The Limited Effect of a History of COVID-19 on Antibody Titers and Adverse Reactions Following BNT162b2 Vaccination: A Single-Center Prospective Study.

Background and Objectives: The need for, and ideal frequency of, the vaccination against coronavirus disease 2019 (COVID-19) of previously infected individuals have not yet been sufficiently evaluated. The aim of this study was to examine the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody status and adverse reactions after vaccination among medical staff with or without a history of COVID-19. Materials and Methods: A single-center prospective study was performed at Fukuoka University Chikushi Hospital. We investigated the presence of the anti-SARS-CoV-2 antibody titer among medical staff before and after mRNA vaccination with the BNT162b2. The levels of immunoglobulin G antibody were quantitatively measured at six points-before vaccination, after the first vaccination, at three points after the second vaccination, and finally, after the third vaccination-and the levels were then compared based on the COVID-19 infection history. Results: The previously infected (before the first vaccination) subjects (n = 17) showed a marked increase in antibody titers two weeks after the first vaccination and four weeks after the second vaccination. Although they were able to maintain a certain level of antibody titers until 30 weeks after the second vaccination, the titers fell in the same way as observed in the non-infected subjects. The subjects who did not receive the third vaccination due to adverse reactions to previous vaccines (n = 1) or who were positive for COVID-19 prior to the third vaccination (n = 2) were excluded from the subsequent analyses. Among non-infected subjects (n = 36), smokers had lower peak antibody titers than the others. The previously infected subjects had a significantly higher incidence of adverse reactions after the first vaccination but had a similar incidence of adverse reactions after the second and third vaccinations compared to the non-infected subjects. Conclusions: A history of COVID-19 may influence only the initial increase in anti-SARS-CoV-2 antibody titers and the occurrence of adverse reactions after the first vaccination.

A Case with Iron Deficiency Anemia Developed Aplastic Crisis.

A toddler with an unbalanced diet and gastrointestinal bleeding by juvenile polyp developed an aplastic crisis due to the human parvovirus B19 (HPVB19). Although he exhibited microcytic anemia without iron deficiency in the acute phase of HPVB19 infection, he presented with iron deficiency anemia (IDA) in the chronic phase. IDA results in erythroblast hyperplasia and shortened red blood cell lifespan as like congenital hemolytic diseases, which may lead to an aplastic crisis during HPVB19 infection. It should be noted that iron deficiency is often masked, and microcytic anemia may be a clue for IDA.

Distribution of lag-1 Alleles, ORF7, and ORF8 Genes of Lipopolysaccharide and Sequence-Based Types Among Legionella pneumophila Serogroup 1 Isolates in Japan and China.

Approximately 85% of cases of Legionnaires' disease are caused by Legionella pneumophila serogroup 1. In this study, we analyzed the distribution of lag-1 alleles, ORF 7 and ORF 8 genes of lipopolysaccharide (LPS) and sequence-based types of 616 L. pneumophila serogroup 1 strains isolated in Japan (206 clinical, 225 environmental) and China (13 clinical and 172 environmental). The lag-1 gene was harbored by significantly more of the clinical isolates compared with the environmental isolates (90.3 vs. 19.1% and 61.6 vs. 3.0%, respectively; both P < 0.001). ORF 7 genes were detected in 51.0% of Japanese clinical and 36.0% of Japanese environmental (P = 0.001) isolates, as well as 15.3% of Chinese clinical and 9.9% of Chinese environmental isolates (P = 0.544). ORF 8 genes were detected in 12.1% of Japanese clinical and 5.8% of Japanese environmental (P = 0.017) isolates, as well as 7.7% of Chinese clinical and 3.4% of Chinese environmental isolates (P = 0.388). The Japanese and Chinese isolates were assigned to 203 and 36 different sequence-types (ST), respectively. ST1 was predominant. Most isolates with the same ST also had the same lag-1, ORF 7, and ORF 8 gene subgroups. In conclusion, the lag-1 was present in most of the clinical isolates, but was absent from most of the environmental isolates from both China and Japan, regardless of the water source and SBT type. PCR-based serotyping and subgrouping methods can be used to define a hierarchy of virulence genotypes that require stringent surveillance to prevent human disease.

Legionella pneumophila and Other Legionella Species Isolated from Legionellosis Patients in Japan between 2008 and 2016.

The Legionella Reference Center in Japan collected 427 Legionella clinical isolates between 2008 and 2016, including 7 representative isolates from corresponding outbreaks. The collection included 419 Legionella pneumophila isolates, of which 372 belonged to serogroup 1 (SG1) (87%) and the others belonged to SG2 to SG15 except for SG7 and SG11, and 8 isolates of other Legionella species (Legionella bozemanae, Legionella dumoffii, Legionella feeleii, Legionella longbeachae, Legionella londiniensis, and Legionella rubrilucens). L. pneumophila isolates were genotyped by sequence-based typing (SBT) and represented 187 sequence types (STs), of which 126 occurred in a single isolate (index of discrimination of 0.984). These STs were analyzed using minimum spanning tree analysis, resulting in the formation of 18 groups. The pattern of overall ST distribution among L. pneumophila isolates was diverse. In particular, some STs were frequently isolated and were suggested to be related to the infection sources. The major STs were ST23 (35 isolates), ST120 (20 isolates), and ST138 (16 isolates). ST23 was the most prevalent and most causative ST for outbreaks in Japan and Europe. ST138 has been observed only in Japan, where it has caused small-scale outbreaks; 81% of those strains (13 isolates) were suspected or confirmed to infect humans through bath water sources. On the other hand, 11 ST23 strains (31%) and 5 ST120 strains (25%) were suspected or confirmed to infect humans through bath water. These findings suggest that some ST strains frequently cause legionellosis in Japan and are found under different environmental conditions.IMPORTANCELegionella pneumophila serogroup 1 (SG1) is the most frequent cause of legionellosis. Our previous genetic analysis indicated that SG1 environmental isolates represented 8 major clonal complexes, consisting of 3 B groups, 2 C groups, and 3 S groups, which included major environmental isolates derived from bath water, cooling towers, and soil and puddles, respectively. Here, we surveyed clinical isolates collected from patients with legionellosis in Japan between 2008 and 2016. Most strains belonging to the B group were isolated from patients for whom bath water was the suspected or confirmed source of infection. Among the isolates derived from patients whose suspected infection source was soil or dust, most belonged to the S1 group and none belonged to the B or C groups. Additionally, the U group was discovered as a new group, which mainly included clinical isolates with unknown infection sources.

Right ventricular myocardial deformation patterns in children with congenital heart disease associated with right ventricular pressure overload.

AIMS: Longitudinal wall motion of the right ventricle (RV) has been thoroughly studied in patients with RV dysfunction. However, circumferential strain of the RV free wall has yet to be investigated. Therefore, this study was conducted to assess the utility of RV free wall circumferential strain. METHODS AND RESULTS: Strain profile curves were obtained using speckle tracking echocardiography from the subcostal left ventricular (LV) short-axis view in 30 normal children (normal group) and 25 patients with RV pressure overload (RVO group). The time-strain curves of three individual segmental (anterior, lateral, and inferior segments) and global circumferential deformations were evaluated. RV ejection fraction (RVEF), RV systolic pressure (RVSP), and RV fractional area change obtained in the four-chamber view and LV short-axis view [RVFAC (4CH) and RVFAC (SAX), respectively] were measured, and their relationships with RV free wall deformation were assessed. In the normal group, circumferential strain was significantly lower in the anterior segment than in the other segments. The inferior segment had a significantly larger strain than the other segments in the RVO group. Circumferential strain was predominant over longitudinal RV free wall strain in the RVO group (-18.4 ± 3.9 vs. -14.2 ± 3.8%, respectively; P < 0.005), whereas no significant difference between them was observed in the normal group (-23.0 ± 3.9 vs. -22.4 ± 4.7%, respectively). Global circumferential strain had a significantly higher correlation with RVFAC (4CH), RVFAC (SAX), RVEF, and RVSP than global longitudinal strain (P < 0.05 for all). CONCLUSION: RV free wall circumferential strain provides better information about RV function than longitudinal strain in children with RVO.

Fibromyxoid excrescence of the aortic valve that manifested after catheterisation and required resection.

A 2-year-old boy developed fibromyxoid excrescence of the aortic valve 2 years after balloon dilatation for simple coarctation. Transthoracic echocardiography showed a mobile mass on the non-coronary cusp of the aortic valve. Definitive diagnosis was achieved after operative resection. This pathology was attributed to injury during catheter manipulation. Catheterised patients should be followed up carefully to avoid missing morphological changes.

Assessment of the helical ventricular myocardial band using standard echocardiography.

BACKGROUND: The purpose of this study was to assess the feasibility of morphological and functional evaluation of the helical ventricular myocardial band using standard echocardiographic images. METHODS: Echocardiographic data were obtained from 132 normal children. We attempted to identify the echogenic bright line serving as the boundary between the ascending and descending segments in the ventricular septum, and between the left and ascending segments in the left ventricular inferior wall in the helical myocardial band model proposed by Torrent-Guasp. Myocardial deformations on both sides of the bright line were compared using speckle tracking echocardiography. RESULTS: The bright line separating the ascending from descending segment was visible in the mid-ventricular septum in the four-chamber view in all subjects. This echogenic boundary was observed obliquely in the parasternal short-axis view in 116 subjects (87.9%). There was no significant difference in peak longitudinal or circumferential strain between the ascending and descending segments. However, the time from the QRS onset to peak circumferential strain was significantly lower in the descending than ascending segment (394.5 ± 37.0 vs. 432.7 ± 33.1 ms, P < 0.0001), whereas there was no significant difference in the time to peak longitudinal strain (394.4 ± 26.4 vs. 393.2 ± 24.1 ms). The bright line between the left and ascending segment was detected in the short-axis view from the subcostal region in 86 subjects (65.2%). The time to peak circumferential strain was significantly lower in the left than ascending segment (380.1 ± 32.0 vs. 435.7 ± 37.9 ms, P < 0.0001). CONCLUSION: There is a helical ventricular myocardial band that can be observed in standard echocardiographic images.

Assessment of two-component ventricular septum: functional differences in systolic deformation and rotation assessed by speckle tracking imaging.

BACKGROUND: The purpose of this study was to elucidate functional differences in the right and left components of the ventricular septum (Rt and Lt, respectively). METHODS: Strain, strain rate, rotation, and rotation rate profile curves of Rt and Lt were obtained using speckle tracking echocardiography in 38 normal children and adolescents. RESULTS: The echogenic bright line serving as the boundary separating Rt from Lt was consistently visible in the middle of the ventricular septum. There was no significant difference in peak strain or peak strain rate during systole between Rt and Lt. However, the time interval from the onset of QRS-wave to peak strain and peak strain rate were significantly lower in Lt than in Rt in terms of radial and circumferential deformation (P < 0.005, all), whereas there was no significant difference in longitudinal deformation in the time to peak strain or peak strain rate between Rt and Lt. Lt showed counterclockwise rotation, whereas Rt showed clockwise rotation (10.4 ± 2.9° vs. -10.2 ± 2.6°, P < 0.0001). Time to peak rotation was significantly lower in Lt than in Rt (201.7 ± 32.7 msec vs. 370.4 ± 31.2 msec, P < 0.0001). CONCLUSION: Morphologically and functionally the ventricular septum is a two-component structure. Evaluation of deformation and rotation of the 2 components would help in evaluating septal performance.

Echocardiographic assessment of anomalous origin of the left coronary artery from the pulmonary artery.

Transthoracic echocardiography of a 4-month-old boy with heart failure revealed poor left ventricular contractility with severe mitral regurgitation. Deformation analysis revealed significantly decreased circumferential strain in the anterior and anteroseptal segments. Furthermore, post-systolic shortening was evident in the anterior and lateral segments. The pulmonary arterial short-axis view showed that the left coronary artery originated from the pulmonary artery and color Doppler flow mapping showed retrograde flow in the left coronary artery. These findings were quite helpful for concluding the anomalous origin of the left coronary artery from the pulmonary artery.

Right ventricular thrombosis in two patients with pulmonary atresia with intact ventricular septum.

Thrombosis was detected in the right ventricle 7 days after a bidirectional Glenn operation in a 1-year-old boy with pulmonary atresia with intact ventricular septum (PAIVS) and immediately before pulmonary valvuloplasty in a 21-day-old boy with PAIVS. The risk of thrombosis and the blood clotting cascade should be assessed by blood tests, and surveillance echocardiography should be frequently applied in order to diagnose thrombosis early in such patients.

Left atrial volume change throughout the cardiac cycle in children with congenital heart disease associated with increased pulmonary blood flow: evaluation using a novel left atrium-tracking method.

There is a paucity of data regarding the significance of left atrial (LA) volume and its changes throughout the cardiac cycle in pediatric patients with heart disease. The recently developed LA volume-tracking (LAVT) method can automatically construct the LA volume curve. The study group consisted of 48 pediatric patients with ventricular septal defect (n = 34) or patent ductus arteriosus (n = 14) and age-matched healthy controls. Maximum and minimum LA volumes (LAVmax and LAVmin, respectively) were measured. The total LA emptying volume (LAVtotal) was defined as LAVmax--LAVmin. Volume parameters were standardized by dividing by body surface area (BSA). The total LA emptying fraction (%LAVtotal) was defined as the ratio of LAVtotal to LAVmax. In the patient group, there was a positive correlation between the ratio of pulmonary to systemic blood flow (Qp/Qs) and LAVmax/BSA, LAVmin/BSA, and LAVtotal/BSA (r = 0.42, 0.44, and 0.34, respectively). LAVmin/BSA was positively correlated with the ratio of early mitral inflow velocity to early mitral annular diastolic tissue Doppler velocity (E/E') (r = 0.32). The %LAVtotal had a negative correlation with left-ventricular (LV) end-diastolic pressure (r = -0.32). There were significant correlations between serum B-type natriuretic peptide level and LAVmax/BSA, LAVmin/BSA, and %LAVtotal (r = 0.38, 0.49, and -0.35, respectively). The LAVT method is useful in the evaluation of LV diastolic function in pediatric patients with chronic LV volume overload.

Ratio of early diastolic tricuspid inflow to tricuspid lateral annulus velocity reflects pulmonary regurgitation severity but not right ventricular diastolic function in children with repaired Tetralogy of Fallot.

The current study assessed relationships between the ratio of early diastolic tricuspid inflow to tricuspid lateral annular velocity (tricuspid E/e') and right ventricular (RV) function in children after tetralogy of Fallot (TOF) repair. The RV function of 25 asymptomatic children with surgically repaired TOF (age 3.3 ± 2.0 years) was assessed by echocardiography and cardiac catheterization. Right ventricular end-diastolic pressure and volume (RVEDP and RVEDV), systolic pressure, and ejection fraction, as well as mean pulmonary arterial pressure, mean right atrial pressure (RAP), and the severity of both pulmonary regurgitation (PR) and tricuspid regurgitation (TR) were assessed in terms of the contribution to tricuspid E/e'. Univariate analysis discovered a relationship between tricuspid E/e' and RVEDV (R(2) = 0172), pressure half-time of PR (PR-PHT) (R(2) = 0.173), and TR grade (R(2) = 0.145) (p < 0.01 for each). After multivariate adjustment, PR-PHT was significantly associated with tricuspid E/e' (ß = 0.210; p < 0.001). Tricuspid E/e' was not significantly associated with RVEDP or RAP. In conclusion, tricuspid E/e' does not indicate RV diastolic function but reflects the severity of PR in asymptomatic children after TOF repair.

Subclavian and pulmonary artery steal phenomenon in a patient with isolated left subclavian artery and right aortic arch.

We describe a patient with an isolated left subclavian artery associated with right aortic arch, patent ductus arteriosus, and ventricular septal defect. As the isolated left subclavian artery is supplied by the left vertebral artery in which blood flows in the retrograde direction, this anomaly is usually responsible for a congenital subclavian steal phenomenon. Atrophy of the left cerebral hemisphere and inverted left vertebral arterial flow were clearly depicted by echoencephalography in this patient, whose subclavian artery was connected to the main pulmonary artery by a patent ductus arteriosus.

Stent placement in the ductus venosus of a neonate with total anomalous pulmonary venous return.

A newborn with right isomerism, infracardiac total anomalous pulmonary venous return (TAPVR), and obstruction of the ductus venosus underwent stent implantation in the ductus venosus at 4 h after birth. This procedure averted early pulmonary venous obstruction. Since gradual neointimal proliferation subsequently occurred within the stent, the patient underwent stent balloon dilatation at 35 days of age and underwent surgical repair of the TAPVR with a Blalock-Taussig shunt operation at 53 days of age. Finally, the patient was discharged without any complications. Transthoracic echocardiography is very useful to confirm subsequent minimal change within the stent.

A novel bilayer approach to ventricular septal deformation analysis by speckle tracking imaging in children with right ventricular overload.

BACKGROUND: The aim of this study was to evaluate functional differences between the left and right sides of the ventricular septum in children with right ventricular overload. METHODS: Radial, longitudinal, and circumferential strain on both sides of the ventricular septum were compared using speckle-tracking echocardiography in patients with preoperative atrial septal defects (n = 22), postoperative tetralogy of Fallot (n = 23) and age-matched normal controls (n = 44). The duration between peak strain of the left and right ventricular septum (TLt-Rt) was also evaluated. RESULTS: Radial and circumferential strain in the control group were significantly higher on the left than the right ventricular septum (41.3 ± 12.8% vs 22.6 ± 6.8% and -28.0 ± 5.4% vs -22.5 ± 4.8%, respectively; P < .0001 for both), whereas longitudinal strain did not significantly differ (-22.0 ± 4.9% and -20.7 ± 5.2%, respectively). TLt-Rt was 52.9 ± 35.6, 33.4 ± 29.0, and 38.7 ± 31.0 msec for radial, longitudinal, and circumferential strain, respectively. Longitudinal and circumferential strain on both sides were significantly increased in patients with atrial septal defects compared with controls (P < .05), although radial strain was similar on both sides. Radial strain on the right side was significantly increased in patients with tetralogy of Fallot compared with controls (P < .05), whereas that on the left side was significantly reduced (P < .001). Longitudinal strain on both sides was significantly decreased (P < .01 and P < .001 for the left and right sides, respectively). In addition, TLt-Rt in patients with tetralogy of Fallot was significantly increased with radial and circumferential deformation (P < .05 for both). CONCLUSIONS: Deformation of both sides of the ventricular septum functionally differed. Bilayer analysis of the ventricular septum can help in the evaluation of right ventricular performance under volume and pressure overload.