Salivary PCR detection of Helicobacter pylori DNA in Egyptian patients with dyspepsia
Several methods are available for detecting Helicobacter pylori infection: (1) invasive methods based on gastric biopsies, (2) non invasive methods like Urea Breath Test (UBT), serology and stool antigen tests. Importance of salivary PCR in detection of H. pylori is still questionable. To evaluate the role of salivary PCR technique in detecting H. pylori gastric affection in Egyptian patients with dyspepsia and in differentiating between functional dyspepsia and acid-ulcer syndrome. This study included 60 patients with dyspepsia classified into three groups: (Group 1) patients with gastric H. pylori and ulcers or erosions (n= 20), (Group 2) patients with gastric H. pylori and no ulcers or erosions and had functional dyspepsia (n= 20), (Group 3) patients without H. pylori and had functional dyspepsia (n= 20). All underwent upper gastrointestinal endoscopy with biopsies, rapid urease test and salivary samples for H. pylori PCR. Significant difference between the three groups regarding salivary PCR values. No significant difference between Group 1 and Group 2 but both had significant difference with Group 3, significant difference between gastric H. pylori positive patients (n= 40) and negative ones (n= 20). Salivary PCR test had sensitivity of 85%, specificity of 70% in diagnosing H. pylori. PCR value of 534000 Iu/ml had best sensitivity (75%) and specificity (100%) for diagnosing H. pylori, highly significant positive correlation between H. pylori gastric affection and salivary PCR values. No significant difference between patients with acid ulcer syndrome (n=20) and those with functional dyspepsia (n= 40) as regard salivary PCR mean values. Salivary PCR test showed sensitivity of 100%, specificity of 50% in differentiating between patients with acid ulcer syndrome and those with functional dyspepsia. PCR value of 440000 Iu/ml had best sensitivity (100%) and specificity (55%) in differentiating acid ulcer syndrome from functional dyspepsia with non significant. H. pylori salivary PCR may be of value in diagnosing H. pylori gastric affection and is strongly correlated with it but it is of limited value in differentiating between acid ulcer syndrome and functional dyspepsia.
Keywords: Salivary PCR; Helicobacter pylori; Functional dyspepsia; Acid ulcer syndrome