Cold sore virus could lead to schizophrenia

ISLAMABAD (Online) - Cold sore virus could lead to cognitive symptoms characteristic to schizophrenia patients, research led by Johns Hopkins scientists has found. Dr. David J. Schretlen and colleagues found that exposure to cold sore virus may be partially responsible for shrinking regions of the brain and the loss of concentration skills, memory, coordinated movement and dexterity widely seen in patients with schizophrenia. Were finding that some portion of cognitive impairment usually blamed solely on the disease of schizophrenia might actually be a combination of schizophrenia and prior exposure to herpes simplex virus 1 infection, which reproduces in the brain, said Schretlen. The research could lead to new ways to treat or prevent the cognitive impairment that typically accompanies this mental illness, including with antiviral drugs, the scientists say. Doctors have long known that cognitive impairment, including problems with psychomotor speed, concentration, learning, and memory, are prevalent features of schizophrenia. Cognitive deficits often surface months to years before symptoms that are traditionally used to diagnose this disease, such as delusions or hallucinations. Some previous studies have shown that schizophrenic patients with antibodies to herpes simplex virus 1 (HSV-1), the virus that causes cold sores, often have more severe cognitive deficits than patients without these antibodies. Other studies have shown that patients with HSV-1 antibodies have decreased brain volumes compared to patients without the antibodies. However, it has been unclear whether the cognitive deficits are directly related to the decreased brain volume. To investigate, the researchers recruited 40 schizophrenic patients from outpatient clinics at the Johns Hopkins and Sheppard Enoch Pratt hospitals in Baltimore, Md. Blood tests showed that 25 of the patients had antibodies for HSV-1 and 15 didnt. The researchers gave all of the patients tests to measure speed of coordination, organizational skills and verbal memory. The patients then underwent MRI brain scans to measure the volume of particular regions of their brains. As in previous studies, results showed that patients with antibodies to HSV-1 performed significantly worse on the cognitive tests than patients without the antibodies. But expanding on those earlier studies, analysis of the brain scans showed that the same patients who performed poorly on the tests also had reduced brain volume in the anterior cingulate, which controls processing speed and the ability to switch tasks. There was also shrinkage in the cerebellum, which controls motor function. The results suggest that HSV-1 might be directly causing the cognitive deficits by attacking these brain regions, said Schretlen. The researchers said that the results already suggest new ways of treating the disorder. Data from other studies has shown that antiviral medications can reduce psychiatric symptoms in some patients with schizophrenia. If we can identify schizophrenic patients with HSV-1 antibodies early on, it might be possible to reduce the risk or the extent of cognitive deficits, he added. Kids respond better to recommended swine flu vaccine In the first head to head study of the two H1N1 vaccines used in the UK during the recent pandemic has found that the adjuvanted split virus vaccine induced higher immune response rates in young children, but was linked with more reactions than the whole virus vaccine. The data provide important information to guide immunisation policy in influenza pandemic, said the researchers. During the 2009-10 influenza A (H1N1) pandemic, children experienced pandemic A (H1N1) infections at four times the rate of adults and were more commonly admitted to hospital, making them a priority group for vaccination. For the study, the Department of Health purchased two H1N1 vaccines for the national immunisation programme, an adjuvanted split virion vaccine derived from egg culture and a non-adjuvanted whole virion vaccine derived from cell culture. Thus, a team of UK researchers set out to evaluate the safety, reactogenicity (tendency to cause reactions), and immunogenicity (ability to induce an antibody response) of the two vaccines in children aged 6 months to 12 years, to inform the scientific community, policy makers and parents. Over 900 children participated in the study, which took place at five UK centres between 26 September and 11 December 2009, during the second wave of the pandemic in the UK. Kids were grouped by age and were randomised to receive either the split vaccine or the whole virus vaccine in two doses, 21 days apart. Details of reactions, such as fever, tenderness, swelling and redness of the skin, were collected for one week after vaccination. Blood samples were taken before vaccination and after the second dose to measure rises in antibody levels (a process known as seroconversion). The researchers observed that both vaccines were well tolerated. The split virus vaccine was more immunogenic and achieved higher seroconversion rates than the whole virus vaccine, especially in children aged less than 3 years. The split virus vaccine was also associated with more reactions compared with the whole virus vaccine, although these reactions were generally in keeping with the product data produced by the manufacturer. Significantly fewer reactions, including fever, were observed after a first dose of adjuvanted vaccine than a second, especially in younger children. In this first direct comparison of an AS03B adjuvanted split virion versus whole virion non-adjuvanted H1N1 vaccine, the adjuvanted vaccine, while more reactogenic, was more immunogenic and, importantly, achieved high seroconversion rates in children aged less than 3 years. This indicates the potential for improved immunogenicity of influenza vaccines in this age group, concluded the authors.

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