Prospective Assessment of the Distribution of Haptoglobin Phenotype in Septic and Non Septic Pre-term Neonates (PTSH)

The Haptoglobin (Hp) gene locus at chromosome 16q22 is polymorphic with two alleles denoted 1 and 2 .The gene product exists in three phenotypes: 1-1, 2-1, and 2-2. Hp 2 allele DM individuals have larger myocardial infarctions than homozygous Hp 1 DM individuals. This may be due to differences in the antioxidant and anti-inflammatory properties of these proteins.The same phenomenon was demonstrated in a murine coronary ischemia-reperfusion model.

The Haptoglobin is an acute phase protein with anti-oxidant, bacteriostatic and anti-inflammatory functions.

The Haptoglobin 2 allele is found only in man and is believed to have arisen from the Haptoglobin 1 allele by a partial intragenic duplication. Haptoglobin 2 allele frequency is higher than the Haptoglobin 1 allele. It has been hypothesized that the Haptoglobin 2 allele was spread in man due to its selective advantage against life-threatening infections.

In vitro, only the Haptoglobin 2 allele protein, binds to the streptococcus T antigen, resulting in its aggregation and slowing its growth .

We proposed that in individuals homozygous for the Haptoglobin 1 allele (1-1 genotype), the streptococcal infection would be more severe than in individuals with the Haptoglobin 2 allele (2-1 or 2-2 genotype).