his chest wall and extremities, and prolonged bleeding was observed over venipuncture sites. Investigations revealed severe thrombocytopenia (platelets: 41 x 10(9)/L) and a markedly deranged coagulation profile (prothrombin time: 19 seconds [reference: < 10 seconds]; activated partial thromboplastin time: > 120 seconds [reference: 24.2-37.0 seconds], serum D-dimers: 6722 ng/mL [reference: < 500 ng/mL]), suggestive of disseminated intravascular coagulopathy. Clinical examination revealed yellow sclera, hepatomegaly (5 cm), and splenomegaly (2 cm), consistent with hepatitis. Serial chest radiographs showed bilateral pleural effusions, and an ultrasound of the abdomen demonstrated ascites. An echocardiogram showed normal cardiac structure and good contractility of both ventricles. However, a cranial ultrasound revealed bilateral grade 2 intraventricular hemorrhages. Serum C-reactive protein increased to 33.9 mg/L. Liver-function tests were also markedly deranged at this time, with maximum values for serum alanine transferase, bilirubin, alkaline phosphatase, and ammonia concentration of 1354 IU/L, 258 micromol/L, 189 IU/L, and 147 micromol/L, respectively. Serum glucose levels were normal. Over the next 3 days, his fever subsided, and his liver function and clotting profile normalized by day 13 after onset of illness. A stool sample from the older brother, collected 14 days after his onset of illness at home, was positive for coxsackievirus B3 by both virus culture and enterovirus reverse-transcription polymerase chain reaction. He had neutralizing coxsackievirus B3 antibody titers of 1:2560 and 1:1280 on days 14 and 28 after his onset of illness, respectively. No virus was cultured from the mother's stool sample, collected 5 days after her onset of illness, but the enterovirus polymerase chain reaction was positive and maternal sera neutralized the coxsackievirus B3 isolated from the neonate. The maternal sera also showed a more than fourfold rise in antibody titer from 1:80 to 1:640 on days 5 and 16 after her onset of illness, respectively. Neonatal antibody titers also showed a more than fourfold rise from < 1:80 to 1:2560 on days 1 and 21 after his onset of illness, respectively. This demonstrates that both the mother and the neonate had had recent coxsackievirus B3 infections. Serially collected neonatal throat swab and stool samples were culture negative for enterovirus by 4 and 8 days after his onset of illness, respectively. However, enterovirus RNA remained detectable by reverse-transcription polymerase chain reaction in these samples for considerably longer, only becoming undetectable by 16, 23, and 41 days after his onset of illness. We show that even mild household infections may have potentially serious consequences for pregnant women and their infants.

Viral susceptibility of an immortalized human microvascular endothelial cell line

CDC/EU.HMEC-1 is the first immortalized human microvascular endothelial cell line that retains morphologic, phenotypic, and functional characteristics of a normal human microvascular endothelial cell. This study evaluates a variety of viruses and their effects on this human endothelial cell line. The data indicate that adenoviruses, some herpesviruses, reoviruses and most picornaviruses grow well in HMEC-1, with distinctive cytopathic effects. The paramyxoviruses, however, do not appear to propagate, nor does HIV. The findings indicate that microvascular endothelial cells may act as a reservoir of these viruses; it also suggests the possibility that microvascular endothelium could be involved in the processing and presentation of antigen to immune cells.

Cytomegalovirus-induced pneumonitis and myocarditis in newborn mice. A model for perinatal human cytomegalovirus infection

Genetically determined resistance to the lethal effects of infection with murine cytomegalovirus (MCMV) has been reported previously in adult and newborn mice. We examined the pathogenesis of MCMV infection in resistant (CBA, H-2k) and susceptible (BALB/c, H-2d) mice infected intraperitoneally on the day of birth. BALB/c mice developed a severe interstitial pneumonitis and myocarditis 10 days post-infection. Their pulmonary and tissues contained high MCMV titres and large numbers of MCMV-antigen positive cells. MCMV also infected the endothelial and myointimal cells of the coronary arteries in newborn BALB/c mice. Only limited infection and pathological changes were seen in CBA mice. Since the severe disease in BALB/c mice resembles the pneumonitis and less frequently reported myocarditis observed after perinatal HCMV infection, the newborn mouse model will be useful for studying the consequences and treatment of such infections, the influence of the host genotype on disease severity and the possible association between perinatal HCMV infection and atherosclerosis.