Parvovirus B19 Myocarditis: Looking Beyond the Heart.

Human parvovirus B19 represents the most common etiology of myocarditis in the pediatric population. Although it usually causes a benign exanthematic viral infection, parvovirus B19 may also present as disseminated disease with tropism for the myocardium, causing heart failure with high mortality. We present the case of a 2-year-old patient with fulminating acute myocarditis in whom the histological, immunophenotypic, and microbiological findings in necropsy showed multiorgan involvement caused by parvovirus B19. The autopsy revealed changes due to infection with parvovirus B19 as well as hypoxic-ischemic and secondary autoimmune changes. Medullary aplasia was observed, transmural lymphocyte myocarditis, lymphocytosis in the dermis with endothelial cells positive for parvovirus B19 in immunohistochemistry, cholestatic hepatitis due to ischemia and autoimmune hepatitis, lymphadenitis, and signs of hemophagocytosis. We also found hypoxic-ischemic encephalopathy.

[Can we rule out a congenital cytomegalovirus infection when the result of polymerase chain reaction in dried blood spots is negative?]. / ¿Podemos descartar infección congénita por citomegalovirus cuando la reacción en cadena de la polimerasa viral es negativa en la prueba del talón?

INTRODUCTION: The detection of cytomegalovirus (CMV) DNA by real time polymerase chain reaction (rt-PCR) in dried blood spots collected routinely for metabolic screening has been assessed for the retrospective diagnosis of congenital CMV (cCMV) infection in many studies, but not in Spain. The aim of this study is to analyze the diagnostic accuracy of this technique in our hospital. METHODS: A cross-sectional retrospective observational study was conducted including all patients born between January, 2007 and September, 2012 with confirmed cCMV infection. The assessment of CMV DNA was made by using rt-PCR in dried blood spots of these patients. RESULTS: Fourteen patients were included: 4/14 were symptomatic and 4/14 had sequelae. The detection of CMV DNA by rt-PCR was positive in only 7 patients. A statistically significant relationship between low viral load at birth and negative rt-PCR in dried blood spots was demonstrated. CONCLUSIONS: Despite the low number of patients included, our data highlight an important amount of false negative results in the DNA CMV detection by rt-PCR in these samples for the retrospective diagnosis of cCMV infection, especially in cases with low viral load at birth.

1H-NMR Urinary Metabolic Profile, A Promising Tool for the Management of Infants with Human Cytomegalovirus-Infection.

Congenital human cytomegalovirus (HCMV) infection is the most common mother-to-child transmitted infection in the developed world. Certain aspects of its management remain a challenge. Urinary metabolic profiling is a promising tool for use in pediatric conditions. The aim of this study was to investigate the urinary metabolic profile in HCMV-infected infants and controls during acute care hospitalization. Urine samples were collected from 53 patients at five hospitals participating in the Spanish congenital HCMV registry. Thirty-one cases of HCMV infection and 22 uninfected controls were included. Proton nuclear magnetic resonance (1H-NMR) spectra were obtained using NOESYPR1D pulse sequence. The dataset underwent orthogonal projection on latent structures discriminant analysis to identify candidate variables affecting the urinary metabolome: HCMV infection, type of infection, sex, chronological age, gestational age, type of delivery, twins, and diet. Statistically significant discriminative models were obtained only for HCMV infection (p = 0.03) and chronological age (p < 0.01). No significant differences in the metabolomic profile were found between congenital and postnatal HCMV infection. When the HCMV-infected group was analyzed according to chronological age, a statistically significant model was obtained only in the neonatal group (p = 0.01), with the differentiating metabolites being betaine, glycine, alanine, and dimethylamine. Despite the considerable variation in urinary metabolic profiles in a real-life setting, clinical application of metabolomics to the study of HCMV infection seems feasible.

¿Podemos descartar infección congénita por citomegalovirus cuando la reacción en cadena de la polimerasa viral es negativa en la prueba del talón? / Can we rule out a congenital cytomegalovirus infection when the result of polymerase chain reaction in dried blood spots is negative?

INTRODUCCIÓN: La determinación de la presencia de ADN de citomegalovirus (CMV) mediante técnicas de reacción en cadena de la polimerasa a tiempo real (rt-PCR) en la gota de sangre seca en el papel absorbente usado para la realización de la prueba de detección precoz neonatal ha sido validada para el diagnóstico retrospectivo de infección congénita por CMV (CMVc) en estudios realizados en otros países, pero no en el nuestro. El objetivo de este estudio es analizar el valor diagnóstico de esta técnica en nuestro centro. MÉTODOS: Estudio retrospectivo transversal observacional de todos los pacientes con diagnóstico confirmado de CMVc entre enero de 2007 y septiembre de 2012. Se ha determinado la presencia de ADN viral de CMV en las muestras de sangre seca de la prueba del talón de estos pacientes mediante rt-PCR. RESULTADOS: Se incluyeron 14 pacientes; 4/14 sintomáticos y 4/14 con secuelas. La detección de CMV por rt-PCR fue positiva únicamente en 7 de ellos. Se demostró una relación estadísticamente significativa entre la negatividad de la rt-PCR y cargas virales más bajas al nacimiento. CONCLUSIÓN: A pesar del pequeño tamaño muestral, nuestros datos ponen en evidencia la presencia de un número importante de falsos negativos en la detección de CMV por rt-PCR en este tipo de muestras en el diagnóstico de CMVc, especialmente en pacientes con cargas virales bajas al nacimiento

INTRODUCTION: The detection of cytomegalovirus (CMV) DNA by real time polymerase chain reaction (rt-PCR) in dried blood spots collected routinely for metabolic screening has been assessed for the retrospective diagnosis of congenital CMV (cCMV) infection in many studies, but not in Spain. The aim of this study is to analyze the diagnostic accuracy of this technique in our hospital. METHODS: A cross-sectional retrospective observational study was conducted including all patients born between January, 2007 and September, 2012 with confirmed cCMV infection. The assessment of CMV DNA was made by using rt-PCR in dried blood spots of these patients. RESULTS: Fourteen patients were included: 4/14 were symptomatic and 4/14 had sequelae. The detection of CMV DNA by rt-PCR was positive in only 7 patients. A statistically significant relationship between low viral load at birth and negative rt-PCR in dried blood spots was demonstrated. CONCLUSIONS: Despite the low number of patients included, our data highlight an important amount of false negative results in the DNA CMV detection by rt-PCR in these samples for the retrospective diagnosis of cCMV infection, especially in cases with low viral load at birth