Immune responses to administration of a vaccine against Haemophilus influenzae type B in splenectomized and non-splenectomized patients.
OBJECTIVE
we investigated the cause of hypo-responsiveness to vaccines in splenectomized subjects.


METHODS
we evaluated the immune responses to a Haemophilus influenzae type b vaccine and the sizes of lymphocyte subpopulations in 25 splenectomized and 45 non-splenectomized thalassaemic patients, in 12 individuals who had been splenectomized after trauma and in 20 controls.


RESULTS
the immune response in the controls was significantly higher (P < 0.001) than in splenectomized patients after trauma and in both, the response was higher (P < 0.001) than in thalassaemic patients. In asplenic subjects after trauma, percentages of CD3 and CD4 cells were lower (P < 0.001) than in patients in the other groups; the controls had higher percentages of CD8 cells (P < 0.001) than patients in the other groups. The natural logarithm of the mean percentage of (CD19 showed a quadratic trend from thalassaemic patients through asplenic subjects to controls (P < 0.001). Levels of CD16+ natural killer (NK) cells were higher (P < 0.001) only in asplenic subjects after trauma.


CONCLUSIONS
the significant decrease in the immune response of the splenectomized thalassaemic patients vs. non-splenectomized thalassaemic patients may, in part, be due to their basic immunological condition. Thus, the best strategy for protecting these subjects is to vaccinate them before the splenectomy.
Li Volti
S
S
Department of Paediatrics, University of Catania, Italy.
Sciotto
A
A
Fisichella
M
M
Sciacca
A
A
Munda
S E
SE
Mangiagli
A
A
Li Volti
G
G
Lupo
L
L
D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology*; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology; D008297:Male; D013156:Splenectomy / Q000009:adverse effects
D018073:Haemophilus Vaccines