Assessment Of Immune Function Status Using Polysaccharide Vaccination In Secondary Immunodeficiencies

Patients with secondary immunodeficiencies (SID) can suffer complicated infections. However, it is evident that not all individuals develop an impaired immune system. Here we report the results of using a polysaccharide vaccine (S. thyphim Vi) to assess immune system status in SID patients to identify patients who may be at high risk of developing complications and may benefit from immunoglobulin replacement therapy. SID patients that were referred to the Immunodeficiency (ID) outpatient clinic of the Allergy Service. Vaccination consists on i.m administration Typhim Vi (Sanofi Pasteur). Antibodies specific for the TyphimVi vaccines were measured by the VaccZymeTM Human Anti- Salmonella typhi Vi IgG Enzyme Immunoassay (Binding Site Group) before and 4 weeks after vaccination. The measurement range of the test is 7.4 - 600 U / mL. Ten SID patients (8/2 female/male) were clinical evaluated. Basal level of specific IgG to S. typhy ranged from <7,4 U/mL (8 patients) to 22.5 U/mL. Post-vaccination specific IgG to S. typhi were performed in 6 individuals. 3 were classified as non-responders (7,4-8,5 U/mL) whereas 3 were classfied as responders (120.3, 283.2 and >600 U/mL) based on specific post-vaccination IgG. After clinical evaluation, all non-responders patients have an indication of Ig replacement therapy to prevent life-threatening complications. Typhim Vi polysaccharide vaccination can be use as a good and objective method to assess the immune funcion in SID patients.