Immunogenicity of influenza H1N1 vaccination in mixed connective tissue disease: effect of disease and therapy

OBJECTIVE: To assess the potential acute effects regarding the immunogenicity and safety of non-adjuvanted influenza A H1N1/2009 vaccine in patients with mixed connective tissue disease and healthy controls. METHODS: Sixty-nine mixed connective tissue disease patients that were confirmed by Kasukawa's classification criteria and 69 age- and gender-matched controls participated in the study; the participants were vaccinated with the non-adjuvanted influenza A/California/7/2009 (H1N1) virus-like strain. The percentages of seroprotec-tion, seroconversion, geometric mean titer and factor increase in the geometric mean titer were calculated. The patients were clinically evaluated, and blood samples were collected pre- and 21 days post-vaccination to evaluate C-reactive protein, muscle enzymes and autoantibodies. Anti-H1N1 titers were determined using an influenza hemagglutination inhibition assay. ClinicalTrials.gov: NCT01151644. RESULTS: Before vaccination, no difference was observed regarding the seroprotection rates (p = 1.0) and geometric mean titer (p = 0.83) between the patients and controls. After vaccination, seroprotection (75.4% vs. 71%, (p = 0.7), seroconversion (68.1% vs. 65.2%, (p = 1.00) and factor increase in the geometric mean titer (10.0 vs. 8.0, p = 0.40) were similar in the two groups. Further evaluation of seroconversion in patients with and without current or previous history of muscle disease (p = 0.20), skin ulcers (p = 0.48), lupus-like cutaneous disease (p = 0.74), secondary Sjogren syndrome (p = 0.78), scleroderma-pattern in the nailfold capillaroscopy (p = 1.0), lymphopenia #1000/mm³ on two or more occasions (p = 1.0), hypergammaglobulinemia $1.6 g/d (p = 0.60), pulmonary hypertension (p = 1.0) and pulmonary fibrosis (p = 0.80) revealed comparable rates. Seroconversion rates were also similar in patients with and without immunosuppressants. Disease parameters, such as C-reactive protein (p = 0.94), aldolase (p = 0.73), creatine phosphokinase (p = 0.40) and ribonucleoprotein antibody levels (p = 0.98), remained largely unchanged pre and post-vaccination. No severe side effects were reported. CONCLUSIONS: The non-adjuvanted influenza A/H1N1 vaccination immune response in mixed connective tissue disease patients is adequate and does not depend on the disease manifestations and therapy.

Presumptive rapid diagnosis of parvovirus infection in patients with Erythema infectiosum-like illness

In September 1987 an outbreak of exanthematous illness ressembling erythma infectiosum occurres at an elementary school of Säo Paulo city. Attempts to isolate virus from the nasofaryngeal secretion and urine and serum samples collected from the ill children in acute phase of illness resulted negative. Nevertheless, parvovirus-like particles of about 24 nm in diameter were observed by negative staining electron microscopy in concentraded urine of seven out of eight ill patients and in nasopharyngeal secretion of one out of four patients. No similar viral particle was observed in concentred urine samples collected on the same occasion from their classmates without evident signs of illness. This is a proposal of an alternative test for a rapid and sensitive presumptive diagnosis of human parvovirus infection