Publications by authors named "C Gysin"

57 Publications

Improved Diagnostics Help to Identify Clinical Features and Biomarkers That Predict Mycoplasma pneumoniae Community-acquired Pneumonia in Children.

Clin Infect Dis 2020 10;71(7):1645-1654

Division of Infectious Diseases and Hospital Epidemiology, University Children's Hospital Zurich, Zurich, Switzerland.

Background: There are no reliable signs or symptoms that differentiate Mycoplasma pneumoniae (Mp) infection in community-acquired pneumonia (CAP) from other etiologies. Additionally, current diagnostic tests do not reliably distinguish between Mp infection and carriage. We previously determined that the measurement of Mp-specific immunoglobulin M antibody-secreting cells (ASCs) by enzyme-linked immunospot assay allowed for differentiation between infection and carriage. Using this new diagnostic test, we aimed to identify clinical and laboratory features associated with Mp infection.

Methods: This is a prospective cohort study of children, 3-18 years of age, with CAP from 2016 to 2017. Clinical features and biomarkers were compared between Mp-positive and -negative groups by Mann-Whitney U test or Fisher exact test, as appropriate. Area under the receiver operating characteristic curve (AUC) differences and optimal thresholds were determined by using the DeLong test and Youden J statistic, respectively.

Results: Of 63 CAP patients, 29 were Mp-positive (46%). Mp positivity was statistically associated with older age (median, 8.6 vs 4.7 years), no underlying disease, family with respiratory symptoms, prior antibiotic treatment, prolonged prodromal respiratory symptoms and fever, and extrapulmonary (skin) manifestations. Lower levels of C-reactive protein, white blood cell count, absolute neutrophil count, and procalcitonin (PCT), specifically PCT <0.25 μg/L, were statistically associated with Mp infection. A combination of age >5 years (AUC = 0.77), prodromal fever and respiratory symptoms >6 days (AUC = 0.79), and PCT <0.25 μg/L (AUC = 0.81) improved diagnostic performance (AUC = 0.90) (P = .05).

Conclusions: A combination of clinical features and biomarkers may aid physicians in identifying patients at high risk for Mp CAP.
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October 2020

Classical versus controlled rapid sequence induction and intubation in children with bleeding tonsils (a retrospective audit).

Acta Anaesthesiol Scand 2020 01 10;64(1):41-47. Epub 2019 Oct 10.

Department of Anaesthesia, University Children's Hospital, Zurich, Switzerland.

Purpose: To determine whether bag-mask ventilation between induction of anaesthesia and tracheal intubation in children with post-tonsillectomy bleeding reduces the incidence of hypoxaemia and difficult direct laryngoscopy without increasing perioperative respiratory complications.

Methods: Medical records, anaesthesia protocols and vital sign data were analysed from February 2005 to March 2017 for patients undergoing anaesthesia for surgical revision of bleeding tonsils. Type of rapid sequence induction and intubation (RSII; classical, ie, apnoeic, vs controlled, ie, with gentle bag-mask ventilation) was noted. Primary outcomes were incidence of moderate and severe hypoxaemia, grade of direct laryngoscopic views as well as occurrence of noted tracheal intubation difficulties. Haemodynamic alterations during RSII and perioperative adverse events such as noted gastric regurgitation, pulmonary aspiration and perioperative pulmonary morbidity were also recorded.

Results: A classical RSII was performed for 22 surgical revisions in 22 children and a controlled RSII was used for 88 surgical revisions in 81 children. Patients undergoing controlled RSII had less incidence of severe hypoxaemia (1 vs 3; P = .025), better direct laryngoscopic views (P = .048) and less hypertension (5 vs 9; P < .001) than those patients managed by classical RSII. No tracheal intubation difficulties occurred. There was no significant perioperative pulmonary morbidity reported in either group.

Conclusions: Controlled RSII had advantages over classical RSII in children with post-tonsillectomy bleeding and may become a strategic option in these patients to avoid hypoxaemia, difficult laryngoscopy and hypertension during induction of anaesthesia and tracheal intubation. Bag-mask ventilation in patients with bleeding tonsils did not lead to pulmonary morbidity.
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January 2020

Bone marrow T helper cells with a Th1 phenotype induce activation and proliferation of leukemic cells in precursor B acute lymphoblastic leukemia patients.

Oncogene 2019 03 7;38(13):2420-2431. Epub 2018 Dec 7.

Experimental Infectious Diseases and Cancer Research, Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.

Precursor B cell acute lymphoblastic leukemia (BCP-ALL) constitutes the leading cause of cancer-related death in children. While chromosomal alterations contribute to BCP-ALL pathogenesis, they are insufficient for leukemia development. Epidemiological data and evidence from a mouse model suggest that immune responses to infections may trigger the emergence of leukemia, but the mechanisms remain unclear. Here, we show that T helper (Th) cells from bone marrow of pediatric BCP-ALL patients can be attracted and activated by autologous BCP-ALL cells. Bone-marrow Th cells supportively interacted with BCP-ALL cells, inducing upregulation of important surface molecules and BCP-ALL cell proliferation. These Th cells displayed a Th1-like phenotype and produced high levels of IFN-γ. IFN-γ was responsible for the upregulation of CD38 in BCP-ALL cells, a molecule which we found to be associated with early relapse, and accountable for the production of IP-10, a chemokine involved in BCP-ALL migration and drug resistance. Thus, our data provide mechanistic support for an involvement of Th cell immune responses in the propagation of BCP-ALL and suggest that BCP-ALL cell-supportive Th cells may serve as therapeutic target.
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March 2019

Bilateral congenital deafness: What investigations should be performed?

Swiss Med Wkly 2017 3;147:w14416. Epub 2017 Mar 3.

Working Group Paediatric Otolaryngology, Swiss Society of Otolaryngology.

Background: The introduction of newborn hearing screening has led to earlier identification of children with congenital sensorineural hearing loss (SNHL). Aetiological clarification offers several benefits. There is currently a lack of agreement on which examinations should be recommended.

Objective: Descriptive review of the literature reporting investigations performed to establish the aetiology of congenital SNHL and comparison of the management policy in Swiss referral centres.

Methods: PubMed Search from 1985 to March 2016 with specific search terms; study selection according to inclusion/exclusion criteria; narrative analysis by use of defined criteria and question-naire.

Results: Ninety-two studies were finally included in this review. Forty studies investigated more than a single aetiology. Overall frequencies of aetiological parameters investigated were: genetic (47 studies), radiological (35), ophthalmic (35), serological (32), cardiac (25), renal (14), endocrine (12), neurological (8). Most of the studies were retrospective and various limitations such as poor population description, incomplete data or deficiencies in methodological quality were frequently detected. The variability detected in the investigative approach chosen by Swiss referral centres reflects the heterogeneous data seen in the literature.

Conclusions: The evidence in the literature regarding an appro-priate evaluation is mostly of low quality and difficult to assess owing to high heterogeneity. Nevertheless, imaging, genetic testing, neuropaediatric and ophthalmological evaluations, electrocardiograms and cytomegalovirus analysis have been identified as examinations to be included in the assessment of children with congenital SNHL. There is a need for international consensus on the various issues of such an evaluation, such as choice of investigations and diagnostic criteria.
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October 2017