AQP4 and clostridium difficile infection: Amongst the different AQP4 peptides, a statistically significant response was only seen for AQP4 p156-170: T-cell proliferation with a CDI ≥ 3 was observed in 4/8 (50%) of patients with AQP4-Ab but in none of the other groups (corrected p-value 0.02).