CNA.42

CNA.42 is a monoclonal antibody directed against a fixative-resistant antigen of follicular dendritic reticulum cells.

CNA.42, was generated using the CEM T- cell line.

It recognizes a 120-kd formalin-resistant glycosylated antigen that is mainly expressed by follicular dendritic reticulum cells (FDRCs). This antigen is also expressed by a few mononuclear cells in the paracortical area of reactive lymph nodes and by some cortical thymocytes.

CNA.42 shows either intact FDRC networks or FDRC networks dispersed among malignant cells.

In follicular lymphomas, the follicular pattern was highlighted by CNA.42 MAb.

Expanded FDRC networks are found in angioimmunoblastic T-cell lymphomas. Neoplastic cells are positive in 43.6% of T- cell and 4.6% of B-cell lymphomas.

The highest percentage of cases with positive neoplastic cells was found in anaplastic large-cell lymphomas (62.5%).

In Hodgkin’s disease, FDRC networks, sometimes encasing Hodgkin and Reed-Sternberg (HRS) cells, were found.

HRS cells were also stained by this antibody in 21.9%of the cases examined.

A variety of normal nonlymphoid tissues and nonhematopoietic tumors, such as some neurogenic tumors, carcinoma, and occasional sarcomas, are found to be positive.

Analysis of the reactivity of CNA.42 antibody with FDRCs of lymphoid tissue from different animal species shows similar reactivity to that observed in humans, suggesting widespread evolutionary conservation of the antigen recognized by this antibody.

In daily diagnostic practice, CNA.42 MAb seems to be a suitable FDRC marker and possibly has an auxiliary role in recognizing T-cell lymphomas.

References

 American Journal of Pathology, Vol 151, 1577-1585,