Published online Sep 14, 2013. doi: 10.3748/wjg.v19.i34.5727
Revised: July 24, 2013
Accepted: August 4, 2013
Published online: September 14, 2013
Processing time: 118 Days and 14.5 Hours
AIM: To study the diagnostic value of immunoglobulin heavy chain (IgH) and T-cell receptor γ (TCR-γ) gene monoclonal rearrangements in primary gastric lymphoma (PGL).
METHODS: A total of 48 patients with suspected PGL at our hospital were prospectively enrolled in this study from January 2009 to December 2011. The patients were divided into three groups (a PGL group, a gastric linitis plastica group, and a benign gastric ulcer group) based on the pathological results (gastric mucosal specimens obtained by endoscopy or surgery) and follow-up. Endoscopic ultrasonography (EUS) and EUS-guided biopsy were performed in all the patients. The tissue specimens were used for histopathological examination and for IgH and TCR-γ gene rearrangement polymerase chain reaction analyses.
RESULTS: EUS and EUS-guided biopsy were successfully performed in all 48 patients. In the PGL group (n = 21), monoclonal IgH gene rearrangements were detected in 14 (66.7%) patients. A positive result for each set of primers was found in 12 (57.1%), 8 (38.1%), and 4 (19.0%) cases using FR1/JH, FR2/JH, and FR3/JH primers, respectively. Overall, 12 (75%) patients with mucosal-associated lymphoid tissue lymphoma (n = 16) and 2 (40%) patients with diffuse large B-cell lymphoma (n = 5) were positive for monoclonal IgH gene rearrangements. No patients in the gastric linitis plastica group (n = 17) and only one (10%) patient in the benign gastric ulcer group (n = 10) were positive for a monoclonal IgH gene rearrangement. No TCR-γ gene monoclonal rearrangements were detected. The sensitivity of monoclonal IgH gene rearrangements was 66.7% for a PGL diagnosis, and the specificity was 96.4%. In the PGL group, 8 (100%) patients with stage IIE PGL (n = 8) and 6 (46.1%) patients with stage IE PGL (n = 13) were positive for monoclonal IgH gene rearrangements.
CONCLUSION: IgH gene rearrangements may be associated with PGL staging and may be useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica.
Core tip: In 2003, a new primer system was successfully developed and standardized for the detection of clonally rearranged immunoglobulin (Ig) and T-cell receptor (TCR) genes. This study was a prospective analysis of Ig heavy chain (IgH) and TCR-γ gene rearrangements using the new primer system and endoscopic biopsy specimens from patients with suspected primary gastric lymphoma (PGL). Our study revealed that the detection of monoclonal IgH gene rearrangements is useful for the diagnosis of PGL and for differentiating between PGL and gastric linitis plastica. Monoclonal IgH gene rearrangements may be associated with PGL staging. The sensitivity and the specificity of IgH gene rearrangements for the diagnosis of PGL were 66.7% and 96.4%, respectively.