Prognostic significance of lung resistance protein (LRP)‎ and multidrug resistance protein (MRP1)‎in patients with diffuse large b-cell lymphomas (DLBCL)‎

Abstract EN

Aim of the work : drug resistance of non-Hodgkin's lymphomas may involve mechanisms of the multidrug resistance phenotype including the lung resistance protein (LRP) and the multidrug resistance protein (MRP1).

To determine the prognostic significance of these multidrug resistance factors, we studied LRP and MRP1 expression and their impact on clinical outcome in previously untreated 48 patients with diffuse large B-cell lymphomas.

Patients and methods : LRP and MRP1 expression were immunohistochemically assessed by means of the monoclonal antibodies LRP-56 and MRPr1, respectively.

Results : LRP was positive in 23 % and MRP1 in 44 % of the patients.

LRP expression was associated with higher tumor stage (p = 0.03), elevated serum lactate dehydroge-nase levels (p = 0.01) and the International Prognostic Index (p = 0.0001).

LRP-positive patients had a lower complete response rate to chemotherapy than LRP-negative patients (18 versus 65 % ; p = 0.006) and a shorter overall survival (median of 0.9 years versus undetermined, p = 0.001).

MRP1 expression was independent of clinical and laboratory parameters and had no impact on the outcome of chemotherapy or survival of the patients.

Conclusion : our results suggest that LRP expression may be an important mechanism of drug resistance and is associated with a worse clinical outcome in previously untreated diffuse large B-cell lymphomas.

Thus, the reversal of LRP-mediated drug resistance may improve clinical outcome in diffuse large B-cell lymphoma in the future.