Effectiveness of Modified Vaccinia Ankara-Bavaria Nordic Vaccination in a Population at High Risk of Mpox: A Spanish Cohort Study.

BACKGROUND: With more than 7500 cases reported since April 2022, Spain has experienced the highest incidence of mpox in Europe. From 12 July onward, the modified vaccinia Ankara-Bavaria Nordic (MVA-BN) smallpox vaccine was offered as pre-exposure prophylaxis for those receiving pre-exposure prophylaxis for human immunodeficiency virus (HIV-PrEP). Our aim was to assess the effectiveness of 1 dose of MVA-BN vaccine as pre-exposure prophylaxis against mpox virus (MPXV) infection in persons on HIV-PrEP. METHODS: National retrospective cohort study between 12 July and 12 December 2022. Individuals aged ≥18 years receiving HIV-PrEP as of 12 July with no previous MPXV infection or vaccination were eligible. Each day, we matched individuals receiving a first dose of vaccine and unvaccinated controls of the same age and region. We used a Kaplan-Meier estimator, calculated risk ratios (RR) and vaccine effectiveness (VE = [1 - RR]x100). RESULTS: We included 5660 matched pairs, with a median follow-up of 62 days (interquartile range, 24-97). Mpox cumulative incidence was 5.6 per 1000 (25 cases) in unvaccinated and 3.5 per 1000 (18 cases) in vaccinated. No effect was found during days 0-6 post-vaccination (VE, -38.3; 95% confidence interval [CI], -332.7 to 46.4), but VE was 65% at ≥7 days (95% CI, 22.9 to 88.0) and 79% at ≥14 days (95% CI, 33.3 to 100.0) post-vaccination. CONCLUSIONS: One dose of MVA-BN vaccine offered protection against mpox in most-at-risk population shortly after the vaccination. Further studies need to assess the VE of a second dose and the duration of protection over time.

Duration of antibiotic therapy among paediatricians: A national survey of current clinical practice in Spain.

OBJECTIVES: Appropriate duration of antibiotic treatment is a key principle to reduce the emergence of bacterial resistance and antibiotic harm. The aim of this study was to document current clinical practice among Spanish paediatricians in terms of the duration of antibiotic therapy in both inpatient and outpatient settings, mapping the difference between practice and guidelines, and thus identifying opportunities to improve practice. METHODS: A national exploratory work survey was distributed in 2020 as a questionnaire about seven main infectious syndromes in children: genitourinary; skin and soft tissue; osteoarticular; ear, nose and throat; pneumonia; central nervous system; and bacteraemia. The answers were contrasted with current recommendations regarding the duration of antibiotic therapy. Demographic analysis was also performed. RESULTS: The survey was completed by 992 paediatricians in Spain, representing 9.5% of paediatricians working in the Spanish national health system. Hospital care clinicians accounted for 42.7% (6662/15590) of responses. The antibiotic duration used in practice was longer than recommended in 40.8% (6359/15590) of responses, and shorter than recommended in 16% (1705/10654) of responses. Only 25% (249/992) and 23% (229/992) of respondents indicated that they would prescribe antibiotics for the recommended treatment duration for lower urinary tract infection and community-acquired pneumonia (AI evidence). Among severe hospital-managed infections, a tendency towards longer courses of antibiotics was found for non-complicated meningococcal infections and non-complicated pneumococcal, Gram-negative and S. aureus bacteraemia. CONCLUSIONS: A noteworthy tendency towards prescribing antibiotics for longer than recommended among paediatricians was evidenced in this nationwide study, highlighting a wide range of opportunities for potential improvement.

Effectiveness of a Meningococcal Group B Vaccine (4CMenB) in Children.

BACKGROUND: In September 2015, the four-component, protein-based meningococcal serogroup B vaccine (4CMenB; Bexsero) became available for private purchase in Spain. METHODS: We conducted a nationwide matched case-control study to assess the effectiveness of 4CMenB in preventing invasive meningococcal disease in children. The study included all laboratory-confirmed cases of invasive meningococcal disease in children younger than 60 months of age between October 5, 2015, and October 6, 2019, in Spain. Each case patient was matched with four controls according to date of birth and province. 4CMenB vaccination status of the case patients and controls was compared with the use of multivariate conditional logistic regression. RESULTS: We compared 306 case patients (243 [79.4%] with serogroup B disease) with 1224 controls. A total of 35 case patients (11.4%) and 298 controls (24.3%) had received at least one dose of 4CMenB. The effectiveness of complete vaccination with 4CMenB (defined as receipt of at least 2 doses, administered in accordance with the manufacturer's recommendations) was 76% (95% confidence interval [CI], 57 to 87) against invasive meningococcal disease caused by any serogroup, and partial vaccination was 54% (95% CI, 18 to 74) effective. Complete vaccination resulted in an effectiveness of 71% (95% CI, 45 to 85) against meningococcal serogroup B disease. Vaccine effectiveness with at least one dose of 4CMenB was 64% (95% CI, 41 to 78) against serogroup B disease and 82% (95% CI, 21 to 96) against non-serogroup B disease. With the use of the genetic Meningococcal Antigen Typing System, serogroup B strains that were expected to be covered by 4CMenB were detected in 44 case patients, none of whom had been vaccinated. CONCLUSIONS: Complete vaccination with 4CMenB was found to be effective in preventing invasive disease by serogroup B and non-serogroup B meningococci in children younger than 5 years of age.

Bronchiolitis before and after the SARS-CoV-2 pandemic: Twelve years of experience in a Spanish paediatric hospital.

INTRODUCTION: Acute bronchiolitis is the main cause of hospitalization in children under 2 years of age, with a regular seasonality, mostly due to the respiratory syncytial virus. OBJECTIVES: To describe the epidemiology of bronchiolitis hospitalizations in our center in the last 12 years, and analyze the changes in clinical characteristics, microbiology, and adverse outcomes during the SARS-CoV-2 pandemic. METHODS: Observational study including patients admitted for bronchiolitis between April 2010 and December 2021 in a Spanish tertiary paediatric hospital. Relevant demographic, clinical, microbiological, and adverse outcome variables were collected in an anonymized database. The pandemic period (April 2020 to December 2021) was compared to 2010-2015 seasons using appropriate statistical tests. RESULTS: There were 2138 bronchiolitis admissions, with a mean of 195.6 per year between 2010 and 2019 and a 2-4-month peak between November and March. In the expected season of 2020, there was a 94.4% reduction of bronchiolitis hospitalizations, with only 11 cases admitted in the first year of the pandemic. Bronchiolitis cases increased from the summer of 2021 during a 6-month long peak, reaching a total of 171 cases. Length of stay was significantly shorter during the pandemic, but no differences were found in clinical and microbiological characteristics or other adverse outcomes. CONCLUSIONS: The SARS-CoV-2 pandemic has modified the seasonality of bronchiolitis hospitalizations, with a dramatic decrease in cases during the expected season of 2020-2021, and an extemporaneous summer-autumn peak in 2021 with longer duration but similar patient characteristics and risk factors.

Molecular epidemiology of paediatric invasive pneumococcal disease in Andalusia, Spain.

This study aimed to assess the impact of the introduction of pneumococcal conjugate vaccine 13 (PCV13) on the molecular epidemiology of invasive pneumococcal disease (IPD) in children from Andalusia. A population-based prospective surveillance study was conducted on IPD in children aged <14 years from Andalusia (2018-2020). Pneumococcal invasive isolates collected between 2006 and 2009 in the two largest tertiary hospitals in Andalusia were used as pre-PCV13 controls for comparison of serotype/genotype distribution. Overall IPD incidence rate was 3.55 cases per 100 000 in 2018; increased non-significantly to 4.20 cases per 100 000 in 2019 and declined in 2020 to 1.69 cases per 100 000 (incidence rate ratio 2020 vs. 2019: 0.40, 95% confidence interval (CI) 0.20-0.89, P = 0.01). Proportion of IPD cases due to PCV13 serotypes in 2018-2020 was 28% (P = 0.0001 for comparison with 2006-2009). Serotypes 24F (15%) and 11A (8.3%) were the most frequently identified non-PCV13 serotypes (NVT) in 2018-2020. Penicillin- and/or ampicillin-resistant clones mostly belonged to clonal complex 156 (serotype 14-ST156 and ST2944 and serotype 11A-ST6521). The proportion of IPD cases caused by PCV13 serotypes declined significantly after the initiation of the PCV13 vaccination programme in 2016. Certain NVT, such as serotypes 24F and 11A, warrant future monitoring in IPD owing to invasive potential and/or antibiotic resistance rates.

Clinical-epidemiological characteristics of Pneumocystis jirovecii pneumonia in a tertiary hospital in Spain.

INTRODUCTION: HIV infection was the main risk of suffering Pneumocystis jirovecii pneumonia (PJP). The clinical-epidemiological characteristics of PJP have currently changed, with there being few studies on this. METHODS: A retrospective observational study was carried out on paediatric patients diagnosed with PJP over a 17 year period in a third level hospital in Spain. RESULTS: A total of 23 patients were included, of whom 7/23 (47.8%) suffered a haematological disease, 5/23 (21.7%) a primary immunodeficiency, and 4/23 (17.4%) an HIV infection. Prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) was received by 11/23 (47.8%) patients. All were treated with TMP-SMX and 18/23 (78.3%) with systemic glucocorticoids. There were six (26.1%) deaths, of which one of them (16.7%) suffered an HIV infection. A higher mortality was seen in the non-HIV patients with greater leucocytosis, greater CO2 retention, and a higher heart rate at onset, differences not observed in HIV patients. No differences were found in mortality in relation to the predisposing factor, use of pTMP-SMX, or treatment with glucocorticoids. CONCLUSIONS: Paediatric patients with haematological cancers are currently the main risk group of developing PJP in this age group. No differences were found in mortality between patients with or without HIV infection as predisposing factor. The mortality among non-HIV patients was higher in those that had greater leucocytosis, greater CO2 retention, and increased heart rate at onset. A better prognosis was not seen in patients that received prophylaxis with TMP-SMX prior to the development of the PJP, or in those that received glucocorticoids as part of the treatment.

Distinct Laboratory and Clinical Features of Secondary Hemophagocytic Lymphohistiocytosis in Pediatric Visceral Leishmaniasis: A Retrospective Analysis of 127 Children in Andalusia, Spain (2004-2019).

BACKGROUND: Visceral leishmaniasis (VL) is an endemic in Southern Europe. However, details regarding disease burden, clinical presentations, laboratory markers, management and outcome in children are scarce. METHODS: Medical records of children (<14 years) admitted with VL to 10 pediatric units in Andalusia (2004-2019) were retrospectively reviewed. VL diagnosis was based on clinical presentation, serology, microscopy and molecular methods. Diagnosis of secondary hemophagocytic lymphohistiocytosis (sHLH) was established using the hemophagocytic lymphohistiocytosis-2004 criteria. RESULTS: A total of 127 patients were identified. Median age was 14.5 months; the main clinical presentations were fever and splenomegaly (95.3% each). Cytopenias were the most common laboratory abnormalities. Diagnostics as well as treatment regimens varied over time and the participating centers. Liposomal amphotericin B was prescribed in 97.6%; relapses as well as adverse events were rarely observed (3.1% each). Thirty-seven patients, diagnosed with sHLH required longer hospital admission (P = 0.001), an increased number of platelet (P < 0.006) and red blood cell (P = 0.0001) transfusions and pediatric intensive care unit admission (P = 0.007). Monocytopenia (P = 0.011) and high C-reactive protein levels (P = 0.031), variables not included in the hemophagocytic lymphohistiocytosis-2004 criteria, were associated with sHLH. One patient deceased in the context of the Leishmania infection. CONCLUSIONS: We report data on the largest pediatric VL cohort from Europe, commonly associated with sHLH. Raised C-reactive protein levels and monocytopenia appear to be associated with sHLH. The latter may help to identify these patients and to guide decisions regarding need of additional supportive clinical care and immunomodulatory therapies. The observed high rate of heterogeneity in terms of diagnosis and management warrants the establishment of appropriate guidelines.

Executive Summary of the Consensus Document on the Diagnosis and Management of Patients with Primary Immunodeficiencies.

Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available.

Executive Summary of the Consensus Document on the Diagnosis and Management of Patients with Primary Immunodeficiencies.

Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available.

Influence of pneumococcal vaccination on the hospitalization of healthy pediatric patients due to typical Community-Acquired Pneumonia.

INTRODUCTION: Community-Acquired Pneumonia (CAP) is one of the most frequent causes of hospital admission in children. Our objective is to measure the impact of the introduction of pneumococcal conjugate vaccines on the hospitalization of previously healthy children due to CAP. METHOD: From 2011 to 2016, a partially retrospective, prospective, and descriptive study was carried out on healthy pediatric patients (3 months-14 years old) with CAP, who required hospital admission. Clinical, epidemiological, and demographic characteristics were collected, and vaccination status was obtained from medical records. RESULTS: A total of 292 cases were included, with a mean age of 33.4 months, 54% males. There was a progressive and significant 42% decrease in the number of admissions each year, without significant changes in the annual percentage of parapneumonic pleural effusion (PPE). Fifty-six percent of patients were immunized with a pneumococcal conjugate vaccine (PCV). The percentage of children who were not vaccinated decreased by 14%, and the coverage with PCV-13 increased by 46%. This revealed a significant increase of PPE in vaccinated patients with PCV-7 (63%) compared with unvaccinated (45%) and with PCV-13 (57%), without association with the presence of severe PPE. Moreover, no significant differences in severity or hospital stay were observed in unvaccinated patients, compared to those who were vaccinated. In >2-year-olds, we observed a significant increase in PPE (59%) compared to 45% in younger children. CONCLUSIONS: The increase in vaccination coverage with PCV-13 resulted in a decrease in hospitalizations due to CAP and PPE. Vaccination with PCV-7 is associated in our sample with an increase in PPE but not with severe PPE nor an increase in the hospital stay. There was an epidemiological shift of severe forms of pneumonia and empyema at later ages (>2 years).

Consensus Document on Community-Acquired Pneumonia in Children. SENP-SEPAR-SEIP. / Documento de consenso sobre la neumonía adquirida en la comunidad en los niños. SENP-SEPAR-SEIP.

Community-acquired pneumonia (CAP) is a prevalent disease among children and is frequently associated with both diagnostic and therapeutic uncertainties. Consensus has been reached between SEPAR, SENP and SEIP, and their conclusions are as follows.

The challenges of influenza for public health.

Influenza, an infectious disease of the respiratory system, represents a major burden for public health. This disease affects all age groups with different prognosis, being life threatening for vulnerable individuals. Despite influenza being a vaccine-preventable disease, the control of the infection needs annual vaccination campaigns and constant improvements. Herein, the main challenges of influenza in relation to the pathogenic agent, the available vaccines and the health impact identified during the Light on Vax event, an expert meeting organized by the Asociación Española de Vacunología [Spanish Vaccinology Association] (AEV), are reported. Further possible steps in the control of influenza are also suggested. Ideally, the development of innovative and universal vaccines that would confer life-lasting and broader-spectrum immunity is highly desirable.

[Recommendations for vaccination against ROTAvirus in PREMature newborns (ROTAPREM)]. / Recomendaciones para la vacunación frente al ROTAvirus de los recién nacidos PREMaturos (ROTAPREM).

Rotavirus (RV) is the leading cause of severe acute gastroenteritis in infants worldwide. Most children are infected by RV by the age of 5years, and especially in the first 2years. Two oral attenuated vaccines against RV are licensed in industrialised countries, which have proven to be safe and effective against the disease. The main objective of these vaccines has been to reproduce the natural history of infection and protect against severe disease in the first months of life. Preterm infants are at higher risk of severe RV infection compared to full-term infants and infants with normal birth weight. Data collected on RV vaccination in preterm infants demonstrated that RV vaccines are effective and safe, compared with full-term infants, with a marginal risk of horizontal viral transmission and dissemination when vaccination is performed during hospitalisation. Preterm infants frequently require admission to hospital after the beginning of the 12th week of life, which suggests that they should receive RV vaccines during admission according to the official immunisation schedule.

[Immunisation schedule of the Spanish Association of Paediatrics: 2019 recommendations]. / Calendario de vacunaciones de la Asociación Española de Pediatría: recomendaciones 2019.

The Advisory Committee on Vaccines of the Spanish Association of Paediatrics annually publishes the immunisation schedule considered optimal for children resident in Spain, according to available evidence on current vaccines. As regards funded immunisations, the 2+1 strategy (2, 4, 11 months) with hexavalent (DTPa-IPV-Hib-HB) and 13-valent pneumococcal vaccines are recommended. Administration of the 6-year booster dose with DTPa is recommended, with a poliomyelitis dose for children who had received the 2+1 scheme, as well as Tdap vaccine for adolescents and pregnant women in every pregnancy between 27 and 32 weeks gestation. The 2-dose scheme should be used for MMR (12 months and 3-4 years) and varicella (15 months and 3-4 years). MMRV vaccine could be applied as the second dose. Vaccination against HPV is recommended in both genders, preferably at 12 years of age. A stronger effort should be made to improve vaccination coverage. The new 9-valent vaccine is now available, expanding the coverage for both genders. Tetravalent meningococcal vaccine (MenACWY) is recommended at 12 months and 12-14 years, with a catch-up up at 19 years of age. It is also recommended in infants older than 6 weeks of age with risk factors, or travellers to countries with high incidence of ACWY meningococcal serogroups. As regards non-funded immunisations, it is recommended meningococcal B vaccination, with a 2+1 schedule, and requests that it be included in the National Immunisation Program. Vaccination against rotavirus is recommended in all infants.

Linezolid-containing Treatment Regimens for Tuberculosis in Children.

BACKGROUND: In recent years, there is an increasing interest in the use of linezolid for the treatment of tuberculosis (TB). METHODS: Patients less than 18 years of age who received linezolid within the Spanish Pediatric TB Network from 2001 to 2016 were retrospectively included. Treatment characteristics, adverse events (AEs) and outcomes were analyzed. RESULTS: Fifteen children were included (53% male) with a median age of 3.6 years [interquartile range (IQR): 1.6-6.2]. Median follow-up was 54 months (IQR: 38-76). The reasons for linezolid use were drug-resistant TB in 8 (53%) patients, drug-induced liver injury in 5 (33%) patients and chronic liver disease in 2 (13%) patients. Four children (26%) were on immunosuppressive therapy when TB was diagnosed. Five children (33%) were diagnosed with extrapulmonary TB. The median duration of linezolid treatment was 13 months (IQR: 7.5-17). Nine patients had 13 linezolid-related AEs. Hematologic toxicity was observed in 8 patients (53%) and gastrointestinal intolerance in 3 patients (20%). In 2 patients, linezolid dose was reduced, and in 2 patients, linezolid was discontinued because of AEs. A 2-year-old girl went back to her country of birth and was lost to follow-up. No relapses were observed among the other 14 patients (93%). CONCLUSIONS: Linezolid may be considered when treating children with drug-resistant TB but also in the cases of patients with chronic liver disease or drug-induced liver injury. However, AEs should be closely monitored. Further studies are needed to determine the optimum dosage and the optimal duration of linezolid treatment in children.

Does exposure of pregnant women to epidemic respiratory syncytial virus affect the severity of bronchiolitis?

INTRODUCTION: Passive transplacental immunity against respiratory syncytial virus (RSV) appears to mediate in the protection of the infant for the first 6 months of life. Lower environmental exposure in pregnant women to RSV epidemic may influence the susceptibility of these infants to infection by lowering the levels of antibodies that are transferred to the fetus. OBJECTIVES: To contrast the risk of severe disease progression in infants with acute bronchiolitis by RSV, according to the mother's level of exposure to epidemic. METHOD: Retrospective cohort study of previously healthy infants with RSV-acute bronchiolitis during 5 epidemics was made. We compared the severity of the infection in those born during the period of risk (when is less likely the mother's exposure to epidemic and the transfer of antibodies to the fetus: October 15th-December 15th in our latitude) with the rest of acute bronchiolitis. Bivariate analysis was performed regarding birth in period of risk and the rest of variables, using the Chi-square test. Multivariate logistic regression analysis was performed to study possible classical confounding factors. RESULTS: 695 infants were included in the study. 356 infants were born during the period of risk. Of the 56 patients requiring admission to PICU, 40 of them (71.4%) were born in this period (p=0.002). In the multivariate analysis, the birth in the period of risk showed a 6.5 OR (95% CI: 2.13-19.7) independently of the rest of variables. CONCLUSIONS: The worst clinical disease progression of the acute bronchiolitis by the RSV in less than 6 months age is related to lower exposure of the pregnant woman to the RSV epidemic.

[Child hospital admissions associated with influenza virus infection in 6 Spanish cities (2014-2016)]. / Hospitalizaciones infantiles asociadas a infección por virus de la gripe en 6 ciudades de España (2014-2016).

INTRODUCTION: There are only a limited number of studies on the impact of influenza in the Spanish child population. The present work intends to increase this knowledge by studying some key aspects, such as the incidence of hospital admissions, clinic variables, comorbidities, and the vaccination status in the hospitalised children. METHODS: A retrospective, observational study was conducted by reviewing the medical records of children under 15 years and hospitalised due to community acquired influenza confirmed microbiologically, during 2́flu seasons (2014-2015 and 2015-2016). The study was carried out in 10 hospitals of 6cities, which represent approximately 12% of the Spanish child population. RESULTS: A total of 907 children were admitted to hospital with main diagnosis of influenza infection (447 <2 years), estimating an average annual rate of hospitalisation incidence of 0.51 cases / 1,000 children (95% CI; 0.48-0.55). Just under half (45%) of the cases had an underlying disease considered a risk factor for severe influenza, and most (74%) had not been vaccinated. The percentage of children with underlying diseases increased with age, from 26% in children <6 months to 74% in children >10 years. Admission to the PICU was required in 10% (92) of the cases, mainly due to acute respiratory failure. CONCLUSION: Influenza continues to be an important cause of hospitalisation in the Spanish child population. Children <6 months of age and children with underlying diseases make up the majority (> 50%) of the cases. Many of the severe forms of childhood influenza that occur today could be avoided if current vaccination guidelines were met.

Apnea in infants hospitalized with pertussis: Incidence and gestational smoking association.

BACKGROUND: Apnea is a life-threatening complication of pertussis, now a re-emerging cause of infant hospitalization worldwide. The incidence of apnea during pertussis ranges widely. The aim of this study was therefore to determine the incidence of apnea in hospitalized infants diagnosed with pertussis and to identify relevant risk factors for apnea. METHODS: This was a retrospective analytical study. We included children hospitalized with pertussis at a tertiary hospital during a 5 year period from 2010 to 2015. Nasopharyngeal aspirates (NPA) were obtained in all subjects. Real-time polymerase chain reaction was used to test NPA samples for Bordetella pertussis. The daily charts were assessed to identify inpatients with apnea. Multivariable logistic regression was performed to identify independent risk factors for inpatient apnea. RESULTS: Inpatient apnea was identified in 51 of 147 infants with pertussis confirmation (34.7%: 95%CI: 27-42%). Maternal smoking during pregnancy was the only statistically significant, independent predictor of inpatient apnea (OR: 4.48; 95%CI: 1.35-14.8). No statistically significant association was found with gender, corrected age; birthweight, caregiver smoking; lactation, weight at admission <3rd percentile, or hematological parameters. CONCLUSIONS: The incidence of pertussis apnea was nearly one in three hospitalized infants, and was fourfold more frequent in infants whose mothers smoked during pregnancy.

X-Linked Severe Combined Immunodeficiency and Hepatoblastoma: A Case Report and Review of Literature.

Severe combined immunodeficiency is an inherited disease with profoundly defective T cells, B cells, and natural killer cells. X-linked severe combined immunodeficiency is the most common form. In this report, we describe a 4-month-old male infant who was admitted to our hospital with progressive breathlessness and abdominal mass. He was diagnosed with hepatoblastoma and presented a pneumocystis jirovecii pneumonia at the beginning of chemotherapy. Definitive diagnosis of X-linked severe combined immunodeficiency was established by DNA analysis of the interleukin 2 receptor gamma chain gene. This case is the first report which describes an X-linked severe combined immunodeficiency patient with hepatoblastoma.