Test for CD20 Expression Recommended before Retreatment with Rituximab

[Guest guest]

European Journal Of Haematology

Volume 70 Issue 5 Page 330 - May 2003

Case Report

Loss of CD20 expression in relapsed lymphomas after rituximab therapy

Joud H. Haidar1, Ali Shamseddine2, Ziad Salem2, Yasser Abou Mrad2,

Michel R. Nasr1, Ghazi Zaatari1, Ali Bazarbachi2

Abstract:

The response rate at relapse to rituximab in prior responders B-cell

non-Hodgkin's lymphoma (NHL) patients is below 50%. Loss of CD20

expression after rituximab therapy may explain this secondary

resistance. However, the frequency of CD20 negative relapses cannot

be assessed since most patients that relapsed after rituximab therapy

have not been re-biopsied. Here, we present two patients with CD20

positive low grade B-cell NHL that lost the cell surface and

cytoplasmic expression at relapse after rituximab therapy.

Our findings suggest that confirmation of CD20 expression on the

malignant B cells is required whenever rituximab therapy is

considered.