Repp86: a new prognostic marker in mantle cell lymphoma

Objectives: Proliferation indices are important prognostic factors for the clinical outcome of patients with mantle cell lymphoma (MCL). We investigated whether the expression of repp86 (restrictedly expressed proliferation-associated protein 86 kDa), a new proliferation specific marker expressed in the cell cycle phases G(2), S and M, but not in G(1), correlates with the clinical course in patients with MCL. Patients and Methods: Biopsy specimens from 94 untreated patients enrolled in two multicenter trials were investigated immunohistochemically with monoclonal antibodies against CD20, CD5, CD3, CD23, cyclin D1, and repp86 (Ki-S2). Results: Patients with 0-1% repp86 expression had a median overall survival time of 71.0 months, compared with 38.2 months for patients with 1-5% positive cells and 25.4 months for patients with 5-10% positive tumor cells. Patients with repp86 expression of more than 10% showed the shortest survival (median: 15.0 months). Kaplan-Meier analysis revealed a significant difference in the overall survival time between patients with very high (> 10%) and very low (0-1%) repp86 expression (P < 0.0001) in the tumor cells. The multivariate analysis revealed repp86 expression to be superior to other clinical characteristics as a prognostic factor (P = 0.0016). Conclusion: Based on these findings, repp86 expression is a new important prognostic factor in MCL.