Abstract: Objective  To investigate expression and prognosis of XIAP and Omi/HtrA2 in diffuse large B cell lymphoma (DLBCL) and the relationship with prognosis.Methods  Paraffin sections were collected from 59 patients with DLBCL and 30 patients with lymph node hyperplasia (RHL).The XIAP and Omi/HtrA2 proteins in both groups were stained by immunoh is to  chemical method, the relationship of their expressions with clinical parameters and prognosis of DLBCL were analyzed.Results  XIAP and Omi/HtrA2 were highly expressed in DLBCL, but lower expressed or even not expressed in RHL.  The average positive rate of XIAP in DLBCL was 61.02%, and that of RHL was 36.67%(P＜0.05). The average positive rate of Omi/HtrA2 in DLBCL was 52.54%, and that of RHL was 30.00%(P＜0.05). The positive expressions of XIAP and Omi/HtrA2  were associated with clinical stage, pathological type, LDH level, and IPI score of DLBCL(P＜0.05), but were not associated with gender, age, extranodal involvement, and symptom grouping(P＞0.05).The expressions of XIAP and Omi/HtrA2 were negatively correlated(P<0.05). Kaplanmeier survival analysis showed that the expression of XIAP was correlated with the prognosis of patients with DLBCL(P＜0.05),but the expression of Omi/HtrA2 was not correlated with the prognosis of DLBCL patients(P＞0.05).Conclusion  XIAP and Omi/HtrA2 are both highly expressed in DLBCL, and there are negatively correlated.  The upregulation of Omi/HtrA2 and the suppression of  XIAP expression can provide a basis for DLBCL targeted therapy. XIAP, a prognostic factor related to  DLBCL,  will expect to be an indicator of DLBCL prognosis.

Key words: lymphoma, large Bcell, diffuse, XIAP, Omi/HtrA2, prognosis