Using comprehensive genomic and functional analyses for resolving genotype-phenotype mismatches in children with suspected CMMRD in Lebanon: an IRRDC study.

Constitutional mismatch repair deficiency (CMMRD) is an aggressive and highly penetrant cancer predisposition syndrome. Because of its variable clinical presentation and phenotypical overlap with neurofibromatosis, timely diagnosis remains challenging, especially in countries with limited resources. Since current tests are either difficult to implement or interpret or both we used a novel and relatively inexpensive functional genomic assay (LOGIC) which has been recently reported to have high sensitivity and specificity in diagnosing CMMRD. Here we report the clinical and molecular characteristics of nine patients diagnosed with cancer and suspected to have CMMRD and highlight the challenges with variant interpretation and immunohistochemical analysis that led to an uncertain interpretation of genetic findings in 6 of the 9 patients. Using LOGIC, we were able to confirm the diagnosis of CMMRD in 7 and likely exclude it in 2 patients, resolving ambiguous result interpretation. LOGIC also enabled predictive testing of asymptomatic siblings for early diagnosis and implementation of surveillance. This study highlights the varied manifestations and practical limitations of current diagnostic criteria for CMMRD, and the importance of international collaboration for implementing robust and low-cost functional assays for resolving diagnostic challenges.

The impact of vaccination on the burden of invasive pneumococcal disease from a nationwide surveillance program in Lebanon: an unexpected increase in mortality driven by non-vaccine serotypes.

BACKGROUND: The impact of pneumococcal conjugate vaccines (PCVs) on the burden of invasive pneumococcal disease (IPD) and serotype distribution was examined across age groups from data collected by the Lebanese Inter-Hospital Pneumococcal Surveillance Program. METHODS: Between 2005 and 2020, 593 invasive Streptococcus pneumoniae isolates were collected from 79 hospitals throughout Lebanon. Serotypes and antimicrobial resistance (AMR) profiles were identified, and trends compared over 3 eras: PCV7, post-PCV7/ pre-PCV13, and PCV13 eras. RESULTS: The prevalence of PCV7 serotypes decreased significantly from 43.6% in the PCV7 era to 17.8% during the PCV13 era (p<0.001). PCV13-only serotypes remained stable in the PCV13 compared to the post-PCV7 eras, especially serotypes 1 and 3, whereas non-vaccine types (NVT) increased throughout the study period, especially 24 and 16F. The mortality rate increased substantially from 12.5% (PCV7 era) to 24.8% (PCV13 era). A significant decrease in AMR was observed across the three study eras. CONCLUSION: PCVs substantially impacted IPD and AMR in vaccinated and unvaccinated populations despite an increase in mortality driven by NVT. Broadening the recommendation of vaccination to include older age-groups, using higher valency vaccines, and implementing stringent antimicrobial stewardship are likely to further impact the burden of IPD.

Placement of Labcor Pulmonary Conduit Results in a High Incidence of Postoperative Fever.

BACKGROUND: Fever in the postoperative period in cardiac patients is common. The purpose of this study is to recognize the risk factors for prolonged postoperative fever in cardiac patients with pulmonary conduit insertion. METHODS: Patients were identified retrospectively by looking at the International Classification of Diseases, Ninth Revision, Clinical Modification procedure code for pulmonary conduit insertion between June 2009 and December 2015 at the American University of Beirut Medical Center. Data about preoperative, perioperative, and postoperative variables were collected. Data entry and analysis were performed using SPSS version 22. RESULTS: The study identified 59 patients. The most common type of pulmonary conduit used was the Contegra type (57.6%) (n = 34), followed by the Labcor type (20.3%; n = 12). Postoperative fever occurred in 61% of patients (n = 36). Fourteen patients (38.8%) had a prolonged fever that lasted for more than seven days. Prolonged postoperative fever was significantly associated with the Labcor pulmonary conduit (P value < .001) and a longer duration of pacing wires (P value: .039). Significantly prolonged fever that lasted for more than 21 days occurred in five patients who all had inserted the Labcor pulmonary conduit. CONCLUSIONS: The Labcor pulmonary conduit type is a risk factor for prolonged postoperative fever. The protracted use of pacing wires could be a consequence of the prolonged fever rather than a cause. In the absence of a demonstrable infectious etiology for prolonged postoperative fever in cardiac patients with pulmonary conduit insertion, the Labcor pulmonary conduit could be the underlying cause. Alternative management of such cases may lead to decreased antibiotic use and morbidity.

Prevalence and characteristics of acute respiratory virus infections in pediatric cancer patients.

BACKGROUND: Patients with pediatric cancer have a higher risk of morbidity and mortality because of respiratory viral infections than other patient populations. OBJECTIVES: To investigate the causative viruses of respiratory infections and their burden among patients with pediatric cancer in Lebanon. STUDY DESIGN: Nasopharyngeal swabs along with clinical and demographic data were collected from patients with pediatric cancer presenting febrile episodes with upper respiratory tract symptoms. Total nucleic acid was extracted from specimens followed by the real-time PCR analysis targeting 14 respiratory viruses to estimate the frequency of infections. RESULTS: We obtained 89 nasopharyngeal swabs from patients with pediatric cancer (mean age, 5.8 ± 4.2 years). Real-time PCR confirmed viral infection in 77 swabs (86.5%). Among these, 151 respiratory viruses were detected. Several viruses cocirculated within the same period; respiratory syncytial virus (RSV) being the most common (45.45%), followed by parainfluenza virus (PIV; 26%), influenza type B (26%), human metapneumovirus (24.6%), and human coronavirus (HCoV; 24.6%). Coinfections were detected in 55% of the subjects, and most of them involved RSV with one or more other viruses. A strong correlation was found between PIV, Flu (influenza of any type), RSV, and HCoV with the incidence of coinfections. RSV was associated with lower respiratory tract infections, nasal congestion, bronchitis, and bacteremia. HCoV was associated with bronchiolitis; rhinovirus was associated with hospital admission. CONCLUSION: Patients with pediatric cancer have a high burden of respiratory viral infections and a high incidence of coinfections. Molecular diagnostics can improve management of febrile episodes and reduce antibiotic use.

Characterization of human Influenza Viruses in Lebanon during 2010-2011 and 2011-2012 post-pandemic seasons.

OBJECTIVE: To genetically characterize human influenza viruses and their susceptibilities to antivirals during two post-pandemic seasons in Lebanon. METHODS: Influenza virus was isolated from nasopharyngeal swabs that were obtained from patients with influenza-like illness during 2010-2012 and further analyzed both phenotypically and genotypically. RESULTS: During the 2010-2011 season, both 2009 pandemic H1N1 (H1N1p) and B viruses co-circulated with equal prevalence, while the H3N2 virus predominated during the 2011-2012 season. All H3N2 and H1N1 viruses were resistant to amantadine. Importantly, all viruses of the influenza A and B types were susceptible to the neuraminidase (NA) inhibitors oseltamivir, zanamivir, peramivir, and laninamivir. Nonetheless, all 2011-2012 H1N1p isolates had three mutations (V241I, N369K, and N386S) in the NA gene that were suggested to be permissive of the H275Y mutation, which confers resistance to oseltamivir. We also detected one H1N1p virus during the 2010-2011 season with a 4-fold decrease in susceptibility to oseltamivir due to an NA-S247N mutation. This isolate was phylogenetically distinct from other H1N1p viruses that were isolated in other regions. CONCLUSIONS: Influenza A viruses with reduced susceptibility to oseltamivir and mutations permissive for acquiring NA resistance-conferring mutation with minimal burden on their fitness were isolated in Lebanon.