CagA-Positive Helicobacter pylori Infection and Reduced Sperm Motility, Vitality, and Normal Morphology

Abstract EN

Helicobacter pylori (HP) infection, particularly when caused by strains expressing CagA, may be considered a concomitant cause of male and female reduced fertility.

This study explored, in 87 HP-infected males, the relationship between infection by CagA-positive HP strains and sperm parameters.

HP infection and CagA status were determined by ELISA and Western blotting; semen analysis was performed following WHO guidelines.

The amino acid sequence of human enzymes involved in glycolysis and oxidative metabolism were “blasted” with peptides expressed by HP J99.

Thirty-seven patients (42.5%) were seropositive for CagA.

Sperm motility (18% versus 32%; P<0.01), sperm vitality (35% versus 48%; P<0.01) and the percentage of sperm with normal forms (18% versus 22%; P<0.05) in the CagA-positive group were significantly reduced versus those in the CagA-negative group.

All the considered enzymes showed partial linear homology with HP peptides, but four enzymes aligned with four different segments of the same cag island protein.

We hypothesize a relationship between infection by strains expressing CagA and decreased sperm quality.

Potentially increased systemic levels of inflammatory cytokines that occur in infection by CagA-positive strains and autoimmune phenomena that involve molecular mimicry could explain the pathogenetic mechanism of alterations observed.