Safety and Efficacy of Vaccination Against Influenza in Patients With Scleroderma

Fifty patients with scleroderma and 30 healthy , aged matched controls will participate in the study.

After signing informed consent, all subjects will be vaccinated with the inactivated split virion vaccine which recommended by the WHO this fall.

Patients will be evaluated at weel 0 and 6 weeks later. Clinical evaluation will be based on the modified Rodnan score, number of digital ischemic ulcers, presence of gastrointestinal and respiratory symptoms, number of swollen and tender joints, visual global evaluation of the physician , ESR and CRP Blood with be collected on the day of vaccination and 6 weeks later.

The immunogenicity of the vaccine will be tested by Haemagglutination inhibition (HI) test.

Influenza virus has two important surface glycoproteins: the haemagglutinin (HA) and the neuraminidase (NA). Antigenic classification and subtyping of influenza viruses is based on these two glycoproteins. HA plays a key role in virus cell entry by binding to cell surface receptors, which are found also on red blood cells of certain species. Binding to red cells results in haemagglutination, which can be observed as a carpet of agglutinated red cells at the bottom of a tube or microtitre well. In the HI test, antibody directed against the viral haemagglutinins block the virus from binding to the blood cells and thus inhibits the haemagglutination reaction.