Positive relationship between a polymorphism in Helicobacter pylori neutrophil-activating protein a gene and iron-deficiency anemia.
BACKGROUND
Numerous studies have suggested a link between iron-deficiency anemia (IDA) and Helicobacter pylori infection. Previously, we found that strains isolated from IDA patients showed higher levels of Fe ion uptake and Fe-ion-dependent rapid proliferation than those of strains derived from patients without IDA.


METHODS
Twenty-four H. pylori strains from IDA patients (IDA strains) and 25 strains from patients who had H. pylori gastritis without anemia (non-IDA strains) were examined. Their nucleotide sequences of napA, fur, and feoB, which contribute to Fe ion uptake, were determined.


RESULTS
Numerous polymorphisms of the three genes were found in both strains. Frequency of neutrophil-activating protein A (NapA), which encoded by napA, with threonine at amino acid residue No. 70 (Thr70-type NapA) was significantly higher in IDA strains than in non-IDA strains. Strains with Thr70-type NapA showed significantly higher levels of Fe(3+) and Fe(2+) uptake than did strains with other types, Ser70-type of NapA, which is found in standard strains. Other significantly different occurrences of polymorphisms between IDA and non-IDA groups were not observed in these genes.


CONCLUSIONS
The results suggest that H. pylori strains with Thr70-type NapA have enhanced Fe ion uptake ability and are associated with the pathogenesis of IDA.
Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Japan.
Shin-Ichi
S
Yokota
Nariaki
N
Toita
Soh
S
Yamamoto
Nobuhiro
N
Fujii
Mutsuko
M
Konno
D000595:Amino Acid Sequence; D018798:Anemia, Iron-Deficiency / Q000150:complications / Q000235:genetics* / Q000276:immunology / Q000821:virology; D001426:Bacterial Proteins / Q000235:genetics*; D005260:Female; D016481:Helicobacter Infections / Q000150:complications* / Q000235:genetics* / Q000276:immunology; D016480:Helicobacter pylori / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000276:immunology; D011110:Polymorphism, Genetic; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; C092412:neutrophil-activating protein A, Helicobacter pylori; D007501:Iron