[Role of host response during severe bacterial infection]

Risk Factors in Children Older Than 5 Years With Pneumococcal Meningitis: Data From a National Network

BACKGROUND

The occurrence of meningitis in children >5 years old may be associated with specific predisposing factors that can be anatomic, such as cerebrospinal fluid fistula or breach, or related to genetic susceptibility or N inborn or acquired immunologic defect. This study aimed to assess the anatomical and immunologic risk factors in children >5 years old with pneumococcal meningitis and prospectively enrolled in the French national meningitis network.

METHODS

We analyzed all data for children who were 5-15 years old with a diagnosis of pneumococcal meningitis between 2001 and 2013. We describe the frequency and typology of the anatomic or immunologic risk factors, the clinical features and the pneumococcal serotypes.

RESULTS

Among the 316 patients with pneumococcal meningitis, the mortality rate was 9.5% and 23.1% of cases presented complications (abscess, coma, hemodynamic failure, thrombophlebitis cerebral or deafness). In total, 108 children (34%) showed risk factors, the most frequent being anatomic: 70 cases (22.8%) were related to a cerebrospinal fluid breach or fistula and 55 (17.9%) to immunodeficiency, primary or acquired. Serotype data were available for 207 pneumococcal isolates (65.5%). The most frequent serotypes were as follows: 3, 18C, 19A and 19F between 2001 and 2009 and 19F, 3, 19A, 12F, 22F, 17F and 24F after 2009.

CONCLUSIONS

We describe the largest cohort of children >5 years old with pneumococcal meningitis. One third of the children had risk factors justifying a complete immunologic and radiologic work-up.

Application of clinical proteomics in diagnosis and management of trauma patients

Poly-trauma remains a medical entity with major implications, for patient's morbidity, mortality and healthcare economics. Advances in molecular medicine have improved diagnostic techniques in detecting devastating complication after major trauma. Patients at high risk of multiple organ dysfunction syndrome (MODS) or adult respiratory distress syndrome (ARDS), could be identified early, monitored and treated. Proteomics is the systematic evaluation of proteins produced by the cell under normal or pathological circumstances. Investigating protein production will allow us to identify and modify disease natural history and treatment. In this review, we summarise the proteomic methods currently applied in trauma research.

[Multifocal infection due to Mycobacterium intracellulare: first case of interferon gamma receptor partial dominant deficiency in tropical French territory]

Nontuberculous mycobacterial infections are rare in immunocompetent children, and usually present as adenitis. We report a case of a 6-year-old girl with a multifocal chronic osteomyelitis and pulmonary localisation due to Mycobacterium intracellulare associated with an autosomal dominant mutation of interferon gamma receptor 1 gene (INFGR1) leading to a syndrome of mendelian predisposition to mycobacteria infections by partial deficiency of intracellular signalisation of gamma interferon. This child has been cured with anti-mycobacteria drugs and gamma interferon. This report focus on the importance of looking for a susceptibility of the host to infectious diseases, which can lead to a specific treatment. As far as we know, this is the first case described in a tropical area.

Cytokine profiling of pulmonary aspergillosis

Aspergillus fumigatus is ubiquitous and yet causes invasive, chronic and allergic disease of the lung. Chronic cavitary pulmonary aspergillosis (CCPA) is a slowly destructive form of pulmonary aspergillosis, without immunocompromise. We hypothesized that CCPA cytokine gene polymorphisms would differ from patients with allergic bronchopulmonary aspergillosis (ABPA) and uninfected controls. We have profiled functional cytokine gene polymorphisms for interleukin (IL)-10, IL-15, transforming growth factors (TGF)-beta1, tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma in patients with CCPA (n = 24) who were compared with other forms of aspergillosis (mostly ABPA) (n = 15) and with ethnically matched controls (n = 65-330). Results are described with reference to the high-producing genotype in each case. Susceptibility to aspergillosis (all patients compared with normal controls) was associated with higher frequency of the IL-15 +13689*A allele (OR = 2.37, P = 0.0028) and A/A genotype (chi(2) = 10.31, P < 0.001), with a lower frequency of the TNF-alpha-308*A/A genotype (chi(2) = 11.05, P < 0.01). Within the aspergillosis patients, CCPA is associated with lower frequency of the IL-10 -1082*G allele (OR = 0.38, P = 0.0006) and G/G genotype (chi(2) = 22.45, P < 0.001) and with a lower frequency of the TGF-beta1 +869 *T allele (OR +0.42, P < 0.0029) and T/T genotype (chi(2) = 17.82, P < 0.001) compared with non-CCPA patients and normal controls. Patients infected with Aspergillus appear to be higher producers of IL-15, a Th2-promoting cytokine, and lower producers of TNF-alpha, a cytokine central in protective responses. CCPA occurs in patients who are genetically lower producers of both IL-10 and TGF-beta1. As these cytokines are regulatory and anti-inflammatory, CCPA may be a consequence of poor inflammatory response control in the lung.

LPS induces the interaction of a transcription factor, LPS-induced TNF-alpha factor, and STAT6(B) with effects on multiple cytokines

TNF-alpha is a pivotal cytokine whose overproduction can be lethal. Previously, we identified a transcription factor, LPS-induced TNF-alpha factor (LITAF), that regulates TNF-alpha transcription. We now report the discovery and characterization of a regulatory cofactor that we call signal transducer and activator of transcription (STAT) 6(B) because of its considerable homology to STAT6 [here referred to as STAT6(A)]. The STAT6(B) gene expression was found to be activated by LPS. Furthermore, we show that cotransfection of STAT6(B) and LITAF induces an interaction between the two proteins, consequently forming a complex that subsequently translocates into the nucleus and up-regulates the transcription of cytokines. The effect of the complex on a panel of cytokines was tested. In addition, the specific role of LITAF in this complex was established with experiments, including RNA interference technology. Overall, these findings describe roles for LITAF, STAT6(B), and the LITAF-STAT6(B) complex in the regulation of inflammatory cytokines in response to LPS stimulation in mammalian cells.