All IHC stains will include a positive control tissue

• CD25 identifies an antigen found in certain peripheral T-cell lymphomas (such as cutaneous t-cell lymphomas)
• This marker can identify patients who are eligible to be treated with ONTAK (diftitoxin denileukin), which has shown significant success in the treatment of refractory peripheral T-cell lymphomas

Submit a formalin-fixed, paraffin-embedded tissue

Formalin-fixed, paraffin-embedded (FFPE) tissue block

FFPE tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled block
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided

Specifications

• CD25 is expressed by peripheral T-cell lymphomas, and is useful in identifying patients who may be eligible for monoclonal directed therapy
• CD25 has also been shown to identify neoplastic mast cells, and distinguish them from reactive mastocytosis
• CD25 expression is seen in certain B cell malignancies, such as Hairy cell leukemia
• Activated T and B cells can also express CD25

Staining pattern

• Cell surface membrane

References

1. Talpur R, et al: Treatment of refractory peripheral T-cell lymphoma with diftitoxin denileukin (ONTAK).
2. Dang NH et al: Phase II study of denileukin diftitox for relapsed/refractory B non-Hodgkin's lymphoma. J Clin Oncol. 2004 Sep 7.
3. Jones D et al: Degree of CD25 expression in T-cell lymphoma is dependent on tissue site: implications for targeted therapy. Clin Cancer REs. 2004 Aug 15; 10(16):5587-94.
4. Sotlar K et al: CD25 indicates the neoplastic phenotype of mast cells; a noel immunohistochemical marker for the diagnosis of systemic mastocytosis (SM) in routinely processed bone marrow biopsy specimens. Am J Surg Pathol 2004, 28:1319-1325.