A combination of serum anti- antibody titer and Kyoto classification score could provide a more accurate diagnosis of .

BACKGROUND

We previously showed that the endoscopic Kyoto classification for gastritis could predict infection in individuals with a high negative titer of serum anti- antibodies. This study evaluated infection and the Kyoto classification score in patients with a low negative titer (<3 U/ml), high negative titer (3-9.9 U/ml), low positive titer (10-49.9 U/ml), and high positive titer (≥50 U/ml).

METHODS

Serum antibody levels, Kyoto classification score and histology were investigated in 870 individuals with no history of -eradication therapy. Urea breath tests (UBTs) were additionally conducted for patients with a low negative titer and a Kyoto score ≥1 or an antibody titer ≥10 U/ml and a Kyoto score of 0 or 1. UBTs and/or histological studies were conducted for participants with a high negative titer.

RESULTS

False diagnoses based on anti- antibody titers were observed in 0.3% of the low-negative-titer group, 11.7% of the high-negative-titer group, 18.9% of the low-positive-titer group and 2.2% of the high-positive-titer group. Surprisingly, false diagnoses based on antibody titers were noted in 63.2% of patients with a low positive titer and a Kyoto score of 0 and in 62.5% of patients with a high negative titer and a Kyoto score ≥2, respectively.

CONCLUSIONS

Endoscopic findings could predict false diagnoses determined using serum antibody titers.