At the present 4835 babies were vaccinated in the 4th day of life, 1 and 6 month of age, at Policlinico S.Matteo of Pavia (Northern Italy) against Hepatitis B virus with recombinant vaccine. Babies were classified as True Non-Responders (TNRs) if they had an antibody level lower than 10mIU/ml even after the booster dose, Slow Responders (SRs) if they had an antibody level lower than 10mIU/ml at seroconversion but higher than 100mIU/ml after the booster dose. Low Responders (LRs) if they had an anti-HBs level between 10 and 40 mIU/ml at seroconversion and Responders (Rs) if the immunisation rate was greater than 40 mIU/ml. Within this cohort, 184 babies were typed for HLA class I, II and III (C4A, C4B, Bf) genes: namely 16 TNRs, 43 SRs, 49 LRs and 76 Rs. We stressed the involvement of HLA genes in the response to vaccination . Here we performed a family studies, recruiting the members of 10 families with a TNR child and 17 with a SR child, that were HLA-typed (class I, II and III). Relatives followed a vaccination program in order to evaluate their antibody level at seroconversion and we performed a linkage analysis. In the TNR probands' pedigrees we found 1 TNR father, 2 LR mothers and 1LR brother; while in the SR probands' families we found 1 SR sister. Transmission disequilibrium test showed that C4AQO gene in TNRs families was transmitted from parent to child 100% of times (5/5 times; p=0.031) and in SRs families in 90% of times (9/10; p=0.01) instead of the expected 50%. Not significant LOD score values were found: but the highest positive value was obtained near the C4A locus (1.58).
|Number of pages||1|
|Journal||European Journal of Immunogenetics|
|Publication status||Published - 2001|
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