Human respiratory syncytial virus (RSV) is the leading cause of severe lower respiratory tract infection, such as bronchiolitis, bronchitis, or pneumonia, in both infants and the elderly. Despite the global burden of diseases attributable to RSV infection, no clinically approved vaccine is available, and a humanized monoclonal antibody for prophylaxis is not readily affordable in developing countries. There are several hurdles to the successful development of RSV vaccines: immune-vulnerable target populations such as premature infants, pregnant women, and immunocompromised people; safety concerns associated with vaccine-enhanced diseases; repeated infection; and waning memory. To develop successful strategies for the prevention of RSV infection, it is necessary to understand the protective and pathologic roles of host immune responses to RSV infection. In this review, we will summarize the positive and negative relationship between RSV infection and host immunity and discuss strategies for the development of the first successful RSV vaccine.
Humans ; Immunity ; Immunocompromised Host ; Respiratory Syncytial Virus Infections/immunology/*prevention & control ; *Respiratory Syncytial Virus Vaccines ; Respiratory Syncytial Viruses/*physiology

OBJECTIVETo characterize the differences between clinical manifestations in immunocompromised patients (ICPs) and non-immunocompromised patients (non-ICPs) with tuberculosis.

METHODSUnderlying diseases, clinical presentations, misdiagnosis, treatment and prognosis, etc, were analyzed retrospectively in 115 tuberculosis patients, including 39 ICPs and 76 non-ICPs.

RESULTSCompared with non-ICPs, the individuals who were ICP had more expectoration (64.1% vs 35.5%), pulmonary moist rale (41.0% vs 9.2%), miliary pulmonary tuberculosis (30.8% vs 2.6%), pleural effusion (48.7% vs 25.0%) and lymphadenopathy (18.0% vs 4.0%). ICPs had less lung cavity (15.4% vs 22.4%) and pleural thickening (15.4% vs 23.7%) compared to non-ICPs. Pulmonary tuberculosis in ICPs was prone to be misdiagnosed as pneumonia (23.1% vs 6.6%). Pulmonary tuberculosis was found in the apicoposterior segment (SI + SII) in more cases in non-ICPs (21.7%, 10/46) than ICPs (10.3%, 3/29). The diagnostic value of tuberculin skin test and adenosine deaminase in pleural effusions was limited in ICPs. ICPs had significantly poorer prognoses than non-ICPs.

CONCLUSIONThe clinical manifestations of ICPs with tuberculosis are atypical, misdiagnosis often occurs, resulting in a worse prognosis.

Adult ; Aged ; Female ; Humans ; Immunocompromised Host ; physiology ; Male ; Middle Aged ; Tuberculosis, Lymph Node ; diagnosis ; Tuberculosis, Miliary ; diagnosis ; Tuberculosis, Pulmonary ; diagnosis ; physiopathology

BACKGROUND/AIMS: There is an increased risk for inflammatory bowel disease (IBD) patients to develop infections due to the use of immunomodulators and biologics. Several infections are preventable by immunizations. This study investigated the knowledge and awareness of Korean gastroenterologists regarding the vaccination of patients with IBD. METHODS: A self-reported questionnaire was sent by e-mail to the faculty members of tertiary hospitals. Gastroenterologists were asked ten questions regarding the immunization of patients with IBD. A total of 56 gastroenterologists completed the questionnaire. RESULTS: A majority of gastroenterologists (>60%) had rarely or never recorded an immunization history from their patients with IBD. Moreover, 50% to 70% of the gastroenterologists did not know that live vaccines should be avoided in immunosuppressed patients. The most commonly mentioned resistance to vaccinations was "the lack of concern and knowledge regarding vaccination." Gastroenterologists more frequently asked about the immunization history of influenza, pneumococcal, hepatitis A, and hepatitis B vaccines and recommended these vaccines more often than others. CONCLUSIONS: Korean gastroenterologists' awareness and knowledge regarding the vaccination of patients with IBD were very poor. Intensive educational programs on immunization guidelines directed toward gastroenterologists who care for patients with IBD are required to ensure that these patients receive the necessary vaccinations.
Clinical Competence/*standards ; Female ; Gastroenterology/*standards ; Health Knowledge, Attitudes, Practice ; Humans ; Immunocompetence/physiology ; Immunocompromised Host/physiology ; Inflammatory Bowel Diseases/*complications ; Male ; Medical History Taking/standards ; Questionnaires ; Republic of Korea ; Vaccination/*standards

Toxoplasmic encephalitis is caused by reactivation of bradyzoites to rapidly dividing tachyzoites of the apicomplexan parasite Toxoplasma gondii in immunocompromised hosts. Diagnosis of this life-threatening disease is problematic, because it is difficult to discriminate between these 2 stages. Toxoplasma PCR assays using gDNA as a template have been unable to discriminate between an increase or decrease in SAG1 and BAG1 expression between the active tachyzoite stage and the latent bradyzoite stage. In the present study, real-time RT-PCR assay was used to detect the expression of bradyzoite (BAG1)- and tachyzoite-specific genes (SAG1) during bradyzoite/tachyzoite stage conversion in mice infected with T. gondii Tehran strain after dexamethasone sodium phosphate (DXM) administration. The conversion reaction was observed in the lungs and brain tissues of experimental mice, indicated by SAG1 expression at day 6 after DXM administration, and continued until day 14. Bradyzoites were also detected in both organs throughout the study; however, it decreased at day 14 significantly. It is suggested that during the reactivation period, bradyzoites not only escape from the cysts and reinvade neighboring cells as tachyzoites, but also converted to new bradyzoites. In summary, the real-time RT-PCR assay provided a reliable, fast, and quantitative way of detecting T. gondii reactivation in an animal model. Thus, this method may be useful for diagnosing stage conversion in clinical specimens of immunocompromised patients (HIV or transplant patients) for early identification of tachyzoite-bradyzoite stage conversion.
Animals ; Antigens, Protozoan/*biosynthesis ; Brain/parasitology ; Female ; *Gene Expression ; Heat-Shock Proteins/*biosynthesis ; Immunocompromised Host ; Life Cycle Stages ; Lung/parasitology ; Mice ; Protozoan Proteins/*biosynthesis ; Real-Time Polymerase Chain Reaction ; Toxoplasma/*genetics/physiology ; Toxoplasmosis, Animal

No abstract available.
Anti-Bacterial Agents/therapeutic use ; Aorta/pathology ; Bacteremia/*complications/drug therapy/*microbiology ; Ceftriaxone/therapeutic use ; Female ; Gram-Positive Bacterial Infections/*complications/drug therapy/*pathology ; Hematoma/*complications ; Humans ; *Immunocompromised Host ; Middle Aged ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Tomography, X-Ray Computed ; Weissella/classification/genetics/isolation & purification/*physiology

Sphingobacterium spiritivorum has been rarely isolated from clinical specimens of immunocompromised patients, and there have been no case reports of S. spiritivorum infection in Korea to our knowledge. We report a case of S. spiritivorum bacteremia in a 68-yr-old woman, who was diagnosed with acute myeloid leukemia and subsequently received chemotherapy. One day after chemotherapy ended, her body temperature increased to 38.3degrees C. A gram-negative bacillus was isolated in aerobic blood cultures and identified as S. spiritivorum by an automated biochemical system. A 16S rRNA sequencing analysis confirmed that the isolate was S. spiritivorum. The patient received antibiotic therapy for 11 days but died of septic shock. This is the first reported case of human S. spiritivorum infection in Korea. Although human infection is rare, S. spiritivorum can be a fatal opportunistic pathogen in immunocompromised patients.
Aged ; Anti-Bacterial Agents/therapeutic use ; Bacteremia/*complications/drug therapy/*microbiology ; Bone Marrow Cells/pathology ; Fatal Outcome ; Female ; Humans ; Immunocompromised Host ; Leukemia, Myeloid, Acute/*complications ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Shock, Septic/etiology/microbiology ; Sphingobacterium/classification/genetics/isolation & purification/*physiology

Studies were performed to determine the effects of Bcell suppression on the pathogenesis of Subgroup J avian leukosis virus (ALV-J) in broiler chickens. Neonatal chickens were treated with cyclophosphamide (CY) or PBS, and then infected with ALV-J (ADOL-7501) at 2 weeks of age. CY treatment induced B cell specific immunosuppression throughout the experiment confirmed by decreased bursal weight, intact lymphocyte mitogenetic activity stimulated by Con A and increased relative subpopulation of CD3-positive cells as measured by flow cytometry. Chickens in this experiment had Mareks disease virus exposure prior to three weeks of age as determined by the presence of lymphocytic infiltration and antibody. Virus neutralizing antibody against ALV-J was first observed at 6 weeks post-infection in some of the infected chickens in the PBS group. As expected, none of the chickens from the CY group and uninfected chickens developed virus-neutralizing antibody. The viremic status was measured by real time RT-PCR using SYBR green I dye. The percentage of viremic chickens was significantly higher, and more chickens had high titered viremia, in the CY treated group. No neoplastic foci consistent with ALVJ infection were observed in any of the experimental chickens. The frequency and intensity of viral antigen expression determined by immunohistochemistry was significantly higher in tissues from CY treated birds than those of PBS treated chickens at 3 weeks post-infection. This study showed that B cell specific immunosuppression with CY treatment in chickens resulted in increase in viremia and viral antigen load in tissues.
Animals ; Avian Leukosis/*immunology/virology ; Avian leukosis virus/genetics/*immunology ; Body Weight/physiology ; Bursa of Fabricius/immunology ; *Chickens ; Concanavalin A/immunology ; Cyclophosphamide/*pharmacology ; Flow Cytometry/veterinary ; Immunocompromised Host ; Immunohistochemistry/veterinary ; Immunophenotyping/veterinary ; Immunosuppressive Agents/*pharmacology ; Lymphocyte Activation/drug effects/immunology ; Organic Chemicals/chemistry ; Poultry Diseases/immunology/*virology ; RNA, Viral/chemistry/genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Spleen/immunology/virology ; Statistics, Nonparametric ; Viremia/veterinary

Strongyloides stercoralis is a soil transmitted intestinal nematode that is endemic in the tropical and subtropical regions. In most individuals who are infected, chronic, usually asymptomatic, gastrointestinal infection persists. But, in immunocompromized hosts or in patients receiving immunosuppressive therapy, autoinfection of S. stercoralis may result in the dissemination of larvae, leading to fatal hyperinfection and increased rate of complications. We report a case of hyperinfective strongyloidiasis with bacterial meningitis in a patient receiving steroid therapy. Strongyloidiasis was diagnosed by the presence of filariform larvae of S. stercoralis in the bronchoalveolar lavage cytology and upper gastrointestinal endoscopic biopsy specimen. Her clinical symptoms had progressively aggravated and developed bacterial meningitis during treatment. She died despite aggressive antibiotic and antihelminthic therapy.
Adrenal Insufficiency/drug therapy ; Aged ; Animals ; Bronchoalveolar Lavage Fluid/parasitology ; Endoscopy, Gastrointestinal ; Enterococcus faecium/isolation & purification ; Female ; Humans ; Immunocompromised Host ; Intestinal Mucosa/pathology ; Larva/physiology ; Magnetic Resonance Imaging ; Meningitis, Bacterial/complications/*diagnosis/microbiology ; Steroids/adverse effects/therapeutic use ; Strongyloides stercoralis/growth & development/isolation & purification ; Strongyloidiasis/complications/*diagnosis/parasitology