Investigation of cardiomyopathy in children with cirrhotic and noncirrhotic portal hypertension.

BACKGROUND: Cirrhotic cardiomyopathy (CCMP) is a functional disorder characterized by electrophysiological disturbances, and diastolic and/or systolic dysfunction in patients with liver disease. This disorder is a well-defined entity in adults, but pediatric data are limited. The aim of the study was to determine the incidence, features, and risk factors of CCMP in children with portal hypertension (PHT). METHODS: This study included 50 children with cirrhotic PHT (40/50) and noncirrhotic PHT (10/50). Fifty healthy children were also selected for the control group. Electrocardiography and echocardiography were used to evaluate cardiac functions. Corrected QT (QTc) ≥ 0.45 was accepted as prolonged on electrocardiography. The study group was divided into 3 groups: cirrhotic, noncirrhotic, and control. Then, the CCMP group was created according to the diagnostic criteria. Latent CCMP was diagnosed in the presence of prolonged-QTc along with a minor criterion (tachycardia). Manifest CCMP was diagnosed in the presence of at least 2 major criteria (prolonged-QTc along with abnormal echocardiographic findings). Moreover, in this study, the risk factors for CCMP were investigated. RESULTS: The CCMP group included 10 cases (20%). Nine of these cases had latent CCMP (18%), and the remaining one (2%) had manifest CCMP. All of the cases with CCMP had cirrhosis and ascites. None of the patients with CCMP had severe cardiac symptoms, but they were already using some cardioprotective drugs such as propanolol and spironolactone. As risk factors for CCMP, pediatric end-stage liver disease scores, Child-Pugh scores, and ascites grades were found to be significant for the determination of CCMP. The most important risk factor was ascites severity (P = 0.001, odds ratio 9.4). CONCLUSIONS: Approximately 20% of children with PHT have CCMP. A detailed cardiac examination should be carried out periodically in children with cirrhotic PHT, especially in the presence of ascites and high Child-Pugh score.

Outcomes of the extracardiac fontan procedure using cardiopulmonary bypass: early results.

BACKGROUND: Although the avoidance of cardiopulmonary bypass during the Fontan procedure has potential advantages, using cardiopulmonary bypass during this procedure has no adverse effects in terms of morbidity and mortality rates. In this study, we assessed the postoperative outcomes of our first 9 patients who have undergone extracardiac Fontan operation by the same surgeon using cardiopulmonary bypass. METHODS: Between September 2011 and April 2013, 9 consecutive patients (3 males and 6 females) underwent extracardiac Fontan operation. All operations were performed under cardiopulmonary bypass at normothermia by the same surgeon. The age of patients ranged between 4 and 17 (9.8 ± 4.2) years. Previous operations performed on these patients were modified Blalock-Taussig shunt procedure in 2 patients, bidirectional cavopulmonary shunt operation in 6 patients, and pulmonary arterial banding in 1 patient. Except 2 patients who required intracardiac intervention, cross-clamping was not applied. In all patients, the extracardiac Fontan procedure was carried out by interposing an appropriately sized tube graft between the inferior vena cava and right pulmonary artery. RESULTS: The mean intraoperative Fontan pressure and transpulmonary gradient were 12.3 ± 2.5 and 6.9 ± 2.2 mm Hg, respectively. Intraoperative fenestration was not required. There was no mortality and 7 patients were discharged without complications. Complications included persistent pleural effusion in 1 patient and a transient neurological event in 1 patient. All patients were weaned off mechanical ventilation within 24 hours. The mean arterial oxygen saturation increased from 76.1% ± 5.3% to 93.5% ± 2.2%. All patients were in sinus rhythm postoperatively. Five patients required blood and blood-product transfusions. The mean intensive care unit and hospital stay periods were 2.9 ± 1.7 and 8.2 ± 1.9 days, respectively. CONCLUSIONS: The extracardiac Fontan operation performed using cardiopulmonary bypass provides satisfactory results in short-term follow-up and is associated with favorable postoperative hemodynamics and morbidity rates.

Introduction to a Norwood program in an emerging economy: learning curve of a single center.

BACKGROUND: There has been a notable improvement in the outcome of stage 1 palliation for hypoplastic left heart syndrome (HLHS) in recent years. Nevertheless, developing a new Norwood program requires a steep learning curve, especially in emerging economies where rapid population growth brings a high volume of patients but, on the other hand, resources are limited. In this paper we aimed to summarize the initial results of a single center. METHODS: Hospital records of 21 patients were reviewed for all patients having a stage 1 palliation procedure for HLHS between May 2011 and May 2013. There were 13 male (62%) and 8 female (38%) patients. Median age was 14 days (range, 4-74 days) and median weight was 3030 g (2600-3900 g). HLHS was defined as mitral or aortic stenosis or atresia (or both) in the presence of normally related great vessels and a hypoplastic left ventricle. Transthoracic echocardiography was the diagnostic modality used in all patients. All procedures but one were performed using an antegrade selective cerebral perfusion method and moderate hypothermia. Cerebral perfusion was monitored with cerebral oximetry in all patients. Modified ultrafiltration was routinely used in all patients. RESULTS: Overall hospital mortality was 47.6% (n = 10). Mortality rates considerably decreased from the first year to second year (69% and 12.5% respectively). No risk factors were identified for mortality. CONCLUSIONS: Surgical palliation of neonates with hypoplastic left heart syndrome continues to be a challenge. To decrease the overall mortality nationwide and improve outcomes, a referral center with a dedicated team is necessary in emerging economies.

Importance of adhesion molecules for children with congenital heart disease.

BACKGROUND: The aim of our study was to compare the blood levels of adhesion molecules in children with different heart diseases and pulmonary flow rates. METHODS: In this study, we evaluated the levels of soluble intercellular adhesion molecule-1 and soluble vascular cellular adhesion molecule-1 in blood samples of 65 children with different congenital heart diseases. The patients were divided into four groups according to their pulmonary blood flow. The first group had increased pulmonary blood flow with pulmonary hypertension and left-to-right shunt. The second group had increased pulmonary blood flow without pulmonary hypertension and left-to-right shunt. The third group had decreased pulmonary blood flow with cyanotic congenital heart disease and the fourth group had normal pulmonary blood flow with left ventricle outflow tract obstruction and aortic stenosis. RESULT: The highest soluble intercellular and vascular cellular adhesion molecule-1 levels with the mean values of 420.2 nanograms per millilitre and 1382.1 nanograms per millilitre, respectively, were measured in the first group and the lowest levels with the mean values of 104.4 and 358.6 nanograms per millilitre, respectively, were measured in the fourth group. The highest pulmonary blood pressure levels were found in the first group. CONCLUSION: Endothelial activity is influenced not only by left-to-right shunt with pulmonary hypertension, but also by decreased pulmonary blood flow in cyanotic heart diseases. Adhesion molecules are valuable markers of endothelial activity in congenital heart diseases, and they are influenced by pulmonary blood flow rate.

Comparison of humoral immune response in heterologous and homologous COVID-19 booster vaccine groups using CoronaVac and mRNA-based BNT162b2 vaccines.

BACKGROUND: Heterologous COVID-19 booster vaccination is an alternative strategy to homologous vaccination, especially in developing countries, due to shortages, delays, or unequal distribution of COVID-19 vaccines. We compared cohorts vaccinated with different vaccine combinations to investigate whether a heterologous booster dose of mRNA-based BNT162b2 vaccine boosts the immune response in individuals primed with the CoronaVac vaccine. METHODS: Anti-RBD IgG is generally measured 4 weeks after primary immunization and 4 weeks after booster vaccination. Data on anti-receptor-binding domain (anti-RBD) IgG antibody titers and clinical characteristics were provided by infection control units. RESULTS: The highest median anti-RBD IgG antibody titers (14589 AU/mL) after primary immunization was observed in the group vaccinated with two doses of BNT162b2 vaccine. Antibody titers were lower 4 months or more after the second CoronaVac vaccine dose in CoronaVac recipients with or without previous COVID-19. In the homologous COVID-19 booster vaccine group (primed with two doses of CoronaVac 4 weeks apart and a single booster dose of CoronaVac) the median anti-RBD titers decreased from 1025 to 242 AU/mL before the booster dose. In the heterologous group (primed with two doses of CoronaVac 4 weeks apart and a single booster dose of BNT162b2), the median anti-RBD titer increased to 31624 AU/mL, a 132-fold increase, 16 days after the booster dose. CONCLUSIONS: After the second dose of CoronaVac, protective neutralizing antibody levels decrease over time, and a booster dose is required. Heterologous COVID-19 booster vaccination with BNT162b2 is effective at boosting neutralizing antibody levels.

Modified Nikaidoh operation in a patient with dextro-transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction.

The optimal surgical management for patients with transposition of the great arteries (TGA), ventricular septal defect (VSD) and left ventricular outflow tract obstruction (LVOTO) remains controversial. We describe the case of a patient with TGA, a remote restrictive VSD, and LVOTO who underwent a successful modified Nikaidoh operation.

Electrocardiographic findings at initial diagnosis in children with isolated left ventricular noncompaction.

BACKGROUND: The aim of this study was to comprehensively evaluate electrocardiographic (ECG) findings of isolated left ventricular noncompaction (IVNC) patients at initial diagnosis and to explore the correlation between them and the clinical, echocardiographic, and magnetic resonance imaging (MRI) findings. METHODS: Twenty-three patients diagnosed with IVNC by echocardiography and cardiac MRI between January 2006 and June 2010 were enrolled in this study. The patients were examined with standard ECG and 24-hour Holter ECG. For comparison purpose, ECGs of 50 healthy children of similar ages and demographic characteristics were taken. RESULTS: In 87% of patients, ECG abnormalities were found. The most frequently seen ECG findings were left ventricular hypertrophy, ST-segment depression, and negative T wave related to abnormal repolarization particularly in DII, DIII, and V(4-6) leads, as well as prolonged PR and QTc intervals. No ECG features or patterns were found that were specific to the disease. In contrast to adult patients, while no intraventricular conduction defects (particularly in the left bundle brach) were found in any of our patients, 13% had considerable bradycardia and one required a pacemaker. The Holter ECG recordings showed supraventricular tachycardia attacks in two patients and a short ventricular tachycardia attack in one. Patients whose echocardiograms and MRI showed left ventricular systolic dysfunction and left ventricular dilatation had signs of left ventricular hypertrophy and repolarization abnormality on their ECGs, but there was no significant difference in PR, QRS, and QTc intervals. CONCLUSION: Regardless of how frequently left ventricular hypertrophy and repolarization abnormalities are found on IVNC patients' initial ECGs, we think that they are not unique to the disease but are related to the severity of the cardiomyopathy.

The Use of Social Network in Daily Pediatric Practice and Education: Turkish Pediatric Atelier.

Using social media applications in pediatric education is not outdated, and its effectiveness has not been tested yet. For this reason, we shared the first results of the Pediatric Atelier experience that we realized through telegram application. We make an online survey to investigate the needs, requirements, pleasure, and suggestions of members through a web-based questionnaire. This cross-sectional survey study was delivered only to participants who were members of the workshop via their email addresses. Online questionnaires organized using Google Forms were sent to pediatric workshop members between March and June 2019. The questionnaire consisted of questions that measured the participants' basic demographic data, the use of the workshop, and the overall impact of the workshop on their professional behavior. While the institutions and positions of the participants were recorded, no other personal data (such as address and telephone) were collected. Among the 997 members, 417 (42%) of them answered the questionnaire. Respondents included 300 (72%) pediatrician, 21 (5%) pediatric subspeciality fellows, and 75 (18%) pediatric subspecialists. Of the 417 respondents, 217 (52%) were working in Istanbul, and 200 (48%) were working in other cities of Turkey. Among the responders, 233 (56%) were working in private hospitals or doctor offices. A total of 520 cases were consulted in 241 days of study period. Most consultations (n = 309, %59) were made from the Istanbul metropolitan area, and 203 (40%) consultations were from other cities of Turkey. The most frequently consulted departments were Pediatric infectious diseases: 166 (32%), Pediatric hematology and oncology: 56 (11%), and Neonatology: 43 (8%). Of the 520 consulted cases, 44 (8%) were related to life-threatening events, and 25 of them were hospitalized in the intensive care units, and 6 of them were required surgical operations. Of the 94% of responders thought this platform was useful and 82% of them stated that the case counseling part of the atelier was the most useful part. We think that the development of technology and artificial intelligence may lead to the usage of on-line platforms or systems in clinical medical practice. Clinical Trial Registration (if any). Registry name, registration number, web link to study on registry, and data sharing statement.

Transient complete atrioventricular block during liver transplantation.

Intraoperative dysrhythmias commonly occur in the surgical management of congenital heart diseases. It may also be seen in other surgical procedures. The initiating factors for an arrhythmia during surgery is usually a transient insult such as hypoxemia, cardiac ischemia, catecholamine excess, electrolyte abnormality and acidosis. CAVB is a life-threatening dysrhythmia in all ages. We herein report a case of transient CAVB in a 30-month-old boy during living-related liver transplantation for bile duct paucity-associated liver cirrhosis. Moreover, we discuss the probable etiology and treatment of CAVB in liver transplantation.

Obesity risk factors in Turkish children.

On the basis of the knowledge that the prevalence of obesity in children has increased steadily in recent years, this study aimed to assess the association between obesity and certain risk factors in a group of 6- to 14-year-old children living in Istanbul. The study was carried out at the Istanbul University School of Medicine Hospital. Data were collected from 592 children aged between 6 and 14 years who were examined in general pediatrics clinics. Weight and height measurements were performed on the children and their parents. The children were classified as obese and nonobese in accordance with the body mass index reference values for Turkish children. Energy intake of children was estimated with a 3-day food consumption recording form. A structured questionnaire was used to collect the information from the parents on possible risk factors causing obesity. The physical activity state of the children was assessed. A logistic regression model was developed to examine the relationships between obesity and possible risk factors. Almost 32% (n = 184) and 69% (n = 408) of children were assessed as obese and nonobese, respectively. Although there was no difference in daily energy intakes of obese and nonobese children, 13.6% of obese and 40.9% of nonobese children were reported to do physical activity regularly. Obesity was strongly associated with parental obesity. Furthermore, energy intake; having regular physical activity; presence of obesity in the mother, the father, and the mother's family; and having a mother working out of home were also significantly associated with obesity. Creating awareness in mothers on the importance of a healthy nutrition and encouraging families to participate in physical activities are important points in the prevention of childhood obesity.

Repolarization abnormalities in Duchenne-type muscular dystrophy.

OBJECTIVES: Duchenne-type muscular dystrophy (DMD) is an X-linked recessive inherited disease affecting mainly the skeletal and cardiac muscles. We aimed to seek associations between the incidence of ventricular arrhythmias and corrected QT (QTc) dispersion and its component, corrected JT (JTc) dispersion in patients with DMD. STUDY DESIGN: The study included 43 consecutive male patients (mean age 8.8+/-3.0 years; range 3 to 17 years) with DMD. On standard 12-lead electrocardiograms (ECG) the QT and JT intervals and the corrected QT (QTc) and JTc dispersions were calculated. Ventricular extrasystoles were assessed on 24-hour Holter ECG recordings. Ventricular dysrhythmic patterns were evaluated according to the Lown-Wolf classification. The results were compared with those of a control group of 34 healthy children (mean age 9.5+/-3.1 years). RESULTS: The mean QTc and JTc dispersion values were significantly higher in DMD patients compared to controls (QTc: 78.0+/-20.6 msec vs. 50.9+/-16.5 msec; JTc: 77.6+/-20.5 msec vs. 50.8+/-17.7 msec; p<0.05). The results of Holter monitoring were evaluated in 36 patients and in 33 controls. Ventricular extrasystoles were found in six patients (16.7%) and in one (grade I) control subject (3%). The incidence of pathological findings was significantly higher in the study group (p<0.05), including grade I pathology in four patients, grade II pathology in one patient, and grade IV in one patient. QTc and JTc dispersion values of the patients with and without ventricular extrasystoles showed no statistically significant difference (p>0.05). CONCLUSION: Similar QTc and JTc dispersion values detected in patients with and without ventricular extrasystoles may suggest that ventricular repolarization abnormalities occur in early life and may predispose to the development of ventricular arrhythmias in the long-term.

Fever-Associated Supraventricular Tachycardia after 4CMenB Vaccination in an Infant.

Meningococcal serogroup B vaccine 4CMenB (Bexsero) is a new four-component protein vaccine developed to prevent Neisseria meningitidis serogroup B infections. Case. We report a girl with fever and supraventricular tachycardia (SVT) 6-8 hours after the second dose of 4CMenB. SVT was unresponsive to the first dose of adenosine but terminated after the fourth dose of adenosine. During three months of follow-up, she was free of further SVT attacks. Conclusion. This is the first report of ECG-proven SVT after 4CMenB vaccination. Even if fever is coexistent, SVT should be considered after persistent tachycardia and 4CMenB vaccination.

Dietary intakes of adolescents living in Edirne, Turkey.

OBJECTIVE: To assess the dietary intakes of the adolescents in the area of Edirne, Turkey. DESIGN: Cross-sectional, prospective, epidemiological study. SETTINGS AND SUBJECTS: Our study group consists of 1944 adolescents aged between 12 to 17 years; 940 females and 1004 males. INTERVENTIONS: Three-day self-reported food records were collected from the subjects and evaluated by a nutrient database program. Reported nutrient intake data were analyzed for gender differences. Minitab statistical program was used to compare nutritional data of subjects. RESULTS: Energy, calcium, magnesium, folic acid, vitamins A, E, thiamine, and fiber intakes of whole adolescents, and also iron intakes of female adolescents were most likely to be inadequate compared with the recommendations. Iron, calcium, folic acid, thiamine, and fiber intakes were below two thirds of RDA/DRI in a large proportion of the adolescents. The intakes of protein, riboflavin, vitamin C, phosphorus and zinc were found to be adequate in a large percentage of the subjects. Forty eight percent of females and 60.1 % of males were below 2/3 of the RDA for energy. CONCLUSION: Pediatricians and dietitians should train the adolescents living in our region and our country on practical strategies for making healthy food choices rich in nutrient content relative to energy value to ensure intakes that approach the recommendations.

Long term follow-up results of 139 Turkish children and adolescents with rheumatic heart disease.

We aimed to evaluate the predictors of the severity of chronic rheumatic valvar disease. The long term follow-up records of 139 patients with chronic rheumatic carditis were reviewed. Children were followed-up on an outpatient basis for a period ranging from 1-16 years (5.0 +/- 3.7 years). Mitral regurgitation either isolated (51%, n=71) or combined with aortic regurgitation (AR) (49%, n=68) was observed in all cases of the initial attack of rheumatic carditis. AR at initial attack of the rheumatic carditis was found to be affected by gender (AR was more associated with males, p = 0.032), combined mitral and aortic regurgitation (CMAR), and presence of MR at initial attack (p = 0.000 and p = 0.012, respectively) with univariate analysis. The effect of CMAR on AR at initial attack was also significant by multivariate analysis (p = 0.000). CMAR, MR, and AR at initial attack had significant effects on CMAR at final evaluation (p = 0.000, p = 0.020, and p = 0.000, respectively) in univariate analysis. Multivariate analysis revealed the significant effects of CMAR and MR at initial attack on CMAR at final evaluation (p = 0.000 and p = 0.005, respectively). Univariate analysis showed that MR and AR at initial attack, and CMAR at final evaluation, had significant effects on MR at final evaluation (p = 0.000, p = 0.029, and p = 0.000, respectively). MR at initial attack and CMAR at final evaluation had significant effects on MR at final evaluation with multivariate analysis (p = 0.001 and p = 0.003, respectively). AR at final evaluation was affected by CMAR and AR at initial attack (p = 0.000 and p = 0.000, respectively), and CMAR and MR at final evaluation (p = 0.000 and p = 0.000, respectively) with both univariate and multivariate analysis. Mitral valve prolapsus was more common in patients with a longer duration (37.5%, 6 out of 16) than those with a shorter duration (11%, 14 out of 123) and the difference was significant (p = 0.020). In conclusion, the initial severity of valve involvement and the presence of CMAR at initial attack were found to be the best predictors for the severity of chronic rheumatic valvar disease in this study.

Personal characteristics of enuretic children: an epidemiological study from South-East Europe.

INTRODUCTION: This study examined the personal characteristics of enuretic children and investigated the risk factors of nocturnal enuresis among schoolchildren. METHODS: It was a cross-sectional and descriptive questionnaire study and 2,000 children were stratified according to school population, age and gender. The questionnaire was designed for parents to collect information about the prevalence and associated factors as well. RESULTS: Nocturnal enuresis was reported in 159 cases (9.8%). The parameters of bladder control after 2 years of age, urination more than 5 times a day, urinary infection history, history of psychological or physical trauma, siblings with health problems, large family size, lack of a private bedroom, and constipation were more frequent in enuretics (p < 0.05). The parameters of having fecal incontinence, parents and siblings with nocturnal enuresis, low educational level of the mother and poor school performance seem to be risk factors for nocturnal enuresis. However, the parental concern level was high, approximately half of the enuretic children did not visit a physician for management of the problem. CONCLUSION: Nocturnal enuresis could be a multifactorial problem originating from bladder dysfunction, deranged sleep patterns and psychological and hereditary predisposition. Hereditary disposition and having fecal incontinence may be important risk factors for enuresis.

Congenital heart disease in children with Down's syndrome: Turkish experience of 13 years.

BACKGROUND: Down's syndrome (DS) is the most common chromosomal abnormality due to a trisomy of chromosome 21 commonly associated with congenital heart defects (CHDs). This study aimed to evaluate the frequency and types of CHD patterns in Turkish children with DS. METHOD: The data relate to paediatric patients with DS who underwent cardiologic screening between 1994 and 2007 and were reviewed in our Paediatric Cardiology unit. RESULTS: Four hundred and twenty-one out of the 1042 paediatric patients with DS studied over a 13-year period had associated CHD. Of these, 320 (77.6%) had a single cardiac lesion, while the remaining 92 patients (22.4%) had multiple defects. The most common single defect was an atrioventricular septal defect (AVSD) found in 141 patients (34.2%), followed by 69 patients (16.7%) showing secundum type atrial septal defect, and ventricular septal defect in 68 patients (16.5%). AVSDs were the leading type, isolated or combined with other cardiac anomalies with an overall occurrence of 19.8% of paediatric patients with DS, and 49.2% of paediatric patients with both DS and CHD. CONCLUSION: This is the first study concerning the frequency and type of CHD observed in Turkish children with DS. The high frequency of AVSD in Turkish children with DS implied that early screening for CHDs by echocardiography is crucial. The correction of AVSDs in paediatric patients with DS should be performed in the first 6 months of life to avoid irreversible haemodynamic consequences of the defect.

The effects of surgical repair on P-wave dispersion in children with secundum atrial septal defect.

INTRODUCTION: Atrial septal defect (ASD) is one of the most common congenital heart diseases in children. P-wave dispersion has been reported to be associated with non-homogeneous propagation of sinus impulses. The heterogeneity of atrial conduction time may predispose the atria to arrhythmias. The aim of this study was to determine the impact of surgical repair on P-wave indices in children with isolated secundum ASD. METHODS: Children with isolated secundum ASD undergoing surgical repair (n=50; mean age, 7.0+/-3.0 years) and healthy controls (n=51; mean age, 7.6+/-2.7 years) were compared. Maximum P-wave duration (Pmax), shortest duration (Pmin) and P-wave dispersion (Pd) were measured using 12-lead surface electrocardiography. RESULTS: Mean Pmax was found to be significantly higher in children with ASD compared with controls (95.2+/-10.8 vs 84.1+/-9.2 msec; P<0.001), and Pd before surgery was significantly higher compared with controls (47.4+/-12.0 vs 38.8+/-9.7 msec; P<0.001). Both P-wave indices were significantly decreased within the first year after surgical closure - the values decreased to those comparable to healthy controls (Pmax, 86.2+/-9.7 msec; Pd, 39.8+/-10.7 msec; P>0.05). CONCLUSION: Surgical closure of ASD in children decreases Pmax and P-wave conduction time. We speculate that earlier closure of the defect may play an important role in avoiding permanent changes in the atrial myocardium and atrial fibrillation in adulthood.

[A case of Hennekam syndrome presenting with massive pericardial effusion]. / Hennekam sendromlu bir olguda basvuru nedeni olarak perikard efüzyonu.

Hennekam syndrome is an autosomal recessive disease characterized by intestinal lymphangiectasia accompanied by severe lymphedema of the limbs, genitalia, and face, and learning difficulties. A 38-month-old boy was admitted with breathing difficulty. He had facial abnormalities and preputial hyperplasia consistent with Hennekam syndrome. Lymphangiography showed lymphedema in the left eye and right foot. Teleradiography showed cardiomegaly and echocardiography showed massive pericardial effusion. He first underwent pericardiocentesis for the removal of pericardial effusion, but pericardial tube drainage was required upon recurrence of effusion. On the fifth day, the drain was removed because of significant decrease in the drainage.

Comparison of humoral immune response in heterologous and homologous COVID-19 booster vaccine groups using CoronaVac and mRNA-based BNT162b2 vaccines

ABSTRACT Background: Heterologous COVID-19 booster vaccination is an alternative strategy to homologous vaccination, especially in developing countries, due to shortages, delays, or unequal distribution of COVID-19 vaccines. We compared cohorts vaccinated with different vaccine combinations to investigate whether a heterologous booster dose of mRNA-based BNT162b2 vaccine boosts the immune response in individuals primed with the CoronaVac vaccine. Methods: Anti-RBD IgG is generally measured 4 weeks after primary immunization and 4 weeks after booster vaccination. Data on anti-receptor-binding domain (anti-RBD) IgG antibody titers and clinical characteristics were provided by infection control units. Results: The highest median anti-RBD IgG antibody titers (14589 AU/mL) after primary immunization was observed in the group vaccinated with two doses of BNT162b2 vaccine. Antibody titers were lower 4 months or more after the second CoronaVac vaccine dose in CoronaVac recipients with or without previous COVID-19. In the homologous COVID-19 booster vaccine group (primed with two doses of CoronaVac 4 weeks apart and a single booster dose of CoronaVac) the median anti-RBD titers decreased from 1025 to 242 AU/mL before the booster dose. In the heterologous group (primed with two doses of CoronaVac 4 weeks apart and a single booster dose of BNT162b2), the median anti-RBD titer increased to 31624 AU/mL, a 132-fold increase, 16 days after the booster dose. Conclusions: After the second dose of CoronaVac, protective neutralizing antibody levels decrease over time, and a booster dose is required. Heterologous COVID-19 booster vaccination with BNT162b2 is effective at boosting neutralizing antibody levels.