Association between beta-2 adrenergic receptor variants and clinical outcomes in children and adolescents with acute asthma

ABSTRACT Objective To investigate whether different genotypes of p.Arg16Gly, p.Gln27Glu, p.Arg19Cys and p.Thr164Ile variants interfere in response to treatment in children and adolescents with moderate to severe acute asthma. Methods This sample comprised patients aged 2 to 17 years with a history of at least two wheezing episodes and current moderate to severe asthma exacerbation. All patients received multiple doses of albuterol and ipratropium bromide delivered via pressurized metered-dose inhaler with holding chamber and systemic corticosteroids. Hospital admission was defined as the primary outcome. Secondary outcomes were changes in forced expiratory volume in the first second after 1 hour of treatment, and for outpatients, length of stay in the emergency room. Variants were genotyped by sequencing. Results A total of 60 patients were evaluated. Hospital admission rates were significantly higher in carriers of the genotype AA relative to those with genotype AG or GG, within the p.Arg16Gly variant (p=0.03, test χ2, alpha=0.05). Secondary outcomes did not differ between genotypes. Conclusion Hospital admission rates were significantly higher among carriers of the genotype AA within the p.Arg16Gly variant. Trial registration: ClinicalTrials.gov: NCT01323010

Estudo comparativo de detecção de metapneumovírus humano pelos métodos de PCR e imunofluorescência direta / Comparative study of human metapneumovirus detection by PCR and direct immunofluorescence methods

INTRODUÇÃO: O metapneumovírus humano (MPVh) causa infecções respiratórias em crianças, adultos e idosos imunodeprimidos. O diagnóstico é realizado por imunofluorescência (IF) ou biologia molecular. OBJETIVO: Detectar o MPVh em amostras clínicas pelos métodos de reação em cadeia da polimerase (PCR) e imunofluorescência direta (IFD). RESULTADOS: Das 202 amostras, a positividade foi de 2 por cento e 4 por cento para IFD e RT-PCR, respectivamente. Sensibilidade e especificidade da IFD foram de 50 por cento e 100 por cento, respectivamente, considerando o PCR com transcrição reversa (RT-PCR) como padrão-ouro. CONCLUSÃO: O estudo indica a RT-PCR como o melhor método para a identificação de MPVh em amostras clínicas respiratórias e mostra a importância da padronização do teste para inclusão na rotina laboratorial.

INTRODUCTION: Human metapneumovirus (HMPV) is responsible for respiratory infections in children and immunocompromised adults and elders. It is commonly diagnosed by immunofluorescence or molecular biology. OBJECTIVE: To detect HMPV in clinical samples by polymerase chain reaction (PCR) and direct imunofluorescence (DIF) methods. RESULTS: Two percent of 202 samples were positive for DIF and 4 percent of them for reverse transcriptase PCR (RT-PCR), respectively. Considering RT-PCR as gold standard, DIF sensitivity and specificity were 50 percent and 100 percent, respectively. CONCLUSION: Not only does the study show that RT-PCR is the best method for HMPV detection in clinical respiratory samples but it also substantiates the importance of test standardization in laboratory routine.

Real-time PCR in infectious uveitis as an alternative diagnosis / PCR em tempo real em uveites infecciosas como um diagnóstico alternativo

PURPOSE: Uveitis is a major visual impairment disease affecting parts or the entire uveal tract and occasionally the sclera, the cornea or the optic nerve. The disease is a major cause of ocular morbidity and blindness in immunocompetent and immunocompromised patients. In this work we analyzed the sensitivity and specificity of real-time PCR to detect the etiological agent from blood, plasma, vitreous and aqueous humor and compared with the diagnostic hypothesis. METHODS: Twenty-seven patients (13 male) were studied and Real-time PCR method was used for the detection of herpes simplex virus 1 (HSV-1), herpes simplex virus 2 (HSV-2), varicella zoster virus (VZV), cytomegalovirus (CMV), Mycobacterium tuberculosis (TB) and Toxoplasma gondii (Toxo) in the aqueous humor as well as in the vitreous, blood and plasma. RESULTS: Our results showed the presence of Toxo, CMV, VZV or HSV-2 in 19.2 percent of aqueous humor samples, and in 30 percent of vitreous humor samples. In plasma and blood samples, only CMV was detected (11.1 percent and 3.7 percent, respectively). CONCLUSION: Real-time PCR was able to detect and to confirm diagnostic hypothesis in uveitis. Our data also confirms that vitreous humor is the best source for molecular diagnosis of infectious uveitis but indicates aqueous humor samples that are easier to obtain may also be appropriate to be tested by Real-time PCR.

OBJETIVO: Uveíte é a maior causa de doença ocular que afeta o trato uveal, e ocasionalmente a esclera, cornea e o nervo óptico. Esta doença é a maior causa de morbidade ocular e cegueira em pacientes imunocompetentes e imunossuprimidos. Neste trabalho nós analisamos a sensiblidade e especificidade do PCR em tempo real para detectar agentes etiológicos no sangue, plasma, humor vítreo e aquoso, e comparamos com a hipótese diagnóstica. MÉTODOS: Vinte e sete pacientes (13 homens) foram estudados e o método de PCR em tempo real foi usado para detectar o vírus da herpes simples 1 (HSV-1), vírus da herpes simples 2 (HSV-2), vírus varicella zoster (VZV), citomegalovírus (CMV), Mycobacterium tuberculosis (TB) e Toxoplama gondii (Toxo) no humor aquoso e vítreo, além do sangue e plasma. RESULTADOS: Nossos resultados mostraram a presença de Toxo, CMV, VZV ou HSV-2 em 19,2 por cento das amostras de humor aquoso, e em 30 por cento das amostras de humor vítreo. Nas amostras de plasma e sangue somente CMV foi detectado (11,1 por cento e 3,7 por cento, respectivamente). CONCLUSÃO: PCR em tempo real foi capaz de detectar e confirmar a hipótese diagnóstica em uveíte. Nossos dados confirmam que o humor vítreo é a melhor fonte para diagnóstico molecular de uveíte infecciosa, porém o humor aquoso também foi uma fonte importante de detecção, além de ser mais fácil de se obter.

High rate of viral identification and coinfections in infants with acute bronchiolitis

OBJECTIVES: To determine the viruses and risk factors associated with hospital and intensive care unit (ICU) admissions in infants with acute bronchiolitis. INTRODUCTION: Bronchiolitis is a major cause of morbidity in infants. Widespread use of molecular-based methods has yielded new insights about its etiology, but the impact of viral etiologies on early outcomes is still unclear. METHODS: Seventy-seven infants with bronchiolitis who were under two years of age and visited an emergency unit were included. Using molecular-based methods, samples were tested for 12 different respiratory viruses. Logistic regression models were used to identify clinical and virological variables associated with the main endpoints: hospital admission and ICU admission. RESULTS: We identified at least one virus in 93.5 percent of patients, and coinfections were found in nearly 40 percent of patients. RSV was the most common pathogen (63.6 percent), followed by rhinovirus (39 percent). Identification of RSV was only associated with an increased risk of hospital admission in the univariate model. Younger age and enterovirus infection were associated with an increased risk of hospital admission, while atopy of a first-degree relative showed a protective effect. Prematurity was associated with an increased risk of admission to the ICU. Coinfections were not associated with worse outcomes. CONCLUSIONS: Molecular-based methods resulted in high rates of viral identification but did not change the significant role of RSV in acute bronchiolitis. Younger age and enterovirus infection were risk factors for hospital admission, while prematurity appeared to be a significant risk factor for admission to the ICU in acute viral bronchiolitis.