Síndrome de Kartagener: diagnóstico neonatal. A propósito de un caso / Kartagener syndrome: neonatal diagnosis. A case report

El síndrome de Kartagener es una enfermedad hereditaria autosómica recesiva caracterizada por la asociación de discinesia ciliar primaria y la tríada situs inversus total, sinusitis crónicas y bronquiectasias. Su prevalencia varía en 1/15 000-1/30 000, pero se estima que muchos pacientes con discinesia ciliar primaria no han sido diagnosticados. Su presentación clínica es inespecífica y heterogénea, y no hay una única prueba gold standard para su diagnóstico. Esto, unido a las limitaciones y no disponibilidad de las pruebas, hace que el diagnóstico se retrase. Un diagnóstico y tratamiento adecuados de forma precoz modifican el pronóstico. En los últimos años, las sociedades han publicado algoritmos diagnósticos para pacientes con clínica sugestiva. Por ello, es importante una puesta al día y enfatizar en la necesidad de una sospecha clínica ante las manifestaciones clínicas de esta enfermedad. Se presenta a un recién nacido con este síndrome diagnosticado por estudio genético en un hospital secundario.

Kartagener Syndrome is an inherited autosomal recessive disorder characterized by primary ciliary dyskinesia and the triad of situs inversus viscerum, chronic sinus disease and bronchiectasis. Its prevalence varies from 1/15 000 to 1/30 000 but it is estimated that a lot of patients with primary ciliary dyskinesia have not been diagnosed as such. Its clinical presentation is non-specific and heterogeneous, and there is not a single, gold standard, diagnostic test. The diagnosis is often delayed because of these reasons and limitations and no availability of diagnostic tests. Early diagnosis and treatment change patient's prognosis. In addition, Scientific Societies have published recent diagnostic algorithm to evaluate the patient with suspected primary ciliary dyskinesia. Therefore, it is important to keep up to date with all the latest articles. We present the case of a newborn with this syndrome diagnosed by genetic analysis in a secondary care hospital.

Surfactant preparations for preterm infants with respiratory distress syndrome: past, present, and future / 소아과

Following the first successful trial of surfactant replacement therapy for preterm infants with respiratory distress syndrome (RDS) by Fujiwara in 1980, several animal-derived natural surfactants and synthetic surfactants have been developed. Synthetic surfactants were designed to overcome limitations of natural surfactants such as cost, immune reactions, and infections elicited by animal proteins contained in natural surfactants. However, first-generation synthetic surfactants that are protein-free have failed to prove their superiority over natural surfactants because they lack surfactant protein (SP). Lucinactant, a second-generation synthetic surfactant containing the SP-B analog, was better or at least as effective as the natural surfactant, suggesting that lucinactant could act an alternative to natural surfactants. Lucinactant was approved by the U. S. Food and Drug Administration in March 2012 as the fifth surfactant to treat neonatal RDS. CHF5633, a second-generation synthetic surfactant containing SP-B and SP-C analogs, was effective and safe in a human multicenter cohort study for preterm infants. Many comparative studies of natural surfactants used worldwide have reported different efficacies for different preparations. However, these differences are believed to due to site variations, not actual differences. The more important thing than the composition of the surfactant in improving outcome is the timing and mode of administration of the surfactant. Novel synthetic surfactants containing synthetic phospholipid incorporated with SP-B and SP-C analogs will potentially represent alternatives to natural surfactants in the future, while improvement of treatment modalities with less-invasive or noninvasive methods of surfactant administration will be the most important task to be resolved.

Association between vitamin D level at birth and respiratory morbidities in very-low-birth-weight infants / 소아과

PURPOSE: This study aimed to evaluate vitamin D status at birth in very-low-birth-weight infants (VLBWIs: <1,500 g) and to determine the association between vitamin D level and respiratory morbidity. METHODS: A retrospective study was conducted at Soonchunhyang University Bucheon Hospital between November 2013 and November 2017. We collected blood samples and data on respiratory morbidity from 230 VLBWIs on the first day of life. Patients who were transferred to other hospitals (n=19), died before 36 weeks of gestational age (n=18), or whose blood samples were not collected immediately after birth (n=5) were excluded. Finally, 188 patients were enrolled. VLBWIs with different vitamin D levels were compared with respect to demographic features, maternal diseases, respiratory morbidities, and other neonatal diseases. RESULTS: The mean serum vitamin D level, as measured by 25-hydroxyvitamin D (25(OH)D), was 13.4±9.3 ng/mL. The incidence of vitamin D deficiency (<20 ng/mL) was 79.8%, and 44.1% of preterm infants had severe vitamin D deficiency (<10 ng/mL). Logistic analysis shows that a low serum 25(OH)D level (<20 ng/mL) was a risk factor for respiratory distress syndrome (odds ratio [OR], 4.32; P=0.010) and bronchopulmonary dysplasia (OR, 4.11; P=0.035). CONCLUSION: The results showed that 79.8% of preterm infants in this study had vitamin D deficiency at birth. Low vitamin D status was associated with respiratory morbidity, but the exact mechanism was unknown. Additional studies on the association between vitamin D level and neonatal morbidity are required.

Effect of Dlk1 and Jagged1 gene on the proliferation and transdifferentiation of the primary type Ⅱ alveolar epithelial cells / 中华实用儿科临床杂志

Objective To study the effects of the Notch ligands Dlk1 and recombinant human nucleu factorκB (Jagged1) on the proliferation and transdifferentiation of the type Ⅱ alveolar epithelial cells when the Notch signaling pathway activated.Methods The primary type Ⅱ alveolar epithelial cells (AEC Ⅱ) cultured with recombinant protein Dlk1 and recombinant human nucleu factor-κB (rhNF-κB) (activator of Jagged1),respectively,and then cultured with DMEM (containing 120 mL/L FBS) as controls.Proliferation and differentiation conditions of the AEC Ⅱ were observed at 48 h,72 h,96 h time point by the light microscope and electron microscopes separately.Cell number was counted with hemacytometer; the proliferation rate was measured by methyl thiazolyl tetrazolium (MTT) ; Immunofluorescence double standard method was used to detect the AEC Ⅱ specific surfactant protein C (SP-C) and AEC Ⅰ specific protein aquaporin5 (AQPS) ;the expression of SP-C,AQPS,Dlk1,Jagged1,Notch1 and Hes1 mRNA were detected by real time-PCR.Results The cell population and proliferation:compared with control group,AEC Ⅱ proliferation was promoted in the Dlk1 group [cell numbers (× 109/L) 9.05 ± 0.45 vs 7.95 ± 0.65,11.68 ± 0.43 vs 8.68 ± 0.52,11.55 ± 0.17 vs 8.73 ± 0.48,all P ＜ 0.05 ; MTT results (value A) 0.699 ± 0.050 vs 0.462 ± 0.080,0.912 ± 0.080 vs 0.535 ±0.040,0.726 ±0.050 vs 0.540 ±0.020,all P ＜0.05] and decelerated AEC Ⅱ transdifferentiation into AEC Ⅰ ; while AEC Ⅱ proliferation was inhibited in rhNF-κB group [cell numbers (× 109/L) 4.95 ± 0.33 vs 7.95 ± 0.65,4.73 ±0.71 vs 8.68 ± 0.52,4.04 ± 0.11 vs 8.73 ± 0.48,all P ＜ 0.05; MTT results (value A) 0.398 ± 0.030 vs 0.462 ± 0.080,0.402 ± 0.070 vs 0.535 ± 0.040,0.380 ± 0.110 vs 0.540 ± 0.020,all P ＜ 0.05] and accelerated AEC Ⅱ transdifferentiation into AEC Ⅰ.One-Way ANOVA showed that the difference among the 3 groups had statistical significance (cell numbers:F =486.73,P =0.02; cell proliferation:F =37.16,P =0.02).The mRNA expression:compared with control group,the expression of SP-C mRNA of Dlk1 group was significantly higher (P ＜ 0.05) while the expression of AQP5 mRNA was remarkably lower and delayed (P ＜ 0.05),the expression of Jagged1 mRNA was weak or little,Dlk1 and Notch1 mRNA were up-regulated (P ＜ 0.05),and the Hes1 mRNA was reduced (P ＜ 0.05) ; the expression of SP-C mRNA of rhNF-κB group was significantly reduced (P ＜ 0.05),while the AQP5 mRNA expressed ahead of time and increased (P ＜ 0.05),Jagged1,Hes1 and Notch1 mRNA were higher (P ＜ 0.05),and the Dlk1 mRNA was weak.One-Way ANOVA showed that the difference in the expressions of SP-C,AQP5,D1k1,Jagged1,Hes1 and Notch1 mRNA among the 3 groups had staistical significance (F =96.80,P =0.01 ; F =82.55,P =0.01 ; F =269.80,P=0.00;F =312.34,P =0.00;F =169.17,P =0.01;F =19.85,P =0.02).Conclusions There are varied effects on proliferation and differentiation of the AEC Ⅱ when the Notch signaling is activated by different ligands:Dlk1 promoted proliferation and inhibited differentiation,while Jagged1 inhibited proliferation and promoted transdifferentiation.

Genetic risk factors associated with respiratory distress syndrome / 소아과

Respiratory distress syndrome (RDS) among preterm infants is typically due to a quantitative deficiency of pulmonary surfactant. Aside from the degree of prematurity, diverse environmental and genetic factors can affect the development of RDS. The variance of the risk of RDS in various races/ethnicities or monozygotic/dizygotic twins has suggested genetic influences on this disorder. So far, several specific mutations in genes encoding surfactant-associated molecules have confirmed this. Specific genetic variants contributing to the regulation of pulmonary development, its structure and function, or the inflammatory response could be candidate risk factors for the development of RDS. This review summarizes the background that suggests the genetic predisposition of RDS, the identified mutations, and candidate genetic polymorphisms of pulmonary surfactant proteins associated with RDS.

Surfactant protein B gene polymorphism in preterm babies with respiratory distress syndrome

The etiology of respiratory distress syndrome (RDS) is multifactorial and multigenic. Studies have suggested that polymorphisms and mutations in the surfactant protein B (SP-B) gene are associated with the pathogenesis of RDS. The objectives of this study were to determine and compare the frequencies of SP-B gene polymorphisms in preterm babies with and without RDS. We studied 151 neonates: 79 preterm babies without RDS and 72 preterm newborns with RDS. The following four SP-B gene polymorphisms were analyzed: A/C at -18, C/T at 1580, A/G at 9306, and G/C at nucleotide 8714. The polymorphisms were detected by PCR amplification of genomic DNA and genotyping. The genotypes were determined using PCR-based converted restriction fragment length polymorphisms. The control group consisted of 42 (53 percent) girls and 37 (47 percent) boys. Weight ranged from 1170 to 3260 g and mean gestational age (GA) was 33.9 weeks (range: 29 to 35 weeks and 6 days). The RDS group consisted of 31 (43 percent) girls and 41 (57 percent) boys. Weight ranged from 614 to 2410 g and mean GA was 32 weeks (range: 26 to 35 weeks). The logistic regression model showed that GA was the variable that most contributed to the occurrence of RDS. The AG genotype of the A/G polymorphism at position 9306 of the SP-B gene was a protective factor in this population (OR = 0.1681; 95 percentCI = 0.0426-0.6629). We did not detect differences in the frequencies of the other polymorphisms between the two groups of newborns.

Estudio controlado del tratamiento de la enfermedad de membrana hialina del recién nacido pretérmino con surfactante pulmonar exógeno (porcino vs. bovino) / Treatment of hyaline membrane disease in the preterm newborn with exogenous lung surfanctant. A controlled study

Introducción: La enfermedad de membrana hialina (EMH) por deficiencia de surfactante pulmonar en el neonato prematuro es una causa importante de morbimortalidad. El surfactante pulmonar exógeno ha revolucionado el tratamiento de esta entidad en países desarrollados, aunque este beneficio ha sido menor en países en vías de desarrollo. El surfactante porcino de manufactura cubana es económico, y su uso comparado con otros surfactantes es desconocido. Material y métodos: Se llevó a cabo un estudio prospectivo, controlado, aleatorizado, abierto, en 44 recién nacidos prematuros con EMH. Un grupo recibió surfactante bovino (SB) (Survanta), y el otro surfactante porcino (SP) de fabricación cubana (Surfacen). Se evaluó la respuesta en variables de oxigenación y ventilación, días de oxígeno suplementario, ventilación mecánica, incidencia de complicaciones, tiempo de hospitalización y mortalidad. Resultados: 23 pacientes recibieron el surfactante bovino, y 21 el porcino. Los dos grupos fueron similares clínicamente y en sus patrones de respuesta de oxigenación y ventilación, con una tendencia a mayor incremento inicial en la oxigenación en el grupo tratado con SP. La incidencia de complicaciones fue similar en los dos grupos. Fallecieron 10 pacientes (47.6%) en el grupo SP, y 12 (52.2%) en el grupo SB (p>0.05). Conclusiones: El surfactante porcino tuvo efectos clínicos similares al bovino en las variables de oxigenación y ventilación estudiadas; no hubo diferencia significativa en complicaciones y mortalidad. El surfactante porcino es una alternativa efectiva y de menor costo que el surfactante bovino para el tratamiento de la EMH.

Background: Hyaline membrane disease (HMD) due to lung surfactant deficiency in the preterm newborn is an important cause of neonatal morbidity and mortality. Exogenous lung surfactant has transformed HMD therapy in developed countries, but an equivalent benefit has not been accomplished in developing countries due to a variety of factors. Porcine surfactant developed in Cuba is an inexpensive alternative to other surfactants, and its use has not been studied in our settings. Methods: A randomized, open, prospective and controlled trial was undertaken in 44 preterm newborns with HMD diagnosis. One group received bovine surfactant (BS) (Survanta) and the other Cuban porcine surfactant (PS) (Surfacen). The following clinical response variables were evaluated: oxygenation and ventilation indexes, days with supple mentary oxygen, days with mechanical ventilation, incidence of compli cations, time of hospitalization, and mortality. Results: 23 Patients received bovine surfactant and 21 the porcine type. The two groups were clinically similar, with patterns of oxygenation and ventilation response that were the same between groups, with a tendency to higher initial oxygenation increase in the PS group. The incidence of complications was similar between groups. Ten Patients (47.6%) died in the PS group, versus 12 (52.2%) in the BS group (p>0.05) Conclusions: Porcine surfactant had similar clinical effects than bovine surfactant in the oxygenation and ventilation variables, with no significant differences in complications or mortality. Porcine surfactant is an effective and lower cost alternative to bovine surfactant in the treatment of HMD.