797 Immunological Reconstitution of Humoral Response to Pneumococcal Polysaccharide Antigens after HAART in Patients with Previous Immune System Deterioration (< 200 CD4+ Lymphocytes) V. Falco*, E. Ribera, M. J. Cruz, O. Len, M. Crespo, D. Rodriguez, M. J. Rodriguez, I. Ocana, A. Pahissa Hosp V Hebrón, Barcelona, Spain
Background: Pneumococcal vaccination is recommended to HIV-infected patients (pts) with > 200 CD4+ lymphocytes. However, little is known about the humoral response in patients with a previous CD4+ nadir < 200. The aim of the study is to analyze the reconstitution of humoral response to the 23 valent polysaccharide pneumococcal vaccine in a group of pts who have experienced an increase to > 200 CD4+ lymphocytes after HAART.
Methods: Determination of specific antipneumococcal IgG by an ELISA method before and 4 wks after antipneumococcal vaccination with the 23 valent polysaccharide vaccine in 3 groups of pts: 1) 30 healthy volunteers; 2) 14 HIV-infected pts with > 200 CD4+ lymphocytes treated with HAART and who have never had a CD4+ count < 200; and 3) 27 HIV-infected pts with a nadir CD4+ lymphocyte count < 200 who have experienced a recovery of the CD4+ lymphocytes to more than 200 after HAART. We have defined a significant antibody response as = 2-fold increase of specific IgG title at 4 wks compared with baseline value. Chi squared test or Fisher exact test have been used to compare categorical variables (antibody response within the groups) and t-student test to compare continuous variables. A p value < 0.05 has been considered significant.
Results: A significant response was observed in 90% (27/30) of healthy controls; 78.6% (11/14) HIV-infected pts of group B and 70.4% (19/27) HIV-infected pts of group C without significant differences within the 3 groups. The mean increase in specific IgG was 6.2 ±3.8 in healthy controls, 3.7 ±2.7 in pts of group B and 5.6 ±6.7 in pts of group C without significant differences within the groups. A significant response was even observed in those pts of group C with a previous CD4+ nadir < 50. However, pts of group C who were vaccinated during the first year following immune recovery (CD4+ > 200) tended to present a lower number of responses (64.7%) than those vaccinated later (80%), although the difference was not significant (p = 0.66).
Conclusion: HIV-infected pts with < 200 CD4+ lymphocytes who experience a CD4+ recovery following HAART present an adequate humoral response against pneumococcal polysaccharide antigens.
