In Thailand,direct demonstration of H.pylori infection in gastric mucosa specimens, such as mucosal culture and mucosal histological examination,is usually recommended.However,in resourcelimited settings where adequate culture facilities and expertise are lacking,false negative results may often be a consequence.CLO R test is widely used in clinical practice,but may also give false negative results.The aim of this study was to utilize the nested-PCR for confirmation of H.pylori detection by CLO R test.
Materials and Methods:
A total of 122 patients who underwent esophagogastroduodenoscopy at Uttaradit Hospital between October 2003-2005 were enrolled and completed the study.Gastric biopsy specimens were taken and sent for culture,histologic examination,rapid urease test and nested-PCR assay.
There were 73 males and 49 females (mean age 57 14.8,range 18 to 85 yrs.).Endoscopic findings revealed gastritis in 72 (59%),gastric ulcers in 35 (28.7%),duodenal ulcers in 12 (9.8%)and combined ulcers in 3 patients (2.4%).H.pylori were detected in 37,43,93,and 96 samples by culture,histology,urease test and PCR technique,respectively.PCR technique yielded a sensitivity of 97.8%,which is higher than other methods.The sensitivities of culture,histology and rapid urease test were 39.8%,45.2%and 96.8%,respectively. However,PCR technique was associated with a specificity of 82.8%,lower than 100%by culture and 89.7%by rapid urease test,while the specificity of histology was 69.5%.Both CLO R test and PCR assay gave highly accurate results.
Results from this study demonstrated high sensitivity,specificity and accuracy of PCR technique for detecting H.pylori infection.This technique offers another option for a good diagnostic tool in such a limited resource setting as ours.
[Thai J Gastroenterol 2008;9(1):25-29.]